diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs.cpp | 115 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs.h | 37 |
2 files changed, 152 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 76794fa414..edb02fabb2 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -177,6 +177,46 @@ type_size(const struct glsl_type *type) } } +/** + * Returns how many MRFs an FS opcode will write over. + * + * Note that this is not the 0 or 1 implied writes in an actual gen + * instruction -- the FS opcodes often generate MOVs in addition. + */ +int +fs_visitor::implied_mrf_writes(fs_inst *inst) +{ + if (inst->mlen == 0) + return 0; + + switch (inst->opcode) { + case FS_OPCODE_RCP: + case FS_OPCODE_RSQ: + case FS_OPCODE_SQRT: + case FS_OPCODE_EXP2: + case FS_OPCODE_LOG2: + case FS_OPCODE_SIN: + case FS_OPCODE_COS: + return 1; + case FS_OPCODE_POW: + return 2; + case FS_OPCODE_TEX: + case FS_OPCODE_TXB: + case FS_OPCODE_TXL: + return 1; + case FS_OPCODE_FB_WRITE: + return 2; + case FS_OPCODE_PULL_CONSTANT_LOAD: + case FS_OPCODE_UNSPILL: + return 1; + case FS_OPCODE_SPILL: + return 2; + default: + assert(!"not reached"); + return inst->mlen; + } +} + int fs_visitor::virtual_grf_alloc(int size) { @@ -3066,6 +3106,78 @@ fs_visitor::compute_to_mrf() return progress; } +/** + * Walks through basic blocks, locking for repeated MRF writes and + * removing the later ones. + */ +bool +fs_visitor::remove_duplicate_mrf_writes() +{ + fs_inst *last_mrf_move[16]; + bool progress = false; + + memset(last_mrf_move, 0, sizeof(last_mrf_move)); + + foreach_iter(exec_list_iterator, iter, this->instructions) { + fs_inst *inst = (fs_inst *)iter.get(); + + switch (inst->opcode) { + case BRW_OPCODE_DO: + case BRW_OPCODE_WHILE: + case BRW_OPCODE_IF: + case BRW_OPCODE_ELSE: + case BRW_OPCODE_ENDIF: + memset(last_mrf_move, 0, sizeof(last_mrf_move)); + continue; + default: + break; + } + + if (inst->opcode == BRW_OPCODE_MOV && + inst->dst.file == MRF) { + fs_inst *prev_inst = last_mrf_move[inst->dst.hw_reg]; + if (prev_inst && inst->equals(prev_inst)) { + inst->remove(); + progress = true; + continue; + } + } + + /* Clear out the last-write records for MRFs that were overwritten. */ + if (inst->dst.file == MRF) { + last_mrf_move[inst->dst.hw_reg] = NULL; + } + + if (inst->mlen > 0) { + /* Found a SEND instruction, which will include two of fewer + * implied MRF writes. We could do better here. + */ + for (int i = 0; i < implied_mrf_writes(inst); i++) { + last_mrf_move[inst->base_mrf + i] = NULL; + } + } + + /* Clear out any MRF move records whose sources got overwritten. */ + if (inst->dst.file == GRF) { + for (unsigned int i = 0; i < Elements(last_mrf_move); i++) { + if (last_mrf_move[i] && + last_mrf_move[i]->src[0].reg == inst->dst.reg) { + last_mrf_move[i] = NULL; + } + } + } + + if (inst->opcode == BRW_OPCODE_MOV && + inst->dst.file == MRF && + inst->src[0].file == GRF && + !inst->predicated) { + last_mrf_move[inst->dst.hw_reg] = inst; + } + } + + return progress; +} + bool fs_visitor::virtual_grf_interferes(int a, int b) { @@ -3438,6 +3550,9 @@ brw_wm_fs_emit(struct brw_context *brw, struct brw_wm_compile *c) bool progress; do { progress = false; + + progress = v.remove_duplicate_mrf_writes() || progress; + v.calculate_live_intervals(); progress = v.propagate_constants() || progress; progress = v.register_coalesce() || progress; diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h index f546fabd55..de7b15312a 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.h +++ b/src/mesa/drivers/dri/i965/brw_fs.h @@ -148,6 +148,21 @@ public: fs_reg(enum register_file file, int hw_reg, uint32_t type); fs_reg(class fs_visitor *v, const struct glsl_type *type); + bool equals(fs_reg *r) + { + return (file == r->file && + reg == r->reg && + reg_offset == r->reg_offset && + hw_reg == r->hw_reg && + type == r->type && + negate == r->negate && + abs == r->abs && + memcmp(&fixed_hw_reg, &r->fixed_hw_reg, + sizeof(fixed_hw_reg)) == 0 && + smear == r->smear && + imm.u == r->imm.u); + } + /** Register file: ARF, GRF, MRF, IMM. */ enum register_file file; /** virtual register number. 0 = fixed hw reg */ @@ -270,6 +285,26 @@ public: assert(src[2].reg_offset >= 0); } + bool equals(fs_inst *inst) + { + return (opcode == inst->opcode && + dst.equals(&inst->dst) && + src[0].equals(&inst->src[0]) && + src[1].equals(&inst->src[1]) && + src[2].equals(&inst->src[2]) && + saturate == inst->saturate && + predicated == inst->predicated && + conditional_mod == inst->conditional_mod && + mlen == inst->mlen && + base_mrf == inst->base_mrf && + sampler == inst->sampler && + target == inst->target && + eot == inst->eot && + header_present == inst->header_present && + shadow_compare == inst->shadow_compare && + offset == inst->offset); + } + int opcode; /* BRW_OPCODE_* or FS_OPCODE_* */ fs_reg dst; fs_reg src[3]; @@ -372,6 +407,7 @@ public: bool register_coalesce(); bool compute_to_mrf(); bool dead_code_eliminate(); + bool remove_duplicate_mrf_writes(); bool virtual_grf_interferes(int a, int b); void generate_code(); void generate_fb_write(fs_inst *inst); @@ -409,6 +445,7 @@ public: struct brw_reg interp_reg(int location, int channel); int setup_uniform_values(int loc, const glsl_type *type); void setup_builtin_uniform_values(ir_variable *ir); + int implied_mrf_writes(fs_inst *inst); struct brw_context *brw; const struct gl_fragment_program *fp; |