From 3c8dc48ad1d4061a2a1d0b9ea3126350b98274f0 Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Wed, 6 Mar 2013 10:48:55 -0800 Subject: [PATCH] i965/vec4: Add basic common subexpression elimination. [mattst88]: Modified to perform CSE on instructions with the same writemask. Offered no improvement before. total instructions in shared programs: 1995633 -> 1995185 (-0.02%) instructions in affected programs: 14410 -> 13962 (-3.11%) Reviewed-by: Matt Turner Signed-off-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/Makefile.sources | 1 + src/mesa/drivers/dri/i965/brw_vec4.cpp | 1 + src/mesa/drivers/dri/i965/brw_vec4.h | 2 + src/mesa/drivers/dri/i965/brw_vec4_cse.cpp | 232 +++++++++++++++++++++ 4 files changed, 236 insertions(+) create mode 100644 src/mesa/drivers/dri/i965/brw_vec4_cse.cpp diff --git a/src/mesa/drivers/dri/i965/Makefile.sources b/src/mesa/drivers/dri/i965/Makefile.sources index eb5ba60a28a..e2356795e3a 100644 --- a/src/mesa/drivers/dri/i965/Makefile.sources +++ b/src/mesa/drivers/dri/i965/Makefile.sources @@ -102,6 +102,7 @@ i965_FILES = \ brw_util.c \ brw_vec4.cpp \ brw_vec4_copy_propagation.cpp \ + brw_vec4_cse.cpp \ brw_vec4_generator.cpp \ brw_vec4_gs.c \ brw_vec4_gs_visitor.cpp \ diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp index 5ba7d9cb741..b60cd1fd9d5 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp @@ -1675,6 +1675,7 @@ vec4_visitor::run() progress = dead_control_flow_eliminate(this) || progress; progress = opt_copy_propagation() || progress; progress = opt_algebraic() || progress; + progress = opt_cse() || progress; progress = opt_register_coalesce() || progress; } while (progress); diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h index 9d76beaf2af..87247ea1ec2 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4.h +++ b/src/mesa/drivers/dri/i965/brw_vec4.h @@ -384,6 +384,8 @@ public: bool dead_code_eliminate(); bool virtual_grf_interferes(int a, int b); bool opt_copy_propagation(); + bool opt_cse_local(bblock_t *, exec_list *); + bool opt_cse(); bool opt_algebraic(); bool opt_register_coalesce(); void opt_set_dependency_control(); diff --git a/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp new file mode 100644 index 00000000000..11e911f2b64 --- /dev/null +++ b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp @@ -0,0 +1,232 @@ +/* + * Copyright © 2012, 2013, 2014 Intel Corporation + * + * 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. + */ + +#include "brw_vec4.h" +#include "brw_cfg.h" + +using namespace brw; + +/** @file brw_vec4_cse.cpp + * + * Support for local common subexpression elimination. + * + * See Muchnick's Advanced Compiler Design and Implementation, section + * 13.1 (p378). + */ + +namespace { +struct aeb_entry : public exec_node { + /** The instruction that generates the expression value. */ + vec4_instruction *generator; + + /** The temporary where the value is stored. */ + src_reg tmp; +}; +} + +static bool +is_expression(const vec4_instruction *const inst) +{ + switch (inst->opcode) { + case BRW_OPCODE_SEL: + case BRW_OPCODE_NOT: + case BRW_OPCODE_AND: + case BRW_OPCODE_OR: + case BRW_OPCODE_XOR: + case BRW_OPCODE_SHR: + case BRW_OPCODE_SHL: + case BRW_OPCODE_ASR: + case BRW_OPCODE_ADD: + case BRW_OPCODE_MUL: + case BRW_OPCODE_FRC: + case BRW_OPCODE_RNDU: + case BRW_OPCODE_RNDD: + case BRW_OPCODE_RNDE: + case BRW_OPCODE_RNDZ: + case BRW_OPCODE_LINE: + case BRW_OPCODE_PLN: + case BRW_OPCODE_MAD: + case BRW_OPCODE_LRP: + return true; + case SHADER_OPCODE_RCP: + case SHADER_OPCODE_RSQ: + case SHADER_OPCODE_SQRT: + case SHADER_OPCODE_EXP2: + case SHADER_OPCODE_LOG2: + case SHADER_OPCODE_POW: + case SHADER_OPCODE_INT_QUOTIENT: + case SHADER_OPCODE_INT_REMAINDER: + case SHADER_OPCODE_SIN: + case SHADER_OPCODE_COS: + return inst->mlen == 0; + default: + return false; + } +} + +static bool +is_expression_commutative(enum opcode op) +{ + switch (op) { + case BRW_OPCODE_AND: + case BRW_OPCODE_OR: + case BRW_OPCODE_XOR: + case BRW_OPCODE_ADD: + case BRW_OPCODE_MUL: + return true; + default: + return false; + } +} + +static bool +operands_match(enum opcode op, src_reg *xs, src_reg *ys) +{ + if (!is_expression_commutative(op)) { + return xs[0].equals(ys[0]) && xs[1].equals(ys[1]) && xs[2].equals(ys[2]); + } else { + return (xs[0].equals(ys[0]) && xs[1].equals(ys[1])) || + (xs[1].equals(ys[0]) && xs[0].equals(ys[1])); + } +} + +static bool +instructions_match(vec4_instruction *a, vec4_instruction *b) +{ + return a->opcode == b->opcode && + a->saturate == b->saturate && + a->conditional_mod == b->conditional_mod && + a->dst.type == b->dst.type && + a->dst.writemask == b->dst.writemask && + operands_match(a->opcode, a->src, b->src); +} + +bool +vec4_visitor::opt_cse_local(bblock_t *block, exec_list *aeb) +{ + bool progress = false; + + void *cse_ctx = ralloc_context(NULL); + + for (vec4_instruction *inst = (vec4_instruction *)block->start; + inst != block->end->next; + inst = (vec4_instruction *) inst->next) { + + /* Skip some cases. */ + if (is_expression(inst) && !inst->predicate && inst->mlen == 0 && + !inst->conditional_mod) + { + bool found = false; + + foreach_in_list_use_after(aeb_entry, entry, aeb) { + /* Match current instruction's expression against those in AEB. */ + if (instructions_match(inst, entry->generator)) { + found = true; + progress = true; + break; + } + } + + if (!found) { + /* Our first sighting of this expression. Create an entry. */ + aeb_entry *entry = ralloc(cse_ctx, aeb_entry); + entry->tmp = src_reg(); /* file will be BAD_FILE */ + entry->generator = inst; + aeb->push_tail(entry); + } else { + /* This is at least our second sighting of this expression. + * If we don't have a temporary already, make one. + */ + bool no_existing_temp = entry->tmp.file == BAD_FILE; + if (no_existing_temp) { + entry->tmp = src_reg(this, glsl_type::float_type); + entry->tmp.type = inst->dst.type; + entry->tmp.swizzle = BRW_SWIZZLE_XYZW; + + vec4_instruction *copy = MOV(entry->generator->dst, entry->tmp); + entry->generator->insert_after(copy); + entry->generator->dst = dst_reg(entry->tmp); + } + + /* dest <- temp */ + assert(inst->dst.type == entry->tmp.type); + vec4_instruction *copy = MOV(inst->dst, entry->tmp); + copy->force_writemask_all = inst->force_writemask_all; + inst->insert_before(copy); + + /* Set our iterator so that next time through the loop inst->next + * will get the instruction in the basic block after the one we've + * removed. + */ + vec4_instruction *prev = (vec4_instruction *)inst->prev; + + inst->remove(); + + /* Appending an instruction may have changed our bblock end. */ + if (inst == block->end) { + block->end = prev; + } + + inst = prev; + } + } + + foreach_in_list_safe(aeb_entry, entry, aeb) { + for (int i = 0; i < 3; i++) { + /* Kill all AEB entries that use the destination we just + * overwrote. + */ + if (inst->dst.file == entry->generator->src[i].file && + inst->dst.reg == entry->generator->src[i].reg) { + entry->remove(); + ralloc_free(entry); + break; + } + } + } + } + + ralloc_free(cse_ctx); + + if (progress) + invalidate_live_intervals(); + + return progress; +} + +bool +vec4_visitor::opt_cse() +{ + bool progress = false; + + cfg_t cfg(&instructions); + + for (int b = 0; b < cfg.num_blocks; b++) { + bblock_t *block = cfg.blocks[b]; + exec_list aeb; + + progress = opt_cse_local(block, &aeb) || progress; + } + + return progress; +} -- 2.30.2