glsl: Delete the ir_binop_bfm and ir_triop_bfi opcodes.

[mesa.git] / src / mesa / state_tracker / st_glsl_to_tgsi.cpp

/*
 * Copyright (C) 2005-2007  Brian Paul   All Rights Reserved.
 * Copyright (C) 2008  VMware, Inc.   All Rights Reserved.
 * Copyright © 2010 Intel Corporation
 * Copyright © 2011 Bryan Cain
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

/**
 * \file glsl_to_tgsi.cpp
 *
 * Translate GLSL IR to TGSI.
 */

#include "st_glsl_to_tgsi.h"

#include "glsl_parser_extras.h"
#include "ir_optimization.h"

#include "main/errors.h"
#include "main/shaderobj.h"
#include "main/uniforms.h"
#include "main/shaderapi.h"
#include "program/prog_instruction.h"
#include "program/sampler.h"

#include "pipe/p_context.h"
#include "pipe/p_screen.h"
#include "tgsi/tgsi_ureg.h"
#include "tgsi/tgsi_info.h"
#include "util/u_math.h"
#include "util/u_memory.h"
#include "st_program.h"
#include "st_mesa_to_tgsi.h"


#define PROGRAM_IMMEDIATE PROGRAM_FILE_MAX
#define PROGRAM_ANY_CONST ((1 << PROGRAM_STATE_VAR) |    \
                           (1 << PROGRAM_CONSTANT) |     \
                           (1 << PROGRAM_UNIFORM))

#define MAX_GLSL_TEXTURE_OFFSET 4

class st_src_reg;
class st_dst_reg;

static int swizzle_for_size(int size);

/**
 * This struct is a corresponding struct to TGSI ureg_src.
 */
class st_src_reg {
public:
   st_src_reg(gl_register_file file, int index, const glsl_type *type)
   {
      this->file = file;
      this->index = index;
      if (type && (type->is_scalar() || type->is_vector() || type->is_matrix()))
         this->swizzle = swizzle_for_size(type->vector_elements);
      else
         this->swizzle = SWIZZLE_XYZW;
      this->negate = 0;
      this->index2D = 0;
      this->type = type ? type->base_type : GLSL_TYPE_ERROR;
      this->reladdr = NULL;
      this->reladdr2 = NULL;
      this->has_index2 = false;
      this->double_reg2 = false;
      this->array_id = 0;
      this->is_double_vertex_input = false;
   }

   st_src_reg(gl_register_file file, int index, int type)
   {
      this->type = type;
      this->file = file;
      this->index = index;
      this->index2D = 0;
      this->swizzle = SWIZZLE_XYZW;
      this->negate = 0;
      this->reladdr = NULL;
      this->reladdr2 = NULL;
      this->has_index2 = false;
      this->double_reg2 = false;
      this->array_id = 0;
      this->is_double_vertex_input = false;
   }

   st_src_reg(gl_register_file file, int index, int type, int index2D)
   {
      this->type = type;
      this->file = file;
      this->index = index;
      this->index2D = index2D;
      this->swizzle = SWIZZLE_XYZW;
      this->negate = 0;
      this->reladdr = NULL;
      this->reladdr2 = NULL;
      this->has_index2 = false;
      this->double_reg2 = false;
      this->array_id = 0;
      this->is_double_vertex_input = false;
   }

   st_src_reg()
   {
      this->type = GLSL_TYPE_ERROR;
      this->file = PROGRAM_UNDEFINED;
      this->index = 0;
      this->index2D = 0;
      this->swizzle = 0;
      this->negate = 0;
      this->reladdr = NULL;
      this->reladdr2 = NULL;
      this->has_index2 = false;
      this->double_reg2 = false;
      this->array_id = 0;
      this->is_double_vertex_input = false;
   }

   explicit st_src_reg(st_dst_reg reg);

   gl_register_file file; /**< PROGRAM_* from Mesa */
   int index; /**< temporary index, VERT_ATTRIB_*, VARYING_SLOT_*, etc. */
   int index2D;
   GLuint swizzle; /**< SWIZZLE_XYZWONEZERO swizzles from Mesa. */
   int negate; /**< NEGATE_XYZW mask from mesa */
   int type; /** GLSL_TYPE_* from GLSL IR (enum glsl_base_type) */
   /** Register index should be offset by the integer in this reg. */
   st_src_reg *reladdr;
   st_src_reg *reladdr2;
   bool has_index2;
   /*
    * Is this the second half of a double register pair?
    * currently used for input mapping only.
    */
   bool double_reg2;
   unsigned array_id;
   bool is_double_vertex_input;
};

class st_dst_reg {
public:
   st_dst_reg(gl_register_file file, int writemask, int type, int index)
   {
      this->file = file;
      this->index = index;
      this->index2D = 0;
      this->writemask = writemask;
      this->cond_mask = COND_TR;
      this->reladdr = NULL;
      this->reladdr2 = NULL;
      this->has_index2 = false;
      this->type = type;
      this->array_id = 0;
   }

   st_dst_reg(gl_register_file file, int writemask, int type)
   {
      this->file = file;
      this->index = 0;
      this->index2D = 0;
      this->writemask = writemask;
      this->cond_mask = COND_TR;
      this->reladdr = NULL;
      this->reladdr2 = NULL;
      this->has_index2 = false;
      this->type = type;
      this->array_id = 0;
   }

   st_dst_reg()
   {
      this->type = GLSL_TYPE_ERROR;
      this->file = PROGRAM_UNDEFINED;
      this->index = 0;
      this->index2D = 0;
      this->writemask = 0;
      this->cond_mask = COND_TR;
      this->reladdr = NULL;
      this->reladdr2 = NULL;
      this->has_index2 = false;
      this->array_id = 0;
   }

   explicit st_dst_reg(st_src_reg reg);

   gl_register_file file; /**< PROGRAM_* from Mesa */
   int index; /**< temporary index, VERT_ATTRIB_*, VARYING_SLOT_*, etc. */
   int index2D;
   int writemask; /**< Bitfield of WRITEMASK_[XYZW] */
   GLuint cond_mask:4;
   int type; /** GLSL_TYPE_* from GLSL IR (enum glsl_base_type) */
   /** Register index should be offset by the integer in this reg. */
   st_src_reg *reladdr;
   st_src_reg *reladdr2;
   bool has_index2;
   unsigned array_id;
};

st_src_reg::st_src_reg(st_dst_reg reg)
{
   this->type = reg.type;
   this->file = reg.file;
   this->index = reg.index;
   this->swizzle = SWIZZLE_XYZW;
   this->negate = 0;
   this->reladdr = reg.reladdr;
   this->index2D = reg.index2D;
   this->reladdr2 = reg.reladdr2;
   this->has_index2 = reg.has_index2;
   this->double_reg2 = false;
   this->array_id = reg.array_id;
   this->is_double_vertex_input = false;
}

st_dst_reg::st_dst_reg(st_src_reg reg)
{
   this->type = reg.type;
   this->file = reg.file;
   this->index = reg.index;
   this->writemask = WRITEMASK_XYZW;
   this->cond_mask = COND_TR;
   this->reladdr = reg.reladdr;
   this->index2D = reg.index2D;
   this->reladdr2 = reg.reladdr2;
   this->has_index2 = reg.has_index2;
   this->array_id = reg.array_id;
}

class glsl_to_tgsi_instruction : public exec_node {
public:
   DECLARE_RALLOC_CXX_OPERATORS(glsl_to_tgsi_instruction)

   unsigned op;
   st_dst_reg dst[2];
   st_src_reg src[4];
   /** Pointer to the ir source this tree came from for debugging */
   ir_instruction *ir;
   GLboolean cond_update;
   bool saturate;
   st_src_reg sampler; /**< sampler register */
   int sampler_array_size; /**< 1-based size of sampler array, 1 if not array */
   int tex_target; /**< One of TEXTURE_*_INDEX */
   glsl_base_type tex_type;
   GLboolean tex_shadow;

   st_src_reg tex_offsets[MAX_GLSL_TEXTURE_OFFSET];
   unsigned tex_offset_num_offset;
   int dead_mask; /**< Used in dead code elimination */

   class function_entry *function; /* Set on TGSI_OPCODE_CAL or TGSI_OPCODE_BGNSUB */
   const struct tgsi_opcode_info *info;
};

class variable_storage : public exec_node {
public:
   variable_storage(ir_variable *var, gl_register_file file, int index,
                    unsigned array_id = 0)
      : file(file), index(index), var(var), array_id(array_id)
   {
      /* empty */
   }

   gl_register_file file;
   int index;
   ir_variable *var; /* variable that maps to this, if any */
   unsigned array_id;
};

class immediate_storage : public exec_node {
public:
   immediate_storage(gl_constant_value *values, int size32, int type)
   {
      memcpy(this->values, values, size32 * sizeof(gl_constant_value));
      this->size32 = size32;
      this->type = type;
   }

   /* doubles are stored across 2 gl_constant_values */
   gl_constant_value values[4];
   int size32; /**< Number of 32-bit components (1-4) */
   int type; /**< GL_DOUBLE, GL_FLOAT, GL_INT, GL_BOOL, or GL_UNSIGNED_INT */
};

class function_entry : public exec_node {
public:
   ir_function_signature *sig;

   /**
    * identifier of this function signature used by the program.
    *
    * At the point that TGSI instructions for function calls are
    * generated, we don't know the address of the first instruction of
    * the function body.  So we make the BranchTarget that is called a
    * small integer and rewrite them during set_branchtargets().
    */
   int sig_id;

   /**
    * Pointer to first instruction of the function body.
    *
    * Set during function body emits after main() is processed.
    */
   glsl_to_tgsi_instruction *bgn_inst;

   /**
    * Index of the first instruction of the function body in actual TGSI.
    *
    * Set after conversion from glsl_to_tgsi_instruction to TGSI.
    */
   int inst;

   /** Storage for the return value. */
   st_src_reg return_reg;
};

static st_src_reg undef_src = st_src_reg(PROGRAM_UNDEFINED, 0, GLSL_TYPE_ERROR);
static st_dst_reg undef_dst = st_dst_reg(PROGRAM_UNDEFINED, SWIZZLE_NOOP, GLSL_TYPE_ERROR);

struct array_decl {
   unsigned mesa_index;
   unsigned array_id;
   unsigned array_size;
   unsigned array_type;
};

static unsigned
find_array_type(struct array_decl *arrays, unsigned count, unsigned array_id)
{
   unsigned i;

   for (i = 0; i < count; i++) {
      struct array_decl *decl = &arrays[i];

      if (array_id == decl->array_id) {
         return decl->array_type;
      }
   }
   return GLSL_TYPE_ERROR;
}

struct rename_reg_pair {
   int old_reg;
   int new_reg;
};

struct glsl_to_tgsi_visitor : public ir_visitor {
public:
   glsl_to_tgsi_visitor();
   ~glsl_to_tgsi_visitor();

   function_entry *current_function;

   struct gl_context *ctx;
   struct gl_program *prog;
   struct gl_shader_program *shader_program;
   struct gl_shader *shader;
   struct gl_shader_compiler_options *options;

   int next_temp;

   unsigned *array_sizes;
   unsigned max_num_arrays;
   unsigned next_array;

   struct array_decl input_arrays[PIPE_MAX_SHADER_INPUTS];
   unsigned num_input_arrays;
   struct array_decl output_arrays[PIPE_MAX_SHADER_OUTPUTS];
   unsigned num_output_arrays;

   int num_address_regs;
   int samplers_used;
   glsl_base_type sampler_types[PIPE_MAX_SAMPLERS];
   int sampler_targets[PIPE_MAX_SAMPLERS];   /**< One of TGSI_TEXTURE_* */
   bool indirect_addr_consts;
   int wpos_transform_const;

   int glsl_version;
   bool native_integers;
   bool have_sqrt;
   bool have_fma;

   variable_storage *find_variable_storage(ir_variable *var);

   int add_constant(gl_register_file file, gl_constant_value values[8],
                    int size, int datatype, GLuint *swizzle_out);

   function_entry *get_function_signature(ir_function_signature *sig);

   st_src_reg get_temp(const glsl_type *type);
   void reladdr_to_temp(ir_instruction *ir, st_src_reg *reg, int *num_reladdr);

   st_src_reg st_src_reg_for_double(double val);
   st_src_reg st_src_reg_for_float(float val);
   st_src_reg st_src_reg_for_int(int val);
   st_src_reg st_src_reg_for_type(int type, int val);

   /**
    * \name Visit methods
    *
    * As typical for the visitor pattern, there must be one \c visit method for
    * each concrete subclass of \c ir_instruction.  Virtual base classes within
    * the hierarchy should not have \c visit methods.
    */
   /*@{*/
   virtual void visit(ir_variable *);
   virtual void visit(ir_loop *);
   virtual void visit(ir_loop_jump *);
   virtual void visit(ir_function_signature *);
   virtual void visit(ir_function *);
   virtual void visit(ir_expression *);
   virtual void visit(ir_swizzle *);
   virtual void visit(ir_dereference_variable  *);
   virtual void visit(ir_dereference_array *);
   virtual void visit(ir_dereference_record *);
   virtual void visit(ir_assignment *);
   virtual void visit(ir_constant *);
   virtual void visit(ir_call *);
   virtual void visit(ir_return *);
   virtual void visit(ir_discard *);
   virtual void visit(ir_texture *);
   virtual void visit(ir_if *);
   virtual void visit(ir_emit_vertex *);
   virtual void visit(ir_end_primitive *);
   virtual void visit(ir_barrier *);
   /*@}*/

   st_src_reg result;

   /** List of variable_storage */
   exec_list variables;

   /** List of immediate_storage */
   exec_list immediates;
   unsigned num_immediates;

   /** List of function_entry */
   exec_list function_signatures;
   int next_signature_id;

   /** List of glsl_to_tgsi_instruction */
   exec_list instructions;

   glsl_to_tgsi_instruction *emit_asm(ir_instruction *ir, unsigned op,
                                      st_dst_reg dst = undef_dst,
                                      st_src_reg src0 = undef_src,
                                      st_src_reg src1 = undef_src,
                                      st_src_reg src2 = undef_src,
                                      st_src_reg src3 = undef_src);

   glsl_to_tgsi_instruction *emit_asm(ir_instruction *ir, unsigned op,
                                      st_dst_reg dst, st_dst_reg dst1,
                                      st_src_reg src0 = undef_src,
                                      st_src_reg src1 = undef_src,
                                      st_src_reg src2 = undef_src,
                                      st_src_reg src3 = undef_src);

   unsigned get_opcode(ir_instruction *ir, unsigned op,
                    st_dst_reg dst,
                    st_src_reg src0, st_src_reg src1);

   /**
    * Emit the correct dot-product instruction for the type of arguments
    */
   glsl_to_tgsi_instruction *emit_dp(ir_instruction *ir,
                                     st_dst_reg dst,
                                     st_src_reg src0,
                                     st_src_reg src1,
                                     unsigned elements);

   void emit_scalar(ir_instruction *ir, unsigned op,
                    st_dst_reg dst, st_src_reg src0);

   void emit_scalar(ir_instruction *ir, unsigned op,
                    st_dst_reg dst, st_src_reg src0, st_src_reg src1);

   void emit_arl(ir_instruction *ir, st_dst_reg dst, st_src_reg src0);

   bool try_emit_mad(ir_expression *ir,
              int mul_operand);
   bool try_emit_mad_for_and_not(ir_expression *ir,
              int mul_operand);

   void emit_swz(ir_expression *ir);

   bool process_move_condition(ir_rvalue *ir);

   void simplify_cmp(void);

   void rename_temp_registers(int num_renames, struct rename_reg_pair *renames);
   void get_first_temp_read(int *first_reads);
   void get_last_temp_read_first_temp_write(int *last_reads, int *first_writes);
   void get_last_temp_write(int *last_writes);

   void copy_propagate(void);
   int eliminate_dead_code(void);

   void merge_two_dsts(void);
   void merge_registers(void);
   void renumber_registers(void);

   void emit_block_mov(ir_assignment *ir, const struct glsl_type *type,
                       st_dst_reg *l, st_src_reg *r,
                       st_src_reg *cond, bool cond_swap);

   void *mem_ctx;
};

static st_dst_reg address_reg = st_dst_reg(PROGRAM_ADDRESS, WRITEMASK_X, GLSL_TYPE_FLOAT, 0);
static st_dst_reg address_reg2 = st_dst_reg(PROGRAM_ADDRESS, WRITEMASK_X, GLSL_TYPE_FLOAT, 1);
static st_dst_reg sampler_reladdr = st_dst_reg(PROGRAM_ADDRESS, WRITEMASK_X, GLSL_TYPE_FLOAT, 2);

static void
fail_link(struct gl_shader_program *prog, const char *fmt, ...) PRINTFLIKE(2, 3);

static void
fail_link(struct gl_shader_program *prog, const char *fmt, ...)
{
   va_list args;
   va_start(args, fmt);
   ralloc_vasprintf_append(&prog->InfoLog, fmt, args);
   va_end(args);

   prog->LinkStatus = GL_FALSE;
}

static int
swizzle_for_size(int size)
{
   static const int size_swizzles[4] = {
      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_X, SWIZZLE_X, SWIZZLE_X),
      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Y, SWIZZLE_Y),
      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z),
      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_W),
   };

   assert((size >= 1) && (size <= 4));
   return size_swizzles[size - 1];
}

static unsigned
num_inst_dst_regs(const glsl_to_tgsi_instruction *op)
{
   return op->info->num_dst;
}

static unsigned
num_inst_src_regs(const glsl_to_tgsi_instruction *op)
{
   return op->info->is_tex ? op->info->num_src - 1 : op->info->num_src;
}

glsl_to_tgsi_instruction *
glsl_to_tgsi_visitor::emit_asm(ir_instruction *ir, unsigned op,
                               st_dst_reg dst, st_dst_reg dst1,
                               st_src_reg src0, st_src_reg src1,
                               st_src_reg src2, st_src_reg src3)
{
   glsl_to_tgsi_instruction *inst = new(mem_ctx) glsl_to_tgsi_instruction();
   int num_reladdr = 0, i, j;
   bool dst_is_double[2];

   op = get_opcode(ir, op, dst, src0, src1);

   /* If we have to do relative addressing, we want to load the ARL
    * reg directly for one of the regs, and preload the other reladdr
    * sources into temps.
    */
   num_reladdr += dst.reladdr != NULL || dst.reladdr2;
   num_reladdr += dst1.reladdr != NULL || dst1.reladdr2;
   num_reladdr += src0.reladdr != NULL || src0.reladdr2 != NULL;
   num_reladdr += src1.reladdr != NULL || src1.reladdr2 != NULL;
   num_reladdr += src2.reladdr != NULL || src2.reladdr2 != NULL;
   num_reladdr += src3.reladdr != NULL || src3.reladdr2 != NULL;

   reladdr_to_temp(ir, &src3, &num_reladdr);
   reladdr_to_temp(ir, &src2, &num_reladdr);
   reladdr_to_temp(ir, &src1, &num_reladdr);
   reladdr_to_temp(ir, &src0, &num_reladdr);

   if (dst.reladdr || dst.reladdr2) {
      if (dst.reladdr)
         emit_arl(ir, address_reg, *dst.reladdr);
      if (dst.reladdr2)
         emit_arl(ir, address_reg2, *dst.reladdr2);
      num_reladdr--;
   }
   if (dst1.reladdr) {
      emit_arl(ir, address_reg, *dst1.reladdr);
      num_reladdr--;
   }
   assert(num_reladdr == 0);

   inst->op = op;
   inst->info = tgsi_get_opcode_info(op);
   inst->dst[0] = dst;
   inst->dst[1] = dst1;
   inst->src[0] = src0;
   inst->src[1] = src1;
   inst->src[2] = src2;
   inst->src[3] = src3;
   inst->ir = ir;
   inst->dead_mask = 0;
   /* default to float, for paths where this is not initialized
    * (since 0==UINT which is likely wrong):
    */
   inst->tex_type = GLSL_TYPE_FLOAT;

   inst->function = NULL;

   /* Update indirect addressing status used by TGSI */
   if (dst.reladdr || dst.reladdr2) {
      switch(dst.file) {
      case PROGRAM_STATE_VAR:
      case PROGRAM_CONSTANT:
      case PROGRAM_UNIFORM:
         this->indirect_addr_consts = true;
         break;
      case PROGRAM_IMMEDIATE:
         assert(!"immediates should not have indirect addressing");
         break;
      default:
         break;
      }
   }
   else {
      for (i = 0; i < 4; i++) {
         if(inst->src[i].reladdr) {
            switch(inst->src[i].file) {
            case PROGRAM_STATE_VAR:
            case PROGRAM_CONSTANT:
            case PROGRAM_UNIFORM:
               this->indirect_addr_consts = true;
               break;
            case PROGRAM_IMMEDIATE:
               assert(!"immediates should not have indirect addressing");
               break;
            default:
               break;
            }
         }
      }
   }

   this->instructions.push_tail(inst);

   /*
    * This section contains the double processing.
    * GLSL just represents doubles as single channel values,
    * however most HW and TGSI represent doubles as pairs of register channels.
    *
    * so we have to fixup destination writemask/index and src swizzle/indexes.
    * dest writemasks need to translate from single channel write mask
    * to a dual-channel writemask, but also need to modify the index,
    * if we are touching the Z,W fields in the pre-translated writemask.
    *
    * src channels have similiar index modifications along with swizzle
    * changes to we pick the XY, ZW pairs from the correct index.
    *
    * GLSL [0].x -> TGSI [0].xy
    * GLSL [0].y -> TGSI [0].zw
    * GLSL [0].z -> TGSI [1].xy
    * GLSL [0].w -> TGSI [1].zw
    */
   for (j = 0; j < 2; j++) {
      dst_is_double[j] = false;
      if (inst->dst[j].type == GLSL_TYPE_DOUBLE)
         dst_is_double[j] = true;
      else if (inst->dst[j].file == PROGRAM_OUTPUT && inst->dst[j].type == GLSL_TYPE_ARRAY) {
         unsigned type = find_array_type(this->output_arrays, this->num_output_arrays, inst->dst[j].array_id);
         if (type == GLSL_TYPE_DOUBLE)
            dst_is_double[j] = true;
      }
   }

   if (dst_is_double[0] || dst_is_double[1] ||
       inst->src[0].type == GLSL_TYPE_DOUBLE) {
      glsl_to_tgsi_instruction *dinst = NULL;
      int initial_src_swz[4], initial_src_idx[4];
      int initial_dst_idx[2], initial_dst_writemask[2];
      /* select the writemask for dst0 or dst1 */
      unsigned writemask = inst->dst[0].file == PROGRAM_UNDEFINED ? inst->dst[1].writemask : inst->dst[0].writemask;

      /* copy out the writemask, index and swizzles for all src/dsts. */
      for (j = 0; j < 2; j++) {
         initial_dst_writemask[j] = inst->dst[j].writemask;
         initial_dst_idx[j] = inst->dst[j].index;
      }

      for (j = 0; j < 4; j++) {
         initial_src_swz[j] = inst->src[j].swizzle;
         initial_src_idx[j] = inst->src[j].index;
      }

      /*
       * scan all the components in the dst writemask
       * generate an instruction for each of them if required.
       */
      while (writemask) {

         int i = u_bit_scan(&writemask);

         /* first time use previous instruction */
         if (dinst == NULL) {
            dinst = inst;
         } else {
            /* create a new instructions for subsequent attempts */
            dinst = new(mem_ctx) glsl_to_tgsi_instruction();
            *dinst = *inst;
            dinst->next = NULL;
            dinst->prev = NULL;
            this->instructions.push_tail(dinst);
         }

         /* modify the destination if we are splitting */
         for (j = 0; j < 2; j++) {
            if (dst_is_double[j]) {
               dinst->dst[j].writemask = (i & 1) ? WRITEMASK_ZW : WRITEMASK_XY;
               dinst->dst[j].index = initial_dst_idx[j];
               if (i > 1)
                     dinst->dst[j].index++;
            } else {
               /* if we aren't writing to a double, just get the bit of the initial writemask
                  for this channel */
               dinst->dst[j].writemask = initial_dst_writemask[j] & (1 << i);
            }
         }

         /* modify the src registers */
         for (j = 0; j < 4; j++) {
            int swz = GET_SWZ(initial_src_swz[j], i);

            if (dinst->src[j].type == GLSL_TYPE_DOUBLE) {
               dinst->src[j].index = initial_src_idx[j];
               if (swz > 1) {
                  dinst->src[j].double_reg2 = true;
                  dinst->src[j].index++;
               }

               if (swz & 1)
                  dinst->src[j].swizzle = MAKE_SWIZZLE4(SWIZZLE_Z, SWIZZLE_W, SWIZZLE_Z, SWIZZLE_W);
               else
                  dinst->src[j].swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_X, SWIZZLE_Y);

            } else {
               /* some opcodes are special case in what they use as sources
                  - F2D is a float src0, DLDEXP is integer src1 */
               if (op == TGSI_OPCODE_F2D ||
                   op == TGSI_OPCODE_DLDEXP ||
                   (op == TGSI_OPCODE_UCMP && dst_is_double[0])) {
                  dinst->src[j].swizzle = MAKE_SWIZZLE4(swz, swz, swz, swz);
               }
            }
         }
      }
      inst = dinst;
   }


   return inst;
}

glsl_to_tgsi_instruction *
glsl_to_tgsi_visitor::emit_asm(ir_instruction *ir, unsigned op,
                               st_dst_reg dst,
                               st_src_reg src0, st_src_reg src1,
                               st_src_reg src2, st_src_reg src3)
{
   return emit_asm(ir, op, dst, undef_dst, src0, src1, src2, src3);
}

/**
 * Determines whether to use an integer, unsigned integer, or float opcode
 * based on the operands and input opcode, then emits the result.
 */
unsigned
glsl_to_tgsi_visitor::get_opcode(ir_instruction *ir, unsigned op,
                                 st_dst_reg dst,
                                 st_src_reg src0, st_src_reg src1)
{
   int type = GLSL_TYPE_FLOAT;

   if (op == TGSI_OPCODE_MOV)
       return op;

   assert(src0.type != GLSL_TYPE_ARRAY);
   assert(src0.type != GLSL_TYPE_STRUCT);
   assert(src1.type != GLSL_TYPE_ARRAY);
   assert(src1.type != GLSL_TYPE_STRUCT);

   if (src0.type == GLSL_TYPE_DOUBLE || src1.type == GLSL_TYPE_DOUBLE)
      type = GLSL_TYPE_DOUBLE;
   else if (src0.type == GLSL_TYPE_FLOAT || src1.type == GLSL_TYPE_FLOAT)
      type = GLSL_TYPE_FLOAT;
   else if (native_integers)
      type = src0.type == GLSL_TYPE_BOOL ? GLSL_TYPE_INT : src0.type;

#define case5(c, f, i, u, d)                    \
   case TGSI_OPCODE_##c: \
      if (type == GLSL_TYPE_DOUBLE)           \
         op = TGSI_OPCODE_##d; \
      else if (type == GLSL_TYPE_INT)       \
         op = TGSI_OPCODE_##i; \
      else if (type == GLSL_TYPE_UINT) \
         op = TGSI_OPCODE_##u; \
      else \
         op = TGSI_OPCODE_##f; \
      break;

#define case4(c, f, i, u)                    \
   case TGSI_OPCODE_##c: \
      if (type == GLSL_TYPE_INT) \
         op = TGSI_OPCODE_##i; \
      else if (type == GLSL_TYPE_UINT) \
         op = TGSI_OPCODE_##u; \
      else \
         op = TGSI_OPCODE_##f; \
      break;

#define case3(f, i, u)  case4(f, f, i, u)
#define case4d(f, i, u, d)  case5(f, f, i, u, d)
#define case3fid(f, i, d) case5(f, f, i, i, d)
#define case2fi(f, i)   case4(f, f, i, i)
#define case2iu(i, u)   case4(i, LAST, i, u)

#define casecomp(c, f, i, u, d)                   \
   case TGSI_OPCODE_##c: \
      if (type == GLSL_TYPE_DOUBLE) \
         op = TGSI_OPCODE_##d; \
      else if (type == GLSL_TYPE_INT || type == GLSL_TYPE_SUBROUTINE)       \
         op = TGSI_OPCODE_##i; \
      else if (type == GLSL_TYPE_UINT) \
         op = TGSI_OPCODE_##u; \
      else if (native_integers) \
         op = TGSI_OPCODE_##f; \
      else \
         op = TGSI_OPCODE_##c; \
      break;

   switch(op) {
      case3fid(ADD, UADD, DADD);
      case3fid(MUL, UMUL, DMUL);
      case3fid(MAD, UMAD, DMAD);
      case3fid(FMA, UMAD, DFMA);
      case3(DIV, IDIV, UDIV);
      case4d(MAX, IMAX, UMAX, DMAX);
      case4d(MIN, IMIN, UMIN, DMIN);
      case2iu(MOD, UMOD);

      casecomp(SEQ, FSEQ, USEQ, USEQ, DSEQ);
      casecomp(SNE, FSNE, USNE, USNE, DSNE);
      casecomp(SGE, FSGE, ISGE, USGE, DSGE);
      casecomp(SLT, FSLT, ISLT, USLT, DSLT);

      case2iu(ISHR, USHR);

      case3fid(SSG, ISSG, DSSG);
      case3fid(ABS, IABS, DABS);

      case2iu(IBFE, UBFE);
      case2iu(IMSB, UMSB);
      case2iu(IMUL_HI, UMUL_HI);

      case3fid(SQRT, SQRT, DSQRT);

      case3fid(RCP, RCP, DRCP);
      case3fid(RSQ, RSQ, DRSQ);

      case3fid(FRC, FRC, DFRAC);
      case3fid(TRUNC, TRUNC, DTRUNC);
      case3fid(CEIL, CEIL, DCEIL);
      case3fid(FLR, FLR, DFLR);
      case3fid(ROUND, ROUND, DROUND);

      default: break;
   }

   assert(op != TGSI_OPCODE_LAST);
   return op;
}

glsl_to_tgsi_instruction *
glsl_to_tgsi_visitor::emit_dp(ir_instruction *ir,
                              st_dst_reg dst, st_src_reg src0, st_src_reg src1,
                              unsigned elements)
{
   static const unsigned dot_opcodes[] = {
      TGSI_OPCODE_DP2, TGSI_OPCODE_DP3, TGSI_OPCODE_DP4
   };

   return emit_asm(ir, dot_opcodes[elements - 2], dst, src0, src1);
}

/**
 * Emits TGSI scalar opcodes to produce unique answers across channels.
 *
 * Some TGSI opcodes are scalar-only, like ARB_fp/vp.  The src X
 * channel determines the result across all channels.  So to do a vec4
 * of this operation, we want to emit a scalar per source channel used
 * to produce dest channels.
 */
void
glsl_to_tgsi_visitor::emit_scalar(ir_instruction *ir, unsigned op,
                                  st_dst_reg dst,
                                  st_src_reg orig_src0, st_src_reg orig_src1)
{
   int i, j;
   int done_mask = ~dst.writemask;

   /* TGSI RCP is a scalar operation splatting results to all channels,
    * like ARB_fp/vp.  So emit as many RCPs as necessary to cover our
    * dst channels.
    */
   for (i = 0; i < 4; i++) {
      GLuint this_mask = (1 << i);
      st_src_reg src0 = orig_src0;
      st_src_reg src1 = orig_src1;

      if (done_mask & this_mask)
         continue;

      GLuint src0_swiz = GET_SWZ(src0.swizzle, i);
      GLuint src1_swiz = GET_SWZ(src1.swizzle, i);
      for (j = i + 1; j < 4; j++) {
         /* If there is another enabled component in the destination that is
          * derived from the same inputs, generate its value on this pass as
          * well.
          */
         if (!(done_mask & (1 << j)) &&
             GET_SWZ(src0.swizzle, j) == src0_swiz &&
             GET_SWZ(src1.swizzle, j) == src1_swiz) {
            this_mask |= (1 << j);
         }
      }
      src0.swizzle = MAKE_SWIZZLE4(src0_swiz, src0_swiz,
                                   src0_swiz, src0_swiz);
      src1.swizzle = MAKE_SWIZZLE4(src1_swiz, src1_swiz,
                                   src1_swiz, src1_swiz);

      dst.writemask = this_mask;
      emit_asm(ir, op, dst, src0, src1);
      done_mask |= this_mask;
   }
}

void
glsl_to_tgsi_visitor::emit_scalar(ir_instruction *ir, unsigned op,
                                  st_dst_reg dst, st_src_reg src0)
{
   st_src_reg undef = undef_src;

   undef.swizzle = SWIZZLE_XXXX;

   emit_scalar(ir, op, dst, src0, undef);
}

void
glsl_to_tgsi_visitor::emit_arl(ir_instruction *ir,
                               st_dst_reg dst, st_src_reg src0)
{
   int op = TGSI_OPCODE_ARL;

   if (src0.type == GLSL_TYPE_INT || src0.type == GLSL_TYPE_UINT)
      op = TGSI_OPCODE_UARL;

   assert(dst.file == PROGRAM_ADDRESS);
   if (dst.index >= this->num_address_regs)
      this->num_address_regs = dst.index + 1;

   emit_asm(NULL, op, dst, src0);
}

int
glsl_to_tgsi_visitor::add_constant(gl_register_file file,
                                   gl_constant_value values[8], int size, int datatype,
                                   GLuint *swizzle_out)
{
   if (file == PROGRAM_CONSTANT) {
      return _mesa_add_typed_unnamed_constant(this->prog->Parameters, values,
                                              size, datatype, swizzle_out);
   }

   assert(file == PROGRAM_IMMEDIATE);

   int index = 0;
   immediate_storage *entry;
   int size32 = size * (datatype == GL_DOUBLE ? 2 : 1);
   int i;

   /* Search immediate storage to see if we already have an identical
    * immediate that we can use instead of adding a duplicate entry.
    */
   foreach_in_list(immediate_storage, entry, &this->immediates) {
      immediate_storage *tmp = entry;

      for (i = 0; i * 4 < size32; i++) {
         int slot_size = MIN2(size32 - (i * 4), 4);
         if (tmp->type != datatype || tmp->size32 != slot_size)
            break;
         if (memcmp(tmp->values, &values[i * 4],
                    slot_size * sizeof(gl_constant_value)))
            break;

         /* Everything matches, keep going until the full size is matched */
         tmp = (immediate_storage *)tmp->next;
      }

      /* The full value matched */
      if (i * 4 >= size32)
         return index;

      index++;
   }

   for (i = 0; i * 4 < size32; i++) {
      int slot_size = MIN2(size32 - (i * 4), 4);
      /* Add this immediate to the list. */
      entry = new(mem_ctx) immediate_storage(&values[i * 4], slot_size, datatype);
      this->immediates.push_tail(entry);
      this->num_immediates++;
   }
   return index;
}

st_src_reg
glsl_to_tgsi_visitor::st_src_reg_for_float(float val)
{
   st_src_reg src(PROGRAM_IMMEDIATE, -1, GLSL_TYPE_FLOAT);
   union gl_constant_value uval;

   uval.f = val;
   src.index = add_constant(src.file, &uval, 1, GL_FLOAT, &src.swizzle);

   return src;
}

st_src_reg
glsl_to_tgsi_visitor::st_src_reg_for_double(double val)
{
   st_src_reg src(PROGRAM_IMMEDIATE, -1, GLSL_TYPE_DOUBLE);
   union gl_constant_value uval[2];

   uval[0].u = *(uint32_t *)&val;
   uval[1].u = *(((uint32_t *)&val) + 1);
   src.index = add_constant(src.file, uval, 1, GL_DOUBLE, &src.swizzle);

   return src;
}

st_src_reg
glsl_to_tgsi_visitor::st_src_reg_for_int(int val)
{
   st_src_reg src(PROGRAM_IMMEDIATE, -1, GLSL_TYPE_INT);
   union gl_constant_value uval;

   assert(native_integers);

   uval.i = val;
   src.index = add_constant(src.file, &uval, 1, GL_INT, &src.swizzle);

   return src;
}

st_src_reg
glsl_to_tgsi_visitor::st_src_reg_for_type(int type, int val)
{
   if (native_integers)
      return type == GLSL_TYPE_FLOAT ? st_src_reg_for_float(val) :
                                       st_src_reg_for_int(val);
   else
      return st_src_reg_for_float(val);
}

static int
attrib_type_size(const struct glsl_type *type, bool is_vs_input)
{
   unsigned int i;
   int size;

   switch (type->base_type) {
   case GLSL_TYPE_UINT:
   case GLSL_TYPE_INT:
   case GLSL_TYPE_FLOAT:
   case GLSL_TYPE_BOOL:
      if (type->is_matrix()) {
         return type->matrix_columns;
      } else {
         /* Regardless of size of vector, it gets a vec4. This is bad
          * packing for things like floats, but otherwise arrays become a
          * mess.  Hopefully a later pass over the code can pack scalars
          * down if appropriate.
          */
         return 1;
      }
      break;
   case GLSL_TYPE_DOUBLE:
      if (type->is_matrix()) {
         if (type->vector_elements <= 2 || is_vs_input)
            return type->matrix_columns;
         else
            return type->matrix_columns * 2;
      } else {
         /* For doubles if we have a double or dvec2 they fit in one
          * vec4, else they need 2 vec4s.
          */
         if (type->vector_elements <= 2 || is_vs_input)
            return 1;
         else
            return 2;
      }
      break;
   case GLSL_TYPE_ARRAY:
      assert(type->length > 0);
      return attrib_type_size(type->fields.array, is_vs_input) * type->length;
   case GLSL_TYPE_STRUCT:
      size = 0;
      for (i = 0; i < type->length; i++) {
         size += attrib_type_size(type->fields.structure[i].type, is_vs_input);
      }
      return size;
   case GLSL_TYPE_SAMPLER:
   case GLSL_TYPE_IMAGE:
   case GLSL_TYPE_SUBROUTINE:
      /* Samplers take up one slot in UNIFORMS[], but they're baked in
       * at link time.
       */
      return 1;
   case GLSL_TYPE_ATOMIC_UINT:
   case GLSL_TYPE_INTERFACE:
   case GLSL_TYPE_VOID:
   case GLSL_TYPE_ERROR:
      assert(!"Invalid type in type_size");
      break;
   }
   return 0;
}

static int
type_size(const struct glsl_type *type)
{
  return attrib_type_size(type, false);
}

/**
 * If the given GLSL type is an array or matrix or a structure containing
 * an array/matrix member, return true.  Else return false.
 *
 * This is used to determine which kind of temp storage (PROGRAM_TEMPORARY
 * or PROGRAM_ARRAY) should be used for variables of this type.  Anytime
 * we have an array that might be indexed with a variable, we need to use
 * the later storage type.
 */
static bool
type_has_array_or_matrix(const glsl_type *type)
{
   if (type->is_array() || type->is_matrix())
      return true;

   if (type->is_record()) {
      for (unsigned i = 0; i < type->length; i++) {
         if (type_has_array_or_matrix(type->fields.structure[i].type)) {
            return true;
         }
      }
   }

   return false;
}


/**
 * In the initial pass of codegen, we assign temporary numbers to
 * intermediate results.  (not SSA -- variable assignments will reuse
 * storage).
 */
st_src_reg
glsl_to_tgsi_visitor::get_temp(const glsl_type *type)
{
   st_src_reg src;

   src.type = native_integers ? type->base_type : GLSL_TYPE_FLOAT;
   src.reladdr = NULL;
   src.negate = 0;

   if (!options->EmitNoIndirectTemp && type_has_array_or_matrix(type)) {
      if (next_array >= max_num_arrays) {
         max_num_arrays += 32;
         array_sizes = (unsigned*)
            realloc(array_sizes, sizeof(array_sizes[0]) * max_num_arrays);
      }

      src.file = PROGRAM_ARRAY;
      src.index = next_array << 16 | 0x8000;
      array_sizes[next_array] = type_size(type);
      ++next_array;

   } else {
      src.file = PROGRAM_TEMPORARY;
      src.index = next_temp;
      next_temp += type_size(type);
   }

   if (type->is_array() || type->is_record()) {
      src.swizzle = SWIZZLE_NOOP;
   } else {
      src.swizzle = swizzle_for_size(type->vector_elements);
   }

   return src;
}

variable_storage *
glsl_to_tgsi_visitor::find_variable_storage(ir_variable *var)
{

   foreach_in_list(variable_storage, entry, &this->variables) {
      if (entry->var == var)
         return entry;
   }

   return NULL;
}

void
glsl_to_tgsi_visitor::visit(ir_variable *ir)
{
   if (strcmp(ir->name, "gl_FragCoord") == 0) {
      struct gl_fragment_program *fp = (struct gl_fragment_program *)this->prog;

      fp->OriginUpperLeft = ir->data.origin_upper_left;
      fp->PixelCenterInteger = ir->data.pixel_center_integer;
   }

   if (ir->data.mode == ir_var_uniform && strncmp(ir->name, "gl_", 3) == 0) {
      unsigned int i;
      const ir_state_slot *const slots = ir->get_state_slots();
      assert(slots != NULL);

      /* Check if this statevar's setup in the STATE file exactly
       * matches how we'll want to reference it as a
       * struct/array/whatever.  If not, then we need to move it into
       * temporary storage and hope that it'll get copy-propagated
       * out.
       */
      for (i = 0; i < ir->get_num_state_slots(); i++) {
         if (slots[i].swizzle != SWIZZLE_XYZW) {
            break;
         }
      }

      variable_storage *storage;
      st_dst_reg dst;
      if (i == ir->get_num_state_slots()) {
         /* We'll set the index later. */
         storage = new(mem_ctx) variable_storage(ir, PROGRAM_STATE_VAR, -1);
         this->variables.push_tail(storage);

         dst = undef_dst;
      } else {
         /* The variable_storage constructor allocates slots based on the size
          * of the type.  However, this had better match the number of state
          * elements that we're going to copy into the new temporary.
          */
         assert((int) ir->get_num_state_slots() == type_size(ir->type));

         dst = st_dst_reg(get_temp(ir->type));

         storage = new(mem_ctx) variable_storage(ir, dst.file, dst.index);

         this->variables.push_tail(storage);
      }


      for (unsigned int i = 0; i < ir->get_num_state_slots(); i++) {
         int index = _mesa_add_state_reference(this->prog->Parameters,
                                               (gl_state_index *)slots[i].tokens);

         if (storage->file == PROGRAM_STATE_VAR) {
            if (storage->index == -1) {
               storage->index = index;
            } else {
               assert(index == storage->index + (int)i);
            }
         } else {
            /* We use GLSL_TYPE_FLOAT here regardless of the actual type of
             * the data being moved since MOV does not care about the type of
             * data it is moving, and we don't want to declare registers with
             * array or struct types.
             */
            st_src_reg src(PROGRAM_STATE_VAR, index, GLSL_TYPE_FLOAT);
            src.swizzle = slots[i].swizzle;
            emit_asm(ir, TGSI_OPCODE_MOV, dst, src);
            /* even a float takes up a whole vec4 reg in a struct/array. */
            dst.index++;
         }
      }

      if (storage->file == PROGRAM_TEMPORARY &&
          dst.index != storage->index + (int) ir->get_num_state_slots()) {
         fail_link(this->shader_program,
                  "failed to load builtin uniform `%s'  (%d/%d regs loaded)\n",
                  ir->name, dst.index - storage->index,
                  type_size(ir->type));
      }
   }
}

void
glsl_to_tgsi_visitor::visit(ir_loop *ir)
{
   emit_asm(NULL, TGSI_OPCODE_BGNLOOP);

   visit_exec_list(&ir->body_instructions, this);

   emit_asm(NULL, TGSI_OPCODE_ENDLOOP);
}

void
glsl_to_tgsi_visitor::visit(ir_loop_jump *ir)
{
   switch (ir->mode) {
   case ir_loop_jump::jump_break:
      emit_asm(NULL, TGSI_OPCODE_BRK);
      break;
   case ir_loop_jump::jump_continue:
      emit_asm(NULL, TGSI_OPCODE_CONT);
      break;
   }
}


void
glsl_to_tgsi_visitor::visit(ir_function_signature *ir)
{
   assert(0);
   (void)ir;
}

void
glsl_to_tgsi_visitor::visit(ir_function *ir)
{
   /* Ignore function bodies other than main() -- we shouldn't see calls to
    * them since they should all be inlined before we get to glsl_to_tgsi.
    */
   if (strcmp(ir->name, "main") == 0) {
      const ir_function_signature *sig;
      exec_list empty;

      sig = ir->matching_signature(NULL, &empty, false);

      assert(sig);

      foreach_in_list(ir_instruction, ir, &sig->body) {
         ir->accept(this);
      }
   }
}

bool
glsl_to_tgsi_visitor::try_emit_mad(ir_expression *ir, int mul_operand)
{
   int nonmul_operand = 1 - mul_operand;
   st_src_reg a, b, c;
   st_dst_reg result_dst;

   ir_expression *expr = ir->operands[mul_operand]->as_expression();
   if (!expr || expr->operation != ir_binop_mul)
      return false;

   expr->operands[0]->accept(this);
   a = this->result;
   expr->operands[1]->accept(this);
   b = this->result;
   ir->operands[nonmul_operand]->accept(this);
   c = this->result;

   this->result = get_temp(ir->type);
   result_dst = st_dst_reg(this->result);
   result_dst.writemask = (1 << ir->type->vector_elements) - 1;
   emit_asm(ir, TGSI_OPCODE_MAD, result_dst, a, b, c);

   return true;
}

/**
 * Emit MAD(a, -b, a) instead of AND(a, NOT(b))
 *
 * The logic values are 1.0 for true and 0.0 for false.  Logical-and is
 * implemented using multiplication, and logical-or is implemented using
 * addition.  Logical-not can be implemented as (true - x), or (1.0 - x).
 * As result, the logical expression (a & !b) can be rewritten as:
 *
 *     - a * !b
 *     - a * (1 - b)
 *     - (a * 1) - (a * b)
 *     - a + -(a * b)
 *     - a + (a * -b)
 *
 * This final expression can be implemented as a single MAD(a, -b, a)
 * instruction.
 */
bool
glsl_to_tgsi_visitor::try_emit_mad_for_and_not(ir_expression *ir, int try_operand)
{
   const int other_operand = 1 - try_operand;
   st_src_reg a, b;

   ir_expression *expr = ir->operands[try_operand]->as_expression();
   if (!expr || expr->operation != ir_unop_logic_not)
      return false;

   ir->operands[other_operand]->accept(this);
   a = this->result;
   expr->operands[0]->accept(this);
   b = this->result;

   b.negate = ~b.negate;

   this->result = get_temp(ir->type);
   emit_asm(ir, TGSI_OPCODE_MAD, st_dst_reg(this->result), a, b, a);

   return true;
}

void
glsl_to_tgsi_visitor::reladdr_to_temp(ir_instruction *ir,
                                      st_src_reg *reg, int *num_reladdr)
{
   if (!reg->reladdr && !reg->reladdr2)
      return;

   if (reg->reladdr) emit_arl(ir, address_reg, *reg->reladdr);
   if (reg->reladdr2) emit_arl(ir, address_reg2, *reg->reladdr2);

   if (*num_reladdr != 1) {
      st_src_reg temp = get_temp(reg->type == GLSL_TYPE_DOUBLE ? glsl_type::dvec4_type : glsl_type::vec4_type);

      emit_asm(ir, TGSI_OPCODE_MOV, st_dst_reg(temp), *reg);
      *reg = temp;
   }

   (*num_reladdr)--;
}

void
glsl_to_tgsi_visitor::visit(ir_expression *ir)
{
   unsigned int operand;
   st_src_reg op[ARRAY_SIZE(ir->operands)];
   st_src_reg result_src;
   st_dst_reg result_dst;

   /* Quick peephole: Emit MAD(a, b, c) instead of ADD(MUL(a, b), c)
    */
   if (ir->operation == ir_binop_add) {
      if (try_emit_mad(ir, 1))
         return;
      if (try_emit_mad(ir, 0))
         return;
   }

   /* Quick peephole: Emit OPCODE_MAD(-a, -b, a) instead of AND(a, NOT(b))
    */
   if (!native_integers && ir->operation == ir_binop_logic_and) {
      if (try_emit_mad_for_and_not(ir, 1))
         return;
      if (try_emit_mad_for_and_not(ir, 0))
         return;
   }

   if (ir->operation == ir_quadop_vector)
      assert(!"ir_quadop_vector should have been lowered");

   for (operand = 0; operand < ir->get_num_operands(); operand++) {
      this->result.file = PROGRAM_UNDEFINED;
      ir->operands[operand]->accept(this);
      if (this->result.file == PROGRAM_UNDEFINED) {
         printf("Failed to get tree for expression operand:\n");
         ir->operands[operand]->print();
         printf("\n");
         exit(1);
      }
      op[operand] = this->result;

      /* Matrix expression operands should have been broken down to vector
       * operations already.
       */
      assert(!ir->operands[operand]->type->is_matrix());
   }

   int vector_elements = ir->operands[0]->type->vector_elements;
   if (ir->operands[1]) {
      vector_elements = MAX2(vector_elements,
                             ir->operands[1]->type->vector_elements);
   }

   this->result.file = PROGRAM_UNDEFINED;

   /* Storage for our result.  Ideally for an assignment we'd be using
    * the actual storage for the result here, instead.
    */
   result_src = get_temp(ir->type);
   /* convenience for the emit functions below. */
   result_dst = st_dst_reg(result_src);
   /* Limit writes to the channels that will be used by result_src later.
    * This does limit this temp's use as a temporary for multi-instruction
    * sequences.
    */
   result_dst.writemask = (1 << ir->type->vector_elements) - 1;

   switch (ir->operation) {
   case ir_unop_logic_not:
      if (result_dst.type != GLSL_TYPE_FLOAT)
         emit_asm(ir, TGSI_OPCODE_NOT, result_dst, op[0]);
      else {
         /* Previously 'SEQ dst, src, 0.0' was used for this.  However, many
          * older GPUs implement SEQ using multiple instructions (i915 uses two
          * SGE instructions and a MUL instruction).  Since our logic values are
          * 0.0 and 1.0, 1-x also implements !x.
          */
         op[0].negate = ~op[0].negate;
         emit_asm(ir, TGSI_OPCODE_ADD, result_dst, op[0], st_src_reg_for_float(1.0));
      }
      break;
   case ir_unop_neg:
      if (result_dst.type == GLSL_TYPE_INT || result_dst.type == GLSL_TYPE_UINT)
         emit_asm(ir, TGSI_OPCODE_INEG, result_dst, op[0]);
      else if (result_dst.type == GLSL_TYPE_DOUBLE)
         emit_asm(ir, TGSI_OPCODE_DNEG, result_dst, op[0]);
      else {
         op[0].negate = ~op[0].negate;
         result_src = op[0];
      }
      break;
   case ir_unop_subroutine_to_int:
      emit_asm(ir, TGSI_OPCODE_MOV, result_dst, op[0]);
      break;
   case ir_unop_abs:
      emit_asm(ir, TGSI_OPCODE_ABS, result_dst, op[0]);
      break;
   case ir_unop_sign:
      emit_asm(ir, TGSI_OPCODE_SSG, result_dst, op[0]);
      break;
   case ir_unop_rcp:
      emit_scalar(ir, TGSI_OPCODE_RCP, result_dst, op[0]);
      break;

   case ir_unop_exp2:
      emit_scalar(ir, TGSI_OPCODE_EX2, result_dst, op[0]);
      break;
   case ir_unop_exp:
   case ir_unop_log:
      assert(!"not reached: should be handled by ir_explog_to_explog2");
      break;
   case ir_unop_log2:
      emit_scalar(ir, TGSI_OPCODE_LG2, result_dst, op[0]);
      break;
   case ir_unop_sin:
      emit_scalar(ir, TGSI_OPCODE_SIN, result_dst, op[0]);
      break;
   case ir_unop_cos:
      emit_scalar(ir, TGSI_OPCODE_COS, result_dst, op[0]);
      break;
   case ir_unop_saturate: {
      glsl_to_tgsi_instruction *inst;
      inst = emit_asm(ir, TGSI_OPCODE_MOV, result_dst, op[0]);
      inst->saturate = true;
      break;
   }

   case ir_unop_dFdx:
   case ir_unop_dFdx_coarse:
      emit_asm(ir, TGSI_OPCODE_DDX, result_dst, op[0]);
      break;
   case ir_unop_dFdx_fine:
      emit_asm(ir, TGSI_OPCODE_DDX_FINE, result_dst, op[0]);
      break;
   case ir_unop_dFdy:
   case ir_unop_dFdy_coarse:
   case ir_unop_dFdy_fine:
   {
      /* The X component contains 1 or -1 depending on whether the framebuffer
       * is a FBO or the window system buffer, respectively.
       * It is then multiplied with the source operand of DDY.
       */
      static const gl_state_index transform_y_state[STATE_LENGTH]
         = { STATE_INTERNAL, STATE_FB_WPOS_Y_TRANSFORM };

      unsigned transform_y_index =
         _mesa_add_state_reference(this->prog->Parameters,
                                   transform_y_state);

      st_src_reg transform_y = st_src_reg(PROGRAM_STATE_VAR,
                                          transform_y_index,
                                          glsl_type::vec4_type);
      transform_y.swizzle = SWIZZLE_XXXX;

      st_src_reg temp = get_temp(glsl_type::vec4_type);

      emit_asm(ir, TGSI_OPCODE_MUL, st_dst_reg(temp), transform_y, op[0]);
      emit_asm(ir, ir->operation == ir_unop_dFdy_fine ?
           TGSI_OPCODE_DDY_FINE : TGSI_OPCODE_DDY, result_dst, temp);
      break;
   }

   case ir_unop_frexp_sig:
      emit_asm(ir, TGSI_OPCODE_DFRACEXP, result_dst, undef_dst, op[0]);
      break;

   case ir_unop_frexp_exp:
      emit_asm(ir, TGSI_OPCODE_DFRACEXP, undef_dst, result_dst, op[0]);
      break;

   case ir_unop_noise: {
      /* At some point, a motivated person could add a better
       * implementation of noise.  Currently not even the nvidia
       * binary drivers do anything more than this.  In any case, the
       * place to do this is in the GL state tracker, not the poor
       * driver.
       */
      emit_asm(ir, TGSI_OPCODE_MOV, result_dst, st_src_reg_for_float(0.5));
      break;
   }

   case ir_binop_add:
      emit_asm(ir, TGSI_OPCODE_ADD, result_dst, op[0], op[1]);
      break;
   case ir_binop_sub:
      emit_asm(ir, TGSI_OPCODE_SUB, result_dst, op[0], op[1]);
      break;

   case ir_binop_mul:
      emit_asm(ir, TGSI_OPCODE_MUL, result_dst, op[0], op[1]);
      break;
   case ir_binop_div:
      if (result_dst.type == GLSL_TYPE_FLOAT || result_dst.type == GLSL_TYPE_DOUBLE)
         assert(!"not reached: should be handled by ir_div_to_mul_rcp");
      else
         emit_asm(ir, TGSI_OPCODE_DIV, result_dst, op[0], op[1]);
      break;
   case ir_binop_mod:
      if (result_dst.type == GLSL_TYPE_FLOAT)
         assert(!"ir_binop_mod should have been converted to b * fract(a/b)");
      else
         emit_asm(ir, TGSI_OPCODE_MOD, result_dst, op[0], op[1]);
      break;

   case ir_binop_less:
      emit_asm(ir, TGSI_OPCODE_SLT, result_dst, op[0], op[1]);
      break;
   case ir_binop_greater:
      emit_asm(ir, TGSI_OPCODE_SLT, result_dst, op[1], op[0]);
      break;
   case ir_binop_lequal:
      emit_asm(ir, TGSI_OPCODE_SGE, result_dst, op[1], op[0]);
      break;
   case ir_binop_gequal:
      emit_asm(ir, TGSI_OPCODE_SGE, result_dst, op[0], op[1]);
      break;
   case ir_binop_equal:
      emit_asm(ir, TGSI_OPCODE_SEQ, result_dst, op[0], op[1]);
      break;
   case ir_binop_nequal:
      emit_asm(ir, TGSI_OPCODE_SNE, result_dst, op[0], op[1]);
      break;
   case ir_binop_all_equal:
      /* "==" operator producing a scalar boolean. */
      if (ir->operands[0]->type->is_vector() ||
          ir->operands[1]->type->is_vector()) {
         st_src_reg temp = get_temp(native_integers ?
                                    glsl_type::uvec4_type :
                                    glsl_type::vec4_type);

         if (native_integers) {
            st_dst_reg temp_dst = st_dst_reg(temp);
            st_src_reg temp1 = st_src_reg(temp), temp2 = st_src_reg(temp);

            if (ir->operands[0]->type->is_boolean() &&
                ir->operands[1]->as_constant() &&
                ir->operands[1]->as_constant()->is_one()) {
               emit_asm(ir, TGSI_OPCODE_MOV, st_dst_reg(temp), op[0]);
            } else {
               emit_asm(ir, TGSI_OPCODE_SEQ, st_dst_reg(temp), op[0], op[1]);
            }

            /* Emit 1-3 AND operations to combine the SEQ results. */
            switch (ir->operands[0]->type->vector_elements) {
            case 2:
               break;
            case 3:
               temp_dst.writemask = WRITEMASK_Y;
               temp1.swizzle = SWIZZLE_YYYY;
               temp2.swizzle = SWIZZLE_ZZZZ;
               emit_asm(ir, TGSI_OPCODE_AND, temp_dst, temp1, temp2);
               break;
            case 4:
               temp_dst.writemask = WRITEMASK_X;
               temp1.swizzle = SWIZZLE_XXXX;
               temp2.swizzle = SWIZZLE_YYYY;
               emit_asm(ir, TGSI_OPCODE_AND, temp_dst, temp1, temp2);
               temp_dst.writemask = WRITEMASK_Y;
               temp1.swizzle = SWIZZLE_ZZZZ;
               temp2.swizzle = SWIZZLE_WWWW;
               emit_asm(ir, TGSI_OPCODE_AND, temp_dst, temp1, temp2);
            }

            temp1.swizzle = SWIZZLE_XXXX;
            temp2.swizzle = SWIZZLE_YYYY;
            emit_asm(ir, TGSI_OPCODE_AND, result_dst, temp1, temp2);
         } else {
            emit_asm(ir, TGSI_OPCODE_SNE, st_dst_reg(temp), op[0], op[1]);

            /* After the dot-product, the value will be an integer on the
             * range [0,4].  Zero becomes 1.0, and positive values become zero.
             */
            emit_dp(ir, result_dst, temp, temp, vector_elements);

            /* Negating the result of the dot-product gives values on the range
             * [-4, 0].  Zero becomes 1.0, and negative values become zero.
             * This is achieved using SGE.
             */
            st_src_reg sge_src = result_src;
            sge_src.negate = ~sge_src.negate;
            emit_asm(ir, TGSI_OPCODE_SGE, result_dst, sge_src, st_src_reg_for_float(0.0));
         }
      } else {
         emit_asm(ir, TGSI_OPCODE_SEQ, result_dst, op[0], op[1]);
      }
      break;
   case ir_binop_any_nequal:
      /* "!=" operator producing a scalar boolean. */
      if (ir->operands[0]->type->is_vector() ||
          ir->operands[1]->type->is_vector()) {
         st_src_reg temp = get_temp(native_integers ?
                                    glsl_type::uvec4_type :
                                    glsl_type::vec4_type);
         if (ir->operands[0]->type->is_boolean() &&
             ir->operands[1]->as_constant() &&
             ir->operands[1]->as_constant()->is_zero()) {
            emit_asm(ir, TGSI_OPCODE_MOV, st_dst_reg(temp), op[0]);
         } else {
            emit_asm(ir, TGSI_OPCODE_SNE, st_dst_reg(temp), op[0], op[1]);
         }

         if (native_integers) {
            st_dst_reg temp_dst = st_dst_reg(temp);
            st_src_reg temp1 = st_src_reg(temp), temp2 = st_src_reg(temp);

            /* Emit 1-3 OR operations to combine the SNE results. */
            switch (ir->operands[0]->type->vector_elements) {
            case 2:
               break;
            case 3:
               temp_dst.writemask = WRITEMASK_Y;
               temp1.swizzle = SWIZZLE_YYYY;
               temp2.swizzle = SWIZZLE_ZZZZ;
               emit_asm(ir, TGSI_OPCODE_OR, temp_dst, temp1, temp2);
               break;
            case 4:
               temp_dst.writemask = WRITEMASK_X;
               temp1.swizzle = SWIZZLE_XXXX;
               temp2.swizzle = SWIZZLE_YYYY;
               emit_asm(ir, TGSI_OPCODE_OR, temp_dst, temp1, temp2);
               temp_dst.writemask = WRITEMASK_Y;
               temp1.swizzle = SWIZZLE_ZZZZ;
               temp2.swizzle = SWIZZLE_WWWW;
               emit_asm(ir, TGSI_OPCODE_OR, temp_dst, temp1, temp2);
            }

            temp1.swizzle = SWIZZLE_XXXX;
            temp2.swizzle = SWIZZLE_YYYY;
            emit_asm(ir, TGSI_OPCODE_OR, result_dst, temp1, temp2);
         } else {
            /* After the dot-product, the value will be an integer on the
             * range [0,4].  Zero stays zero, and positive values become 1.0.
             */
            glsl_to_tgsi_instruction *const dp =
                  emit_dp(ir, result_dst, temp, temp, vector_elements);
            if (this->prog->Target == GL_FRAGMENT_PROGRAM_ARB) {
               /* The clamping to [0,1] can be done for free in the fragment
                * shader with a saturate.
                */
               dp->saturate = true;
            } else {
               /* Negating the result of the dot-product gives values on the range
                * [-4, 0].  Zero stays zero, and negative values become 1.0.  This
                * achieved using SLT.
                */
               st_src_reg slt_src = result_src;
               slt_src.negate = ~slt_src.negate;
               emit_asm(ir, TGSI_OPCODE_SLT, result_dst, slt_src, st_src_reg_for_float(0.0));
            }
         }
      } else {
         emit_asm(ir, TGSI_OPCODE_SNE, result_dst, op[0], op[1]);
      }
      break;

   case ir_binop_logic_xor:
      if (native_integers)
         emit_asm(ir, TGSI_OPCODE_XOR, result_dst, op[0], op[1]);
      else
         emit_asm(ir, TGSI_OPCODE_SNE, result_dst, op[0], op[1]);
      break;

   case ir_binop_logic_or: {
      if (native_integers) {
         /* If integers are used as booleans, we can use an actual "or"
          * instruction.
          */
         assert(native_integers);
         emit_asm(ir, TGSI_OPCODE_OR, result_dst, op[0], op[1]);
      } else {
         /* After the addition, the value will be an integer on the
          * range [0,2].  Zero stays zero, and positive values become 1.0.
          */
         glsl_to_tgsi_instruction *add =
            emit_asm(ir, TGSI_OPCODE_ADD, result_dst, op[0], op[1]);
         if (this->prog->Target == GL_FRAGMENT_PROGRAM_ARB) {
            /* The clamping to [0,1] can be done for free in the fragment
             * shader with a saturate if floats are being used as boolean values.
             */
            add->saturate = true;
         } else {
            /* Negating the result of the addition gives values on the range
             * [-2, 0].  Zero stays zero, and negative values become 1.0.  This
             * is achieved using SLT.
             */
            st_src_reg slt_src = result_src;
            slt_src.negate = ~slt_src.negate;
            emit_asm(ir, TGSI_OPCODE_SLT, result_dst, slt_src, st_src_reg_for_float(0.0));
         }
      }
      break;
   }

   case ir_binop_logic_and:
      /* If native integers are disabled, the bool args are stored as float 0.0
       * or 1.0, so "mul" gives us "and".  If they're enabled, just use the
       * actual AND opcode.
       */
      if (native_integers)
         emit_asm(ir, TGSI_OPCODE_AND, result_dst, op[0], op[1]);
      else
         emit_asm(ir, TGSI_OPCODE_MUL, result_dst, op[0], op[1]);
      break;

   case ir_binop_dot:
      assert(ir->operands[0]->type->is_vector());
      assert(ir->operands[0]->type == ir->operands[1]->type);
      emit_dp(ir, result_dst, op[0], op[1],
              ir->operands[0]->type->vector_elements);
      break;

   case ir_unop_sqrt:
      if (have_sqrt) {
         emit_scalar(ir, TGSI_OPCODE_SQRT, result_dst, op[0]);
      } else {
         /* sqrt(x) = x * rsq(x). */
         emit_scalar(ir, TGSI_OPCODE_RSQ, result_dst, op[0]);
         emit_asm(ir, TGSI_OPCODE_MUL, result_dst, result_src, op[0]);
         /* For incoming channels <= 0, set the result to 0. */
         op[0].negate = ~op[0].negate;
         emit_asm(ir, TGSI_OPCODE_CMP, result_dst,
              op[0], result_src, st_src_reg_for_float(0.0));
      }
      break;
   case ir_unop_rsq:
      emit_scalar(ir, TGSI_OPCODE_RSQ, result_dst, op[0]);
      break;
   case ir_unop_i2f:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_I2F, result_dst, op[0]);
         break;
      }
      /* fallthrough to next case otherwise */
   case ir_unop_b2f:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_AND, result_dst, op[0], st_src_reg_for_float(1.0));
         break;
      }
      /* fallthrough to next case otherwise */
   case ir_unop_i2u:
   case ir_unop_u2i:
      /* Converting between signed and unsigned integers is a no-op. */
      result_src = op[0];
      break;
   case ir_unop_b2i:
      if (native_integers) {
         /* Booleans are stored as integers using ~0 for true and 0 for false.
          * GLSL requires that int(bool) return 1 for true and 0 for false.
          * This conversion is done with AND, but it could be done with NEG.
          */
         emit_asm(ir, TGSI_OPCODE_AND, result_dst, op[0], st_src_reg_for_int(1));
      } else {
         /* Booleans and integers are both stored as floats when native
          * integers are disabled.
          */
         result_src = op[0];
      }
      break;
   case ir_unop_f2i:
      if (native_integers)
         emit_asm(ir, TGSI_OPCODE_F2I, result_dst, op[0]);
      else
         emit_asm(ir, TGSI_OPCODE_TRUNC, result_dst, op[0]);
      break;
   case ir_unop_f2u:
      if (native_integers)
         emit_asm(ir, TGSI_OPCODE_F2U, result_dst, op[0]);
      else
         emit_asm(ir, TGSI_OPCODE_TRUNC, result_dst, op[0]);
      break;
   case ir_unop_bitcast_f2i:
      result_src = op[0];
      result_src.type = GLSL_TYPE_INT;
      break;
   case ir_unop_bitcast_f2u:
      result_src = op[0];
      result_src.type = GLSL_TYPE_UINT;
      break;
   case ir_unop_bitcast_i2f:
   case ir_unop_bitcast_u2f:
      result_src = op[0];
      result_src.type = GLSL_TYPE_FLOAT;
      break;
   case ir_unop_f2b:
      emit_asm(ir, TGSI_OPCODE_SNE, result_dst, op[0], st_src_reg_for_float(0.0));
      break;
   case ir_unop_d2b:
      emit_asm(ir, TGSI_OPCODE_SNE, result_dst, op[0], st_src_reg_for_double(0.0));
      break;
   case ir_unop_i2b:
      if (native_integers)
         emit_asm(ir, TGSI_OPCODE_USNE, result_dst, op[0], st_src_reg_for_int(0));
      else
         emit_asm(ir, TGSI_OPCODE_SNE, result_dst, op[0], st_src_reg_for_float(0.0));
      break;
   case ir_unop_trunc:
      emit_asm(ir, TGSI_OPCODE_TRUNC, result_dst, op[0]);
      break;
   case ir_unop_ceil:
      emit_asm(ir, TGSI_OPCODE_CEIL, result_dst, op[0]);
      break;
   case ir_unop_floor:
      emit_asm(ir, TGSI_OPCODE_FLR, result_dst, op[0]);
      break;
   case ir_unop_round_even:
      emit_asm(ir, TGSI_OPCODE_ROUND, result_dst, op[0]);
      break;
   case ir_unop_fract:
      emit_asm(ir, TGSI_OPCODE_FRC, result_dst, op[0]);
      break;

   case ir_binop_min:
      emit_asm(ir, TGSI_OPCODE_MIN, result_dst, op[0], op[1]);
      break;
   case ir_binop_max:
      emit_asm(ir, TGSI_OPCODE_MAX, result_dst, op[0], op[1]);
      break;
   case ir_binop_pow:
      emit_scalar(ir, TGSI_OPCODE_POW, result_dst, op[0], op[1]);
      break;

   case ir_unop_bit_not:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_NOT, result_dst, op[0]);
         break;
      }
   case ir_unop_u2f:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_U2F, result_dst, op[0]);
         break;
      }
   case ir_binop_lshift:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_SHL, result_dst, op[0], op[1]);
         break;
      }
   case ir_binop_rshift:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_ISHR, result_dst, op[0], op[1]);
         break;
      }
   case ir_binop_bit_and:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_AND, result_dst, op[0], op[1]);
         break;
      }
   case ir_binop_bit_xor:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_XOR, result_dst, op[0], op[1]);
         break;
      }
   case ir_binop_bit_or:
      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_OR, result_dst, op[0], op[1]);
         break;
      }

      assert(!"GLSL 1.30 features unsupported");
      break;

   case ir_binop_ubo_load: {
      ir_constant *const_uniform_block = ir->operands[0]->as_constant();
      ir_constant *const_offset_ir = ir->operands[1]->as_constant();
      unsigned const_offset = const_offset_ir ? const_offset_ir->value.u[0] : 0;
      unsigned const_block = const_uniform_block ? const_uniform_block->value.u[0] + 1 : 0;
      st_src_reg index_reg = get_temp(glsl_type::uint_type);
      st_src_reg cbuf;

      cbuf.type = ir->type->base_type;
      cbuf.file = PROGRAM_CONSTANT;
      cbuf.index = 0;
      cbuf.reladdr = NULL;
      cbuf.negate = 0;

      assert(ir->type->is_vector() || ir->type->is_scalar());

      if (const_offset_ir) {
         /* Constant index into constant buffer */
         cbuf.reladdr = NULL;
         cbuf.index = const_offset / 16;
      }
      else {
         /* Relative/variable index into constant buffer */
         emit_asm(ir, TGSI_OPCODE_USHR, st_dst_reg(index_reg), op[1],
              st_src_reg_for_int(4));
         cbuf.reladdr = ralloc(mem_ctx, st_src_reg);
         memcpy(cbuf.reladdr, &index_reg, sizeof(index_reg));
      }

      if (const_uniform_block) {
         /* Constant constant buffer */
         cbuf.reladdr2 = NULL;
         cbuf.index2D = const_block;
         cbuf.has_index2 = true;
      }
      else {
         /* Relative/variable constant buffer */
         cbuf.reladdr2 = ralloc(mem_ctx, st_src_reg);
         cbuf.index2D = 1;
         memcpy(cbuf.reladdr2, &op[0], sizeof(st_src_reg));
         cbuf.has_index2 = true;
      }

      cbuf.swizzle = swizzle_for_size(ir->type->vector_elements);
      if (cbuf.type == GLSL_TYPE_DOUBLE)
         cbuf.swizzle += MAKE_SWIZZLE4(const_offset % 16 / 8,
                                       const_offset % 16 / 8,
                                       const_offset % 16 / 8,
                                       const_offset % 16 / 8);
      else
         cbuf.swizzle += MAKE_SWIZZLE4(const_offset % 16 / 4,
                                       const_offset % 16 / 4,
                                       const_offset % 16 / 4,
                                       const_offset % 16 / 4);

      if (ir->type->base_type == GLSL_TYPE_BOOL) {
         emit_asm(ir, TGSI_OPCODE_USNE, result_dst, cbuf, st_src_reg_for_int(0));
      } else {
         emit_asm(ir, TGSI_OPCODE_MOV, result_dst, cbuf);
      }
      break;
   }
   case ir_triop_lrp:
      /* note: we have to reorder the three args here */
      emit_asm(ir, TGSI_OPCODE_LRP, result_dst, op[2], op[1], op[0]);
      break;
   case ir_triop_csel:
      if (this->ctx->Const.NativeIntegers)
         emit_asm(ir, TGSI_OPCODE_UCMP, result_dst, op[0], op[1], op[2]);
      else {
         op[0].negate = ~op[0].negate;
         emit_asm(ir, TGSI_OPCODE_CMP, result_dst, op[0], op[1], op[2]);
      }
      break;
   case ir_triop_bitfield_extract:
      emit_asm(ir, TGSI_OPCODE_IBFE, result_dst, op[0], op[1], op[2]);
      break;
   case ir_quadop_bitfield_insert:
      emit_asm(ir, TGSI_OPCODE_BFI, result_dst, op[0], op[1], op[2], op[3]);
      break;
   case ir_unop_bitfield_reverse:
      emit_asm(ir, TGSI_OPCODE_BREV, result_dst, op[0]);
      break;
   case ir_unop_bit_count:
      emit_asm(ir, TGSI_OPCODE_POPC, result_dst, op[0]);
      break;
   case ir_unop_find_msb:
      emit_asm(ir, TGSI_OPCODE_IMSB, result_dst, op[0]);
      break;
   case ir_unop_find_lsb:
      emit_asm(ir, TGSI_OPCODE_LSB, result_dst, op[0]);
      break;
   case ir_binop_imul_high:
      emit_asm(ir, TGSI_OPCODE_IMUL_HI, result_dst, op[0], op[1]);
      break;
   case ir_triop_fma:
      /* In theory, MAD is incorrect here. */
      if (have_fma)
         emit_asm(ir, TGSI_OPCODE_FMA, result_dst, op[0], op[1], op[2]);
      else
         emit_asm(ir, TGSI_OPCODE_MAD, result_dst, op[0], op[1], op[2]);
      break;
   case ir_unop_interpolate_at_centroid:
      emit_asm(ir, TGSI_OPCODE_INTERP_CENTROID, result_dst, op[0]);
      break;
   case ir_binop_interpolate_at_offset:
      emit_asm(ir, TGSI_OPCODE_INTERP_OFFSET, result_dst, op[0], op[1]);
      break;
   case ir_binop_interpolate_at_sample:
      emit_asm(ir, TGSI_OPCODE_INTERP_SAMPLE, result_dst, op[0], op[1]);
      break;

   case ir_unop_d2f:
      emit_asm(ir, TGSI_OPCODE_D2F, result_dst, op[0]);
      break;
   case ir_unop_f2d:
      emit_asm(ir, TGSI_OPCODE_F2D, result_dst, op[0]);
      break;
   case ir_unop_d2i:
      emit_asm(ir, TGSI_OPCODE_D2I, result_dst, op[0]);
      break;
   case ir_unop_i2d:
      emit_asm(ir, TGSI_OPCODE_I2D, result_dst, op[0]);
      break;
   case ir_unop_d2u:
      emit_asm(ir, TGSI_OPCODE_D2U, result_dst, op[0]);
      break;
   case ir_unop_u2d:
      emit_asm(ir, TGSI_OPCODE_U2D, result_dst, op[0]);
      break;
   case ir_unop_unpack_double_2x32:
   case ir_unop_pack_double_2x32:
      emit_asm(ir, TGSI_OPCODE_MOV, result_dst, op[0]);
      break;

   case ir_binop_ldexp:
      if (ir->operands[0]->type->base_type == GLSL_TYPE_DOUBLE) {
         emit_asm(ir, TGSI_OPCODE_DLDEXP, result_dst, op[0], op[1]);
      } else {
         assert(!"Invalid ldexp for non-double opcode in glsl_to_tgsi_visitor::visit()");
      }
      break;

   case ir_unop_pack_half_2x16:
      emit_asm(ir, TGSI_OPCODE_PK2H, result_dst, op[0]);
      break;
   case ir_unop_unpack_half_2x16:
      emit_asm(ir, TGSI_OPCODE_UP2H, result_dst, op[0]);
      break;

   case ir_unop_pack_snorm_2x16:
   case ir_unop_pack_unorm_2x16:
   case ir_unop_pack_snorm_4x8:
   case ir_unop_pack_unorm_4x8:

   case ir_unop_unpack_snorm_2x16:
   case ir_unop_unpack_unorm_2x16:
   case ir_unop_unpack_half_2x16_split_x:
   case ir_unop_unpack_half_2x16_split_y:
   case ir_unop_unpack_snorm_4x8:
   case ir_unop_unpack_unorm_4x8:

   case ir_binop_pack_half_2x16_split:
   case ir_quadop_vector:
   case ir_binop_vector_extract:
   case ir_triop_vector_insert:
   case ir_binop_carry:
   case ir_binop_borrow:
   case ir_unop_ssbo_unsized_array_length:
      /* This operation is not supported, or should have already been handled.
       */
      assert(!"Invalid ir opcode in glsl_to_tgsi_visitor::visit()");
      break;

   case ir_unop_get_buffer_size:
      assert(!"Not implemented yet");
      break;
   }

   this->result = result_src;
}


void
glsl_to_tgsi_visitor::visit(ir_swizzle *ir)
{
   st_src_reg src;
   int i;
   int swizzle[4];

   /* Note that this is only swizzles in expressions, not those on the left
    * hand side of an assignment, which do write masking.  See ir_assignment
    * for that.
    */

   ir->val->accept(this);
   src = this->result;
   assert(src.file != PROGRAM_UNDEFINED);
   assert(ir->type->vector_elements > 0);

   for (i = 0; i < 4; i++) {
      if (i < ir->type->vector_elements) {
         switch (i) {
         case 0:
            swizzle[i] = GET_SWZ(src.swizzle, ir->mask.x);
            break;
         case 1:
            swizzle[i] = GET_SWZ(src.swizzle, ir->mask.y);
            break;
         case 2:
            swizzle[i] = GET_SWZ(src.swizzle, ir->mask.z);
            break;
         case 3:
            swizzle[i] = GET_SWZ(src.swizzle, ir->mask.w);
            break;
         }
      } else {
         /* If the type is smaller than a vec4, replicate the last
          * channel out.
          */
         swizzle[i] = swizzle[ir->type->vector_elements - 1];
      }
   }

   src.swizzle = MAKE_SWIZZLE4(swizzle[0], swizzle[1], swizzle[2], swizzle[3]);

   this->result = src;
}

/* Test if the variable is an array. Note that geometry and
 * tessellation shader inputs are outputs are always arrays (except
 * for patch inputs), so only the array element type is considered.
 */
static bool
is_inout_array(unsigned stage, ir_variable *var, bool *is_2d)
{
   const glsl_type *type = var->type;

   if ((stage == MESA_SHADER_VERTEX && var->data.mode == ir_var_shader_in) ||
       (stage == MESA_SHADER_FRAGMENT && var->data.mode == ir_var_shader_out))
      return false;

   *is_2d = false;

   if (((stage == MESA_SHADER_GEOMETRY && var->data.mode == ir_var_shader_in) ||
        (stage == MESA_SHADER_TESS_EVAL && var->data.mode == ir_var_shader_in) ||
        stage == MESA_SHADER_TESS_CTRL) &&
       !var->data.patch) {
      if (!var->type->is_array())
         return false; /* a system value probably */

      type = var->type->fields.array;
      *is_2d = true;
   }

   return type->is_array() || type->is_matrix();
}

void
glsl_to_tgsi_visitor::visit(ir_dereference_variable *ir)
{
   variable_storage *entry = find_variable_storage(ir->var);
   ir_variable *var = ir->var;
   bool is_2d;

   if (!entry) {
      switch (var->data.mode) {
      case ir_var_uniform:
         entry = new(mem_ctx) variable_storage(var, PROGRAM_UNIFORM,
                                               var->data.location);
         this->variables.push_tail(entry);
         break;
      case ir_var_shader_in:
         /* The linker assigns locations for varyings and attributes,
          * including deprecated builtins (like gl_Color), user-assign
          * generic attributes (glBindVertexLocation), and
          * user-defined varyings.
          */
         assert(var->data.location != -1);

         if (is_inout_array(shader->Stage, var, &is_2d)) {
            struct array_decl *decl = &input_arrays[num_input_arrays];

            decl->mesa_index = var->data.location;
            decl->array_id = num_input_arrays + 1;
            if (is_2d) {
               decl->array_size = type_size(var->type->fields.array);
               decl->array_type = var->type->fields.array->without_array()->base_type;
            } else {
               decl->array_size = type_size(var->type);
               decl->array_type = var->type->without_array()->base_type;
            }
            num_input_arrays++;

            entry = new(mem_ctx) variable_storage(var,
                                                  PROGRAM_INPUT,
                                                  var->data.location,
                                                  decl->array_id);
         }
         else {
            entry = new(mem_ctx) variable_storage(var,
                                                  PROGRAM_INPUT,
                                                  var->data.location);
         }
         this->variables.push_tail(entry);
         break;
      case ir_var_shader_out:
         assert(var->data.location != -1);

         if (is_inout_array(shader->Stage, var, &is_2d)) {
            struct array_decl *decl = &output_arrays[num_output_arrays];

            decl->mesa_index = var->data.location;
            decl->array_id = num_output_arrays + 1;
            if (is_2d) {
               decl->array_size = type_size(var->type->fields.array);
               decl->array_type = var->type->fields.array->without_array()->base_type;
            } else {
               decl->array_size = type_size(var->type);
               decl->array_type = var->type->without_array()->base_type;
            }
            num_output_arrays++;

            entry = new(mem_ctx) variable_storage(var,
                                                  PROGRAM_OUTPUT,
                                                  var->data.location,
                                                  decl->array_id);
         }
         else {
            entry = new(mem_ctx) variable_storage(var,
                                                  PROGRAM_OUTPUT,
                                                  var->data.location
                                                  + var->data.index);
         }
         this->variables.push_tail(entry);
         break;
      case ir_var_system_value:
         entry = new(mem_ctx) variable_storage(var,
                                               PROGRAM_SYSTEM_VALUE,
                                               var->data.location);
         break;
      case ir_var_auto:
      case ir_var_temporary:
         st_src_reg src = get_temp(var->type);

         entry = new(mem_ctx) variable_storage(var, src.file, src.index);
         this->variables.push_tail(entry);

         break;
      }

      if (!entry) {
         printf("Failed to make storage for %s\n", var->name);
         exit(1);
      }
   }

   this->result = st_src_reg(entry->file, entry->index, var->type);
   this->result.array_id = entry->array_id;
   if (this->shader->Stage == MESA_SHADER_VERTEX && var->data.mode == ir_var_shader_in && var->type->is_double())
      this->result.is_double_vertex_input = true;
   if (!native_integers)
      this->result.type = GLSL_TYPE_FLOAT;
}

static void
shrink_array_declarations(struct array_decl *arrays, unsigned count,
                          GLbitfield64 usage_mask,
                          GLbitfield64 double_usage_mask,
                          GLbitfield patch_usage_mask)
{
   unsigned i, j;

   /* Fix array declarations by removing unused array elements at both ends
    * of the arrays. For example, mat4[3] where only mat[1] is used.
    */
   for (i = 0; i < count; i++) {
      struct array_decl *decl = &arrays[i];

      /* Shrink the beginning. */
      for (j = 0; j < decl->array_size; j++) {
         if (decl->mesa_index >= VARYING_SLOT_PATCH0) {
            if (patch_usage_mask &
                BITFIELD64_BIT(decl->mesa_index - VARYING_SLOT_PATCH0 + j))
               break;
         }
         else {
            if (usage_mask & BITFIELD64_BIT(decl->mesa_index+j))
               break;
            if (double_usage_mask & BITFIELD64_BIT(decl->mesa_index+j-1))
               break;
         }

         decl->mesa_index++;
         decl->array_size--;
         j--;
      }

      /* Shrink the end. */
      for (j = decl->array_size-1; j >= 0; j--) {
         if (decl->mesa_index >= VARYING_SLOT_PATCH0) {
            if (patch_usage_mask &
                BITFIELD64_BIT(decl->mesa_index - VARYING_SLOT_PATCH0 + j))
               break;
         }
         else {
            if (usage_mask & BITFIELD64_BIT(decl->mesa_index+j))
               break;
            if (double_usage_mask & BITFIELD64_BIT(decl->mesa_index+j-1))
               break;
         }

         decl->array_size--;
      }
   }
}

void
glsl_to_tgsi_visitor::visit(ir_dereference_array *ir)
{
   ir_constant *index;
   st_src_reg src;
   int element_size = type_size(ir->type);
   bool is_2D = false;

   index = ir->array_index->constant_expression_value();

   ir->array->accept(this);
   src = this->result;

   if (ir->array->ir_type != ir_type_dereference_array) {
      switch (this->prog->Target) {
      case GL_TESS_CONTROL_PROGRAM_NV:
         is_2D = (src.file == PROGRAM_INPUT || src.file == PROGRAM_OUTPUT) &&
                 !ir->variable_referenced()->data.patch;
         break;
      case GL_TESS_EVALUATION_PROGRAM_NV:
         is_2D = src.file == PROGRAM_INPUT &&
                 !ir->variable_referenced()->data.patch;
         break;
      case GL_GEOMETRY_PROGRAM_NV:
         is_2D = src.file == PROGRAM_INPUT;
         break;
      }
   }

   if (is_2D)
      element_size = 1;

   if (index) {

      if (this->prog->Target == GL_VERTEX_PROGRAM_ARB &&
          src.file == PROGRAM_INPUT)
         element_size = attrib_type_size(ir->type, true);
      if (is_2D) {
         src.index2D = index->value.i[0];
         src.has_index2 = true;
      } else
         src.index += index->value.i[0] * element_size;
   } else {
      /* Variable index array dereference.  It eats the "vec4" of the
       * base of the array and an index that offsets the TGSI register
       * index.
       */
      ir->array_index->accept(this);

      st_src_reg index_reg;

      if (element_size == 1) {
         index_reg = this->result;
      } else {
         index_reg = get_temp(native_integers ?
                              glsl_type::int_type : glsl_type::float_type);

         emit_asm(ir, TGSI_OPCODE_MUL, st_dst_reg(index_reg),
              this->result, st_src_reg_for_type(index_reg.type, element_size));
      }

      /* If there was already a relative address register involved, add the
       * new and the old together to get the new offset.
       */
      if (!is_2D && src.reladdr != NULL) {
         st_src_reg accum_reg = get_temp(native_integers ?
                                glsl_type::int_type : glsl_type::float_type);

         emit_asm(ir, TGSI_OPCODE_ADD, st_dst_reg(accum_reg),
              index_reg, *src.reladdr);

         index_reg = accum_reg;
      }

      if (is_2D) {
         src.reladdr2 = ralloc(mem_ctx, st_src_reg);
         memcpy(src.reladdr2, &index_reg, sizeof(index_reg));
         src.index2D = 0;
         src.has_index2 = true;
      } else {
         src.reladdr = ralloc(mem_ctx, st_src_reg);
         memcpy(src.reladdr, &index_reg, sizeof(index_reg));
      }
   }

   /* If the type is smaller than a vec4, replicate the last channel out. */
   if (ir->type->is_scalar() || ir->type->is_vector())
      src.swizzle = swizzle_for_size(ir->type->vector_elements);
   else
      src.swizzle = SWIZZLE_NOOP;

   /* Change the register type to the element type of the array. */
   src.type = ir->type->base_type;

   this->result = src;
}

void
glsl_to_tgsi_visitor::visit(ir_dereference_record *ir)
{
   unsigned int i;
   const glsl_type *struct_type = ir->record->type;
   int offset = 0;

   ir->record->accept(this);

   for (i = 0; i < struct_type->length; i++) {
      if (strcmp(struct_type->fields.structure[i].name, ir->field) == 0)
         break;
      offset += type_size(struct_type->fields.structure[i].type);
   }

   /* If the type is smaller than a vec4, replicate the last channel out. */
   if (ir->type->is_scalar() || ir->type->is_vector())
      this->result.swizzle = swizzle_for_size(ir->type->vector_elements);
   else
      this->result.swizzle = SWIZZLE_NOOP;

   this->result.index += offset;
   this->result.type = ir->type->base_type;
}

/**
 * We want to be careful in assignment setup to hit the actual storage
 * instead of potentially using a temporary like we might with the
 * ir_dereference handler.
 */
static st_dst_reg
get_assignment_lhs(ir_dereference *ir, glsl_to_tgsi_visitor *v)
{
   /* The LHS must be a dereference.  If the LHS is a variable indexed array
    * access of a vector, it must be separated into a series conditional moves
    * before reaching this point (see ir_vec_index_to_cond_assign).
    */
   assert(ir->as_dereference());
   ir_dereference_array *deref_array = ir->as_dereference_array();
   if (deref_array) {
      assert(!deref_array->array->type->is_vector());
   }

   /* Use the rvalue deref handler for the most part.  We'll ignore
    * swizzles in it and write swizzles using writemask, though.
    */
   ir->accept(v);
   return st_dst_reg(v->result);
}

/**
 * Process the condition of a conditional assignment
 *
 * Examines the condition of a conditional assignment to generate the optimal
 * first operand of a \c CMP instruction.  If the condition is a relational
 * operator with 0 (e.g., \c ir_binop_less), the value being compared will be
 * used as the source for the \c CMP instruction.  Otherwise the comparison
 * is processed to a boolean result, and the boolean result is used as the
 * operand to the CMP instruction.
 */
bool
glsl_to_tgsi_visitor::process_move_condition(ir_rvalue *ir)
{
   ir_rvalue *src_ir = ir;
   bool negate = true;
   bool switch_order = false;

   ir_expression *const expr = ir->as_expression();

   if (native_integers) {
      if ((expr != NULL) && (expr->get_num_operands() == 2)) {
         enum glsl_base_type type = expr->operands[0]->type->base_type;
         if (type == GLSL_TYPE_INT || type == GLSL_TYPE_UINT ||
             type == GLSL_TYPE_BOOL) {
            if (expr->operation == ir_binop_equal) {
               if (expr->operands[0]->is_zero()) {
                  src_ir = expr->operands[1];
                  switch_order = true;
               }
               else if (expr->operands[1]->is_zero()) {
                  src_ir = expr->operands[0];
                  switch_order = true;
               }
            }
            else if (expr->operation == ir_binop_nequal) {
               if (expr->operands[0]->is_zero()) {
                  src_ir = expr->operands[1];
               }
               else if (expr->operands[1]->is_zero()) {
                  src_ir = expr->operands[0];
               }
            }
         }
      }

      src_ir->accept(this);
      return switch_order;
   }

   if ((expr != NULL) && (expr->get_num_operands() == 2)) {
      bool zero_on_left = false;

      if (expr->operands[0]->is_zero()) {
         src_ir = expr->operands[1];
         zero_on_left = true;
      } else if (expr->operands[1]->is_zero()) {
         src_ir = expr->operands[0];
         zero_on_left = false;
      }

      /*      a is -  0  +            -  0  +
       * (a <  0)  T  F  F  ( a < 0)  T  F  F
       * (0 <  a)  F  F  T  (-a < 0)  F  F  T
       * (a <= 0)  T  T  F  (-a < 0)  F  F  T  (swap order of other operands)
       * (0 <= a)  F  T  T  ( a < 0)  T  F  F  (swap order of other operands)
       * (a >  0)  F  F  T  (-a < 0)  F  F  T
       * (0 >  a)  T  F  F  ( a < 0)  T  F  F
       * (a >= 0)  F  T  T  ( a < 0)  T  F  F  (swap order of other operands)
       * (0 >= a)  T  T  F  (-a < 0)  F  F  T  (swap order of other operands)
       *
       * Note that exchanging the order of 0 and 'a' in the comparison simply
       * means that the value of 'a' should be negated.
       */
      if (src_ir != ir) {
         switch (expr->operation) {
         case ir_binop_less:
            switch_order = false;
            negate = zero_on_left;
            break;

         case ir_binop_greater:
            switch_order = false;
            negate = !zero_on_left;
            break;

         case ir_binop_lequal:
            switch_order = true;
            negate = !zero_on_left;
            break;

         case ir_binop_gequal:
            switch_order = true;
            negate = zero_on_left;
            break;

         default:
            /* This isn't the right kind of comparison afterall, so make sure
             * the whole condition is visited.
             */
            src_ir = ir;
            break;
         }
      }
   }

   src_ir->accept(this);

   /* We use the TGSI_OPCODE_CMP (a < 0 ? b : c) for conditional moves, and the
    * condition we produced is 0.0 or 1.0.  By flipping the sign, we can
    * choose which value TGSI_OPCODE_CMP produces without an extra instruction
    * computing the condition.
    */
   if (negate)
      this->result.negate = ~this->result.negate;

   return switch_order;
}

void
glsl_to_tgsi_visitor::emit_block_mov(ir_assignment *ir, const struct glsl_type *type,
                                     st_dst_reg *l, st_src_reg *r,
                                     st_src_reg *cond, bool cond_swap)
{
   if (type->base_type == GLSL_TYPE_STRUCT) {
      for (unsigned int i = 0; i < type->length; i++) {
         emit_block_mov(ir, type->fields.structure[i].type, l, r,
                        cond, cond_swap);
      }
      return;
   }

   if (type->is_array()) {
      for (unsigned int i = 0; i < type->length; i++) {
         emit_block_mov(ir, type->fields.array, l, r, cond, cond_swap);
      }
      return;
   }

   if (type->is_matrix()) {
      const struct glsl_type *vec_type;

      vec_type = glsl_type::get_instance(type->is_double() ? GLSL_TYPE_DOUBLE : GLSL_TYPE_FLOAT,
                                         type->vector_elements, 1);

      for (int i = 0; i < type->matrix_columns; i++) {
         emit_block_mov(ir, vec_type, l, r, cond, cond_swap);
      }
      return;
   }

   assert(type->is_scalar() || type->is_vector());

   r->type = type->base_type;
   if (cond) {
      st_src_reg l_src = st_src_reg(*l);
      l_src.swizzle = swizzle_for_size(type->vector_elements);

      if (native_integers) {
         emit_asm(ir, TGSI_OPCODE_UCMP, *l, *cond,
              cond_swap ? l_src : *r,
              cond_swap ? *r : l_src);
      } else {
         emit_asm(ir, TGSI_OPCODE_CMP, *l, *cond,
              cond_swap ? l_src : *r,
              cond_swap ? *r : l_src);
      }
   } else {
      emit_asm(ir, TGSI_OPCODE_MOV, *l, *r);
   }
   l->index++;
   r->index++;
   if (type->is_dual_slot_double()) {
      l->index++;
      if (r->is_double_vertex_input == false)
         r->index++;
   }
}

void
glsl_to_tgsi_visitor::visit(ir_assignment *ir)
{
   st_dst_reg l;
   st_src_reg r;

   ir->rhs->accept(this);
   r = this->result;

   l = get_assignment_lhs(ir->lhs, this);

   /* FINISHME: This should really set to the correct maximal writemask for each
    * FINISHME: component written (in the loops below).  This case can only
    * FINISHME: occur for matrices, arrays, and structures.
    */
   if (ir->write_mask == 0) {
      assert(!ir->lhs->type->is_scalar() && !ir->lhs->type->is_vector());

      if (ir->lhs->type->is_array() || ir->lhs->type->without_array()->is_matrix()) {
         if (ir->lhs->type->without_array()->is_double()) {
            switch (ir->lhs->type->without_array()->vector_elements) {
            case 1:
               l.writemask = WRITEMASK_X;
               break;
            case 2:
               l.writemask = WRITEMASK_XY;
               break;
            case 3:
               l.writemask = WRITEMASK_XYZ;
               break;
            case 4:
               l.writemask = WRITEMASK_XYZW;
               break;
            }
         } else
            l.writemask = WRITEMASK_XYZW;
      }
   } else if (ir->lhs->type->is_scalar() &&
              !ir->lhs->type->is_double() &&
              ir->lhs->variable_referenced()->data.mode == ir_var_shader_out) {
      /* FINISHME: This hack makes writing to gl_FragDepth, which lives in the
       * FINISHME: W component of fragment shader output zero, work correctly.
       */
      l.writemask = WRITEMASK_XYZW;
   } else {
      int swizzles[4];
      int first_enabled_chan = 0;
      int rhs_chan = 0;

      l.writemask = ir->write_mask;

      for (int i = 0; i < 4; i++) {
         if (l.writemask & (1 << i)) {
            first_enabled_chan = GET_SWZ(r.swizzle, i);
            break;
         }
      }

      /* Swizzle a small RHS vector into the channels being written.
       *
       * glsl ir treats write_mask as dictating how many channels are
       * present on the RHS while TGSI treats write_mask as just
       * showing which channels of the vec4 RHS get written.
       */
      for (int i = 0; i < 4; i++) {
         if (l.writemask & (1 << i))
            swizzles[i] = GET_SWZ(r.swizzle, rhs_chan++);
         else
            swizzles[i] = first_enabled_chan;
      }
      r.swizzle = MAKE_SWIZZLE4(swizzles[0], swizzles[1],
                                swizzles[2], swizzles[3]);
   }

   assert(l.file != PROGRAM_UNDEFINED);
   assert(r.file != PROGRAM_UNDEFINED);

   if (ir->condition) {
      const bool switch_order = this->process_move_condition(ir->condition);
      st_src_reg condition = this->result;

      emit_block_mov(ir, ir->lhs->type, &l, &r, &condition, switch_order);
   } else if (ir->rhs->as_expression() &&
              this->instructions.get_tail() &&
              ir->rhs == ((glsl_to_tgsi_instruction *)this->instructions.get_tail())->ir &&
              type_size(ir->lhs->type) == 1 &&
              l.writemask == ((glsl_to_tgsi_instruction *)this->instructions.get_tail())->dst[0].writemask) {
      /* To avoid emitting an extra MOV when assigning an expression to a
       * variable, emit the last instruction of the expression again, but
       * replace the destination register with the target of the assignment.
       * Dead code elimination will remove the original instruction.
       */
      glsl_to_tgsi_instruction *inst, *new_inst;
      inst = (glsl_to_tgsi_instruction *)this->instructions.get_tail();
      new_inst = emit_asm(ir, inst->op, l, inst->src[0], inst->src[1], inst->src[2], inst->src[3]);
      new_inst->saturate = inst->saturate;
      inst->dead_mask = inst->dst[0].writemask;
   } else {
      emit_block_mov(ir, ir->rhs->type, &l, &r, NULL, false);
   }
}


void
glsl_to_tgsi_visitor::visit(ir_constant *ir)
{
   st_src_reg src;
   GLdouble stack_vals[4] = { 0 };
   gl_constant_value *values = (gl_constant_value *) stack_vals;
   GLenum gl_type = GL_NONE;
   unsigned int i;
   static int in_array = 0;
   gl_register_file file = in_array ? PROGRAM_CONSTANT : PROGRAM_IMMEDIATE;

   /* Unfortunately, 4 floats is all we can get into
    * _mesa_add_typed_unnamed_constant.  So, make a temp to store an
    * aggregate constant and move each constant value into it.  If we
    * get lucky, copy propagation will eliminate the extra moves.
    */
   if (ir->type->base_type == GLSL_TYPE_STRUCT) {
      st_src_reg temp_base = get_temp(ir->type);
      st_dst_reg temp = st_dst_reg(temp_base);

      foreach_in_list(ir_constant, field_value, &ir->components) {
         int size = type_size(field_value->type);

         assert(size > 0);

         field_value->accept(this);
         src = this->result;

         for (i = 0; i < (unsigned int)size; i++) {
            emit_asm(ir, TGSI_OPCODE_MOV, temp, src);

            src.index++;
            temp.index++;
         }
      }
      this->result = temp_base;
      return;
   }

   if (ir->type->is_array()) {
      st_src_reg temp_base = get_temp(ir->type);
      st_dst_reg temp = st_dst_reg(temp_base);
      int size = type_size(ir->type->fields.array);

      assert(size > 0);
      in_array++;

      for (i = 0; i < ir->type->length; i++) {
         ir->array_elements[i]->accept(this);
         src = this->result;
         for (int j = 0; j < size; j++) {
            emit_asm(ir, TGSI_OPCODE_MOV, temp, src);

            src.index++;
            temp.index++;
         }
      }
      this->result = temp_base;
      in_array--;
      return;
   }

   if (ir->type->is_matrix()) {
      st_src_reg mat = get_temp(ir->type);
      st_dst_reg mat_column = st_dst_reg(mat);

      for (i = 0; i < ir->type->matrix_columns; i++) {
         switch (ir->type->base_type) {
         case GLSL_TYPE_FLOAT:
            values = (gl_constant_value *) &ir->value.f[i * ir->type->vector_elements];

            src = st_src_reg(file, -1, ir->type->base_type);
            src.index = add_constant(file,
                                     values,
                                     ir->type->vector_elements,
                                     GL_FLOAT,
                                     &src.swizzle);
            emit_asm(ir, TGSI_OPCODE_MOV, mat_column, src);
            break;
         case GLSL_TYPE_DOUBLE:
            values = (gl_constant_value *) &ir->value.d[i * ir->type->vector_elements];
            src = st_src_reg(file, -1, ir->type->base_type);
            src.index = add_constant(file,
                                     values,
                                     ir->type->vector_elements,
                                     GL_DOUBLE,
                                     &src.swizzle);
            if (ir->type->vector_elements >= 2) {
               mat_column.writemask = WRITEMASK_XY;
               src.swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_X, SWIZZLE_Y);
               emit_asm(ir, TGSI_OPCODE_MOV, mat_column, src);
            } else {
               mat_column.writemask = WRITEMASK_X;
               src.swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_X, SWIZZLE_X, SWIZZLE_X);
               emit_asm(ir, TGSI_OPCODE_MOV, mat_column, src);
            }
            src.index++;
            if (ir->type->vector_elements > 2) {
               if (ir->type->vector_elements == 4) {
                  mat_column.writemask = WRITEMASK_ZW;
                  src.swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_X, SWIZZLE_Y);
                  emit_asm(ir, TGSI_OPCODE_MOV, mat_column, src);
               } else {
                  mat_column.writemask = WRITEMASK_Z;
                  src.swizzle = MAKE_SWIZZLE4(SWIZZLE_Y, SWIZZLE_Y, SWIZZLE_Y, SWIZZLE_Y);
                  emit_asm(ir, TGSI_OPCODE_MOV, mat_column, src);
                  mat_column.writemask = WRITEMASK_XYZW;
                  src.swizzle = SWIZZLE_XYZW;
               }
               mat_column.index++;
            }
            break;
         default:
            unreachable("Illegal matrix constant type.\n");
            break;
         }
         mat_column.index++;
      }
      this->result = mat;
      return;
   }

   switch (ir->type->base_type) {
   case GLSL_TYPE_FLOAT:
      gl_type = GL_FLOAT;
      for (i = 0; i < ir->type->vector_elements; i++) {
         values[i].f = ir->value.f[i];
      }
      break;
   case GLSL_TYPE_DOUBLE:
      gl_type = GL_DOUBLE;
      for (i = 0; i < ir->type->vector_elements; i++) {
         values[i * 2].i = *(uint32_t *)&ir->value.d[i];
         values[i * 2 + 1].i = *(((uint32_t *)&ir->value.d[i]) + 1);
      }
      break;
   case GLSL_TYPE_UINT:
      gl_type = native_integers ? GL_UNSIGNED_INT : GL_FLOAT;
      for (i = 0; i < ir->type->vector_elements; i++) {
         if (native_integers)
            values[i].u = ir->value.u[i];
         else
            values[i].f = ir->value.u[i];
      }
      break;
   case GLSL_TYPE_INT:
      gl_type = native_integers ? GL_INT : GL_FLOAT;
      for (i = 0; i < ir->type->vector_elements; i++) {
         if (native_integers)
            values[i].i = ir->value.i[i];
         else
            values[i].f = ir->value.i[i];
      }
      break;
   case GLSL_TYPE_BOOL:
      gl_type = native_integers ? GL_BOOL : GL_FLOAT;
      for (i = 0; i < ir->type->vector_elements; i++) {
         values[i].u = ir->value.b[i] ? ctx->Const.UniformBooleanTrue : 0;
      }
      break;
   default:
      assert(!"Non-float/uint/int/bool constant");
   }

   this->result = st_src_reg(file, -1, ir->type);
   this->result.index = add_constant(file,
                                     values,
                                     ir->type->vector_elements,
                                     gl_type,
                                     &this->result.swizzle);
}

function_entry *
glsl_to_tgsi_visitor::get_function_signature(ir_function_signature *sig)
{
   foreach_in_list_use_after(function_entry, entry, &this->function_signatures) {
      if (entry->sig == sig)
         return entry;
   }

   entry = ralloc(mem_ctx, function_entry);
   entry->sig = sig;
   entry->sig_id = this->next_signature_id++;
   entry->bgn_inst = NULL;

   /* Allocate storage for all the parameters. */
   foreach_in_list(ir_variable, param, &sig->parameters) {
      variable_storage *storage;

      storage = find_variable_storage(param);
      assert(!storage);

      st_src_reg src = get_temp(param->type);

      storage = new(mem_ctx) variable_storage(param, src.file, src.index);
      this->variables.push_tail(storage);
   }

   if (!sig->return_type->is_void()) {
      entry->return_reg = get_temp(sig->return_type);
   } else {
      entry->return_reg = undef_src;
   }

   this->function_signatures.push_tail(entry);
   return entry;
}

void
glsl_to_tgsi_visitor::visit(ir_call *ir)
{
   glsl_to_tgsi_instruction *call_inst;
   ir_function_signature *sig = ir->callee;
   function_entry *entry = get_function_signature(sig);
   int i;

   /* Process in parameters. */
   foreach_two_lists(formal_node, &sig->parameters,
                     actual_node, &ir->actual_parameters) {
      ir_rvalue *param_rval = (ir_rvalue *) actual_node;
      ir_variable *param = (ir_variable *) formal_node;

      if (param->data.mode == ir_var_function_in ||
          param->data.mode == ir_var_function_inout) {
         variable_storage *storage = find_variable_storage(param);
         assert(storage);

         param_rval->accept(this);
         st_src_reg r = this->result;

         st_dst_reg l;
         l.file = storage->file;
         l.index = storage->index;
         l.reladdr = NULL;
         l.writemask = WRITEMASK_XYZW;
         l.cond_mask = COND_TR;

         for (i = 0; i < type_size(param->type); i++) {
            emit_asm(ir, TGSI_OPCODE_MOV, l, r);
            l.index++;
            r.index++;
         }
      }
   }

   /* Emit call instruction */
   call_inst = emit_asm(ir, TGSI_OPCODE_CAL);
   call_inst->function = entry;

   /* Process out parameters. */
   foreach_two_lists(formal_node, &sig->parameters,
                     actual_node, &ir->actual_parameters) {
      ir_rvalue *param_rval = (ir_rvalue *) actual_node;
      ir_variable *param = (ir_variable *) formal_node;

      if (param->data.mode == ir_var_function_out ||
          param->data.mode == ir_var_function_inout) {
         variable_storage *storage = find_variable_storage(param);
         assert(storage);

         st_src_reg r;
         r.file = storage->file;
         r.index = storage->index;
         r.reladdr = NULL;
         r.swizzle = SWIZZLE_NOOP;
         r.negate = 0;

         param_rval->accept(this);
         st_dst_reg l = st_dst_reg(this->result);

         for (i = 0; i < type_size(param->type); i++) {
            emit_asm(ir, TGSI_OPCODE_MOV, l, r);
            l.index++;
            r.index++;
         }
      }
   }

   /* Process return value. */
   this->result = entry->return_reg;
}

void
glsl_to_tgsi_visitor::visit(ir_texture *ir)
{
   st_src_reg result_src, coord, cube_sc, lod_info, projector, dx, dy;
   st_src_reg offset[MAX_GLSL_TEXTURE_OFFSET], sample_index, component;
   st_src_reg levels_src;
   st_dst_reg result_dst, coord_dst, cube_sc_dst;
   glsl_to_tgsi_instruction *inst = NULL;
   unsigned opcode = TGSI_OPCODE_NOP;
   const glsl_type *sampler_type = ir->sampler->type;
   ir_rvalue *sampler_index =
      _mesa_get_sampler_array_nonconst_index(ir->sampler);
   bool is_cube_array = false;
   unsigned i;

   /* if we are a cube array sampler */
   if ((sampler_type->sampler_dimensionality == GLSL_SAMPLER_DIM_CUBE &&
        sampler_type->sampler_array)) {
      is_cube_array = true;
   }

   if (ir->coordinate) {
      ir->coordinate->accept(this);

      /* Put our coords in a temp.  We'll need to modify them for shadow,
       * projection, or LOD, so the only case we'd use it as is is if
       * we're doing plain old texturing.  The optimization passes on
       * glsl_to_tgsi_visitor should handle cleaning up our mess in that case.
       */
      coord = get_temp(glsl_type::vec4_type);
      coord_dst = st_dst_reg(coord);
      coord_dst.writemask = (1 << ir->coordinate->type->vector_elements) - 1;
      emit_asm(ir, TGSI_OPCODE_MOV, coord_dst, this->result);
   }

   if (ir->projector) {
      ir->projector->accept(this);
      projector = this->result;
   }

   /* Storage for our result.  Ideally for an assignment we'd be using
    * the actual storage for the result here, instead.
    */
   result_src = get_temp(ir->type);
   result_dst = st_dst_reg(result_src);

   switch (ir->op) {
   case ir_tex:
      opcode = (is_cube_array && ir->shadow_comparitor) ? TGSI_OPCODE_TEX2 : TGSI_OPCODE_TEX;
      if (ir->offset) {
         ir->offset->accept(this);
         offset[0] = this->result;
      }
      break;
   case ir_txb:
      if (is_cube_array ||
          sampler_type == glsl_type::samplerCubeShadow_type) {
         opcode = TGSI_OPCODE_TXB2;
      }
      else {
         opcode = TGSI_OPCODE_TXB;
      }
      ir->lod_info.bias->accept(this);
      lod_info = this->result;
      if (ir->offset) {
         ir->offset->accept(this);
         offset[0] = this->result;
      }
      break;
   case ir_txl:
      opcode = is_cube_array ? TGSI_OPCODE_TXL2 : TGSI_OPCODE_TXL;
      ir->lod_info.lod->accept(this);
      lod_info = this->result;
      if (ir->offset) {
         ir->offset->accept(this);
         offset[0] = this->result;
      }
      break;
   case ir_txd:
      opcode = TGSI_OPCODE_TXD;
      ir->lod_info.grad.dPdx->accept(this);
      dx = this->result;
      ir->lod_info.grad.dPdy->accept(this);
      dy = this->result;
      if (ir->offset) {
         ir->offset->accept(this);
         offset[0] = this->result;
      }
      break;
   case ir_txs:
      opcode = TGSI_OPCODE_TXQ;
      ir->lod_info.lod->accept(this);
      lod_info = this->result;
      break;
   case ir_query_levels:
      opcode = TGSI_OPCODE_TXQ;
      lod_info = undef_src;
      levels_src = get_temp(ir->type);
      break;
   case ir_txf:
      opcode = TGSI_OPCODE_TXF;
      ir->lod_info.lod->accept(this);
      lod_info = this->result;
      if (ir->offset) {
         ir->offset->accept(this);
         offset[0] = this->result;
      }
      break;
   case ir_txf_ms:
      opcode = TGSI_OPCODE_TXF;
      ir->lod_info.sample_index->accept(this);
      sample_index = this->result;
      break;
   case ir_tg4:
      opcode = TGSI_OPCODE_TG4;
      ir->lod_info.component->accept(this);
      component = this->result;
      if (ir->offset) {
         ir->offset->accept(this);
         if (ir->offset->type->base_type == GLSL_TYPE_ARRAY) {
            const glsl_type *elt_type = ir->offset->type->fields.array;
            for (i = 0; i < ir->offset->type->length; i++) {
               offset[i] = this->result;
               offset[i].index += i * type_size(elt_type);
               offset[i].type = elt_type->base_type;
               offset[i].swizzle = swizzle_for_size(elt_type->vector_elements);
            }
         } else {
            offset[0] = this->result;
         }
      }
      break;
   case ir_lod:
      opcode = TGSI_OPCODE_LODQ;
      break;
   case ir_texture_samples:
      opcode = TGSI_OPCODE_TXQS;
      break;
   case ir_samples_identical:
      unreachable("Unexpected ir_samples_identical opcode");
   }

   if (ir->projector) {
      if (opcode == TGSI_OPCODE_TEX) {
         /* Slot the projector in as the last component of the coord. */
         coord_dst.writemask = WRITEMASK_W;
         emit_asm(ir, TGSI_OPCODE_MOV, coord_dst, projector);
         coord_dst.writemask = WRITEMASK_XYZW;
         opcode = TGSI_OPCODE_TXP;
      } else {
         st_src_reg coord_w = coord;
         coord_w.swizzle = SWIZZLE_WWWW;

         /* For the other TEX opcodes there's no projective version
          * since the last slot is taken up by LOD info.  Do the
          * projective divide now.
          */
         coord_dst.writemask = WRITEMASK_W;
         emit_asm(ir, TGSI_OPCODE_RCP, coord_dst, projector);

         /* In the case where we have to project the coordinates "by hand,"
          * the shadow comparator value must also be projected.
          */
         st_src_reg tmp_src = coord;
         if (ir->shadow_comparitor) {
            /* Slot the shadow value in as the second to last component of the
             * coord.
             */
            ir->shadow_comparitor->accept(this);

            tmp_src = get_temp(glsl_type::vec4_type);
            st_dst_reg tmp_dst = st_dst_reg(tmp_src);

            /* Projective division not allowed for array samplers. */
            assert(!sampler_type->sampler_array);

            tmp_dst.writemask = WRITEMASK_Z;
            emit_asm(ir, TGSI_OPCODE_MOV, tmp_dst, this->result);

            tmp_dst.writemask = WRITEMASK_XY;
            emit_asm(ir, TGSI_OPCODE_MOV, tmp_dst, coord);
         }

         coord_dst.writemask = WRITEMASK_XYZ;
         emit_asm(ir, TGSI_OPCODE_MUL, coord_dst, tmp_src, coord_w);

         coord_dst.writemask = WRITEMASK_XYZW;
         coord.swizzle = SWIZZLE_XYZW;
      }
   }

   /* If projection is done and the opcode is not TGSI_OPCODE_TXP, then the shadow
    * comparator was put in the correct place (and projected) by the code,
    * above, that handles by-hand projection.
    */
   if (ir->shadow_comparitor && (!ir->projector || opcode == TGSI_OPCODE_TXP)) {
      /* Slot the shadow value in as the second to last component of the
       * coord.
       */
      ir->shadow_comparitor->accept(this);

      if (is_cube_array) {
         cube_sc = get_temp(glsl_type::float_type);
         cube_sc_dst = st_dst_reg(cube_sc);
         cube_sc_dst.writemask = WRITEMASK_X;
         emit_asm(ir, TGSI_OPCODE_MOV, cube_sc_dst, this->result);
         cube_sc_dst.writemask = WRITEMASK_X;
      }
      else {
         if ((sampler_type->sampler_dimensionality == GLSL_SAMPLER_DIM_2D &&
              sampler_type->sampler_array) ||
             sampler_type->sampler_dimensionality == GLSL_SAMPLER_DIM_CUBE) {
            coord_dst.writemask = WRITEMASK_W;
         } else {
            coord_dst.writemask = WRITEMASK_Z;
         }
         emit_asm(ir, TGSI_OPCODE_MOV, coord_dst, this->result);
         coord_dst.writemask = WRITEMASK_XYZW;
      }
   }

   if (ir->op == ir_txf_ms) {
      coord_dst.writemask = WRITEMASK_W;
      emit_asm(ir, TGSI_OPCODE_MOV, coord_dst, sample_index);
      coord_dst.writemask = WRITEMASK_XYZW;
   } else if (opcode == TGSI_OPCODE_TXL || opcode == TGSI_OPCODE_TXB ||
       opcode == TGSI_OPCODE_TXF) {
      /* TGSI stores LOD or LOD bias in the last channel of the coords. */
      coord_dst.writemask = WRITEMASK_W;
      emit_asm(ir, TGSI_OPCODE_MOV, coord_dst, lod_info);
      coord_dst.writemask = WRITEMASK_XYZW;
   }

   if (sampler_index) {
      sampler_index->accept(this);
      emit_arl(ir, sampler_reladdr, this->result);
   }

   if (opcode == TGSI_OPCODE_TXD)
      inst = emit_asm(ir, opcode, result_dst, coord, dx, dy);
   else if (opcode == TGSI_OPCODE_TXQ) {
      if (ir->op == ir_query_levels) {
         /* the level is stored in W */
         inst = emit_asm(ir, opcode, st_dst_reg(levels_src), lod_info);
         result_dst.writemask = WRITEMASK_X;
         levels_src.swizzle = SWIZZLE_WWWW;
         emit_asm(ir, TGSI_OPCODE_MOV, result_dst, levels_src);
      } else
         inst = emit_asm(ir, opcode, result_dst, lod_info);
   } else if (opcode == TGSI_OPCODE_TXQS) {
      inst = emit_asm(ir, opcode, result_dst);
   } else if (opcode == TGSI_OPCODE_TXF) {
      inst = emit_asm(ir, opcode, result_dst, coord);
   } else if (opcode == TGSI_OPCODE_TXL2 || opcode == TGSI_OPCODE_TXB2) {
      inst = emit_asm(ir, opcode, result_dst, coord, lod_info);
   } else if (opcode == TGSI_OPCODE_TEX2) {
      inst = emit_asm(ir, opcode, result_dst, coord, cube_sc);
   } else if (opcode == TGSI_OPCODE_TG4) {
      if (is_cube_array && ir->shadow_comparitor) {
         inst = emit_asm(ir, opcode, result_dst, coord, cube_sc);
      } else {
         inst = emit_asm(ir, opcode, result_dst, coord, component);
      }
   } else
      inst = emit_asm(ir, opcode, result_dst, coord);

   if (ir->shadow_comparitor)
      inst->tex_shadow = GL_TRUE;

   inst->sampler.index = _mesa_get_sampler_uniform_value(ir->sampler,
                                                         this->shader_program,
                                                         this->prog);
   if (sampler_index) {
      inst->sampler.reladdr = ralloc(mem_ctx, st_src_reg);
      memcpy(inst->sampler.reladdr, &sampler_reladdr, sizeof(sampler_reladdr));
      inst->sampler_array_size =
         ir->sampler->as_dereference_array()->array->type->array_size();
   } else {
      inst->sampler_array_size = 1;
   }

   if (ir->offset) {
      for (i = 0; i < MAX_GLSL_TEXTURE_OFFSET && offset[i].file != PROGRAM_UNDEFINED; i++)
         inst->tex_offsets[i] = offset[i];
      inst->tex_offset_num_offset = i;
   }

   switch (sampler_type->sampler_dimensionality) {
   case GLSL_SAMPLER_DIM_1D:
      inst->tex_target = (sampler_type->sampler_array)
         ? TEXTURE_1D_ARRAY_INDEX : TEXTURE_1D_INDEX;
      break;
   case GLSL_SAMPLER_DIM_2D:
      inst->tex_target = (sampler_type->sampler_array)
         ? TEXTURE_2D_ARRAY_INDEX : TEXTURE_2D_INDEX;
      break;
   case GLSL_SAMPLER_DIM_3D:
      inst->tex_target = TEXTURE_3D_INDEX;
      break;
   case GLSL_SAMPLER_DIM_CUBE:
      inst->tex_target = (sampler_type->sampler_array)
         ? TEXTURE_CUBE_ARRAY_INDEX : TEXTURE_CUBE_INDEX;
      break;
   case GLSL_SAMPLER_DIM_RECT:
      inst->tex_target = TEXTURE_RECT_INDEX;
      break;
   case GLSL_SAMPLER_DIM_BUF:
      inst->tex_target = TEXTURE_BUFFER_INDEX;
      break;
   case GLSL_SAMPLER_DIM_EXTERNAL:
      inst->tex_target = TEXTURE_EXTERNAL_INDEX;
      break;
   case GLSL_SAMPLER_DIM_MS:
      inst->tex_target = (sampler_type->sampler_array)
         ? TEXTURE_2D_MULTISAMPLE_ARRAY_INDEX : TEXTURE_2D_MULTISAMPLE_INDEX;
      break;
   default:
      assert(!"Should not get here.");
   }

   inst->tex_type = ir->type->base_type;

   this->result = result_src;
}

void
glsl_to_tgsi_visitor::visit(ir_return *ir)
{
   if (ir->get_value()) {
      st_dst_reg l;
      int i;

      assert(current_function);

      ir->get_value()->accept(this);
      st_src_reg r = this->result;

      l = st_dst_reg(current_function->return_reg);

      for (i = 0; i < type_size(current_function->sig->return_type); i++) {
         emit_asm(ir, TGSI_OPCODE_MOV, l, r);
         l.index++;
         r.index++;
      }
   }

   emit_asm(ir, TGSI_OPCODE_RET);
}

void
glsl_to_tgsi_visitor::visit(ir_discard *ir)
{
   if (ir->condition) {
      ir->condition->accept(this);
      st_src_reg condition = this->result;

      /* Convert the bool condition to a float so we can negate. */
      if (native_integers) {
         st_src_reg temp = get_temp(ir->condition->type);
         emit_asm(ir, TGSI_OPCODE_AND, st_dst_reg(temp),
              condition, st_src_reg_for_float(1.0));
         condition = temp;
      }

      condition.negate = ~condition.negate;
      emit_asm(ir, TGSI_OPCODE_KILL_IF, undef_dst, condition);
   } else {
      /* unconditional kil */
      emit_asm(ir, TGSI_OPCODE_KILL);
   }
}

void
glsl_to_tgsi_visitor::visit(ir_if *ir)
{
   unsigned if_opcode;
   glsl_to_tgsi_instruction *if_inst;

   ir->condition->accept(this);
   assert(this->result.file != PROGRAM_UNDEFINED);

   if_opcode = native_integers ? TGSI_OPCODE_UIF : TGSI_OPCODE_IF;

   if_inst = emit_asm(ir->condition, if_opcode, undef_dst, this->result);

   this->instructions.push_tail(if_inst);

   visit_exec_list(&ir->then_instructions, this);

   if (!ir->else_instructions.is_empty()) {
      emit_asm(ir->condition, TGSI_OPCODE_ELSE);
      visit_exec_list(&ir->else_instructions, this);
   }

   if_inst = emit_asm(ir->condition, TGSI_OPCODE_ENDIF);
}


void
glsl_to_tgsi_visitor::visit(ir_emit_vertex *ir)
{
   assert(this->prog->Target == GL_GEOMETRY_PROGRAM_NV);

   ir->stream->accept(this);
   emit_asm(ir, TGSI_OPCODE_EMIT, undef_dst, this->result);
}

void
glsl_to_tgsi_visitor::visit(ir_end_primitive *ir)
{
   assert(this->prog->Target == GL_GEOMETRY_PROGRAM_NV);

   ir->stream->accept(this);
   emit_asm(ir, TGSI_OPCODE_ENDPRIM, undef_dst, this->result);
}

void
glsl_to_tgsi_visitor::visit(ir_barrier *ir)
{
   assert(this->prog->Target == GL_TESS_CONTROL_PROGRAM_NV ||
          this->prog->Target == GL_COMPUTE_PROGRAM_NV);

   emit_asm(ir, TGSI_OPCODE_BARRIER);
}

glsl_to_tgsi_visitor::glsl_to_tgsi_visitor()
{
   result.file = PROGRAM_UNDEFINED;
   next_temp = 1;
   array_sizes = NULL;
   max_num_arrays = 0;
   next_array = 0;
   num_input_arrays = 0;
   num_output_arrays = 0;
   next_signature_id = 1;
   num_immediates = 0;
   current_function = NULL;
   num_address_regs = 0;
   samplers_used = 0;
   indirect_addr_consts = false;
   wpos_transform_const = -1;
   glsl_version = 0;
   native_integers = false;
   mem_ctx = ralloc_context(NULL);
   ctx = NULL;
   prog = NULL;
   shader_program = NULL;
   shader = NULL;
   options = NULL;
   have_sqrt = false;
   have_fma = false;
}

glsl_to_tgsi_visitor::~glsl_to_tgsi_visitor()
{
   free(array_sizes);
   ralloc_free(mem_ctx);
}

extern "C" void free_glsl_to_tgsi_visitor(glsl_to_tgsi_visitor *v)
{
   delete v;
}


/**
 * Count resources used by the given gpu program (number of texture
 * samplers, etc).
 */
static void
count_resources(glsl_to_tgsi_visitor *v, gl_program *prog)
{
   v->samplers_used = 0;

   foreach_in_list(glsl_to_tgsi_instruction, inst, &v->instructions) {
      if (inst->info->is_tex) {
         for (int i = 0; i < inst->sampler_array_size; i++) {
            unsigned idx = inst->sampler.index + i;
            v->samplers_used |= 1 << idx;

            debug_assert(idx < (int)ARRAY_SIZE(v->sampler_types));
            v->sampler_types[idx] = inst->tex_type;
            v->sampler_targets[idx] =
               st_translate_texture_target(inst->tex_target, inst->tex_shadow);

            if (inst->tex_shadow) {
               prog->ShadowSamplers |= 1 << (inst->sampler.index + i);
            }
         }
      }
   }
   prog->SamplersUsed = v->samplers_used;

   if (v->shader_program != NULL)
      _mesa_update_shader_textures_used(v->shader_program, prog);
}

/**
 * Returns the mask of channels (bitmask of WRITEMASK_X,Y,Z,W) which
 * are read from the given src in this instruction
 */
static int
get_src_arg_mask(st_dst_reg dst, st_src_reg src)
{
   int read_mask = 0, comp;

   /* Now, given the src swizzle and the written channels, find which
    * components are actually read
    */
   for (comp = 0; comp < 4; ++comp) {
      const unsigned coord = GET_SWZ(src.swizzle, comp);
      assert(coord < 4);
      if (dst.writemask & (1 << comp) && coord <= SWIZZLE_W)
         read_mask |= 1 << coord;
   }

   return read_mask;
}

/**
 * This pass replaces CMP T0, T1 T2 T0 with MOV T0, T2 when the CMP
 * instruction is the first instruction to write to register T0.  There are
 * several lowering passes done in GLSL IR (e.g. branches and
 * relative addressing) that create a large number of conditional assignments
 * that ir_to_mesa converts to CMP instructions like the one mentioned above.
 *
 * Here is why this conversion is safe:
 * CMP T0, T1 T2 T0 can be expanded to:
 * if (T1 < 0.0)
 *   MOV T0, T2;
 * else
 *   MOV T0, T0;
 *
 * If (T1 < 0.0) evaluates to true then our replacement MOV T0, T2 is the same
 * as the original program.  If (T1 < 0.0) evaluates to false, executing
 * MOV T0, T0 will store a garbage value in T0 since T0 is uninitialized.
 * Therefore, it doesn't matter that we are replacing MOV T0, T0 with MOV T0, T2
 * because any instruction that was going to read from T0 after this was going
 * to read a garbage value anyway.
 */
void
glsl_to_tgsi_visitor::simplify_cmp(void)
{
   int tempWritesSize = 0;
   unsigned *tempWrites = NULL;
   unsigned outputWrites[VARYING_SLOT_TESS_MAX];

   memset(outputWrites, 0, sizeof(outputWrites));

   foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
      unsigned prevWriteMask = 0;

      /* Give up if we encounter relative addressing or flow control. */
      if (inst->dst[0].reladdr || inst->dst[0].reladdr2 ||
          inst->dst[1].reladdr || inst->dst[1].reladdr2 ||
          tgsi_get_opcode_info(inst->op)->is_branch ||
          inst->op == TGSI_OPCODE_BGNSUB ||
          inst->op == TGSI_OPCODE_CONT ||
          inst->op == TGSI_OPCODE_END ||
          inst->op == TGSI_OPCODE_ENDSUB ||
          inst->op == TGSI_OPCODE_RET) {
         break;
      }

      if (inst->dst[0].file == PROGRAM_OUTPUT) {
         assert(inst->dst[0].index < (signed)ARRAY_SIZE(outputWrites));
         prevWriteMask = outputWrites[inst->dst[0].index];
         outputWrites[inst->dst[0].index] |= inst->dst[0].writemask;
      } else if (inst->dst[0].file == PROGRAM_TEMPORARY) {
         if (inst->dst[0].index >= tempWritesSize) {
            const int inc = 4096;

            tempWrites = (unsigned*)
                         realloc(tempWrites,
                                 (tempWritesSize + inc) * sizeof(unsigned));
            if (!tempWrites)
               return;

            memset(tempWrites + tempWritesSize, 0, inc * sizeof(unsigned));
            tempWritesSize += inc;
         }

         prevWriteMask = tempWrites[inst->dst[0].index];
         tempWrites[inst->dst[0].index] |= inst->dst[0].writemask;
      } else
         continue;

      /* For a CMP to be considered a conditional write, the destination
       * register and source register two must be the same. */
      if (inst->op == TGSI_OPCODE_CMP
          && !(inst->dst[0].writemask & prevWriteMask)
          && inst->src[2].file == inst->dst[0].file
          && inst->src[2].index == inst->dst[0].index
          && inst->dst[0].writemask == get_src_arg_mask(inst->dst[0], inst->src[2])) {

         inst->op = TGSI_OPCODE_MOV;
         inst->src[0] = inst->src[1];
      }
   }

   free(tempWrites);
}

/* Replaces all references to a temporary register index with another index. */
void
glsl_to_tgsi_visitor::rename_temp_registers(int num_renames, struct rename_reg_pair *renames)
{
   foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
      unsigned j;
      int k;
      for (j = 0; j < num_inst_src_regs(inst); j++) {
         if (inst->src[j].file == PROGRAM_TEMPORARY)
            for (k = 0; k < num_renames; k++)
               if (inst->src[j].index == renames[k].old_reg)
                  inst->src[j].index = renames[k].new_reg;
      }

      for (j = 0; j < inst->tex_offset_num_offset; j++) {
         if (inst->tex_offsets[j].file == PROGRAM_TEMPORARY)
            for (k = 0; k < num_renames; k++)
               if (inst->tex_offsets[j].index == renames[k].old_reg)
                  inst->tex_offsets[j].index = renames[k].new_reg;
      }

      for (j = 0; j < num_inst_dst_regs(inst); j++) {
         if (inst->dst[j].file == PROGRAM_TEMPORARY)
             for (k = 0; k < num_renames; k++)
                if (inst->dst[j].index == renames[k].old_reg)
                   inst->dst[j].index = renames[k].new_reg;
      }
   }
}

void
glsl_to_tgsi_visitor::get_first_temp_read(int *first_reads)
{
   int depth = 0; /* loop depth */
   int loop_start = -1; /* index of the first active BGNLOOP (if any) */
   unsigned i = 0, j;

   foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
      for (j = 0; j < num_inst_src_regs(inst); j++) {
         if (inst->src[j].file == PROGRAM_TEMPORARY) {
            if (first_reads[inst->src[j].index] == -1)
                first_reads[inst->src[j].index] = (depth == 0) ? i : loop_start;
         }
      }
      for (j = 0; j < inst->tex_offset_num_offset; j++) {
         if (inst->tex_offsets[j].file == PROGRAM_TEMPORARY) {
            if (first_reads[inst->tex_offsets[j].index] == -1)
               first_reads[inst->tex_offsets[j].index] = (depth == 0) ? i : loop_start;
         }
      }
      if (inst->op == TGSI_OPCODE_BGNLOOP) {
         if(depth++ == 0)
            loop_start = i;
      } else if (inst->op == TGSI_OPCODE_ENDLOOP) {
         if (--depth == 0)
            loop_start = -1;
      }
      assert(depth >= 0);
      i++;
   }
}

void
glsl_to_tgsi_visitor::get_last_temp_read_first_temp_write(int *last_reads, int *first_writes)
{
   int depth = 0; /* loop depth */
   int loop_start = -1; /* index of the first active BGNLOOP (if any) */
   unsigned i = 0, j;
   int k;
   foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
      for (j = 0; j < num_inst_src_regs(inst); j++) {
         if (inst->src[j].file == PROGRAM_TEMPORARY)
            last_reads[inst->src[j].index] = (depth == 0) ? i : -2;
      }
      for (j = 0; j < num_inst_dst_regs(inst); j++) {
         if (inst->dst[j].file == PROGRAM_TEMPORARY)
            if (first_writes[inst->dst[j].index] == -1)
               first_writes[inst->dst[j].index] = (depth == 0) ? i : loop_start;
      }
      for (j = 0; j < inst->tex_offset_num_offset; j++) {
         if (inst->tex_offsets[j].file == PROGRAM_TEMPORARY)
            last_reads[inst->tex_offsets[j].index] = (depth == 0) ? i : -2;
      }
      if (inst->op == TGSI_OPCODE_BGNLOOP) {
         if(depth++ == 0)
            loop_start = i;
      } else if (inst->op == TGSI_OPCODE_ENDLOOP) {
         if (--depth == 0) {
            loop_start = -1;
            for (k = 0; k < this->next_temp; k++) {
               if (last_reads[k] == -2) {
                  last_reads[k] = i;
               }
            }
         }
      }
      assert(depth >= 0);
      i++;
   }
}

void
glsl_to_tgsi_visitor::get_last_temp_write(int *last_writes)
{
   int depth = 0; /* loop depth */
   int i = 0, k;
   unsigned j;

   foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
      for (j = 0; j < num_inst_dst_regs(inst); j++) {
         if (inst->dst[j].file == PROGRAM_TEMPORARY)
            last_writes[inst->dst[j].index] = (depth == 0) ? i : -2;
      }

      if (inst->op == TGSI_OPCODE_BGNLOOP)
         depth++;
      else if (inst->op == TGSI_OPCODE_ENDLOOP)
         if (--depth == 0) {
            for (k = 0; k < this->next_temp; k++) {
               if (last_writes[k] == -2) {
                  last_writes[k] = i;
               }
            }
         }
      assert(depth >= 0);
      i++;
   }
}

/*
 * On a basic block basis, tracks available PROGRAM_TEMPORARY register
 * channels for copy propagation and updates following instructions to
 * use the original versions.
 *
 * The glsl_to_tgsi_visitor lazily produces code assuming that this pass
 * will occur.  As an example, a TXP production before this pass:
 *
 * 0: MOV TEMP[1], INPUT[4].xyyy;
 * 1: MOV TEMP[1].w, INPUT[4].wwww;
 * 2: TXP TEMP[2], TEMP[1], texture[0], 2D;
 *
 * and after:
 *
 * 0: MOV TEMP[1], INPUT[4].xyyy;
 * 1: MOV TEMP[1].w, INPUT[4].wwww;
 * 2: TXP TEMP[2], INPUT[4].xyyw, texture[0], 2D;
 *
 * which allows for dead code elimination on TEMP[1]'s writes.
 */
void
glsl_to_tgsi_visitor::copy_propagate(void)
{
   glsl_to_tgsi_instruction **acp = rzalloc_array(mem_ctx,
                                                  glsl_to_tgsi_instruction *,
                                                  this->next_temp * 4);
   int *acp_level = rzalloc_array(mem_ctx, int, this->next_temp * 4);
   int level = 0;

   foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
      assert(inst->dst[0].file != PROGRAM_TEMPORARY
             || inst->dst[0].index < this->next_temp);

      /* First, do any copy propagation possible into the src regs. */
      for (int r = 0; r < 3; r++) {
         glsl_to_tgsi_instruction *first = NULL;
         bool good = true;
         int acp_base = inst->src[r].index * 4;

         if (inst->src[r].file != PROGRAM_TEMPORARY ||
             inst->src[r].reladdr ||
             inst->src[r].reladdr2)
            continue;

         /* See if we can find entries in the ACP consisting of MOVs
          * from the same src register for all the swizzled channels
          * of this src register reference.
          */
         for (int i = 0; i < 4; i++) {
            int src_chan = GET_SWZ(inst->src[r].swizzle, i);
            glsl_to_tgsi_instruction *copy_chan = acp[acp_base + src_chan];

            if (!copy_chan) {
               good = false;
               break;
            }

            assert(acp_level[acp_base + src_chan] <= level);

            if (!first) {
               first = copy_chan;
            } else {
               if (first->src[0].file != copy_chan->src[0].file ||
                   first->src[0].index != copy_chan->src[0].index ||
                   first->src[0].double_reg2 != copy_chan->src[0].double_reg2 ||
                   first->src[0].index2D != copy_chan->src[0].index2D) {
                  good = false;
                  break;
               }
            }
         }

         if (good) {
            /* We've now validated that we can copy-propagate to
             * replace this src register reference.  Do it.
             */
            inst->src[r].file = first->src[0].file;
            inst->src[r].index = first->src[0].index;
            inst->src[r].index2D = first->src[0].index2D;
            inst->src[r].has_index2 = first->src[0].has_index2;
            inst->src[r].double_reg2 = first->src[0].double_reg2;
            inst->src[r].array_id = first->src[0].array_id;

            int swizzle = 0;
            for (int i = 0; i < 4; i++) {
               int src_chan = GET_SWZ(inst->src[r].swizzle, i);
               glsl_to_tgsi_instruction *copy_inst = acp[acp_base + src_chan];
               swizzle |= (GET_SWZ(copy_inst->src[0].swizzle, src_chan) << (3 * i));
            }
            inst->src[r].swizzle = swizzle;
         }
      }

      switch (inst->op) {
      case TGSI_OPCODE_BGNLOOP:
      case TGSI_OPCODE_ENDLOOP:
         /* End of a basic block, clear the ACP entirely. */
         memset(acp, 0, sizeof(*acp) * this->next_temp * 4);
         break;

      case TGSI_OPCODE_IF:
      case TGSI_OPCODE_UIF:
         ++level;
         break;

      case TGSI_OPCODE_ENDIF:
      case TGSI_OPCODE_ELSE:
         /* Clear all channels written inside the block from the ACP, but
          * leaving those that were not touched.
          */
         for (int r = 0; r < this->next_temp; r++) {
            for (int c = 0; c < 4; c++) {
               if (!acp[4 * r + c])
                  continue;

               if (acp_level[4 * r + c] >= level)
                  acp[4 * r + c] = NULL;
            }
         }
         if (inst->op == TGSI_OPCODE_ENDIF)
            --level;
         break;

      default:
         /* Continuing the block, clear any written channels from
          * the ACP.
          */
         for (int d = 0; d < 2; d++) {
            if (inst->dst[d].file == PROGRAM_TEMPORARY && inst->dst[d].reladdr) {
               /* Any temporary might be written, so no copy propagation
                * across this instruction.
                */
               memset(acp, 0, sizeof(*acp) * this->next_temp * 4);
            } else if (inst->dst[d].file == PROGRAM_OUTPUT &&
                       inst->dst[d].reladdr) {
               /* Any output might be written, so no copy propagation
                * from outputs across this instruction.
                */
               for (int r = 0; r < this->next_temp; r++) {
                  for (int c = 0; c < 4; c++) {
                     if (!acp[4 * r + c])
                        continue;

                     if (acp[4 * r + c]->src[0].file == PROGRAM_OUTPUT)
                        acp[4 * r + c] = NULL;
                  }
               }
            } else if (inst->dst[d].file == PROGRAM_TEMPORARY ||
                       inst->dst[d].file == PROGRAM_OUTPUT) {
               /* Clear where it's used as dst. */
               if (inst->dst[d].file == PROGRAM_TEMPORARY) {
                  for (int c = 0; c < 4; c++) {
                     if (inst->dst[d].writemask & (1 << c))
                        acp[4 * inst->dst[d].index + c] = NULL;
                  }
               }

               /* Clear where it's used as src. */
               for (int r = 0; r < this->next_temp; r++) {
                  for (int c = 0; c < 4; c++) {
                     if (!acp[4 * r + c])
                        continue;

                     int src_chan = GET_SWZ(acp[4 * r + c]->src[0].swizzle, c);

                     if (acp[4 * r + c]->src[0].file == inst->dst[d].file &&
                         acp[4 * r + c]->src[0].index == inst->dst[d].index &&
                         inst->dst[d].writemask & (1 << src_chan)) {
                        acp[4 * r + c] = NULL;
                     }
                  }
               }
            }
         }
         break;
      }

      /* If this is a copy, add it to the ACP. */
      if (inst->op == TGSI_OPCODE_MOV &&
          inst->dst[0].file == PROGRAM_TEMPORARY &&
          !(inst->dst[0].file == inst->src[0].file &&
             inst->dst[0].index == inst->src[0].index) &&
          !inst->dst[0].reladdr &&
          !inst->dst[0].reladdr2 &&
          !inst->saturate &&
          inst->src[0].file != PROGRAM_ARRAY &&
          !inst->src[0].reladdr &&
          !inst->src[0].reladdr2 &&
          !inst->src[0].negate) {
         for (int i = 0; i < 4; i++) {
            if (inst->dst[0].writemask & (1 << i)) {
               acp[4 * inst->dst[0].index + i] = inst;
               acp_level[4 * inst->dst[0].index + i] = level;
            }
         }
      }
   }

   ralloc_free(acp_level);
   ralloc_free(acp);
}

/*
 * On a basic block basis, tracks available PROGRAM_TEMPORARY registers for dead
 * code elimination.
 *
 * The glsl_to_tgsi_visitor lazily produces code assuming that this pass
 * will occur.  As an example, a TXP production after copy propagation but
 * before this pass:
 *
 * 0: MOV TEMP[1], INPUT[4].xyyy;
 * 1: MOV TEMP[1].w, INPUT[4].wwww;
 * 2: TXP TEMP[2], INPUT[4].xyyw, texture[0], 2D;
 *
 * and after this pass:
 *
 * 0: TXP TEMP[2], INPUT[4].xyyw, texture[0], 2D;
 */
int
glsl_to_tgsi_visitor::eliminate_dead_code(void)
{
   glsl_to_tgsi_instruction **writes = rzalloc_array(mem_ctx,
                                                     glsl_to_tgsi_instruction *,
                                                     this->next_temp * 4);
   int *write_level = rzalloc_array(mem_ctx, int, this->next_temp * 4);
   int level = 0;
   int removed = 0;

   foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
      assert(inst->dst[0].file != PROGRAM_TEMPORARY
             || inst->dst[0].index < this->next_temp);

      switch (inst->op) {
      case TGSI_OPCODE_BGNLOOP:
      case TGSI_OPCODE_ENDLOOP:
      case TGSI_OPCODE_CONT:
      case TGSI_OPCODE_BRK:
         /* End of a basic block, clear the write array entirely.
          *
          * This keeps us from killing dead code when the writes are
          * on either side of a loop, even when the register isn't touched
          * inside the loop.  However, glsl_to_tgsi_visitor doesn't seem to emit
          * dead code of this type, so it shouldn't make a difference as long as
          * the dead code elimination pass in the GLSL compiler does its job.
          */
         memset(writes, 0, sizeof(*writes) * this->next_temp * 4);
         break;

      case TGSI_OPCODE_ENDIF:
      case TGSI_OPCODE_ELSE:
         /* Promote the recorded level of all channels written inside the
          * preceding if or else block to the level above the if/else block.
          */
         for (int r = 0; r < this->next_temp; r++) {
            for (int c = 0; c < 4; c++) {
               if (!writes[4 * r + c])
                  continue;

               if (write_level[4 * r + c] == level)
                  write_level[4 * r + c] = level-1;
            }
         }
         if(inst->op == TGSI_OPCODE_ENDIF)
            --level;
         break;

      case TGSI_OPCODE_IF:
      case TGSI_OPCODE_UIF:
         ++level;
         /* fallthrough to default case to mark the condition as read */
      default:
         /* Continuing the block, clear any channels from the write array that
          * are read by this instruction.
          */
         for (unsigned i = 0; i < ARRAY_SIZE(inst->src); i++) {
            if (inst->src[i].file == PROGRAM_TEMPORARY && inst->src[i].reladdr){
               /* Any temporary might be read, so no dead code elimination
                * across this instruction.
                */
               memset(writes, 0, sizeof(*writes) * this->next_temp * 4);
            } else if (inst->src[i].file == PROGRAM_TEMPORARY) {
               /* Clear where it's used as src. */
               int src_chans = 1 << GET_SWZ(inst->src[i].swizzle, 0);
               src_chans |= 1 << GET_SWZ(inst->src[i].swizzle, 1);
               src_chans |= 1 << GET_SWZ(inst->src[i].swizzle, 2);
               src_chans |= 1 << GET_SWZ(inst->src[i].swizzle, 3);

               for (int c = 0; c < 4; c++) {
                  if (src_chans & (1 << c))
                     writes[4 * inst->src[i].index + c] = NULL;
               }
            }
         }
         for (unsigned i = 0; i < inst->tex_offset_num_offset; i++) {
            if (inst->tex_offsets[i].file == PROGRAM_TEMPORARY && inst->tex_offsets[i].reladdr){
               /* Any temporary might be read, so no dead code elimination
                * across this instruction.
                */
               memset(writes, 0, sizeof(*writes) * this->next_temp * 4);
            } else if (inst->tex_offsets[i].file == PROGRAM_TEMPORARY) {
               /* Clear where it's used as src. */
               int src_chans = 1 << GET_SWZ(inst->tex_offsets[i].swizzle, 0);
               src_chans |= 1 << GET_SWZ(inst->tex_offsets[i].swizzle, 1);
               src_chans |= 1 << GET_SWZ(inst->tex_offsets[i].swizzle, 2);
               src_chans |= 1 << GET_SWZ(inst->tex_offsets[i].swizzle, 3);

               for (int c = 0; c < 4; c++) {
                  if (src_chans & (1 << c))
                     writes[4 * inst->tex_offsets[i].index + c] = NULL;
               }
            }
         }
         break;
      }

      /* If this instruction writes to a temporary, add it to the write array.
       * If there is already an instruction in the write array for one or more
       * of the channels, flag that channel write as dead.
       */
      for (unsigned i = 0; i < ARRAY_SIZE(inst->dst); i++) {
         if (inst->dst[i].file == PROGRAM_TEMPORARY &&
             !inst->dst[i].reladdr) {
            for (int c = 0; c < 4; c++) {
               if (inst->dst[i].writemask & (1 << c)) {
                  if (writes[4 * inst->dst[i].index + c]) {
                     if (write_level[4 * inst->dst[i].index + c] < level)
                        continue;
                     else
                        writes[4 * inst->dst[i].index + c]->dead_mask |= (1 << c);
                  }
                  writes[4 * inst->dst[i].index + c] = inst;
                  write_level[4 * inst->dst[i].index + c] = level;
               }
            }
         }
      }
   }

   /* Anything still in the write array at this point is dead code. */
   for (int r = 0; r < this->next_temp; r++) {
      for (int c = 0; c < 4; c++) {
         glsl_to_tgsi_instruction *inst = writes[4 * r + c];
         if (inst)
            inst->dead_mask |= (1 << c);
      }
   }

   /* Now actually remove the instructions that are completely dead and update
    * the writemask of other instructions with dead channels.
    */
   foreach_in_list_safe(glsl_to_tgsi_instruction, inst, &this->instructions) {
      if (!inst->dead_mask || !inst->dst[0].writemask)
         continue;
      else if ((inst->dst[0].writemask & ~inst->dead_mask) == 0) {
         inst->remove();
         delete inst;
         removed++;
      } else {
         if (inst->dst[0].type == GLSL_TYPE_DOUBLE) {
            if (inst->dead_mask == WRITEMASK_XY ||
                inst->dead_mask == WRITEMASK_ZW)
               inst->dst[0].writemask &= ~(inst->dead_mask);
         } else
            inst->dst[0].writemask &= ~(inst->dead_mask);
      }
   }

   ralloc_free(write_level);
   ralloc_free(writes);

   return removed;
}

/* merge DFRACEXP instructions into one. */
void
glsl_to_tgsi_visitor::merge_two_dsts(void)
{
   foreach_in_list_safe(glsl_to_tgsi_instruction, inst, &this->instructions) {
      glsl_to_tgsi_instruction *inst2;
      bool merged;
      if (num_inst_dst_regs(inst) != 2)
         continue;

      if (inst->dst[0].file != PROGRAM_UNDEFINED &&
          inst->dst[1].file != PROGRAM_UNDEFINED)
         continue;

      inst2 = (glsl_to_tgsi_instruction *) inst->next;
      do {

         if (inst->src[0].file == inst2->src[0].file &&
             inst->src[0].index == inst2->src[0].index &&
             inst->src[0].type == inst2->src[0].type &&
             inst->src[0].swizzle == inst2->src[0].swizzle)
            break;
         inst2 = (glsl_to_tgsi_instruction *) inst2->next;
      } while (inst2);

      if (!inst2)
         continue;
      merged = false;
      if (inst->dst[0].file == PROGRAM_UNDEFINED) {
         merged = true;
         inst->dst[0] = inst2->dst[0];
      } else if (inst->dst[1].file == PROGRAM_UNDEFINED) {
         inst->dst[1] = inst2->dst[1];
         merged = true;
      }

      if (merged) {
         inst2->remove();
         delete inst2;
      }
   }
}

/* Merges temporary registers together where possible to reduce the number of
 * registers needed to run a program.
 *
 * Produces optimal code only after copy propagation and dead code elimination
 * have been run. */
void
glsl_to_tgsi_visitor::merge_registers(void)
{
   int *last_reads = rzalloc_array(mem_ctx, int, this->next_temp);
   int *first_writes = rzalloc_array(mem_ctx, int, this->next_temp);
   struct rename_reg_pair *renames = rzalloc_array(mem_ctx, struct rename_reg_pair, this->next_temp);
   int i, j;
   int num_renames = 0;

   /* Read the indices of the last read and first write to each temp register
    * into an array so that we don't have to traverse the instruction list as
    * much. */
   for (i = 0; i < this->next_temp; i++) {
      last_reads[i] = -1;
      first_writes[i] = -1;
   }
   get_last_temp_read_first_temp_write(last_reads, first_writes);

   /* Start looking for registers with non-overlapping usages that can be
    * merged together. */
   for (i = 0; i < this->next_temp; i++) {
      /* Don't touch unused registers. */
      if (last_reads[i] < 0 || first_writes[i] < 0) continue;

      for (j = 0; j < this->next_temp; j++) {
         /* Don't touch unused registers. */
         if (last_reads[j] < 0 || first_writes[j] < 0) continue;

         /* We can merge the two registers if the first write to j is after or
          * in the same instruction as the last read from i.  Note that the
          * register at index i will always be used earlier or at the same time
          * as the register at index j. */
         if (first_writes[i] <= first_writes[j] &&
             last_reads[i] <= first_writes[j]) {
            renames[num_renames].old_reg = j;
            renames[num_renames].new_reg = i;
            num_renames++;

            /* Update the first_writes and last_reads arrays with the new
             * values for the merged register index, and mark the newly unused
             * register index as such. */
            last_reads[i] = last_reads[j];
            first_writes[j] = -1;
            last_reads[j] = -1;
         }
      }
   }

   rename_temp_registers(num_renames, renames);
   ralloc_free(renames);
   ralloc_free(last_reads);
   ralloc_free(first_writes);
}

/* Reassign indices to temporary registers by reusing unused indices created
 * by optimization passes. */
void
glsl_to_tgsi_visitor::renumber_registers(void)
{
   int i = 0;
   int new_index = 0;
   int *first_reads = rzalloc_array(mem_ctx, int, this->next_temp);
   struct rename_reg_pair *renames = rzalloc_array(mem_ctx, struct rename_reg_pair, this->next_temp);
   int num_renames = 0;
   for (i = 0; i < this->next_temp; i++) {
      first_reads[i] = -1;
   }
   get_first_temp_read(first_reads);

   for (i = 0; i < this->next_temp; i++) {
      if (first_reads[i] < 0) continue;
      if (i != new_index) {
         renames[num_renames].old_reg = i;
         renames[num_renames].new_reg = new_index;
         num_renames++;
      }
      new_index++;
   }

   rename_temp_registers(num_renames, renames);
   this->next_temp = new_index;
   ralloc_free(renames);
   ralloc_free(first_reads);
}

/* ------------------------- TGSI conversion stuff -------------------------- */
struct label {
   unsigned branch_target;
   unsigned token;
};

/**
 * Intermediate state used during shader translation.
 */
struct st_translate {
   struct ureg_program *ureg;

   unsigned temps_size;
   struct ureg_dst *temps;

   struct ureg_dst *arrays;
   unsigned num_temp_arrays;
   struct ureg_src *constants;
   int num_constants;
   struct ureg_src *immediates;
   int num_immediates;
   struct ureg_dst outputs[PIPE_MAX_SHADER_OUTPUTS];
   struct ureg_src inputs[PIPE_MAX_SHADER_INPUTS];
   struct ureg_dst address[3];
   struct ureg_src samplers[PIPE_MAX_SAMPLERS];
   struct ureg_src systemValues[SYSTEM_VALUE_MAX];
   struct tgsi_texture_offset tex_offsets[MAX_GLSL_TEXTURE_OFFSET];
   unsigned *array_sizes;
   struct array_decl *input_arrays;
   struct array_decl *output_arrays;

   const GLuint *inputMapping;
   const GLuint *outputMapping;

   /* For every instruction that contains a label (eg CALL), keep
    * details so that we can go back afterwards and emit the correct
    * tgsi instruction number for each label.
    */
   struct label *labels;
   unsigned labels_size;
   unsigned labels_count;

   /* Keep a record of the tgsi instruction number that each mesa
    * instruction starts at, will be used to fix up labels after
    * translation.
    */
   unsigned *insn;
   unsigned insn_size;
   unsigned insn_count;

   unsigned procType;  /**< TGSI_PROCESSOR_VERTEX/FRAGMENT */

   boolean error;
};

/** Map Mesa's SYSTEM_VALUE_x to TGSI_SEMANTIC_x */
const unsigned _mesa_sysval_to_semantic[SYSTEM_VALUE_MAX] = {
   /* Vertex shader
    */
   TGSI_SEMANTIC_VERTEXID,
   TGSI_SEMANTIC_INSTANCEID,
   TGSI_SEMANTIC_VERTEXID_NOBASE,
   TGSI_SEMANTIC_BASEVERTEX,
   TGSI_SEMANTIC_BASEINSTANCE,
   TGSI_SEMANTIC_DRAWID,

   /* Geometry shader
    */
   TGSI_SEMANTIC_INVOCATIONID,

   /* Fragment shader
    */
   TGSI_SEMANTIC_POSITION,
   TGSI_SEMANTIC_FACE,
   TGSI_SEMANTIC_SAMPLEID,
   TGSI_SEMANTIC_SAMPLEPOS,
   TGSI_SEMANTIC_SAMPLEMASK,
   TGSI_SEMANTIC_HELPER_INVOCATION,

   /* Tessellation shaders
    */
   TGSI_SEMANTIC_TESSCOORD,
   TGSI_SEMANTIC_VERTICESIN,
   TGSI_SEMANTIC_PRIMID,
   TGSI_SEMANTIC_TESSOUTER,
   TGSI_SEMANTIC_TESSINNER,
};

/**
 * Make note of a branch to a label in the TGSI code.
 * After we've emitted all instructions, we'll go over the list
 * of labels built here and patch the TGSI code with the actual
 * location of each label.
 */
static unsigned *get_label(struct st_translate *t, unsigned branch_target)
{
   unsigned i;

   if (t->labels_count + 1 >= t->labels_size) {
      t->labels_size = 1 << (util_logbase2(t->labels_size) + 1);
      t->labels = (struct label *)realloc(t->labels,
                                          t->labels_size * sizeof(struct label));
      if (t->labels == NULL) {
         static unsigned dummy;
         t->error = TRUE;
         return &dummy;
      }
   }

   i = t->labels_count++;
   t->labels[i].branch_target = branch_target;
   return &t->labels[i].token;
}

/**
 * Called prior to emitting the TGSI code for each instruction.
 * Allocate additional space for instructions if needed.
 * Update the insn[] array so the next glsl_to_tgsi_instruction points to
 * the next TGSI instruction.
 */
static void set_insn_start(struct st_translate *t, unsigned start)
{
   if (t->insn_count + 1 >= t->insn_size) {
      t->insn_size = 1 << (util_logbase2(t->insn_size) + 1);
      t->insn = (unsigned *)realloc(t->insn, t->insn_size * sizeof(t->insn[0]));
      if (t->insn == NULL) {
         t->error = TRUE;
         return;
      }
   }

   t->insn[t->insn_count++] = start;
}

/**
 * Map a glsl_to_tgsi constant/immediate to a TGSI immediate.
 */
static struct ureg_src
emit_immediate(struct st_translate *t,
               gl_constant_value values[4],
               int type, int size)
{
   struct ureg_program *ureg = t->ureg;

   switch(type)
   {
   case GL_FLOAT:
      return ureg_DECL_immediate(ureg, &values[0].f, size);
   case GL_DOUBLE:
      return ureg_DECL_immediate_f64(ureg, (double *)&values[0].f, size);
   case GL_INT:
      return ureg_DECL_immediate_int(ureg, &values[0].i, size);
   case GL_UNSIGNED_INT:
   case GL_BOOL:
      return ureg_DECL_immediate_uint(ureg, &values[0].u, size);
   default:
      assert(!"should not get here - type must be float, int, uint, or bool");
      return ureg_src_undef();
   }
}

/**
 * Map a glsl_to_tgsi dst register to a TGSI ureg_dst register.
 */
static struct ureg_dst
dst_register(struct st_translate *t, gl_register_file file, unsigned index,
             unsigned array_id)
{
   unsigned array;

   switch(file) {
   case PROGRAM_UNDEFINED:
      return ureg_dst_undef();

   case PROGRAM_TEMPORARY:
      /* Allocate space for temporaries on demand. */
      if (index >= t->temps_size) {
         const int inc = 4096;

         t->temps = (struct ureg_dst*)
                    realloc(t->temps,
                            (t->temps_size + inc) * sizeof(struct ureg_dst));
         if (!t->temps)
            return ureg_dst_undef();

         memset(t->temps + t->temps_size, 0, inc * sizeof(struct ureg_dst));
         t->temps_size += inc;
      }

      if (ureg_dst_is_undef(t->temps[index]))
         t->temps[index] = ureg_DECL_local_temporary(t->ureg);

      return t->temps[index];

   case PROGRAM_ARRAY:
      array = index >> 16;

      assert(array < t->num_temp_arrays);

      if (ureg_dst_is_undef(t->arrays[array]))
         t->arrays[array] = ureg_DECL_array_temporary(
            t->ureg, t->array_sizes[array], TRUE);

      return ureg_dst_array_offset(t->arrays[array],
                                   (int)(index & 0xFFFF) - 0x8000);

   case PROGRAM_OUTPUT:
      if (!array_id) {
         if (t->procType == TGSI_PROCESSOR_FRAGMENT)
            assert(index < FRAG_RESULT_MAX);
         else if (t->procType == TGSI_PROCESSOR_TESS_CTRL ||
                  t->procType == TGSI_PROCESSOR_TESS_EVAL)
            assert(index < VARYING_SLOT_TESS_MAX);
         else
            assert(index < VARYING_SLOT_MAX);

         assert(t->outputMapping[index] < ARRAY_SIZE(t->outputs));
         assert(t->outputs[t->outputMapping[index]].File != TGSI_FILE_NULL);
         return t->outputs[t->outputMapping[index]];
      }
      else {
         struct array_decl *decl = &t->output_arrays[array_id-1];
         unsigned mesa_index = decl->mesa_index;
         int slot = t->outputMapping[mesa_index];

         assert(slot != -1 && t->outputs[slot].File == TGSI_FILE_OUTPUT);
         assert(t->outputs[slot].ArrayID == array_id);
         return ureg_dst_array_offset(t->outputs[slot], index - mesa_index);
      }

   case PROGRAM_ADDRESS:
      return t->address[index];

   default:
      assert(!"unknown dst register file");
      return ureg_dst_undef();
   }
}

/**
 * Map a glsl_to_tgsi src register to a TGSI ureg_src register.
 */
static struct ureg_src
src_register(struct st_translate *t, const st_src_reg *reg)
{
   int index = reg->index;
   int double_reg2 = reg->double_reg2 ? 1 : 0;

   switch(reg->file) {
   case PROGRAM_UNDEFINED:
      return ureg_imm4f(t->ureg, 0, 0, 0, 0);

   case PROGRAM_TEMPORARY:
   case PROGRAM_ARRAY:
   case PROGRAM_OUTPUT:
      return ureg_src(dst_register(t, reg->file, reg->index, reg->array_id));

   case PROGRAM_UNIFORM:
      assert(reg->index >= 0);
      return reg->index < t->num_constants ?
               t->constants[reg->index] : ureg_imm4f(t->ureg, 0, 0, 0, 0);
   case PROGRAM_STATE_VAR:
   case PROGRAM_CONSTANT:       /* ie, immediate */
      if (reg->has_index2)
         return ureg_src_register(TGSI_FILE_CONSTANT, reg->index);
      else
         return reg->index >= 0 && reg->index < t->num_constants ?
                  t->constants[reg->index] : ureg_imm4f(t->ureg, 0, 0, 0, 0);

   case PROGRAM_IMMEDIATE:
      assert(reg->index >= 0 && reg->index < t->num_immediates);
      return t->immediates[reg->index];

   case PROGRAM_INPUT:
      /* GLSL inputs are 64-bit containers, so we have to
       * map back to the original index and add the offset after
       * mapping. */
      index -= double_reg2;
      if (!reg->array_id) {
         assert(t->inputMapping[index] < ARRAY_SIZE(t->inputs));
         assert(t->inputs[t->inputMapping[index]].File != TGSI_FILE_NULL);
         return t->inputs[t->inputMapping[index] + double_reg2];
      }
      else {
         struct array_decl *decl = &t->input_arrays[reg->array_id-1];
         unsigned mesa_index = decl->mesa_index;
         int slot = t->inputMapping[mesa_index];

         assert(slot != -1 && t->inputs[slot].File == TGSI_FILE_INPUT);
         assert(t->inputs[slot].ArrayID == reg->array_id);
         return ureg_src_array_offset(t->inputs[slot], index + double_reg2 - mesa_index);
      }

   case PROGRAM_ADDRESS:
      return ureg_src(t->address[reg->index]);

   case PROGRAM_SYSTEM_VALUE:
      assert(reg->index < (int) ARRAY_SIZE(t->systemValues));
      return t->systemValues[reg->index];

   default:
      assert(!"unknown src register file");
      return ureg_src_undef();
   }
}

/**
 * Create a TGSI ureg_dst register from an st_dst_reg.
 */
static struct ureg_dst
translate_dst(struct st_translate *t,
              const st_dst_reg *dst_reg,
              bool saturate)
{
   struct ureg_dst dst = dst_register(t, dst_reg->file, dst_reg->index,
                                      dst_reg->array_id);

   if (dst.File == TGSI_FILE_NULL)
      return dst;

   dst = ureg_writemask(dst, dst_reg->writemask);

   if (saturate)
      dst = ureg_saturate(dst);

   if (dst_reg->reladdr != NULL) {
      assert(dst_reg->file != PROGRAM_TEMPORARY);
      dst = ureg_dst_indirect(dst, ureg_src(t->address[0]));
   }

   if (dst_reg->has_index2) {
      if (dst_reg->reladdr2)
         dst = ureg_dst_dimension_indirect(dst, ureg_src(t->address[1]),
                                           dst_reg->index2D);
      else
         dst = ureg_dst_dimension(dst, dst_reg->index2D);
   }

   return dst;
}

/**
 * Create a TGSI ureg_src register from an st_src_reg.
 */
static struct ureg_src
translate_src(struct st_translate *t, const st_src_reg *src_reg)
{
   struct ureg_src src = src_register(t, src_reg);

   if (src_reg->has_index2) {
      /* 2D indexes occur with geometry shader inputs (attrib, vertex)
       * and UBO constant buffers (buffer, position).
       */
      if (src_reg->reladdr2)
         src = ureg_src_dimension_indirect(src, ureg_src(t->address[1]),
                                           src_reg->index2D);
      else
         src = ureg_src_dimension(src, src_reg->index2D);
   }

   src = ureg_swizzle(src,
                      GET_SWZ(src_reg->swizzle, 0) & 0x3,
                      GET_SWZ(src_reg->swizzle, 1) & 0x3,
                      GET_SWZ(src_reg->swizzle, 2) & 0x3,
                      GET_SWZ(src_reg->swizzle, 3) & 0x3);

   if ((src_reg->negate & 0xf) == NEGATE_XYZW)
      src = ureg_negate(src);

   if (src_reg->reladdr != NULL) {
      assert(src_reg->file != PROGRAM_TEMPORARY);
      src = ureg_src_indirect(src, ureg_src(t->address[0]));
   }

   return src;
}

static struct tgsi_texture_offset
translate_tex_offset(struct st_translate *t,
                     const st_src_reg *in_offset, int idx)
{
   struct tgsi_texture_offset offset;
   struct ureg_src imm_src;
   struct ureg_dst dst;
   int array;

   switch (in_offset->file) {
   case PROGRAM_IMMEDIATE:
      assert(in_offset->index >= 0 && in_offset->index < t->num_immediates);
      imm_src = t->immediates[in_offset->index];

      offset.File = imm_src.File;
      offset.Index = imm_src.Index;
      offset.SwizzleX = imm_src.SwizzleX;
      offset.SwizzleY = imm_src.SwizzleY;
      offset.SwizzleZ = imm_src.SwizzleZ;
      offset.Padding = 0;
      break;
   case PROGRAM_TEMPORARY:
      imm_src = ureg_src(t->temps[in_offset->index]);
      offset.File = imm_src.File;
      offset.Index = imm_src.Index;
      offset.SwizzleX = GET_SWZ(in_offset->swizzle, 0);
      offset.SwizzleY = GET_SWZ(in_offset->swizzle, 1);
      offset.SwizzleZ = GET_SWZ(in_offset->swizzle, 2);
      offset.Padding = 0;
      break;
   case PROGRAM_ARRAY:
      array = in_offset->index >> 16;

      assert(array >= 0);
      assert(array < (int)t->num_temp_arrays);

      dst = t->arrays[array];
      offset.File = dst.File;
      offset.Index = dst.Index + (in_offset->index & 0xFFFF) - 0x8000;
      offset.SwizzleX = GET_SWZ(in_offset->swizzle, 0);
      offset.SwizzleY = GET_SWZ(in_offset->swizzle, 1);
      offset.SwizzleZ = GET_SWZ(in_offset->swizzle, 2);
      offset.Padding = 0;
      break;
   default:
      break;
   }
   return offset;
}

static void
compile_tgsi_instruction(struct st_translate *t,
                         const glsl_to_tgsi_instruction *inst)
{
   struct ureg_program *ureg = t->ureg;
   GLuint i;
   struct ureg_dst dst[2];
   struct ureg_src src[4];
   struct tgsi_texture_offset texoffsets[MAX_GLSL_TEXTURE_OFFSET];

   unsigned num_dst;
   unsigned num_src;
   unsigned tex_target;

   num_dst = num_inst_dst_regs(inst);
   num_src = num_inst_src_regs(inst);

   for (i = 0; i < num_dst; i++)
      dst[i] = translate_dst(t,
                             &inst->dst[i],
                             inst->saturate);

   for (i = 0; i < num_src; i++)
      src[i] = translate_src(t, &inst->src[i]);

   switch(inst->op) {
   case TGSI_OPCODE_BGNLOOP:
   case TGSI_OPCODE_CAL:
   case TGSI_OPCODE_ELSE:
   case TGSI_OPCODE_ENDLOOP:
   case TGSI_OPCODE_IF:
   case TGSI_OPCODE_UIF:
      assert(num_dst == 0);
      ureg_label_insn(ureg,
                      inst->op,
                      src, num_src,
                      get_label(t,
                                inst->op == TGSI_OPCODE_CAL ? inst->function->sig_id : 0));
      return;

   case TGSI_OPCODE_TEX:
   case TGSI_OPCODE_TXB:
   case TGSI_OPCODE_TXD:
   case TGSI_OPCODE_TXL:
   case TGSI_OPCODE_TXP:
   case TGSI_OPCODE_TXQ:
   case TGSI_OPCODE_TXQS:
   case TGSI_OPCODE_TXF:
   case TGSI_OPCODE_TEX2:
   case TGSI_OPCODE_TXB2:
   case TGSI_OPCODE_TXL2:
   case TGSI_OPCODE_TG4:
   case TGSI_OPCODE_LODQ:
      src[num_src] = t->samplers[inst->sampler.index];
      assert(src[num_src].File != TGSI_FILE_NULL);
      if (inst->sampler.reladdr)
         src[num_src] =
            ureg_src_indirect(src[num_src], ureg_src(t->address[2]));
      num_src++;
      for (i = 0; i < inst->tex_offset_num_offset; i++) {
         texoffsets[i] = translate_tex_offset(t, &inst->tex_offsets[i], i);
      }
      tex_target = st_translate_texture_target(inst->tex_target, inst->tex_shadow);

      ureg_tex_insn(ureg,
                    inst->op,
                    dst, num_dst,
                    tex_target,
                    texoffsets, inst->tex_offset_num_offset,
                    src, num_src);
      return;

   case TGSI_OPCODE_SCS:
      dst[0] = ureg_writemask(dst[0], TGSI_WRITEMASK_XY);
      ureg_insn(ureg, inst->op, dst, num_dst, src, num_src);
      break;

   default:
      ureg_insn(ureg,
                inst->op,
                dst, num_dst,
                src, num_src);
      break;
   }
}

/**
 * Emit the TGSI instructions for inverting and adjusting WPOS.
 * This code is unavoidable because it also depends on whether
 * a FBO is bound (STATE_FB_WPOS_Y_TRANSFORM).
 */
static void
emit_wpos_adjustment(struct gl_context *ctx,
                     struct st_translate *t,
                     int wpos_transform_const,
                     boolean invert,
                     GLfloat adjX, GLfloat adjY[2])
{
   struct ureg_program *ureg = t->ureg;

   assert(wpos_transform_const >= 0);

   /* Fragment program uses fragment position input.
    * Need to replace instances of INPUT[WPOS] with temp T
    * where T = INPUT[WPOS] is inverted by Y.
    */
   struct ureg_src wpostrans = ureg_DECL_constant(ureg, wpos_transform_const);
   struct ureg_dst wpos_temp = ureg_DECL_temporary( ureg );
   struct ureg_src *wpos =
      ctx->Const.GLSLFragCoordIsSysVal ?
         &t->systemValues[SYSTEM_VALUE_FRAG_COORD] :
         &t->inputs[t->inputMapping[VARYING_SLOT_POS]];
   struct ureg_src wpos_input = *wpos;

   /* First, apply the coordinate shift: */
   if (adjX || adjY[0] || adjY[1]) {
      if (adjY[0] != adjY[1]) {
         /* Adjust the y coordinate by adjY[1] or adjY[0] respectively
          * depending on whether inversion is actually going to be applied
          * or not, which is determined by testing against the inversion
          * state variable used below, which will be either +1 or -1.
          */
         struct ureg_dst adj_temp = ureg_DECL_local_temporary(ureg);

         ureg_CMP(ureg, adj_temp,
                  ureg_scalar(wpostrans, invert ? 2 : 0),
                  ureg_imm4f(ureg, adjX, adjY[0], 0.0f, 0.0f),
                  ureg_imm4f(ureg, adjX, adjY[1], 0.0f, 0.0f));
         ureg_ADD(ureg, wpos_temp, wpos_input, ureg_src(adj_temp));
      } else {
         ureg_ADD(ureg, wpos_temp, wpos_input,
                  ureg_imm4f(ureg, adjX, adjY[0], 0.0f, 0.0f));
      }
      wpos_input = ureg_src(wpos_temp);
   } else {
      /* MOV wpos_temp, input[wpos]
       */
      ureg_MOV( ureg, wpos_temp, wpos_input );
   }

   /* Now the conditional y flip: STATE_FB_WPOS_Y_TRANSFORM.xy/zw will be
    * inversion/identity, or the other way around if we're drawing to an FBO.
    */
   if (invert) {
      /* MAD wpos_temp.y, wpos_input, wpostrans.xxxx, wpostrans.yyyy
       */
      ureg_MAD( ureg,
                ureg_writemask(wpos_temp, TGSI_WRITEMASK_Y ),
                wpos_input,
                ureg_scalar(wpostrans, 0),
                ureg_scalar(wpostrans, 1));
   } else {
      /* MAD wpos_temp.y, wpos_input, wpostrans.zzzz, wpostrans.wwww
       */
      ureg_MAD( ureg,
                ureg_writemask(wpos_temp, TGSI_WRITEMASK_Y ),
                wpos_input,
                ureg_scalar(wpostrans, 2),
                ureg_scalar(wpostrans, 3));
   }

   /* Use wpos_temp as position input from here on:
    */
   *wpos = ureg_src(wpos_temp);
}


/**
 * Emit fragment position/ooordinate code.
 */
static void
emit_wpos(struct st_context *st,
          struct st_translate *t,
          const struct gl_program *program,
          struct ureg_program *ureg,
          int wpos_transform_const)
{
   const struct gl_fragment_program *fp =
      (const struct gl_fragment_program *) program;
   struct pipe_screen *pscreen = st->pipe->screen;
   GLfloat adjX = 0.0f;
   GLfloat adjY[2] = { 0.0f, 0.0f };
   boolean invert = FALSE;

   /* Query the pixel center conventions supported by the pipe driver and set
    * adjX, adjY to help out if it cannot handle the requested one internally.
    *
    * The bias of the y-coordinate depends on whether y-inversion takes place
    * (adjY[1]) or not (adjY[0]), which is in turn dependent on whether we are
    * drawing to an FBO (causes additional inversion), and whether the the pipe
    * driver origin and the requested origin differ (the latter condition is
    * stored in the 'invert' variable).
    *
    * For height = 100 (i = integer, h = half-integer, l = lower, u = upper):
    *
    * center shift only:
    * i -> h: +0.5
    * h -> i: -0.5
    *
    * inversion only:
    * l,i -> u,i: ( 0.0 + 1.0) * -1 + 100 = 99
    * l,h -> u,h: ( 0.5 + 0.0) * -1 + 100 = 99.5
    * u,i -> l,i: (99.0 + 1.0) * -1 + 100 = 0
    * u,h -> l,h: (99.5 + 0.0) * -1 + 100 = 0.5
    *
    * inversion and center shift:
    * l,i -> u,h: ( 0.0 + 0.5) * -1 + 100 = 99.5
    * l,h -> u,i: ( 0.5 + 0.5) * -1 + 100 = 99
    * u,i -> l,h: (99.0 + 0.5) * -1 + 100 = 0.5
    * u,h -> l,i: (99.5 + 0.5) * -1 + 100 = 0
    */
   if (fp->OriginUpperLeft) {
      /* Fragment shader wants origin in upper-left */
      if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT)) {
         /* the driver supports upper-left origin */
      }
      else if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_ORIGIN_LOWER_LEFT)) {
         /* the driver supports lower-left origin, need to invert Y */
         ureg_property(ureg, TGSI_PROPERTY_FS_COORD_ORIGIN,
                       TGSI_FS_COORD_ORIGIN_LOWER_LEFT);
         invert = TRUE;
      }
      else
         assert(0);
   }
   else {
      /* Fragment shader wants origin in lower-left */
      if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_ORIGIN_LOWER_LEFT))
         /* the driver supports lower-left origin */
         ureg_property(ureg, TGSI_PROPERTY_FS_COORD_ORIGIN,
                       TGSI_FS_COORD_ORIGIN_LOWER_LEFT);
      else if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT))
         /* the driver supports upper-left origin, need to invert Y */
         invert = TRUE;
      else
         assert(0);
   }

   if (fp->PixelCenterInteger) {
      /* Fragment shader wants pixel center integer */
      if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER)) {
         /* the driver supports pixel center integer */
         adjY[1] = 1.0f;
         ureg_property(ureg, TGSI_PROPERTY_FS_COORD_PIXEL_CENTER,
                       TGSI_FS_COORD_PIXEL_CENTER_INTEGER);
      }
      else if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER)) {
         /* the driver supports pixel center half integer, need to bias X,Y */
         adjX = -0.5f;
         adjY[0] = -0.5f;
         adjY[1] = 0.5f;
      }
      else
         assert(0);
   }
   else {
      /* Fragment shader wants pixel center half integer */
      if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER)) {
         /* the driver supports pixel center half integer */
      }
      else if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER)) {
         /* the driver supports pixel center integer, need to bias X,Y */
         adjX = adjY[0] = adjY[1] = 0.5f;
         ureg_property(ureg, TGSI_PROPERTY_FS_COORD_PIXEL_CENTER,
                       TGSI_FS_COORD_PIXEL_CENTER_INTEGER);
      }
      else
         assert(0);
   }

   /* we invert after adjustment so that we avoid the MOV to temporary,
    * and reuse the adjustment ADD instead */
   emit_wpos_adjustment(st->ctx, t, wpos_transform_const, invert, adjX, adjY);
}

/**
 * OpenGL's fragment gl_FrontFace input is 1 for front-facing, 0 for back.
 * TGSI uses +1 for front, -1 for back.
 * This function converts the TGSI value to the GL value.  Simply clamping/
 * saturating the value to [0,1] does the job.
 */
static void
emit_face_var(struct gl_context *ctx, struct st_translate *t)
{
   struct ureg_program *ureg = t->ureg;
   struct ureg_dst face_temp = ureg_DECL_temporary(ureg);
   struct ureg_src face_input = t->inputs[t->inputMapping[VARYING_SLOT_FACE]];

   if (ctx->Const.NativeIntegers) {
      ureg_FSGE(ureg, face_temp, face_input, ureg_imm1f(ureg, 0));
   }
   else {
      /* MOV_SAT face_temp, input[face] */
      ureg_MOV(ureg, ureg_saturate(face_temp), face_input);
   }

   /* Use face_temp as face input from here on: */
   t->inputs[t->inputMapping[VARYING_SLOT_FACE]] = ureg_src(face_temp);
}

static bool
find_array(unsigned attr, struct array_decl *arrays, unsigned count,
           unsigned *array_id, unsigned *array_size)
{
   unsigned i;

   for (i = 0; i < count; i++) {
      struct array_decl *decl = &arrays[i];

      if (attr == decl->mesa_index) {
         *array_id = decl->array_id;
         *array_size = decl->array_size;
         assert(*array_size);
         return true;
      }
   }
   return false;
}

/**
 * Translate intermediate IR (glsl_to_tgsi_instruction) to TGSI format.
 * \param program  the program to translate
 * \param numInputs  number of input registers used
 * \param inputMapping  maps Mesa fragment program inputs to TGSI generic
 *                      input indexes
 * \param inputSemanticName  the TGSI_SEMANTIC flag for each input
 * \param inputSemanticIndex  the semantic index (ex: which texcoord) for
 *                            each input
 * \param interpMode  the TGSI_INTERPOLATE_LINEAR/PERSP mode for each input
 * \param interpLocation the TGSI_INTERPOLATE_LOC_* location for each input
 * \param numOutputs  number of output registers used
 * \param outputMapping  maps Mesa fragment program outputs to TGSI
 *                       generic outputs
 * \param outputSemanticName  the TGSI_SEMANTIC flag for each output
 * \param outputSemanticIndex  the semantic index (ex: which texcoord) for
 *                             each output
 *
 * \return  PIPE_OK or PIPE_ERROR_OUT_OF_MEMORY
 */
extern "C" enum pipe_error
st_translate_program(
   struct gl_context *ctx,
   uint procType,
   struct ureg_program *ureg,
   glsl_to_tgsi_visitor *program,
   const struct gl_program *proginfo,
   GLuint numInputs,
   const GLuint inputMapping[],
   const GLuint inputSlotToAttr[],
   const ubyte inputSemanticName[],
   const ubyte inputSemanticIndex[],
   const GLuint interpMode[],
   const GLuint interpLocation[],
   GLuint numOutputs,
   const GLuint outputMapping[],
   const GLuint outputSlotToAttr[],
   const ubyte outputSemanticName[],
   const ubyte outputSemanticIndex[])
{
   struct st_translate *t;
   unsigned i;
   enum pipe_error ret = PIPE_OK;

   assert(numInputs <= ARRAY_SIZE(t->inputs));
   assert(numOutputs <= ARRAY_SIZE(t->outputs));

   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_FRONT_FACE] ==
          TGSI_SEMANTIC_FACE);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_VERTEX_ID] ==
          TGSI_SEMANTIC_VERTEXID);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_INSTANCE_ID] ==
          TGSI_SEMANTIC_INSTANCEID);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_SAMPLE_ID] ==
          TGSI_SEMANTIC_SAMPLEID);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_SAMPLE_POS] ==
          TGSI_SEMANTIC_SAMPLEPOS);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_SAMPLE_MASK_IN] ==
          TGSI_SEMANTIC_SAMPLEMASK);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_INVOCATION_ID] ==
          TGSI_SEMANTIC_INVOCATIONID);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_VERTEX_ID_ZERO_BASE] ==
          TGSI_SEMANTIC_VERTEXID_NOBASE);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_BASE_VERTEX] ==
          TGSI_SEMANTIC_BASEVERTEX);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_TESS_COORD] ==
          TGSI_SEMANTIC_TESSCOORD);
   assert(_mesa_sysval_to_semantic[SYSTEM_VALUE_HELPER_INVOCATION] ==
          TGSI_SEMANTIC_HELPER_INVOCATION);

   t = CALLOC_STRUCT(st_translate);
   if (!t) {
      ret = PIPE_ERROR_OUT_OF_MEMORY;
      goto out;
   }

   t->procType = procType;
   t->inputMapping = inputMapping;
   t->outputMapping = outputMapping;
   t->ureg = ureg;
   t->num_temp_arrays = program->next_array;
   if (t->num_temp_arrays)
      t->arrays = (struct ureg_dst*)
                  calloc(1, sizeof(t->arrays[0]) * t->num_temp_arrays);

   /*
    * Declare input attributes.
    */
   switch (procType) {
   case TGSI_PROCESSOR_FRAGMENT:
      for (i = 0; i < numInputs; i++) {
         unsigned array_id = 0;
         unsigned array_size;

         if (find_array(inputSlotToAttr[i], program->input_arrays,
                        program->num_input_arrays, &array_id, &array_size)) {
            /* We've found an array. Declare it so. */
            t->inputs[i] = ureg_DECL_fs_input_cyl_centroid(ureg,
                              inputSemanticName[i], inputSemanticIndex[i],
                              interpMode[i], 0, interpLocation[i],
                              array_id, array_size);
            i += array_size - 1;
         }
         else {
            t->inputs[i] = ureg_DECL_fs_input_cyl_centroid(ureg,
                              inputSemanticName[i], inputSemanticIndex[i],
                              interpMode[i], 0, interpLocation[i], 0, 1);
         }
      }
      break;
   case TGSI_PROCESSOR_GEOMETRY:
   case TGSI_PROCESSOR_TESS_EVAL:
   case TGSI_PROCESSOR_TESS_CTRL:
      for (i = 0; i < numInputs; i++) {
         unsigned array_id = 0;
         unsigned array_size;

         if (find_array(inputSlotToAttr[i], program->input_arrays,
                        program->num_input_arrays, &array_id, &array_size)) {
            /* We've found an array. Declare it so. */
            t->inputs[i] = ureg_DECL_input(ureg, inputSemanticName[i],
                                           inputSemanticIndex[i],
                                           array_id, array_size);
            i += array_size - 1;
         }
         else {
            t->inputs[i] = ureg_DECL_input(ureg, inputSemanticName[i],
                                           inputSemanticIndex[i], 0, 1);
         }
      }
      break;
   case TGSI_PROCESSOR_VERTEX:
      for (i = 0; i < numInputs; i++) {
         t->inputs[i] = ureg_DECL_vs_input(ureg, i);
      }
      break;
   default:
      assert(0);
   }

   /*
    * Declare output attributes.
    */
   switch (procType) {
   case TGSI_PROCESSOR_FRAGMENT:
      break;
   case TGSI_PROCESSOR_GEOMETRY:
   case TGSI_PROCESSOR_TESS_EVAL:
   case TGSI_PROCESSOR_TESS_CTRL:
   case TGSI_PROCESSOR_VERTEX:
      for (i = 0; i < numOutputs; i++) {
         unsigned array_id = 0;
         unsigned array_size;

         if (find_array(outputSlotToAttr[i], program->output_arrays,
                        program->num_output_arrays, &array_id, &array_size)) {
            /* We've found an array. Declare it so. */
            t->outputs[i] = ureg_DECL_output_array(ureg,
                                                   outputSemanticName[i],
                                                   outputSemanticIndex[i],
                                                   array_id, array_size);
            i += array_size - 1;
         }
         else {
            t->outputs[i] = ureg_DECL_output(ureg,
                                             outputSemanticName[i],
                                             outputSemanticIndex[i]);
         }
      }
      break;
   default:
      assert(0);
   }

   if (procType == TGSI_PROCESSOR_FRAGMENT) {
      if (proginfo->InputsRead & VARYING_BIT_POS) {
          /* Must do this after setting up t->inputs. */
          emit_wpos(st_context(ctx), t, proginfo, ureg,
                    program->wpos_transform_const);
      }

      if (proginfo->InputsRead & VARYING_BIT_FACE)
         emit_face_var(ctx, t);

      for (i = 0; i < numOutputs; i++) {
         switch (outputSemanticName[i]) {
         case TGSI_SEMANTIC_POSITION:
            t->outputs[i] = ureg_DECL_output(ureg,
                                             TGSI_SEMANTIC_POSITION, /* Z/Depth */
                                             outputSemanticIndex[i]);
            t->outputs[i] = ureg_writemask(t->outputs[i], TGSI_WRITEMASK_Z);
            break;
         case TGSI_SEMANTIC_STENCIL:
            t->outputs[i] = ureg_DECL_output(ureg,
                                             TGSI_SEMANTIC_STENCIL, /* Stencil */
                                             outputSemanticIndex[i]);
            t->outputs[i] = ureg_writemask(t->outputs[i], TGSI_WRITEMASK_Y);
            break;
         case TGSI_SEMANTIC_COLOR:
            t->outputs[i] = ureg_DECL_output(ureg,
                                             TGSI_SEMANTIC_COLOR,
                                             outputSemanticIndex[i]);
            break;
         case TGSI_SEMANTIC_SAMPLEMASK:
            t->outputs[i] = ureg_DECL_output(ureg,
                                             TGSI_SEMANTIC_SAMPLEMASK,
                                             outputSemanticIndex[i]);
            /* TODO: If we ever support more than 32 samples, this will have
             * to become an array.
             */
            t->outputs[i] = ureg_writemask(t->outputs[i], TGSI_WRITEMASK_X);
            break;
         default:
            assert(!"fragment shader outputs must be POSITION/STENCIL/COLOR");
            ret = PIPE_ERROR_BAD_INPUT;
            goto out;
         }
      }
   }
   else if (procType == TGSI_PROCESSOR_VERTEX) {
      for (i = 0; i < numOutputs; i++) {
         if (outputSemanticName[i] == TGSI_SEMANTIC_FOG) {
            /* force register to contain a fog coordinate in the form (F, 0, 0, 1). */
            ureg_MOV(ureg,
                     ureg_writemask(t->outputs[i], TGSI_WRITEMASK_YZW),
                     ureg_imm4f(ureg, 0.0f, 0.0f, 0.0f, 1.0f));
            t->outputs[i] = ureg_writemask(t->outputs[i], TGSI_WRITEMASK_X);
         }
      }
   }

   /* Declare address register.
    */
   if (program->num_address_regs > 0) {
      assert(program->num_address_regs <= 3);
      for (int i = 0; i < program->num_address_regs; i++)
         t->address[i] = ureg_DECL_address(ureg);
   }

   /* Declare misc input registers
    */
   {
      GLbitfield sysInputs = proginfo->SystemValuesRead;

      for (i = 0; sysInputs; i++) {
         if (sysInputs & (1 << i)) {
            unsigned semName = _mesa_sysval_to_semantic[i];

            t->systemValues[i] = ureg_DECL_system_value(ureg, semName, 0);

            if (semName == TGSI_SEMANTIC_INSTANCEID ||
                semName == TGSI_SEMANTIC_VERTEXID) {
               /* From Gallium perspective, these system values are always
                * integer, and require native integer support.  However, if
                * native integer is supported on the vertex stage but not the
                * pixel stage (e.g, i915g + draw), Mesa will generate IR that
                * assumes these system values are floats. To resolve the
                * inconsistency, we insert a U2F.
                */
               struct st_context *st = st_context(ctx);
               struct pipe_screen *pscreen = st->pipe->screen;
               assert(procType == TGSI_PROCESSOR_VERTEX);
               assert(pscreen->get_shader_param(pscreen, PIPE_SHADER_VERTEX, PIPE_SHADER_CAP_INTEGERS));
               (void) pscreen;
               if (!ctx->Const.NativeIntegers) {
                  struct ureg_dst temp = ureg_DECL_local_temporary(t->ureg);
                  ureg_U2F( t->ureg, ureg_writemask(temp, TGSI_WRITEMASK_X), t->systemValues[i]);
                  t->systemValues[i] = ureg_scalar(ureg_src(temp), 0);
               }
            }

            if (procType == TGSI_PROCESSOR_FRAGMENT &&
                semName == TGSI_SEMANTIC_POSITION)
               emit_wpos(st_context(ctx), t, proginfo, ureg,
                         program->wpos_transform_const);

            sysInputs &= ~(1 << i);
         }
      }
   }

   t->array_sizes = program->array_sizes;
   t->input_arrays = program->input_arrays;
   t->output_arrays = program->output_arrays;

   /* Emit constants and uniforms.  TGSI uses a single index space for these,
    * so we put all the translated regs in t->constants.
    */
   if (proginfo->Parameters) {
      t->constants = (struct ureg_src *)
         calloc(proginfo->Parameters->NumParameters, sizeof(t->constants[0]));
      if (t->constants == NULL) {
         ret = PIPE_ERROR_OUT_OF_MEMORY;
         goto out;
      }
      t->num_constants = proginfo->Parameters->NumParameters;

      for (i = 0; i < proginfo->Parameters->NumParameters; i++) {
         switch (proginfo->Parameters->Parameters[i].Type) {
         case PROGRAM_STATE_VAR:
         case PROGRAM_UNIFORM:
            t->constants[i] = ureg_DECL_constant(ureg, i);
            break;

         /* Emit immediates for PROGRAM_CONSTANT only when there's no indirect
          * addressing of the const buffer.
          * FIXME: Be smarter and recognize param arrays:
          * indirect addressing is only valid within the referenced
          * array.
          */
         case PROGRAM_CONSTANT:
            if (program->indirect_addr_consts)
               t->constants[i] = ureg_DECL_constant(ureg, i);
            else
               t->constants[i] = emit_immediate(t,
                                                proginfo->Parameters->ParameterValues[i],
                                                proginfo->Parameters->Parameters[i].DataType,
                                                4);
            break;
         default:
            break;
         }
      }
   }

   if (program->shader) {
      unsigned num_ubos = program->shader->NumUniformBlocks;

      for (i = 0; i < num_ubos; i++) {
         unsigned size = program->shader->UniformBlocks[i]->UniformBufferSize;
         unsigned num_const_vecs = (size + 15) / 16;
         unsigned first, last;
         assert(num_const_vecs > 0);
         first = 0;
         last = num_const_vecs > 0 ? num_const_vecs - 1 : 0;
         ureg_DECL_constant2D(t->ureg, first, last, i + 1);
      }
   }

   /* Emit immediate values.
    */
   t->immediates = (struct ureg_src *)
      calloc(program->num_immediates, sizeof(struct ureg_src));
   if (t->immediates == NULL) {
      ret = PIPE_ERROR_OUT_OF_MEMORY;
      goto out;
   }
   t->num_immediates = program->num_immediates;

   i = 0;
   foreach_in_list(immediate_storage, imm, &program->immediates) {
      assert(i < program->num_immediates);
      t->immediates[i++] = emit_immediate(t, imm->values, imm->type, imm->size32);
   }
   assert(i == program->num_immediates);

   /* texture samplers */
   for (i = 0; i < ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits; i++) {
      if (program->samplers_used & (1 << i)) {
         unsigned type;

         t->samplers[i] = ureg_DECL_sampler(ureg, i);

         switch (program->sampler_types[i]) {
         case GLSL_TYPE_INT:
            type = TGSI_RETURN_TYPE_SINT;
            break;
         case GLSL_TYPE_UINT:
            type = TGSI_RETURN_TYPE_UINT;
            break;
         case GLSL_TYPE_FLOAT:
            type = TGSI_RETURN_TYPE_FLOAT;
            break;
         default:
            unreachable("not reached");
         }

         ureg_DECL_sampler_view( ureg, i, program->sampler_targets[i],
                                 type, type, type, type );
      }
   }

   /* Emit each instruction in turn:
    */
   foreach_in_list(glsl_to_tgsi_instruction, inst, &program->instructions) {
      set_insn_start(t, ureg_get_instruction_number(ureg));
      compile_tgsi_instruction(t, inst);
   }

   /* Fix up all emitted labels:
    */
   for (i = 0; i < t->labels_count; i++) {
      ureg_fixup_label(ureg, t->labels[i].token,
                       t->insn[t->labels[i].branch_target]);
   }

out:
   if (t) {
      free(t->arrays);
      free(t->temps);
      free(t->insn);
      free(t->labels);
      free(t->constants);
      t->num_constants = 0;
      free(t->immediates);
      t->num_immediates = 0;

      if (t->error) {
         debug_printf("%s: translate error flag set\n", __func__);
      }

      FREE(t);
   }

   return ret;
}
/* ----------------------------- End TGSI code ------------------------------ */


/**
 * Convert a shader's GLSL IR into a Mesa gl_program, although without
 * generating Mesa IR.
 */
static struct gl_program *
get_mesa_program(struct gl_context *ctx,
                 struct gl_shader_program *shader_program,
                 struct gl_shader *shader)
{
   glsl_to_tgsi_visitor* v;
   struct gl_program *prog;
   GLenum target = _mesa_shader_stage_to_program(shader->Stage);
   bool progress;
   struct gl_shader_compiler_options *options =
         &ctx->Const.ShaderCompilerOptions[_mesa_shader_enum_to_shader_stage(shader->Type)];
   struct pipe_screen *pscreen = ctx->st->pipe->screen;
   unsigned ptarget = st_shader_stage_to_ptarget(shader->Stage);

   validate_ir_tree(shader->ir);

   prog = ctx->Driver.NewProgram(ctx, target, shader_program->Name);
   if (!prog)
      return NULL;
   prog->Parameters = _mesa_new_parameter_list();
   v = new glsl_to_tgsi_visitor();
   v->ctx = ctx;
   v->prog = prog;
   v->shader_program = shader_program;
   v->shader = shader;
   v->options = options;
   v->glsl_version = ctx->Const.GLSLVersion;
   v->native_integers = ctx->Const.NativeIntegers;

   v->have_sqrt = pscreen->get_shader_param(pscreen, ptarget,
                                            PIPE_SHADER_CAP_TGSI_SQRT_SUPPORTED);
   v->have_fma = pscreen->get_shader_param(pscreen, ptarget,
                                           PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED);

   _mesa_copy_linked_program_data(shader->Stage, shader_program, prog);
   _mesa_generate_parameters_list_for_uniforms(shader_program, shader,
                                               prog->Parameters);

   /* Remove reads from output registers. */
   lower_output_reads(shader->Stage, shader->ir);

   /* Emit intermediate IR for main(). */
   visit_exec_list(shader->ir, v);

   /* Now emit bodies for any functions that were used. */
   do {
      progress = GL_FALSE;

      foreach_in_list(function_entry, entry, &v->function_signatures) {
         if (!entry->bgn_inst) {
            v->current_function = entry;

            entry->bgn_inst = v->emit_asm(NULL, TGSI_OPCODE_BGNSUB);
            entry->bgn_inst->function = entry;

            visit_exec_list(&entry->sig->body, v);

            glsl_to_tgsi_instruction *last;
            last = (glsl_to_tgsi_instruction *)v->instructions.get_tail();
            if (last->op != TGSI_OPCODE_RET)
               v->emit_asm(NULL, TGSI_OPCODE_RET);

            glsl_to_tgsi_instruction *end;
            end = v->emit_asm(NULL, TGSI_OPCODE_ENDSUB);
            end->function = entry;

            progress = GL_TRUE;
         }
      }
   } while (progress);

#if 0
   /* Print out some information (for debugging purposes) used by the
    * optimization passes. */
   {
      int i;
      int *first_writes = rzalloc_array(v->mem_ctx, int, v->next_temp);
      int *first_reads = rzalloc_array(v->mem_ctx, int, v->next_temp);
      int *last_writes = rzalloc_array(v->mem_ctx, int, v->next_temp);
      int *last_reads = rzalloc_array(v->mem_ctx, int, v->next_temp);

      for (i = 0; i < v->next_temp; i++) {
         first_writes[i] = -1;
         first_reads[i] = -1;
         last_writes[i] = -1;
         last_reads[i] = -1;
      }
      v->get_first_temp_read(first_reads);
      v->get_last_temp_read_first_temp_write(last_reads, first_writes);
      v->get_last_temp_write(last_writes);
      for (i = 0; i < v->next_temp; i++)
         printf("Temp %d: FR=%3d FW=%3d LR=%3d LW=%3d\n", i, first_reads[i],
                first_writes[i],
                last_reads[i],
                last_writes[i]);
      ralloc_free(first_writes);
      ralloc_free(first_reads);
      ralloc_free(last_writes);
      ralloc_free(last_reads);
   }
#endif

   /* Perform optimizations on the instructions in the glsl_to_tgsi_visitor. */
   v->simplify_cmp();

   if (shader->Type != GL_TESS_CONTROL_SHADER &&
       shader->Type != GL_TESS_EVALUATION_SHADER)
      v->copy_propagate();

   while (v->eliminate_dead_code());

   v->merge_two_dsts();
   v->merge_registers();
   v->renumber_registers();

   /* Write the END instruction. */
   v->emit_asm(NULL, TGSI_OPCODE_END);

   if (ctx->_Shader->Flags & GLSL_DUMP) {
      _mesa_log("\n");
      _mesa_log("GLSL IR for linked %s program %d:\n",
             _mesa_shader_stage_to_string(shader->Stage),
             shader_program->Name);
      _mesa_print_ir(_mesa_get_log_file(), shader->ir, NULL);
      _mesa_log("\n\n");
   }

   prog->Instructions = NULL;
   prog->NumInstructions = 0;

   do_set_program_inouts(shader->ir, prog, shader->Stage);
   shrink_array_declarations(v->input_arrays, v->num_input_arrays,
                             prog->InputsRead, prog->DoubleInputsRead, prog->PatchInputsRead);
   shrink_array_declarations(v->output_arrays, v->num_output_arrays,
                             prog->OutputsWritten, 0ULL, prog->PatchOutputsWritten);
   count_resources(v, prog);

   /* This must be done before the uniform storage is associated. */
   if (shader->Type == GL_FRAGMENT_SHADER &&
       (prog->InputsRead & VARYING_BIT_POS ||
        prog->SystemValuesRead & (1 << SYSTEM_VALUE_FRAG_COORD))) {
      static const gl_state_index wposTransformState[STATE_LENGTH] = {
         STATE_INTERNAL, STATE_FB_WPOS_Y_TRANSFORM
      };

      v->wpos_transform_const = _mesa_add_state_reference(prog->Parameters,
                                                          wposTransformState);
   }

   _mesa_reference_program(ctx, &shader->Program, prog);

   /* Avoid reallocation of the program parameter list, because the uniform
    * storage is only associated with the original parameter list.
    * This should be enough for Bitmap and DrawPixels constants.
    */
   _mesa_reserve_parameter_storage(prog->Parameters, 8);

   /* This has to be done last.  Any operation the can cause
    * prog->ParameterValues to get reallocated (e.g., anything that adds a
    * program constant) has to happen before creating this linkage.
    */
   _mesa_associate_uniform_storage(ctx, shader_program, prog->Parameters);
   if (!shader_program->LinkStatus) {
      free_glsl_to_tgsi_visitor(v);
      return NULL;
   }

   struct st_vertex_program *stvp;
   struct st_fragment_program *stfp;
   struct st_geometry_program *stgp;
   struct st_tessctrl_program *sttcp;
   struct st_tesseval_program *sttep;

   switch (shader->Type) {
   case GL_VERTEX_SHADER:
      stvp = (struct st_vertex_program *)prog;
      stvp->glsl_to_tgsi = v;
      break;
   case GL_FRAGMENT_SHADER:
      stfp = (struct st_fragment_program *)prog;
      stfp->glsl_to_tgsi = v;
      break;
   case GL_GEOMETRY_SHADER:
      stgp = (struct st_geometry_program *)prog;
      stgp->glsl_to_tgsi = v;
      break;
   case GL_TESS_CONTROL_SHADER:
      sttcp = (struct st_tessctrl_program *)prog;
      sttcp->glsl_to_tgsi = v;
      break;
   case GL_TESS_EVALUATION_SHADER:
      sttep = (struct st_tesseval_program *)prog;
      sttep->glsl_to_tgsi = v;
      break;
   default:
      assert(!"should not be reached");
      return NULL;
   }

   return prog;
}

extern "C" {

static void
st_dump_program_for_shader_db(struct gl_context *ctx,
                              struct gl_shader_program *prog)
{
   /* Dump only successfully compiled and linked shaders to the specified
    * file. This is for shader-db.
    *
    * These options allow some pre-processing of shaders while dumping,
    * because some apps have ill-formed shaders.
    */
   const char *dump_filename = os_get_option("ST_DUMP_SHADERS");
   const char *insert_directives = os_get_option("ST_DUMP_INSERT");

   if (dump_filename && prog->Name != 0) {
      FILE *f = fopen(dump_filename, "a");

      if (f) {
         for (unsigned i = 0; i < prog->NumShaders; i++) {
            const struct gl_shader *sh = prog->Shaders[i];
            const char *source;
            bool skip_version = false;

            if (!sh)
               continue;

            source = sh->Source;

            /* This string mustn't be changed. shader-db uses it to find
             * where the shader begins.
             */
            fprintf(f, "GLSL %s shader %d source for linked program %d:\n",
                    _mesa_shader_stage_to_string(sh->Stage),
                    i, prog->Name);

            /* Dump the forced version if set. */
            if (ctx->Const.ForceGLSLVersion) {
               fprintf(f, "#version %i\n", ctx->Const.ForceGLSLVersion);
               skip_version = true;
            }

            /* Insert directives (optional). */
            if (insert_directives) {
               if (!ctx->Const.ForceGLSLVersion && prog->Version)
                  fprintf(f, "#version %i\n", prog->Version);
               fprintf(f, "%s\n", insert_directives);
               skip_version = true;
            }

            if (skip_version && strncmp(source, "#version ", 9) == 0) {
               const char *next_line = strstr(source, "\n");

               if (next_line)
                  source = next_line + 1;
               else
                  continue;
            }

            fprintf(f, "%s", source);
            fprintf(f, "\n");
         }
         fclose(f);
      }
   }
}

/**
 * Link a shader.
 * Called via ctx->Driver.LinkShader()
 * This actually involves converting GLSL IR into an intermediate TGSI-like IR
 * with code lowering and other optimizations.
 */
GLboolean
st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
{
   struct pipe_screen *pscreen = ctx->st->pipe->screen;
   assert(prog->LinkStatus);

   for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
      if (prog->_LinkedShaders[i] == NULL)
         continue;

      bool progress;
      exec_list *ir = prog->_LinkedShaders[i]->ir;
      gl_shader_stage stage = _mesa_shader_enum_to_shader_stage(prog->_LinkedShaders[i]->Type);
      const struct gl_shader_compiler_options *options =
            &ctx->Const.ShaderCompilerOptions[stage];
      unsigned ptarget = st_shader_stage_to_ptarget(stage);
      bool have_dround = pscreen->get_shader_param(pscreen, ptarget,
                                                   PIPE_SHADER_CAP_TGSI_DROUND_SUPPORTED);
      bool have_dfrexp = pscreen->get_shader_param(pscreen, ptarget,
                                                   PIPE_SHADER_CAP_TGSI_DFRACEXP_DLDEXP_SUPPORTED);

      /* If there are forms of indirect addressing that the driver
       * cannot handle, perform the lowering pass.
       */
      if (options->EmitNoIndirectInput || options->EmitNoIndirectOutput ||
          options->EmitNoIndirectTemp || options->EmitNoIndirectUniform) {
         lower_variable_index_to_cond_assign(prog->_LinkedShaders[i]->Stage, ir,
                                             options->EmitNoIndirectInput,
                                             options->EmitNoIndirectOutput,
                                             options->EmitNoIndirectTemp,
                                             options->EmitNoIndirectUniform);
      }

      if (ctx->Extensions.ARB_shading_language_packing) {
         unsigned lower_inst = LOWER_PACK_SNORM_2x16 |
                               LOWER_UNPACK_SNORM_2x16 |
                               LOWER_PACK_UNORM_2x16 |
                               LOWER_UNPACK_UNORM_2x16 |
                               LOWER_PACK_SNORM_4x8 |
                               LOWER_UNPACK_SNORM_4x8 |
                               LOWER_UNPACK_UNORM_4x8 |
                               LOWER_PACK_UNORM_4x8;

         if (ctx->Extensions.ARB_gpu_shader5)
            lower_inst |= LOWER_PACK_USE_BFI |
                          LOWER_PACK_USE_BFE;
         if (!ctx->st->has_half_float_packing)
            lower_inst |= LOWER_PACK_HALF_2x16 |
                          LOWER_UNPACK_HALF_2x16;

         lower_packing_builtins(ir, lower_inst);
      }

      if (!pscreen->get_param(pscreen, PIPE_CAP_TEXTURE_GATHER_OFFSETS))
         lower_offset_arrays(ir);
      do_mat_op_to_vec(ir);
      lower_instructions(ir,
                         MOD_TO_FLOOR |
                         DIV_TO_MUL_RCP |
                         EXP_TO_EXP2 |
                         LOG_TO_LOG2 |
                         LDEXP_TO_ARITH |
                         (have_dfrexp ? 0 : DFREXP_DLDEXP_TO_ARITH) |
                         CARRY_TO_ARITH |
                         BORROW_TO_ARITH |
                         (have_dround ? 0 : DOPS_TO_DFRAC) |
                         (options->EmitNoPow ? POW_TO_EXP2 : 0) |
                         (!ctx->Const.NativeIntegers ? INT_DIV_TO_MUL_RCP : 0) |
                         (options->EmitNoSat ? SAT_TO_CLAMP : 0));

      do_vec_index_to_cond_assign(ir);
      lower_vector_insert(ir, true);
      lower_quadop_vector(ir, false);
      lower_noise(ir);
      if (options->MaxIfDepth == 0) {
         lower_discard(ir);
      }

      do {
         progress = false;

         progress = do_lower_jumps(ir, true, true, options->EmitNoMainReturn, options->EmitNoCont, options->EmitNoLoops) || progress;

         progress = do_common_optimization(ir, true, true, options,
                                           ctx->Const.NativeIntegers)
           || progress;

         progress = lower_if_to_cond_assign(ir, options->MaxIfDepth) || progress;

      } while (progress);

      validate_ir_tree(ir);
   }

   for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
      struct gl_program *linked_prog;

      if (prog->_LinkedShaders[i] == NULL)
         continue;

      linked_prog = get_mesa_program(ctx, prog, prog->_LinkedShaders[i]);

      if (linked_prog) {
         _mesa_reference_program(ctx, &prog->_LinkedShaders[i]->Program,
                                 linked_prog);
         if (!ctx->Driver.ProgramStringNotify(ctx,
                                              _mesa_shader_stage_to_program(i),
                                              linked_prog)) {
            _mesa_reference_program(ctx, &prog->_LinkedShaders[i]->Program,
                                    NULL);
            _mesa_reference_program(ctx, &linked_prog, NULL);
            return GL_FALSE;
         }
      }

      _mesa_reference_program(ctx, &linked_prog, NULL);
   }

   st_dump_program_for_shader_db(ctx, prog);
   return GL_TRUE;
}

void
st_translate_stream_output_info(glsl_to_tgsi_visitor *glsl_to_tgsi,
                                const GLuint outputMapping[],
                                struct pipe_stream_output_info *so)
{
   unsigned i;
   struct gl_transform_feedback_info *info =
      &glsl_to_tgsi->shader_program->LinkedTransformFeedback;

   for (i = 0; i < info->NumOutputs; i++) {
      so->output[i].register_index =
         outputMapping[info->Outputs[i].OutputRegister];
      so->output[i].start_component = info->Outputs[i].ComponentOffset;
      so->output[i].num_components = info->Outputs[i].NumComponents;
      so->output[i].output_buffer = info->Outputs[i].OutputBuffer;
      so->output[i].dst_offset = info->Outputs[i].DstOffset;
      so->output[i].stream = info->Outputs[i].StreamId;
   }

   for (i = 0; i < PIPE_MAX_SO_BUFFERS; i++) {
      so->stride[i] = info->BufferStride[i];
   }
   so->num_outputs = info->NumOutputs;
}

} /* extern "C" */