freedreno: prepare for a3xx

[mesa.git] / src / gallium / drivers / freedreno / a2xx / fd2_compiler.c

/* -*- mode: C; c-file-style: "k&r"; tab-width 4; indent-tabs-mode: t; -*- */

/*
 * Copyright (C) 2012 Rob Clark <robclark@freedesktop.org>
 *
 * 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.
 *
 * Authors:
 *    Rob Clark <robclark@freedesktop.org>
 */

#include "pipe/p_state.h"
#include "util/u_string.h"
#include "util/u_memory.h"
#include "util/u_inlines.h"
#include "tgsi/tgsi_parse.h"
#include "tgsi/tgsi_ureg.h"
#include "tgsi/tgsi_info.h"
#include "tgsi/tgsi_strings.h"
#include "tgsi/tgsi_dump.h"

#include "fd2_compiler.h"
#include "fd2_program.h"
#include "fd2_util.h"

#include "instr-a2xx.h"
#include "ir-a2xx.h"

struct fd2_compile_context {
        struct fd_program_stateobj *prog;
        struct fd2_shader_stateobj *so;

        struct tgsi_parse_context parser;
        unsigned type;

        /* predicate stack: */
        int pred_depth;
        enum ir2_pred pred_stack[8];

        /* Internal-Temporary and Predicate register assignment:
         *
         * Some TGSI instructions which translate into multiple actual
         * instructions need one or more temporary registers, which are not
         * assigned from TGSI perspective (ie. not TGSI_FILE_TEMPORARY).
         * And some instructions (texture fetch) cannot write directly to
         * output registers.  We could be more clever and re-use dst or a
         * src register in some cases.  But for now don't try to be clever.
         * Eventually we should implement an optimization pass that re-
         * juggles the register usage and gets rid of unneeded temporaries.
         *
         * The predicate register must be valid across multiple TGSI
         * instructions, but internal temporary's do not.  For this reason,
         * once the predicate register is requested, until it is no longer
         * needed, it gets the first register slot after after the TGSI
         * assigned temporaries (ie. num_regs[TGSI_FILE_TEMPORARY]), and the
         * internal temporaries get the register slots above this.
         */

        int pred_reg;
        int num_internal_temps;

        uint8_t num_regs[TGSI_FILE_COUNT];

        /* maps input register idx to prog->export_linkage idx: */
        uint8_t input_export_idx[64];

        /* maps output register idx to prog->export_linkage idx: */
        uint8_t output_export_idx[64];

        /* idx/slot for last compiler generated immediate */
        unsigned immediate_idx;

        // TODO we can skip emit exports in the VS that the FS doesn't need..
        // and get rid perhaps of num_param..
        unsigned num_position, num_param;
        unsigned position, psize;

        uint64_t need_sync;

        /* current exec CF instruction */
        struct ir2_cf *cf;
};

static int
semantic_idx(struct tgsi_declaration_semantic *semantic)
{
        int idx = semantic->Name;
        if (idx == TGSI_SEMANTIC_GENERIC)
                idx = TGSI_SEMANTIC_COUNT + semantic->Index;
        return idx;
}

/* assign/get the input/export register # for given semantic idx as
 * returned by semantic_idx():
 */
static int
export_linkage(struct fd2_compile_context *ctx, int idx)
{
        struct fd_program_stateobj *prog = ctx->prog;

        /* if first time we've seen this export, assign the next available slot: */
        if (prog->export_linkage[idx] == 0xff)
                prog->export_linkage[idx] = prog->num_exports++;

        return prog->export_linkage[idx];
}

static unsigned
compile_init(struct fd2_compile_context *ctx, struct fd_program_stateobj *prog,
                struct fd2_shader_stateobj *so)
{
        unsigned ret;

        ctx->prog = prog;
        ctx->so = so;
        ctx->cf = NULL;
        ctx->pred_depth = 0;

        ret = tgsi_parse_init(&ctx->parser, so->tokens);
        if (ret != TGSI_PARSE_OK)
                return ret;

        ctx->type = ctx->parser.FullHeader.Processor.Processor;
        ctx->position = ~0;
        ctx->psize = ~0;
        ctx->num_position = 0;
        ctx->num_param = 0;
        ctx->need_sync = 0;
        ctx->immediate_idx = 0;
        ctx->pred_reg = -1;
        ctx->num_internal_temps = 0;

        memset(ctx->num_regs, 0, sizeof(ctx->num_regs));
        memset(ctx->input_export_idx, 0, sizeof(ctx->input_export_idx));
        memset(ctx->output_export_idx, 0, sizeof(ctx->output_export_idx));

        /* do first pass to extract declarations: */
        while (!tgsi_parse_end_of_tokens(&ctx->parser)) {
                tgsi_parse_token(&ctx->parser);

                switch (ctx->parser.FullToken.Token.Type) {
                case TGSI_TOKEN_TYPE_DECLARATION: {
                        struct tgsi_full_declaration *decl =
                                        &ctx->parser.FullToken.FullDeclaration;
                        if (decl->Declaration.File == TGSI_FILE_OUTPUT) {
                                unsigned name = decl->Semantic.Name;

                                assert(decl->Declaration.Semantic);  // TODO is this ever not true?

                                ctx->output_export_idx[decl->Range.First] =
                                                semantic_idx(&decl->Semantic);

                                if (ctx->type == TGSI_PROCESSOR_VERTEX) {
                                        switch (name) {
                                        case TGSI_SEMANTIC_POSITION:
                                                ctx->position = ctx->num_regs[TGSI_FILE_OUTPUT];
                                                ctx->num_position++;
                                                break;
                                        case TGSI_SEMANTIC_PSIZE:
                                                ctx->psize = ctx->num_regs[TGSI_FILE_OUTPUT];
                                                ctx->num_position++;
                                                break;
                                        case TGSI_SEMANTIC_COLOR:
                                        case TGSI_SEMANTIC_GENERIC:
                                                ctx->num_param++;
                                                break;
                                        default:
                                                DBG("unknown VS semantic name: %s",
                                                                tgsi_semantic_names[name]);
                                                assert(0);
                                        }
                                } else {
                                        switch (name) {
                                        case TGSI_SEMANTIC_COLOR:
                                        case TGSI_SEMANTIC_GENERIC:
                                                ctx->num_param++;
                                                break;
                                        default:
                                                DBG("unknown PS semantic name: %s",
                                                                tgsi_semantic_names[name]);
                                                assert(0);
                                        }
                                }
                        } else if (decl->Declaration.File == TGSI_FILE_INPUT) {
                                ctx->input_export_idx[decl->Range.First] =
                                                semantic_idx(&decl->Semantic);
                        }
                        ctx->num_regs[decl->Declaration.File] =
                                        MAX2(ctx->num_regs[decl->Declaration.File], decl->Range.Last + 1);
                        break;
                }
                case TGSI_TOKEN_TYPE_IMMEDIATE: {
                        struct tgsi_full_immediate *imm =
                                        &ctx->parser.FullToken.FullImmediate;
                        unsigned n = ctx->so->num_immediates++;
                        memcpy(ctx->so->immediates[n].val, imm->u, 16);
                        break;
                }
                default:
                        break;
                }
        }

        /* TGSI generated immediates are always entire vec4's, ones we
         * generate internally are not:
         */
        ctx->immediate_idx = ctx->so->num_immediates * 4;

        ctx->so->first_immediate = ctx->num_regs[TGSI_FILE_CONSTANT];

        tgsi_parse_free(&ctx->parser);

        return tgsi_parse_init(&ctx->parser, so->tokens);
}

static void
compile_free(struct fd2_compile_context *ctx)
{
        tgsi_parse_free(&ctx->parser);
}

static struct ir2_cf *
next_exec_cf(struct fd2_compile_context *ctx)
{
        struct ir2_cf *cf = ctx->cf;
        if (!cf || cf->exec.instrs_count >= ARRAY_SIZE(ctx->cf->exec.instrs))
                ctx->cf = cf = ir2_cf_create(ctx->so->ir, EXEC);
        return cf;
}

static void
compile_vtx_fetch(struct fd2_compile_context *ctx)
{
        struct ir2_instruction **vfetch_instrs = ctx->so->vfetch_instrs;
        int i;
        for (i = 0; i < ctx->num_regs[TGSI_FILE_INPUT]; i++) {
                struct ir2_instruction *instr = ir2_instr_create(
                                next_exec_cf(ctx), IR2_FETCH);
                instr->fetch.opc = VTX_FETCH;

                ctx->need_sync |= 1 << (i+1);

                ir2_reg_create(instr, i+1, "xyzw", 0);
                ir2_reg_create(instr, 0, "x", 0);

                if (i == 0)
                        instr->sync = true;

                vfetch_instrs[i] = instr;
        }
        ctx->so->num_vfetch_instrs = i;
        ctx->cf = NULL;
}

/*
 * For vertex shaders (VS):
 * --- ------ -------------
 *
 *   Inputs:     R1-R(num_input)
 *   Constants:  C0-C(num_const-1)
 *   Immediates: C(num_const)-C(num_const+num_imm-1)
 *   Outputs:    export0-export(n) and export62, export63
 *      n is # of outputs minus gl_Position (export62) and gl_PointSize (export63)
 *   Temps:      R(num_input+1)-R(num_input+num_temps)
 *
 * R0 could be clobbered after the vertex fetch instructions.. so we
 * could use it for one of the temporaries.
 *
 * TODO: maybe the vertex fetch part could fetch first input into R0 as
 * the last vtx fetch instruction, which would let us use the same
 * register layout in either case.. although this is not what the blob
 * compiler does.
 *
 *
 * For frag shaders (PS):
 * --- ---- -------------
 *
 *   Inputs:     R0-R(num_input-1)
 *   Constants:  same as VS
 *   Immediates: same as VS
 *   Outputs:    export0-export(num_outputs)
 *   Temps:      R(num_input)-R(num_input+num_temps-1)
 *
 * In either case, immediates are are postpended to the constants
 * (uniforms).
 *
 */

static unsigned
get_temp_gpr(struct fd2_compile_context *ctx, int idx)
{
        unsigned num = idx + ctx->num_regs[TGSI_FILE_INPUT];
        if (ctx->type == TGSI_PROCESSOR_VERTEX)
                num++;
        return num;
}

static struct ir2_register *
add_dst_reg(struct fd2_compile_context *ctx, struct ir2_instruction *alu,
                const struct tgsi_dst_register *dst)
{
        unsigned flags = 0, num = 0;
        char swiz[5];

        switch (dst->File) {
        case TGSI_FILE_OUTPUT:
                flags |= IR2_REG_EXPORT;
                if (ctx->type == TGSI_PROCESSOR_VERTEX) {
                        if (dst->Index == ctx->position) {
                                num = 62;
                        } else if (dst->Index == ctx->psize) {
                                num = 63;
                        } else {
                                num = export_linkage(ctx,
                                                ctx->output_export_idx[dst->Index]);
                        }
                } else {
                        num = dst->Index;
                }
                break;
        case TGSI_FILE_TEMPORARY:
                num = get_temp_gpr(ctx, dst->Index);
                break;
        default:
                DBG("unsupported dst register file: %s",
                        tgsi_file_name(dst->File));
                assert(0);
                break;
        }

        swiz[0] = (dst->WriteMask & TGSI_WRITEMASK_X) ? 'x' : '_';
        swiz[1] = (dst->WriteMask & TGSI_WRITEMASK_Y) ? 'y' : '_';
        swiz[2] = (dst->WriteMask & TGSI_WRITEMASK_Z) ? 'z' : '_';
        swiz[3] = (dst->WriteMask & TGSI_WRITEMASK_W) ? 'w' : '_';
        swiz[4] = '\0';

        return ir2_reg_create(alu, num, swiz, flags);
}

static struct ir2_register *
add_src_reg(struct fd2_compile_context *ctx, struct ir2_instruction *alu,
                const struct tgsi_src_register *src)
{
        static const char swiz_vals[] = {
                        'x', 'y', 'z', 'w',
        };
        char swiz[5];
        unsigned flags = 0, num = 0;

        switch (src->File) {
        case TGSI_FILE_CONSTANT:
                num = src->Index;
                flags |= IR2_REG_CONST;
                break;
        case TGSI_FILE_INPUT:
                if (ctx->type == TGSI_PROCESSOR_VERTEX) {
                        num = src->Index + 1;
                } else {
                        num = export_linkage(ctx,
                                        ctx->input_export_idx[src->Index]);
                }
                break;
        case TGSI_FILE_TEMPORARY:
                num = get_temp_gpr(ctx, src->Index);
                break;
        case TGSI_FILE_IMMEDIATE:
                num = src->Index + ctx->num_regs[TGSI_FILE_CONSTANT];
                flags |= IR2_REG_CONST;
                break;
        default:
                DBG("unsupported src register file: %s",
                        tgsi_file_name(src->File));
                assert(0);
                break;
        }

        if (src->Absolute)
                flags |= IR2_REG_ABS;
        if (src->Negate)
                flags |= IR2_REG_NEGATE;

        swiz[0] = swiz_vals[src->SwizzleX];
        swiz[1] = swiz_vals[src->SwizzleY];
        swiz[2] = swiz_vals[src->SwizzleZ];
        swiz[3] = swiz_vals[src->SwizzleW];
        swiz[4] = '\0';

        if ((ctx->need_sync & (uint64_t)(1 << num)) &&
                        !(flags & IR2_REG_CONST)) {
                alu->sync = true;
                ctx->need_sync &= ~(uint64_t)(1 << num);
        }

        return ir2_reg_create(alu, num, swiz, flags);
}

static void
add_vector_clamp(struct tgsi_full_instruction *inst, struct ir2_instruction *alu)
{
        switch (inst->Instruction.Saturate) {
        case TGSI_SAT_NONE:
                break;
        case TGSI_SAT_ZERO_ONE:
                alu->alu.vector_clamp = true;
                break;
        case TGSI_SAT_MINUS_PLUS_ONE:
                DBG("unsupported saturate");
                assert(0);
                break;
        }
}

static void
add_scalar_clamp(struct tgsi_full_instruction *inst, struct ir2_instruction *alu)
{
        switch (inst->Instruction.Saturate) {
        case TGSI_SAT_NONE:
                break;
        case TGSI_SAT_ZERO_ONE:
                alu->alu.scalar_clamp = true;
                break;
        case TGSI_SAT_MINUS_PLUS_ONE:
                DBG("unsupported saturate");
                assert(0);
                break;
        }
}

static void
add_regs_vector_1(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst, struct ir2_instruction *alu)
{
        assert(inst->Instruction.NumSrcRegs == 1);
        assert(inst->Instruction.NumDstRegs == 1);

        add_dst_reg(ctx, alu, &inst->Dst[0].Register);
        add_src_reg(ctx, alu, &inst->Src[0].Register);
        add_src_reg(ctx, alu, &inst->Src[0].Register);
        add_vector_clamp(inst, alu);
}

static void
add_regs_vector_2(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst, struct ir2_instruction *alu)
{
        assert(inst->Instruction.NumSrcRegs == 2);
        assert(inst->Instruction.NumDstRegs == 1);

        add_dst_reg(ctx, alu, &inst->Dst[0].Register);
        add_src_reg(ctx, alu, &inst->Src[0].Register);
        add_src_reg(ctx, alu, &inst->Src[1].Register);
        add_vector_clamp(inst, alu);
}

static void
add_regs_vector_3(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst, struct ir2_instruction *alu)
{
        assert(inst->Instruction.NumSrcRegs == 3);
        assert(inst->Instruction.NumDstRegs == 1);

        add_dst_reg(ctx, alu, &inst->Dst[0].Register);
        /* maybe should re-arrange the syntax some day, but
         * in assembler/disassembler and what ir.c expects
         * is: MULADDv Rdst = Rsrc2 + Rsrc0 * Rscr1
         */
        add_src_reg(ctx, alu, &inst->Src[2].Register);
        add_src_reg(ctx, alu, &inst->Src[0].Register);
        add_src_reg(ctx, alu, &inst->Src[1].Register);
        add_vector_clamp(inst, alu);
}

static void
add_regs_dummy_vector(struct ir2_instruction *alu)
{
        /* create dummy, non-written vector dst/src regs
         * for unused vector instr slot:
         */
        ir2_reg_create(alu, 0, "____", 0); /* vector dst */
        ir2_reg_create(alu, 0, NULL, 0);   /* vector src1 */
        ir2_reg_create(alu, 0, NULL, 0);   /* vector src2 */
}

static void
add_regs_scalar_1(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst, struct ir2_instruction *alu)
{
        assert(inst->Instruction.NumSrcRegs == 1);
        assert(inst->Instruction.NumDstRegs == 1);

        add_regs_dummy_vector(alu);

        add_dst_reg(ctx, alu, &inst->Dst[0].Register);
        add_src_reg(ctx, alu, &inst->Src[0].Register);
        add_scalar_clamp(inst, alu);
}

/*
 * Helpers for TGSI instructions that don't map to a single shader instr:
 */

static void
src_from_dst(struct tgsi_src_register *src, struct tgsi_dst_register *dst)
{
        src->File      = dst->File;
        src->Indirect  = dst->Indirect;
        src->Dimension = dst->Dimension;
        src->Index     = dst->Index;
        src->Absolute  = 0;
        src->Negate    = 0;
        src->SwizzleX  = TGSI_SWIZZLE_X;
        src->SwizzleY  = TGSI_SWIZZLE_Y;
        src->SwizzleZ  = TGSI_SWIZZLE_Z;
        src->SwizzleW  = TGSI_SWIZZLE_W;
}

/* Get internal-temp src/dst to use for a sequence of instructions
 * generated by a single TGSI op.
 */
static void
get_internal_temp(struct fd2_compile_context *ctx,
                struct tgsi_dst_register *tmp_dst,
                struct tgsi_src_register *tmp_src)
{
        int n;

        tmp_dst->File      = TGSI_FILE_TEMPORARY;
        tmp_dst->WriteMask = TGSI_WRITEMASK_XYZW;
        tmp_dst->Indirect  = 0;
        tmp_dst->Dimension = 0;

        /* assign next temporary: */
        n = ctx->num_internal_temps++;
        if (ctx->pred_reg != -1)
                n++;

        tmp_dst->Index = ctx->num_regs[TGSI_FILE_TEMPORARY] + n;

        src_from_dst(tmp_src, tmp_dst);
}

static void
get_predicate(struct fd2_compile_context *ctx, struct tgsi_dst_register *dst,
                struct tgsi_src_register *src)
{
        assert(ctx->pred_reg != -1);

        dst->File      = TGSI_FILE_TEMPORARY;
        dst->WriteMask = TGSI_WRITEMASK_W;
        dst->Indirect  = 0;
        dst->Dimension = 0;
        dst->Index     = get_temp_gpr(ctx, ctx->pred_reg);

        if (src) {
                src_from_dst(src, dst);
                src->SwizzleX  = TGSI_SWIZZLE_W;
                src->SwizzleY  = TGSI_SWIZZLE_W;
                src->SwizzleZ  = TGSI_SWIZZLE_W;
                src->SwizzleW  = TGSI_SWIZZLE_W;
        }
}

static void
push_predicate(struct fd2_compile_context *ctx, struct tgsi_src_register *src)
{
        struct ir2_instruction *alu;
        struct tgsi_dst_register pred_dst;

        /* NOTE blob compiler seems to always puts PRED_* instrs in a CF by
         * themselves:
         */
        ctx->cf = NULL;

        if (ctx->pred_depth == 0) {
                /* assign predicate register: */
                ctx->pred_reg = ctx->num_regs[TGSI_FILE_TEMPORARY];

                get_predicate(ctx, &pred_dst, NULL);

                alu = ir2_instr_create_alu(next_exec_cf(ctx), ~0, PRED_SETNEs);
                add_regs_dummy_vector(alu);
                add_dst_reg(ctx, alu, &pred_dst);
                add_src_reg(ctx, alu, src);
        } else {
                struct tgsi_src_register pred_src;

                get_predicate(ctx, &pred_dst, &pred_src);

                alu = ir2_instr_create_alu(next_exec_cf(ctx), MULv, ~0);
                add_dst_reg(ctx, alu, &pred_dst);
                add_src_reg(ctx, alu, &pred_src);
                add_src_reg(ctx, alu, src);

                // XXX need to make PRED_SETE_PUSHv IR2_PRED_NONE.. but need to make
                // sure src reg is valid if it was calculated with a predicate
                // condition..
                alu->pred = IR2_PRED_NONE;
        }

        /* save previous pred state to restore in pop_predicate(): */
        ctx->pred_stack[ctx->pred_depth++] = ctx->so->ir->pred;

        ctx->cf = NULL;
}

static void
pop_predicate(struct fd2_compile_context *ctx)
{
        /* NOTE blob compiler seems to always puts PRED_* instrs in a CF by
         * themselves:
         */
        ctx->cf = NULL;

        /* restore previous predicate state: */
        ctx->so->ir->pred = ctx->pred_stack[--ctx->pred_depth];

        if (ctx->pred_depth != 0) {
                struct ir2_instruction *alu;
                struct tgsi_dst_register pred_dst;
                struct tgsi_src_register pred_src;

                get_predicate(ctx, &pred_dst, &pred_src);

                alu = ir2_instr_create_alu(next_exec_cf(ctx), ~0, PRED_SET_POPs);
                add_regs_dummy_vector(alu);
                add_dst_reg(ctx, alu, &pred_dst);
                add_src_reg(ctx, alu, &pred_src);
                alu->pred = IR2_PRED_NONE;
        } else {
                /* predicate register no longer needed: */
                ctx->pred_reg = -1;
        }

        ctx->cf = NULL;
}

static void
get_immediate(struct fd2_compile_context *ctx,
                struct tgsi_src_register *reg, uint32_t val)
{
        unsigned neg, swiz, idx, i;
        /* actually maps 1:1 currently.. not sure if that is safe to rely on: */
        static const unsigned swiz2tgsi[] = {
                        TGSI_SWIZZLE_X, TGSI_SWIZZLE_Y, TGSI_SWIZZLE_Z, TGSI_SWIZZLE_W,
        };

        for (i = 0; i < ctx->immediate_idx; i++) {
                swiz = i % 4;
                idx  = i / 4;

                if (ctx->so->immediates[idx].val[swiz] == val) {
                        neg = 0;
                        break;
                }

                if (ctx->so->immediates[idx].val[swiz] == -val) {
                        neg = 1;
                        break;
                }
        }

        if (i == ctx->immediate_idx) {
                /* need to generate a new immediate: */
                swiz = i % 4;
                idx  = i / 4;
                neg  = 0;
                ctx->so->immediates[idx].val[swiz] = val;
                ctx->so->num_immediates = idx + 1;
                ctx->immediate_idx++;
        }

        reg->File      = TGSI_FILE_IMMEDIATE;
        reg->Indirect  = 0;
        reg->Dimension = 0;
        reg->Index     = idx;
        reg->Absolute  = 0;
        reg->Negate    = neg;
        reg->SwizzleX  = swiz2tgsi[swiz];
        reg->SwizzleY  = swiz2tgsi[swiz];
        reg->SwizzleZ  = swiz2tgsi[swiz];
        reg->SwizzleW  = swiz2tgsi[swiz];
}

/* POW(a,b) = EXP2(b * LOG2(a)) */
static void
translate_pow(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst)
{
        struct tgsi_dst_register tmp_dst;
        struct tgsi_src_register tmp_src;
        struct ir2_instruction *alu;

        get_internal_temp(ctx, &tmp_dst, &tmp_src);

        alu = ir2_instr_create_alu(next_exec_cf(ctx), ~0, LOG_CLAMP);
        add_regs_dummy_vector(alu);
        add_dst_reg(ctx, alu, &tmp_dst);
        add_src_reg(ctx, alu, &inst->Src[0].Register);

        alu = ir2_instr_create_alu(next_exec_cf(ctx), MULv, ~0);
        add_dst_reg(ctx, alu, &tmp_dst);
        add_src_reg(ctx, alu, &tmp_src);
        add_src_reg(ctx, alu, &inst->Src[1].Register);

        /* NOTE: some of the instructions, like EXP_IEEE, seem hard-
         * coded to take their input from the w component.
         */
        switch(inst->Dst[0].Register.WriteMask) {
        case TGSI_WRITEMASK_X:
                tmp_src.SwizzleW = TGSI_SWIZZLE_X;
                break;
        case TGSI_WRITEMASK_Y:
                tmp_src.SwizzleW = TGSI_SWIZZLE_Y;
                break;
        case TGSI_WRITEMASK_Z:
                tmp_src.SwizzleW = TGSI_SWIZZLE_Z;
                break;
        case TGSI_WRITEMASK_W:
                tmp_src.SwizzleW = TGSI_SWIZZLE_W;
                break;
        default:
                DBG("invalid writemask!");
                assert(0);
                break;
        }

        alu = ir2_instr_create_alu(next_exec_cf(ctx), ~0, EXP_IEEE);
        add_regs_dummy_vector(alu);
        add_dst_reg(ctx, alu, &inst->Dst[0].Register);
        add_src_reg(ctx, alu, &tmp_src);
        add_scalar_clamp(inst, alu);
}

static void
translate_tex(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst, unsigned opc)
{
        struct ir2_instruction *instr;
        struct ir2_register *reg;
        struct tgsi_dst_register tmp_dst;
        struct tgsi_src_register tmp_src;
        const struct tgsi_src_register *coord;
        bool using_temp = (inst->Dst[0].Register.File == TGSI_FILE_OUTPUT) ||
                        (inst->Instruction.Saturate != TGSI_SAT_NONE);
        int idx;

        if (using_temp || (opc == TGSI_OPCODE_TXP))
                get_internal_temp(ctx, &tmp_dst, &tmp_src);

        if (opc == TGSI_OPCODE_TXP) {
                static const char *swiz[] = {
                                [TGSI_SWIZZLE_X] = "xxxx",
                                [TGSI_SWIZZLE_Y] = "yyyy",
                                [TGSI_SWIZZLE_Z] = "zzzz",
                                [TGSI_SWIZZLE_W] = "wwww",
                };

                /* TXP - Projective Texture Lookup:
                 *
                 *  coord.x = src0.x / src.w
                 *  coord.y = src0.y / src.w
                 *  coord.z = src0.z / src.w
                 *  coord.w = src0.w
                 *  bias = 0.0
                 *
                 *  dst = texture_sample(unit, coord, bias)
                 */
                instr = ir2_instr_create_alu(next_exec_cf(ctx), MAXv, RECIP_IEEE);

                /* MAXv: */
                add_dst_reg(ctx, instr, &tmp_dst)->swizzle = "___w";
                add_src_reg(ctx, instr, &inst->Src[0].Register);
                add_src_reg(ctx, instr, &inst->Src[0].Register);

                /* RECIP_IEEE: */
                add_dst_reg(ctx, instr, &tmp_dst)->swizzle = "x___";
                add_src_reg(ctx, instr, &inst->Src[0].Register)->swizzle =
                                swiz[inst->Src[0].Register.SwizzleW];

                instr = ir2_instr_create_alu(next_exec_cf(ctx), MULv, ~0);
                add_dst_reg(ctx, instr, &tmp_dst)->swizzle = "xyz_";
                add_src_reg(ctx, instr, &tmp_src)->swizzle = "xxxx";
                add_src_reg(ctx, instr, &inst->Src[0].Register);

                coord = &tmp_src;
        } else {
                coord = &inst->Src[0].Register;
        }

        instr = ir2_instr_create(next_exec_cf(ctx), IR2_FETCH);
        instr->fetch.opc = TEX_FETCH;
        instr->fetch.is_cube = (inst->Texture.Texture == TGSI_TEXTURE_3D);
        assert(inst->Texture.NumOffsets <= 1); // TODO what to do in other cases?

        /* save off the tex fetch to be patched later with correct const_idx: */
        idx = ctx->so->num_tfetch_instrs++;
        ctx->so->tfetch_instrs[idx].samp_id = inst->Src[1].Register.Index;
        ctx->so->tfetch_instrs[idx].instr = instr;

        add_dst_reg(ctx, instr, using_temp ? &tmp_dst : &inst->Dst[0].Register);
        reg = add_src_reg(ctx, instr, coord);

        /* blob compiler always sets 3rd component to same as 1st for 2d: */
        if (inst->Texture.Texture == TGSI_TEXTURE_2D)
                reg->swizzle[2] = reg->swizzle[0];

        /* dst register needs to be marked for sync: */
        ctx->need_sync |= 1 << instr->regs[0]->num;

        /* TODO we need some way to know if the tex fetch needs to sync on alu pipe.. */
        instr->sync = true;

        if (using_temp) {
                /* texture fetch can't write directly to export, so if tgsi
                 * is telling us the dst register is in output file, we load
                 * the texture to a temp and the use ALU instruction to move
                 * to output
                 */
                instr = ir2_instr_create_alu(next_exec_cf(ctx), MAXv, ~0);

                add_dst_reg(ctx, instr, &inst->Dst[0].Register);
                add_src_reg(ctx, instr, &tmp_src);
                add_src_reg(ctx, instr, &tmp_src);
                add_vector_clamp(inst, instr);
        }
}

/* SGE(a,b) = GTE((b - a), 1.0, 0.0) */
/* SLT(a,b) = GTE((b - a), 0.0, 1.0) */
static void
translate_sge_slt(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst, unsigned opc)
{
        struct ir2_instruction *instr;
        struct tgsi_dst_register tmp_dst;
        struct tgsi_src_register tmp_src;
        struct tgsi_src_register tmp_const;
        float c0, c1;

        switch (opc) {
        default:
                assert(0);
        case TGSI_OPCODE_SGE:
                c0 = 1.0;
                c1 = 0.0;
                break;
        case TGSI_OPCODE_SLT:
                c0 = 0.0;
                c1 = 1.0;
                break;
        }

        get_internal_temp(ctx, &tmp_dst, &tmp_src);

        instr = ir2_instr_create_alu(next_exec_cf(ctx), ADDv, ~0);
        add_dst_reg(ctx, instr, &tmp_dst);
        add_src_reg(ctx, instr, &inst->Src[0].Register)->flags |= IR2_REG_NEGATE;
        add_src_reg(ctx, instr, &inst->Src[1].Register);

        instr = ir2_instr_create_alu(next_exec_cf(ctx), CNDGTEv, ~0);
        add_dst_reg(ctx, instr, &inst->Dst[0].Register);
        /* maybe should re-arrange the syntax some day, but
         * in assembler/disassembler and what ir.c expects
         * is: MULADDv Rdst = Rsrc2 + Rsrc0 * Rscr1
         */
        get_immediate(ctx, &tmp_const, fui(c0));
        add_src_reg(ctx, instr, &tmp_const);
        add_src_reg(ctx, instr, &tmp_src);
        get_immediate(ctx, &tmp_const, fui(c1));
        add_src_reg(ctx, instr, &tmp_const);
}

/* LRP(a,b,c) = (a * b) + ((1 - a) * c) */
static void
translate_lrp(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst,
                unsigned opc)
{
        struct ir2_instruction *instr;
        struct tgsi_dst_register tmp_dst1, tmp_dst2;
        struct tgsi_src_register tmp_src1, tmp_src2;
        struct tgsi_src_register tmp_const;

        get_internal_temp(ctx, &tmp_dst1, &tmp_src1);
        get_internal_temp(ctx, &tmp_dst2, &tmp_src2);

        get_immediate(ctx, &tmp_const, fui(1.0));

        /* tmp1 = (a * b) */
        instr = ir2_instr_create_alu(next_exec_cf(ctx), MULv, ~0);
        add_dst_reg(ctx, instr, &tmp_dst1);
        add_src_reg(ctx, instr, &inst->Src[0].Register);
        add_src_reg(ctx, instr, &inst->Src[1].Register);

        /* tmp2 = (1 - a) */
        instr = ir2_instr_create_alu(next_exec_cf(ctx), ADDv, ~0);
        add_dst_reg(ctx, instr, &tmp_dst2);
        add_src_reg(ctx, instr, &tmp_const);
        add_src_reg(ctx, instr, &inst->Src[0].Register)->flags |= IR2_REG_NEGATE;

        /* tmp2 = tmp2 * c */
        instr = ir2_instr_create_alu(next_exec_cf(ctx), MULv, ~0);
        add_dst_reg(ctx, instr, &tmp_dst2);
        add_src_reg(ctx, instr, &tmp_src2);
        add_src_reg(ctx, instr, &inst->Src[2].Register);

        /* dst = tmp1 + tmp2 */
        instr = ir2_instr_create_alu(next_exec_cf(ctx), ADDv, ~0);
        add_dst_reg(ctx, instr, &inst->Dst[0].Register);
        add_src_reg(ctx, instr, &tmp_src1);
        add_src_reg(ctx, instr, &tmp_src2);
}

static void
translate_trig(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst,
                unsigned opc)
{
        struct ir2_instruction *instr;
        struct tgsi_dst_register tmp_dst;
        struct tgsi_src_register tmp_src;
        struct tgsi_src_register tmp_const;
        instr_scalar_opc_t op;

        switch (opc) {
        default:
                assert(0);
        case TGSI_OPCODE_SIN:
                op = SIN;
                break;
        case TGSI_OPCODE_COS:
                op = COS;
                break;
        }

        get_internal_temp(ctx, &tmp_dst, &tmp_src);

        tmp_dst.WriteMask = TGSI_WRITEMASK_X;
        tmp_src.SwizzleX = tmp_src.SwizzleY =
                        tmp_src.SwizzleZ = tmp_src.SwizzleW = TGSI_SWIZZLE_X;

        /* maybe should re-arrange the syntax some day, but
         * in assembler/disassembler and what ir.c expects
         * is: MULADDv Rdst = Rsrc2 + Rsrc0 * Rscr1
         */
        instr = ir2_instr_create_alu(next_exec_cf(ctx), MULADDv, ~0);
        add_dst_reg(ctx, instr, &tmp_dst);
        get_immediate(ctx, &tmp_const, fui(0.5));
        add_src_reg(ctx, instr, &tmp_const);
        add_src_reg(ctx, instr, &inst->Src[0].Register);
        get_immediate(ctx, &tmp_const, fui(0.159155));
        add_src_reg(ctx, instr, &tmp_const);

        instr = ir2_instr_create_alu(next_exec_cf(ctx), FRACv, ~0);
        add_dst_reg(ctx, instr, &tmp_dst);
        add_src_reg(ctx, instr, &tmp_src);
        add_src_reg(ctx, instr, &tmp_src);

        instr = ir2_instr_create_alu(next_exec_cf(ctx), MULADDv, ~0);
        add_dst_reg(ctx, instr, &tmp_dst);
        get_immediate(ctx, &tmp_const, fui(-3.141593));
        add_src_reg(ctx, instr, &tmp_const);
        add_src_reg(ctx, instr, &tmp_src);
        get_immediate(ctx, &tmp_const, fui(6.283185));
        add_src_reg(ctx, instr, &tmp_const);

        instr = ir2_instr_create_alu(next_exec_cf(ctx), ~0, op);
        add_regs_dummy_vector(instr);
        add_dst_reg(ctx, instr, &inst->Dst[0].Register);
        add_src_reg(ctx, instr, &tmp_src);
}

/*
 * Main part of compiler/translator:
 */

static void
translate_instruction(struct fd2_compile_context *ctx,
                struct tgsi_full_instruction *inst)
{
        unsigned opc = inst->Instruction.Opcode;
        struct ir2_instruction *instr;
        static struct ir2_cf *cf;

        if (opc == TGSI_OPCODE_END)
                return;

        if (inst->Dst[0].Register.File == TGSI_FILE_OUTPUT) {
                unsigned num = inst->Dst[0].Register.Index;
                /* seems like we need to ensure that position vs param/pixel
                 * exports don't end up in the same EXEC clause..  easy way
                 * to do this is force a new EXEC clause on first appearance
                 * of an position or param/pixel export.
                 */
                if ((num == ctx->position) || (num == ctx->psize)) {
                        if (ctx->num_position > 0) {
                                ctx->cf = NULL;
                                ir2_cf_create_alloc(ctx->so->ir, SQ_POSITION,
                                                ctx->num_position - 1);
                                ctx->num_position = 0;
                        }
                } else {
                        if (ctx->num_param > 0) {
                                ctx->cf = NULL;
                                ir2_cf_create_alloc(ctx->so->ir, SQ_PARAMETER_PIXEL,
                                                ctx->num_param - 1);
                                ctx->num_param = 0;
                        }
                }
        }

        cf = next_exec_cf(ctx);

        /* TODO turn this into a table: */
        switch (opc) {
        case TGSI_OPCODE_MOV:
                instr = ir2_instr_create_alu(cf, MAXv, ~0);
                add_regs_vector_1(ctx, inst, instr);
                break;
        case TGSI_OPCODE_RCP:
                instr = ir2_instr_create_alu(cf, ~0, RECIP_IEEE);
                add_regs_scalar_1(ctx, inst, instr);
                break;
        case TGSI_OPCODE_RSQ:
                instr = ir2_instr_create_alu(cf, ~0, RECIPSQ_IEEE);
                add_regs_scalar_1(ctx, inst, instr);
                break;
        case TGSI_OPCODE_MUL:
                instr = ir2_instr_create_alu(cf, MULv, ~0);
                add_regs_vector_2(ctx, inst, instr);
                break;
        case TGSI_OPCODE_ADD:
                instr = ir2_instr_create_alu(cf, ADDv, ~0);
                add_regs_vector_2(ctx, inst, instr);
                break;
        case TGSI_OPCODE_DP3:
                instr = ir2_instr_create_alu(cf, DOT3v, ~0);
                add_regs_vector_2(ctx, inst, instr);
                break;
        case TGSI_OPCODE_DP4:
                instr = ir2_instr_create_alu(cf, DOT4v, ~0);
                add_regs_vector_2(ctx, inst, instr);
                break;
        case TGSI_OPCODE_MIN:
                instr = ir2_instr_create_alu(cf, MINv, ~0);
                add_regs_vector_2(ctx, inst, instr);
                break;
        case TGSI_OPCODE_MAX:
                instr = ir2_instr_create_alu(cf, MAXv, ~0);
                add_regs_vector_2(ctx, inst, instr);
                break;
        case TGSI_OPCODE_SLT:
        case TGSI_OPCODE_SGE:
                translate_sge_slt(ctx, inst, opc);
                break;
        case TGSI_OPCODE_MAD:
                instr = ir2_instr_create_alu(cf, MULADDv, ~0);
                add_regs_vector_3(ctx, inst, instr);
                break;
        case TGSI_OPCODE_LRP:
                translate_lrp(ctx, inst, opc);
                break;
        case TGSI_OPCODE_FRC:
                instr = ir2_instr_create_alu(cf, FRACv, ~0);
                add_regs_vector_1(ctx, inst, instr);
                break;
        case TGSI_OPCODE_FLR:
                instr = ir2_instr_create_alu(cf, FLOORv, ~0);
                add_regs_vector_1(ctx, inst, instr);
                break;
        case TGSI_OPCODE_EX2:
                instr = ir2_instr_create_alu(cf, ~0, EXP_IEEE);
                add_regs_scalar_1(ctx, inst, instr);
                break;
        case TGSI_OPCODE_POW:
                translate_pow(ctx, inst);
                break;
        case TGSI_OPCODE_ABS:
                instr = ir2_instr_create_alu(cf, MAXv, ~0);
                add_regs_vector_1(ctx, inst, instr);
                instr->regs[1]->flags |= IR2_REG_NEGATE; /* src0 */
                break;
        case TGSI_OPCODE_COS:
        case TGSI_OPCODE_SIN:
                translate_trig(ctx, inst, opc);
                break;
        case TGSI_OPCODE_TEX:
        case TGSI_OPCODE_TXP:
                translate_tex(ctx, inst, opc);
                break;
        case TGSI_OPCODE_CMP:
                instr = ir2_instr_create_alu(cf, CNDGTEv, ~0);
                add_regs_vector_3(ctx, inst, instr);
                // TODO this should be src0 if regs where in sane order..
                instr->regs[2]->flags ^= IR2_REG_NEGATE; /* src1 */
                break;
        case TGSI_OPCODE_IF:
                push_predicate(ctx, &inst->Src[0].Register);
                ctx->so->ir->pred = IR2_PRED_EQ;
                break;
        case TGSI_OPCODE_ELSE:
                ctx->so->ir->pred = IR2_PRED_NE;
                /* not sure if this is required in all cases, but blob compiler
                 * won't combine EQ and NE in same CF:
                 */
                ctx->cf = NULL;
                break;
        case TGSI_OPCODE_ENDIF:
                pop_predicate(ctx);
                break;
        case TGSI_OPCODE_F2I:
                instr = ir2_instr_create_alu(cf, TRUNCv, ~0);
                add_regs_vector_1(ctx, inst, instr);
                break;
        default:
                DBG("unknown TGSI opc: %s", tgsi_get_opcode_name(opc));
                tgsi_dump(ctx->so->tokens, 0);
                assert(0);
                break;
        }

        /* internal temporaries are only valid for the duration of a single
         * TGSI instruction:
         */
        ctx->num_internal_temps = 0;
}

static void
compile_instructions(struct fd2_compile_context *ctx)
{
        while (!tgsi_parse_end_of_tokens(&ctx->parser)) {
                tgsi_parse_token(&ctx->parser);

                switch (ctx->parser.FullToken.Token.Type) {
                case TGSI_TOKEN_TYPE_INSTRUCTION:
                        translate_instruction(ctx,
                                        &ctx->parser.FullToken.FullInstruction);
                        break;
                default:
                        break;
                }
        }

        ctx->cf->cf_type = EXEC_END;
}

int
fd2_compile_shader(struct fd_program_stateobj *prog,
                struct fd2_shader_stateobj *so)
{
        struct fd2_compile_context ctx;

        ir2_shader_destroy(so->ir);
        so->ir = ir2_shader_create();
        so->num_vfetch_instrs = so->num_tfetch_instrs = so->num_immediates = 0;

        if (compile_init(&ctx, prog, so) != TGSI_PARSE_OK)
                return -1;

        if (ctx.type == TGSI_PROCESSOR_VERTEX) {
                compile_vtx_fetch(&ctx);
        } else if (ctx.type == TGSI_PROCESSOR_FRAGMENT) {
                prog->num_exports = 0;
                memset(prog->export_linkage, 0xff,
                                sizeof(prog->export_linkage));
        }

        compile_instructions(&ctx);

        compile_free(&ctx);

        return 0;
}