src/mesa/drivers/dri/i965/brw_fs.h

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27
  28 #pragma once
  29
  30 #include "brw_shader.h"
  31
  32 extern "C" {
  33
  34 #include <sys/types.h>
  35
  36 #include "main/macros.h"
  37 #include "main/shaderobj.h"
  38 #include "main/uniforms.h"
  39 #include "program/prog_parameter.h"
  40 #include "program/prog_print.h"
  41 #include "program/prog_optimize.h"
  42 #include "program/register_allocate.h"
  43 #include "program/sampler.h"
  44 #include "program/hash_table.h"
  45 #include "brw_context.h"
  46 #include "brw_eu.h"
  47 #include "brw_wm.h"
  48 #include "brw_shader.h"
  49 }
  50 #include "glsl/glsl_types.h"
  51 #include "glsl/ir.h"
  52
  53 class bblock_t;
  54 namespace {
  55    struct acp_entry;
  56 }
  57
  58 class fs_reg {
  59 public:
  60    DECLARE_RALLOC_CXX_OPERATORS(fs_reg)
  61
  62    void init();
  63
  64    fs_reg();
  65    fs_reg(float f);
  66    fs_reg(int32_t i);
  67    fs_reg(uint32_t u);
  68    fs_reg(struct brw_reg fixed_hw_reg);
  69    fs_reg(enum register_file file, int reg);
  70    fs_reg(enum register_file file, int reg, uint32_t type);
  71    fs_reg(class fs_visitor *v, const struct glsl_type *type);
  72
  73    bool equals(const fs_reg &r) const;
  74    bool is_zero() const;
  75    bool is_one() const;
  76    bool is_valid_3src() const;
  77
  78    /** Register file: ARF, GRF, MRF, IMM. */
  79    enum register_file file;
  80    /**
  81     * Register number.  For ARF/MRF, it's the hardware register.  For
  82     * GRF, it's a virtual register number until register allocation
  83     */
  84    int reg;
  85    /**
  86     * For virtual registers, this is a hardware register offset from
  87     * the start of the register block (for example, a constant index
  88     * in an array access).
  89     */
  90    int reg_offset;
  91    /** Register type.  BRW_REGISTER_TYPE_* */
  92    int type;
  93    bool negate;
  94    bool abs;
  95    bool sechalf;
  96    struct brw_reg fixed_hw_reg;
  97    int smear; /* -1, or a channel of the reg to smear to all channels. */
  98
  99    /** Value for file == IMM */
 100    union {
 101       int32_t i;
 102       uint32_t u;
 103       float f;
 104    } imm;
 105
 106    fs_reg *reladdr;
 107 };
 108
 109 static const fs_reg reg_undef;
 110 static const fs_reg reg_null_f(ARF, BRW_ARF_NULL, BRW_REGISTER_TYPE_F);
 111 static const fs_reg reg_null_d(ARF, BRW_ARF_NULL, BRW_REGISTER_TYPE_D);
 112
 113 class ip_record : public exec_node {
 114 public:
 115    DECLARE_RALLOC_CXX_OPERATORS(ip_record)
 116
 117    ip_record(int ip)
 118    {
 119       this->ip = ip;
 120    }
 121
 122    int ip;
 123 };
 124
 125 class fs_inst : public backend_instruction {
 126 public:
 127    DECLARE_RALLOC_CXX_OPERATORS(fs_inst)
 128
 129    void init();
 130
 131    fs_inst();
 132    fs_inst(enum opcode opcode);
 133    fs_inst(enum opcode opcode, fs_reg dst);
 134    fs_inst(enum opcode opcode, fs_reg dst, fs_reg src0);
 135    fs_inst(enum opcode opcode, fs_reg dst, fs_reg src0, fs_reg src1);
 136    fs_inst(enum opcode opcode, fs_reg dst,
 137            fs_reg src0, fs_reg src1,fs_reg src2);
 138
 139    bool equals(fs_inst *inst);
 140    bool overwrites_reg(const fs_reg &reg);
 141    bool is_send_from_grf();
 142    bool is_partial_write();
 143
 144    fs_reg dst;
 145    fs_reg src[3];
 146    bool saturate;
 147    int conditional_mod; /**< BRW_CONDITIONAL_* */
 148
 149    /* Chooses which flag subregister (f0.0 or f0.1) is used for conditional
 150     * mod and predication.
 151     */
 152    uint8_t flag_subreg;
 153
 154    int mlen; /**< SEND message length */
 155    int regs_written; /**< Number of vgrfs written by a SEND message, or 1 */
 156    int base_mrf; /**< First MRF in the SEND message, if mlen is nonzero. */
 157    uint32_t texture_offset; /**< Texture offset bitfield */
 158    int sampler;
 159    int target; /**< MRT target. */
 160    bool eot;
 161    bool header_present;
 162    bool shadow_compare;
 163    bool force_uncompressed;
 164    bool force_sechalf;
 165    bool force_writemask_all;
 166    uint32_t offset; /* spill/unspill offset */
 167
 168    /** @{
 169     * Annotation for the generated IR.  One of the two can be set.
 170     */
 171    const void *ir;
 172    const char *annotation;
 173    /** @} */
 174 };
 175
 176 /**
 177  * The fragment shader front-end.
 178  *
 179  * Translates either GLSL IR or Mesa IR (for ARB_fragment_program) into FS IR.
 180  */
 181 class fs_visitor : public backend_visitor
 182 {
 183 public:
 184
 185    fs_visitor(struct brw_context *brw,
 186               struct brw_wm_compile *c,
 187               struct gl_shader_program *shader_prog,
 188               struct gl_fragment_program *fp,
 189               unsigned dispatch_width);
 190    ~fs_visitor();
 191
 192    fs_reg *variable_storage(ir_variable *var);
 193    int virtual_grf_alloc(int size);
 194    void import_uniforms(fs_visitor *v);
 195
 196    void visit(ir_variable *ir);
 197    void visit(ir_assignment *ir);
 198    void visit(ir_dereference_variable *ir);
 199    void visit(ir_dereference_record *ir);
 200    void visit(ir_dereference_array *ir);
 201    void visit(ir_expression *ir);
 202    void visit(ir_texture *ir);
 203    void visit(ir_if *ir);
 204    void visit(ir_constant *ir);
 205    void visit(ir_swizzle *ir);
 206    void visit(ir_return *ir);
 207    void visit(ir_loop *ir);
 208    void visit(ir_loop_jump *ir);
 209    void visit(ir_discard *ir);
 210    void visit(ir_call *ir);
 211    void visit(ir_function *ir);
 212    void visit(ir_function_signature *ir);
 213    void visit(ir_emit_vertex *);
 214    void visit(ir_end_primitive *);
 215
 216    void swizzle_result(ir_texture *ir, fs_reg orig_val, int sampler);
 217
 218    bool can_do_source_mods(fs_inst *inst);
 219
 220    fs_inst *emit(fs_inst inst);
 221    fs_inst *emit(fs_inst *inst);
 222    void emit(exec_list list);
 223
 224    fs_inst *emit(enum opcode opcode);
 225    fs_inst *emit(enum opcode opcode, fs_reg dst);
 226    fs_inst *emit(enum opcode opcode, fs_reg dst, fs_reg src0);
 227    fs_inst *emit(enum opcode opcode, fs_reg dst, fs_reg src0, fs_reg src1);
 228    fs_inst *emit(enum opcode opcode, fs_reg dst,
 229                  fs_reg src0, fs_reg src1, fs_reg src2);
 230
 231    fs_inst *MOV(fs_reg dst, fs_reg src);
 232    fs_inst *NOT(fs_reg dst, fs_reg src);
 233    fs_inst *RNDD(fs_reg dst, fs_reg src);
 234    fs_inst *RNDE(fs_reg dst, fs_reg src);
 235    fs_inst *RNDZ(fs_reg dst, fs_reg src);
 236    fs_inst *FRC(fs_reg dst, fs_reg src);
 237    fs_inst *ADD(fs_reg dst, fs_reg src0, fs_reg src1);
 238    fs_inst *MUL(fs_reg dst, fs_reg src0, fs_reg src1);
 239    fs_inst *MACH(fs_reg dst, fs_reg src0, fs_reg src1);
 240    fs_inst *MAC(fs_reg dst, fs_reg src0, fs_reg src1);
 241    fs_inst *SHL(fs_reg dst, fs_reg src0, fs_reg src1);
 242    fs_inst *SHR(fs_reg dst, fs_reg src0, fs_reg src1);
 243    fs_inst *ASR(fs_reg dst, fs_reg src0, fs_reg src1);
 244    fs_inst *AND(fs_reg dst, fs_reg src0, fs_reg src1);
 245    fs_inst *OR(fs_reg dst, fs_reg src0, fs_reg src1);
 246    fs_inst *XOR(fs_reg dst, fs_reg src0, fs_reg src1);
 247    fs_inst *IF(uint32_t predicate);
 248    fs_inst *IF(fs_reg src0, fs_reg src1, uint32_t condition);
 249    fs_inst *CMP(fs_reg dst, fs_reg src0, fs_reg src1,
 250                 uint32_t condition);
 251    fs_inst *LRP(fs_reg dst, fs_reg a, fs_reg y, fs_reg x);
 252    fs_inst *DEP_RESOLVE_MOV(int grf);
 253    fs_inst *BFREV(fs_reg dst, fs_reg value);
 254    fs_inst *BFE(fs_reg dst, fs_reg bits, fs_reg offset, fs_reg value);
 255    fs_inst *BFI1(fs_reg dst, fs_reg bits, fs_reg offset);
 256    fs_inst *BFI2(fs_reg dst, fs_reg bfi1_dst, fs_reg insert, fs_reg base);
 257    fs_inst *FBH(fs_reg dst, fs_reg value);
 258    fs_inst *FBL(fs_reg dst, fs_reg value);
 259    fs_inst *CBIT(fs_reg dst, fs_reg value);
 260    fs_inst *MAD(fs_reg dst, fs_reg c, fs_reg b, fs_reg a);
 261
 262    int type_size(const struct glsl_type *type);
 263    fs_inst *get_instruction_generating_reg(fs_inst *start,
 264                                            fs_inst *end,
 265                                            fs_reg reg);
 266
 267    exec_list VARYING_PULL_CONSTANT_LOAD(fs_reg dst, fs_reg surf_index,
 268                                         fs_reg varying_offset,
 269                                         uint32_t const_offset);
 270
 271    bool run();
 272    void setup_payload_gen4();
 273    void setup_payload_gen6();
 274    void assign_curb_setup();
 275    void calculate_urb_setup();
 276    void assign_urb_setup();
 277    bool assign_regs();
 278    void assign_regs_trivial();
 279    void setup_payload_interference(struct ra_graph *g, int payload_reg_count,
 280                                    int first_payload_node);
 281    void setup_mrf_hack_interference(struct ra_graph *g,
 282                                     int first_mrf_hack_node);
 283    int choose_spill_reg(struct ra_graph *g);
 284    void spill_reg(int spill_reg);
 285    void split_virtual_grfs();
 286    void compact_virtual_grfs();
 287    void move_uniform_array_access_to_pull_constants();
 288    void setup_pull_constants();
 289    void calculate_live_intervals();
 290    bool opt_algebraic();
 291    bool opt_cse();
 292    bool opt_cse_local(bblock_t *block, exec_list *aeb);
 293    bool opt_copy_propagate();
 294    bool try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry);
 295    bool try_constant_propagate(fs_inst *inst, acp_entry *entry);
 296    bool opt_copy_propagate_local(void *mem_ctx, bblock_t *block,
 297                                  exec_list *acp);
 298    bool register_coalesce();
 299    bool register_coalesce_2();
 300    bool compute_to_mrf();
 301    bool dead_code_eliminate();
 302    bool dead_code_eliminate_local();
 303    bool remove_dead_constants();
 304    bool remove_duplicate_mrf_writes();
 305    bool virtual_grf_interferes(int a, int b);
 306    void schedule_instructions(bool post_reg_alloc);
 307    void insert_gen4_send_dependency_workarounds();
 308    void insert_gen4_pre_send_dependency_workarounds(fs_inst *inst);
 309    void insert_gen4_post_send_dependency_workarounds(fs_inst *inst);
 310    void fail(const char *msg, ...);
 311    void lower_uniform_pull_constant_loads();
 312
 313    void push_force_uncompressed();
 314    void pop_force_uncompressed();
 315    void push_force_sechalf();
 316    void pop_force_sechalf();
 317
 318    void emit_dummy_fs();
 319    fs_reg *emit_fragcoord_interpolation(ir_variable *ir);
 320    fs_inst *emit_linterp(const fs_reg &attr, const fs_reg &interp,
 321                          glsl_interp_qualifier interpolation_mode,
 322                          bool is_centroid);
 323    fs_reg *emit_frontfacing_interpolation(ir_variable *ir);
 324    fs_reg *emit_general_interpolation(ir_variable *ir);
 325    void emit_interpolation_setup_gen4();
 326    void emit_interpolation_setup_gen6();
 327    fs_reg rescale_texcoord(ir_texture *ir, fs_reg coordinate,
 328                            bool is_rect, int sampler, int texunit);
 329    fs_inst *emit_texture_gen4(ir_texture *ir, fs_reg dst, fs_reg coordinate,
 330                               fs_reg shadow_comp, fs_reg lod, fs_reg lod2);
 331    fs_inst *emit_texture_gen5(ir_texture *ir, fs_reg dst, fs_reg coordinate,
 332                               fs_reg shadow_comp, fs_reg lod, fs_reg lod2,
 333                               fs_reg sample_index);
 334    fs_inst *emit_texture_gen7(ir_texture *ir, fs_reg dst, fs_reg coordinate,
 335                               fs_reg shadow_comp, fs_reg lod, fs_reg lod2,
 336                               fs_reg sample_index);
 337    fs_reg fix_math_operand(fs_reg src);
 338    fs_inst *emit_math(enum opcode op, fs_reg dst, fs_reg src0);
 339    fs_inst *emit_math(enum opcode op, fs_reg dst, fs_reg src0, fs_reg src1);
 340    void emit_lrp(fs_reg dst, fs_reg x, fs_reg y, fs_reg a);
 341    void emit_minmax(uint32_t conditionalmod, fs_reg dst,
 342                     fs_reg src0, fs_reg src1);
 343    bool try_emit_saturate(ir_expression *ir);
 344    bool try_emit_mad(ir_expression *ir, int mul_arg);
 345    void try_replace_with_sel();
 346    void emit_bool_to_cond_code(ir_rvalue *condition);
 347    void emit_if_gen6(ir_if *ir);
 348    void emit_unspill(fs_inst *inst, fs_reg reg, uint32_t spill_offset);
 349
 350    void emit_fragment_program_code();
 351    void setup_fp_regs();
 352    fs_reg get_fp_src_reg(const prog_src_register *src);
 353    fs_reg get_fp_dst_reg(const prog_dst_register *dst);
 354    void emit_fp_alu1(enum opcode opcode,
 355                      const struct prog_instruction *fpi,
 356                      fs_reg dst, fs_reg src);
 357    void emit_fp_alu2(enum opcode opcode,
 358                      const struct prog_instruction *fpi,
 359                      fs_reg dst, fs_reg src0, fs_reg src1);
 360    void emit_fp_scalar_write(const struct prog_instruction *fpi,
 361                              fs_reg dst, fs_reg src);
 362    void emit_fp_scalar_math(enum opcode opcode,
 363                             const struct prog_instruction *fpi,
 364                             fs_reg dst, fs_reg src);
 365
 366    void emit_fp_minmax(const struct prog_instruction *fpi,
 367                        fs_reg dst, fs_reg src0, fs_reg src1);
 368
 369    void emit_fp_sop(uint32_t conditional_mod,
 370                     const struct prog_instruction *fpi,
 371                     fs_reg dst, fs_reg src0, fs_reg src1, fs_reg one);
 372
 373    void emit_color_write(int target, int index, int first_color_mrf);
 374    void emit_fb_writes();
 375
 376    void emit_shader_time_begin();
 377    void emit_shader_time_end();
 378    void emit_shader_time_write(enum shader_time_shader_type type,
 379                                fs_reg value);
 380
 381    bool try_rewrite_rhs_to_dst(ir_assignment *ir,
 382                                fs_reg dst,
 383                                fs_reg src,
 384                                fs_inst *pre_rhs_inst,
 385                                fs_inst *last_rhs_inst);
 386    void emit_assignment_writes(fs_reg &l, fs_reg &r,
 387                                const glsl_type *type, bool predicated);
 388    void resolve_ud_negate(fs_reg *reg);
 389    void resolve_bool_comparison(ir_rvalue *rvalue, fs_reg *reg);
 390
 391    fs_reg get_timestamp();
 392
 393    struct brw_reg interp_reg(int location, int channel);
 394    void setup_uniform_values(ir_variable *ir);
 395    void setup_builtin_uniform_values(ir_variable *ir);
 396    int implied_mrf_writes(fs_inst *inst);
 397
 398    void dump_instruction(backend_instruction *inst);
 399
 400    struct gl_fragment_program *fp;
 401    struct brw_wm_compile *c;
 402    unsigned int sanity_param_count;
 403
 404    int param_size[MAX_UNIFORMS * 4];
 405
 406    int *virtual_grf_sizes;
 407    int virtual_grf_count;
 408    int virtual_grf_array_size;
 409    int *virtual_grf_start;
 410    int *virtual_grf_end;
 411    bool live_intervals_valid;
 412
 413    /* This is the map from UNIFORM hw_reg + reg_offset as generated by
 414     * the visitor to the packed uniform number after
 415     * remove_dead_constants() that represents the actual uploaded
 416     * uniform index.
 417     */
 418    int *params_remap;
 419    int nr_params_remap;
 420
 421    struct hash_table *variable_ht;
 422    fs_reg frag_depth;
 423    fs_reg outputs[BRW_MAX_DRAW_BUFFERS];
 424    unsigned output_components[BRW_MAX_DRAW_BUFFERS];
 425    fs_reg dual_src_output;
 426    int first_non_payload_grf;
 427    /** Either BRW_MAX_GRF or GEN7_MRF_HACK_START */
 428    int max_grf;
 429
 430    fs_reg *fp_temp_regs;
 431    fs_reg *fp_input_regs;
 432
 433    /** @{ debug annotation info */
 434    const char *current_annotation;
 435    const void *base_ir;
 436    /** @} */
 437
 438    bool failed;
 439    char *fail_msg;
 440
 441    /* Result of last visit() method. */
 442    fs_reg result;
 443
 444    fs_reg pixel_x;
 445    fs_reg pixel_y;
 446    fs_reg wpos_w;
 447    fs_reg pixel_w;
 448    fs_reg delta_x[BRW_WM_BARYCENTRIC_INTERP_MODE_COUNT];
 449    fs_reg delta_y[BRW_WM_BARYCENTRIC_INTERP_MODE_COUNT];
 450    fs_reg shader_start_time;
 451
 452    int grf_used;
 453
 454    const unsigned dispatch_width; /**< 8 or 16 */
 455
 456    int force_uncompressed_stack;
 457    int force_sechalf_stack;
 458 };
 459
 460 /**
 461  * The fragment shader code generator.
 462  *
 463  * Translates FS IR to actual i965 assembly code.
 464  */
 465 class fs_generator
 466 {
 467 public:
 468    fs_generator(struct brw_context *brw,
 469                 struct brw_wm_compile *c,
 470                 struct gl_shader_program *prog,
 471                 struct gl_fragment_program *fp,
 472                 bool dual_source_output);
 473    ~fs_generator();
 474
 475    const unsigned *generate_assembly(exec_list *simd8_instructions,
 476                                      exec_list *simd16_instructions,
 477                                      unsigned *assembly_size);
 478
 479 private:
 480    void generate_code(exec_list *instructions);
 481    void generate_fb_write(fs_inst *inst);
 482    void generate_pixel_xy(struct brw_reg dst, bool is_x);
 483    void generate_linterp(fs_inst *inst, struct brw_reg dst,
 484                          struct brw_reg *src);
 485    void generate_tex(fs_inst *inst, struct brw_reg dst, struct brw_reg src);
 486    void generate_math1_gen7(fs_inst *inst,
 487                             struct brw_reg dst,
 488                             struct brw_reg src);
 489    void generate_math2_gen7(fs_inst *inst,
 490                             struct brw_reg dst,
 491                             struct brw_reg src0,
 492                             struct brw_reg src1);
 493    void generate_math1_gen6(fs_inst *inst,
 494                             struct brw_reg dst,
 495                             struct brw_reg src);
 496    void generate_math2_gen6(fs_inst *inst,
 497                             struct brw_reg dst,
 498                             struct brw_reg src0,
 499                             struct brw_reg src1);
 500    void generate_math_gen4(fs_inst *inst,
 501                            struct brw_reg dst,
 502                            struct brw_reg src);
 503    void generate_math_g45(fs_inst *inst,
 504                           struct brw_reg dst,
 505                           struct brw_reg src);
 506    void generate_ddx(fs_inst *inst, struct brw_reg dst, struct brw_reg src);
 507    void generate_ddy(fs_inst *inst, struct brw_reg dst, struct brw_reg src,
 508                      bool negate_value);
 509    void generate_spill(fs_inst *inst, struct brw_reg src);
 510    void generate_unspill(fs_inst *inst, struct brw_reg dst);
 511    void generate_uniform_pull_constant_load(fs_inst *inst, struct brw_reg dst,
 512                                             struct brw_reg index,
 513                                             struct brw_reg offset);
 514    void generate_uniform_pull_constant_load_gen7(fs_inst *inst,
 515                                                  struct brw_reg dst,
 516                                                  struct brw_reg surf_index,
 517                                                  struct brw_reg offset);
 518    void generate_varying_pull_constant_load(fs_inst *inst, struct brw_reg dst,
 519                                             struct brw_reg index,
 520                                             struct brw_reg offset);
 521    void generate_varying_pull_constant_load_gen7(fs_inst *inst,
 522                                                  struct brw_reg dst,
 523                                                  struct brw_reg index,
 524                                                  struct brw_reg offset);
 525    void generate_mov_dispatch_to_flags(fs_inst *inst);
 526    void generate_set_simd4x2_offset(fs_inst *inst,
 527                                     struct brw_reg dst,
 528                                     struct brw_reg offset);
 529    void generate_discard_jump(fs_inst *inst);
 530
 531    void generate_pack_half_2x16_split(fs_inst *inst,
 532                                       struct brw_reg dst,
 533                                       struct brw_reg x,
 534                                       struct brw_reg y);
 535    void generate_unpack_half_2x16_split(fs_inst *inst,
 536                                         struct brw_reg dst,
 537                                         struct brw_reg src);
 538
 539    void generate_shader_time_add(fs_inst *inst,
 540                                  struct brw_reg payload,
 541                                  struct brw_reg offset,
 542                                  struct brw_reg value);
 543
 544    void mark_surface_used(unsigned surf_index);
 545
 546    void patch_discard_jumps_to_fb_writes();
 547
 548    struct brw_context *brw;
 549    struct gl_context *ctx;
 550
 551    struct brw_compile *p;
 552    struct brw_wm_compile *c;
 553
 554    struct gl_shader_program *prog;
 555    struct gl_shader *shader;
 556    const struct gl_fragment_program *fp;
 557
 558    unsigned dispatch_width; /**< 8 or 16 */
 559
 560    exec_list discard_halt_patches;
 561    bool dual_source_output;
 562    void *mem_ctx;
 563 };
 564
 565 bool brw_do_channel_expressions(struct exec_list *instructions);
 566 bool brw_do_vector_splitting(struct exec_list *instructions);
 567 bool brw_fs_precompile(struct gl_context *ctx, struct gl_shader_program *prog);