| 0,0 → 1,479 |
|---|
| /* |
| * Copyright © 2012 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. |
| */ |
| |
| /** @file brw_fs_copy_propagation.cpp |
| * |
| * Support for global copy propagation in two passes: A local pass that does |
| * intra-block copy (and constant) propagation, and a global pass that uses |
| * dataflow analysis on the copies available at the end of each block to re-do |
| * local copy propagation with more copies available. |
| * |
| * See Muchnik's Advanced Compiler Design and Implementation, section |
| * 12.5 (p356). |
| */ |
| |
| #define ACP_HASH_SIZE 16 |
| |
| #include "main/bitset.h" |
| #include "brw_fs.h" |
| #include "brw_cfg.h" |
| |
| namespace { /* avoid conflict with opt_copy_propagation_elements */ |
| struct acp_entry : public exec_node { |
| fs_reg dst; |
| fs_reg src; |
| }; |
| |
| struct block_data { |
| /** |
| * Which entries in the fs_copy_prop_dataflow acp table are live at the |
| * start of this block. This is the useful output of the analysis, since |
| * it lets us plug those into the local copy propagation on the second |
| * pass. |
| */ |
| BITSET_WORD *livein; |
| |
| /** |
| * Which entries in the fs_copy_prop_dataflow acp table are live at the end |
| * of this block. This is done in initial setup from the per-block acps |
| * returned by the first local copy prop pass. |
| */ |
| BITSET_WORD *liveout; |
| |
| /** |
| * Which entries in the fs_copy_prop_dataflow acp table are killed over the |
| * course of this block. |
| */ |
| BITSET_WORD *kill; |
| }; |
| |
| class fs_copy_prop_dataflow |
| { |
| public: |
| fs_copy_prop_dataflow(void *mem_ctx, cfg_t *cfg, |
| exec_list *out_acp[ACP_HASH_SIZE]); |
| |
| void setup_kills(); |
| void run(); |
| |
| void *mem_ctx; |
| cfg_t *cfg; |
| |
| acp_entry **acp; |
| int num_acp; |
| int bitset_words; |
| |
| struct block_data *bd; |
| }; |
| } /* anonymous namespace */ |
| |
| fs_copy_prop_dataflow::fs_copy_prop_dataflow(void *mem_ctx, cfg_t *cfg, |
| exec_list *out_acp[ACP_HASH_SIZE]) |
| : mem_ctx(mem_ctx), cfg(cfg) |
| { |
| bd = rzalloc_array(mem_ctx, struct block_data, cfg->num_blocks); |
| |
| num_acp = 0; |
| for (int b = 0; b < cfg->num_blocks; b++) { |
| for (int i = 0; i < ACP_HASH_SIZE; i++) { |
| foreach_list(entry_node, &out_acp[b][i]) { |
| num_acp++; |
| } |
| } |
| } |
| |
| acp = rzalloc_array(mem_ctx, struct acp_entry *, num_acp); |
| |
| bitset_words = BITSET_WORDS(num_acp); |
| |
| int next_acp = 0; |
| for (int b = 0; b < cfg->num_blocks; b++) { |
| bd[b].livein = rzalloc_array(bd, BITSET_WORD, bitset_words); |
| bd[b].liveout = rzalloc_array(bd, BITSET_WORD, bitset_words); |
| bd[b].kill = rzalloc_array(bd, BITSET_WORD, bitset_words); |
| |
| for (int i = 0; i < ACP_HASH_SIZE; i++) { |
| foreach_list(entry_node, &out_acp[b][i]) { |
| acp_entry *entry = (acp_entry *)entry_node; |
| |
| acp[next_acp] = entry; |
| BITSET_SET(bd[b].liveout, next_acp); |
| next_acp++; |
| } |
| } |
| } |
| |
| assert(next_acp == num_acp); |
| |
| setup_kills(); |
| run(); |
| } |
| |
| /** |
| * Walk the set of instructions in the block, marking which entries in the acp |
| * are killed by the block. |
| */ |
| void |
| fs_copy_prop_dataflow::setup_kills() |
| { |
| for (int b = 0; b < cfg->num_blocks; b++) { |
| bblock_t *block = cfg->blocks[b]; |
| |
| for (fs_inst *inst = (fs_inst *)block->start; |
| inst != block->end->next; |
| inst = (fs_inst *)inst->next) { |
| if (inst->dst.file != GRF) |
| continue; |
| |
| for (int i = 0; i < num_acp; i++) { |
| if (inst->overwrites_reg(acp[i]->dst) || |
| inst->overwrites_reg(acp[i]->src)) { |
| BITSET_SET(bd[b].kill, i); |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * Walk the set of instructions in the block, marking which entries in the acp |
| * are killed by the block. |
| */ |
| void |
| fs_copy_prop_dataflow::run() |
| { |
| bool cont = true; |
| |
| while (cont) { |
| cont = false; |
| |
| for (int b = 0; b < cfg->num_blocks; b++) { |
| for (int i = 0; i < bitset_words; i++) { |
| BITSET_WORD new_liveout = (bd[b].livein[i] & |
| ~bd[b].kill[i] & |
| ~bd[b].liveout[i]); |
| if (new_liveout) { |
| bd[b].liveout[i] |= new_liveout; |
| cont = true; |
| } |
| |
| /* Update livein: if it's live at the end of all parents, it's |
| * live at our start. |
| */ |
| BITSET_WORD new_livein = ~bd[b].livein[i]; |
| foreach_list(block_node, &cfg->blocks[b]->parents) { |
| bblock_link *link = (bblock_link *)block_node; |
| bblock_t *block = link->block; |
| new_livein &= bd[block->block_num].liveout[i]; |
| if (!new_livein) |
| break; |
| } |
| if (new_livein) { |
| bd[b].livein[i] |= new_livein; |
| cont = true; |
| } |
| } |
| } |
| } |
| } |
| |
| bool |
| fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry) |
| { |
| if (entry->src.file == IMM) |
| return false; |
| |
| if (inst->src[arg].file != entry->dst.file || |
| inst->src[arg].reg != entry->dst.reg || |
| inst->src[arg].reg_offset != entry->dst.reg_offset) { |
| return false; |
| } |
| |
| /* See resolve_ud_negate() and comment in brw_fs_emit.cpp. */ |
| if (inst->conditional_mod && |
| inst->src[arg].type == BRW_REGISTER_TYPE_UD && |
| entry->src.negate) |
| return false; |
| |
| bool has_source_modifiers = entry->src.abs || entry->src.negate; |
| |
| if ((has_source_modifiers || entry->src.file == UNIFORM || |
| entry->src.smear != -1) && !can_do_source_mods(inst)) |
| return false; |
| |
| if (has_source_modifiers && entry->dst.type != inst->src[arg].type) |
| return false; |
| |
| inst->src[arg].file = entry->src.file; |
| inst->src[arg].reg = entry->src.reg; |
| inst->src[arg].reg_offset = entry->src.reg_offset; |
| if (entry->src.smear != -1) |
| inst->src[arg].smear = entry->src.smear; |
| |
| if (!inst->src[arg].abs) { |
| inst->src[arg].abs = entry->src.abs; |
| inst->src[arg].negate ^= entry->src.negate; |
| } |
| |
| return true; |
| } |
| |
| |
| bool |
| fs_visitor::try_constant_propagate(fs_inst *inst, acp_entry *entry) |
| { |
| bool progress = false; |
| |
| if (entry->src.file != IMM) |
| return false; |
| |
| for (int i = 2; i >= 0; i--) { |
| if (inst->src[i].file != entry->dst.file || |
| inst->src[i].reg != entry->dst.reg || |
| inst->src[i].reg_offset != entry->dst.reg_offset) |
| continue; |
| |
| /* Don't bother with cases that should have been taken care of by the |
| * GLSL compiler's constant folding pass. |
| */ |
| if (inst->src[i].negate || inst->src[i].abs) |
| continue; |
| |
| switch (inst->opcode) { |
| case BRW_OPCODE_MOV: |
| inst->src[i] = entry->src; |
| progress = true; |
| break; |
| |
| case BRW_OPCODE_MACH: |
| case BRW_OPCODE_MUL: |
| case BRW_OPCODE_ADD: |
| if (i == 1) { |
| inst->src[i] = entry->src; |
| progress = true; |
| } else if (i == 0 && inst->src[1].file != IMM) { |
| /* Fit this constant in by commuting the operands. |
| * Exception: we can't do this for 32-bit integer MUL/MACH |
| * because it's asymmetric. |
| */ |
| if ((inst->opcode == BRW_OPCODE_MUL || |
| inst->opcode == BRW_OPCODE_MACH) && |
| (inst->src[1].type == BRW_REGISTER_TYPE_D || |
| inst->src[1].type == BRW_REGISTER_TYPE_UD)) |
| break; |
| inst->src[0] = inst->src[1]; |
| inst->src[1] = entry->src; |
| progress = true; |
| } |
| break; |
| |
| case BRW_OPCODE_CMP: |
| case BRW_OPCODE_IF: |
| if (i == 1) { |
| inst->src[i] = entry->src; |
| progress = true; |
| } else if (i == 0 && inst->src[1].file != IMM) { |
| uint32_t new_cmod; |
| |
| new_cmod = brw_swap_cmod(inst->conditional_mod); |
| if (new_cmod != ~0u) { |
| /* Fit this constant in by swapping the operands and |
| * flipping the test |
| */ |
| inst->src[0] = inst->src[1]; |
| inst->src[1] = entry->src; |
| inst->conditional_mod = new_cmod; |
| progress = true; |
| } |
| } |
| break; |
| |
| case BRW_OPCODE_SEL: |
| if (i == 1) { |
| inst->src[i] = entry->src; |
| progress = true; |
| } else if (i == 0 && inst->src[1].file != IMM) { |
| inst->src[0] = inst->src[1]; |
| inst->src[1] = entry->src; |
| |
| /* If this was predicated, flipping operands means |
| * we also need to flip the predicate. |
| */ |
| if (inst->conditional_mod == BRW_CONDITIONAL_NONE) { |
| inst->predicate_inverse = |
| !inst->predicate_inverse; |
| } |
| progress = true; |
| } |
| break; |
| |
| case SHADER_OPCODE_RCP: |
| /* The hardware doesn't do math on immediate values |
| * (because why are you doing that, seriously?), but |
| * the correct answer is to just constant fold it |
| * anyway. |
| */ |
| assert(i == 0); |
| if (inst->src[0].imm.f != 0.0f) { |
| inst->opcode = BRW_OPCODE_MOV; |
| inst->src[0] = entry->src; |
| inst->src[0].imm.f = 1.0f / inst->src[0].imm.f; |
| progress = true; |
| } |
| break; |
| |
| case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD: |
| inst->src[i] = entry->src; |
| progress = true; |
| break; |
| |
| default: |
| break; |
| } |
| } |
| |
| return progress; |
| } |
| /* Walks a basic block and does copy propagation on it using the acp |
| * list. |
| */ |
| bool |
| fs_visitor::opt_copy_propagate_local(void *mem_ctx, bblock_t *block, |
| exec_list *acp) |
| { |
| bool progress = false; |
| |
| for (fs_inst *inst = (fs_inst *)block->start; |
| inst != block->end->next; |
| inst = (fs_inst *)inst->next) { |
| |
| /* Try propagating into this instruction. */ |
| for (int i = 0; i < 3; i++) { |
| if (inst->src[i].file != GRF) |
| continue; |
| |
| foreach_list(entry_node, &acp[inst->src[i].reg % ACP_HASH_SIZE]) { |
| acp_entry *entry = (acp_entry *)entry_node; |
| |
| if (try_constant_propagate(inst, entry)) |
| progress = true; |
| |
| if (try_copy_propagate(inst, i, entry)) |
| progress = true; |
| } |
| } |
| |
| /* kill the destination from the ACP */ |
| if (inst->dst.file == GRF) { |
| foreach_list_safe(entry_node, &acp[inst->dst.reg % ACP_HASH_SIZE]) { |
| acp_entry *entry = (acp_entry *)entry_node; |
| |
| if (inst->overwrites_reg(entry->dst)) { |
| entry->remove(); |
| } |
| } |
| |
| /* Oops, we only have the chaining hash based on the destination, not |
| * the source, so walk across the entire table. |
| */ |
| for (int i = 0; i < ACP_HASH_SIZE; i++) { |
| foreach_list_safe(entry_node, &acp[i]) { |
| acp_entry *entry = (acp_entry *)entry_node; |
| if (inst->overwrites_reg(entry->src)) |
| entry->remove(); |
| } |
| } |
| } |
| |
| /* If this instruction's source could potentially be folded into the |
| * operand of another instruction, add it to the ACP. |
| */ |
| if (inst->opcode == BRW_OPCODE_MOV && |
| inst->dst.file == GRF && |
| ((inst->src[0].file == GRF && |
| (inst->src[0].reg != inst->dst.reg || |
| inst->src[0].reg_offset != inst->dst.reg_offset)) || |
| inst->src[0].file == UNIFORM || |
| inst->src[0].file == IMM) && |
| inst->src[0].type == inst->dst.type && |
| !inst->saturate && |
| !inst->is_partial_write()) { |
| acp_entry *entry = ralloc(mem_ctx, acp_entry); |
| entry->dst = inst->dst; |
| entry->src = inst->src[0]; |
| acp[entry->dst.reg % ACP_HASH_SIZE].push_tail(entry); |
| } |
| } |
| |
| return progress; |
| } |
| |
| bool |
| fs_visitor::opt_copy_propagate() |
| { |
| bool progress = false; |
| void *mem_ctx = ralloc_context(this->mem_ctx); |
| cfg_t cfg(this); |
| exec_list *out_acp[cfg.num_blocks]; |
| for (int i = 0; i < cfg.num_blocks; i++) |
| out_acp[i] = new exec_list [ACP_HASH_SIZE]; |
| |
| /* First, walk through each block doing local copy propagation and getting |
| * the set of copies available at the end of the block. |
| */ |
| for (int b = 0; b < cfg.num_blocks; b++) { |
| bblock_t *block = cfg.blocks[b]; |
| |
| progress = opt_copy_propagate_local(mem_ctx, block, |
| out_acp[b]) || progress; |
| } |
| |
| /* Do dataflow analysis for those available copies. */ |
| fs_copy_prop_dataflow dataflow(mem_ctx, &cfg, out_acp); |
| |
| /* Next, re-run local copy propagation, this time with the set of copies |
| * provided by the dataflow analysis available at the start of a block. |
| */ |
| for (int b = 0; b < cfg.num_blocks; b++) { |
| bblock_t *block = cfg.blocks[b]; |
| exec_list in_acp[ACP_HASH_SIZE]; |
| |
| for (int i = 0; i < dataflow.num_acp; i++) { |
| if (BITSET_TEST(dataflow.bd[b].livein, i)) { |
| struct acp_entry *entry = dataflow.acp[i]; |
| in_acp[entry->dst.reg % ACP_HASH_SIZE].push_tail(entry); |
| } |
| } |
| |
| progress = opt_copy_propagate_local(mem_ctx, block, in_acp) || progress; |
| } |
| |
| for (int i = 0; i < cfg.num_blocks; i++) |
| delete [] out_acp[i]; |
| ralloc_free(mem_ctx); |
| |
| if (progress) |
| live_intervals_valid = false; |
| |
| return progress; |
| } |