| /* |
| * Copyright (C) 2014 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 "util/u_math.h" |
| |
| #include "ir3.h" |
| #include "ir3_shader.h" |
| |
| /* |
| * Dead code elimination: |
| */ |
| |
| static void |
| mark_array_use(struct ir3_instruction *instr, struct ir3_register *reg) |
| { |
| if (reg->flags & IR3_REG_ARRAY) { |
| struct ir3_array *arr = |
| ir3_lookup_array(instr->block->shader, reg->array.id); |
| arr->unused = false; |
| } |
| } |
| |
| static void |
| instr_dce(struct ir3_instruction *instr, bool falsedep) |
| { |
| /* don't mark falsedep's as used, but otherwise process them normally: */ |
| if (!falsedep) |
| instr->flags &= ~IR3_INSTR_UNUSED; |
| |
| if (ir3_instr_check_mark(instr)) |
| return; |
| |
| if (writes_gpr(instr)) |
| mark_array_use(instr, instr->regs[0]); /* dst */ |
| |
| foreach_src (reg, instr) |
| mark_array_use(instr, reg); /* src */ |
| |
| foreach_ssa_src_n (src, i, instr) { |
| instr_dce(src, __is_false_dep(instr, i)); |
| } |
| } |
| |
| static bool |
| remove_unused_by_block(struct ir3_block *block) |
| { |
| bool progress = false; |
| foreach_instr_safe (instr, &block->instr_list) { |
| if (instr->opc == OPC_END || instr->opc == OPC_CHSH || instr->opc == OPC_CHMASK) |
| continue; |
| if (instr->flags & IR3_INSTR_UNUSED) { |
| if (instr->opc == OPC_META_SPLIT) { |
| struct ir3_instruction *src = ssa(instr->regs[1]); |
| /* tex (cat5) instructions have a writemask, so we can |
| * mask off unused components. Other instructions do not. |
| */ |
| if (src && is_tex_or_prefetch(src) && (src->regs[0]->wrmask > 1)) { |
| src->regs[0]->wrmask &= ~(1 << instr->split.off); |
| |
| /* prune no-longer needed right-neighbors. We could |
| * probably do the same for left-neighbors (ie. tex |
| * fetch that only need .yw components), but that |
| * makes RA a bit more confusing than it already is |
| */ |
| struct ir3_instruction *n = instr; |
| while (n && n->cp.right) |
| n = n->cp.right; |
| while (n->flags & IR3_INSTR_UNUSED) { |
| n = n->cp.left; |
| if (!n) |
| break; |
| n->cp.right = NULL; |
| } |
| } |
| } |
| |
| /* prune false-deps, etc: */ |
| foreach_ssa_use (use, instr) |
| foreach_ssa_srcp_n (srcp, n, use) |
| if (*srcp == instr) |
| *srcp = NULL; |
| |
| list_delinit(&instr->node); |
| progress = true; |
| } |
| } |
| return progress; |
| } |
| |
| static bool |
| find_and_remove_unused(struct ir3 *ir, struct ir3_shader_variant *so) |
| { |
| unsigned i; |
| bool progress = false; |
| |
| ir3_clear_mark(ir); |
| |
| /* initially mark everything as unused, we'll clear the flag as we |
| * visit the instructions: |
| */ |
| foreach_block (block, &ir->block_list) { |
| foreach_instr (instr, &block->instr_list) { |
| /* special case, if pre-fs texture fetch used, we cannot |
| * eliminate the barycentric i/j input |
| */ |
| if (so->num_sampler_prefetch && |
| (instr->opc == OPC_META_INPUT) && |
| (instr->input.sysval == SYSTEM_VALUE_BARYCENTRIC_PERSP_PIXEL)) |
| continue; |
| instr->flags |= IR3_INSTR_UNUSED; |
| } |
| } |
| |
| foreach_array (arr, &ir->array_list) |
| arr->unused = true; |
| |
| foreach_output (out, ir) |
| instr_dce(out, false); |
| |
| foreach_block (block, &ir->block_list) { |
| for (i = 0; i < block->keeps_count; i++) |
| instr_dce(block->keeps[i], false); |
| |
| /* We also need to account for if-condition: */ |
| if (block->condition) |
| instr_dce(block->condition, false); |
| } |
| |
| /* remove un-used instructions: */ |
| foreach_block (block, &ir->block_list) { |
| progress |= remove_unused_by_block(block); |
| } |
| |
| /* remove un-used arrays: */ |
| foreach_array_safe (arr, &ir->array_list) { |
| if (arr->unused) |
| list_delinit(&arr->node); |
| } |
| |
| /* fixup wrmask of split instructions to account for adjusted tex |
| * wrmask's: |
| */ |
| foreach_block (block, &ir->block_list) { |
| foreach_instr (instr, &block->instr_list) { |
| if (instr->opc != OPC_META_SPLIT) |
| continue; |
| |
| struct ir3_instruction *src = ssa(instr->regs[1]); |
| if (!is_tex_or_prefetch(src)) |
| continue; |
| |
| instr->regs[1]->wrmask = src->regs[0]->wrmask; |
| } |
| } |
| |
| /* note that we can end up with unused indirects, but we should |
| * not end up with unused predicates. |
| */ |
| for (i = 0; i < ir->a0_users_count; i++) { |
| struct ir3_instruction *instr = ir->a0_users[i]; |
| if (instr && (instr->flags & IR3_INSTR_UNUSED)) |
| ir->a0_users[i] = NULL; |
| } |
| |
| for (i = 0; i < ir->a1_users_count; i++) { |
| struct ir3_instruction *instr = ir->a1_users[i]; |
| if (instr && (instr->flags & IR3_INSTR_UNUSED)) |
| ir->a1_users[i] = NULL; |
| } |
| |
| /* cleanup unused inputs: */ |
| foreach_input_n (in, n, ir) |
| if (in->flags & IR3_INSTR_UNUSED) |
| ir->inputs[n] = NULL; |
| |
| return progress; |
| } |
| |
| bool |
| ir3_dce(struct ir3 *ir, struct ir3_shader_variant *so) |
| { |
| void *mem_ctx = ralloc_context(NULL); |
| bool progress, made_progress = false; |
| |
| ir3_find_ssa_uses(ir, mem_ctx, true); |
| |
| do { |
| progress = find_and_remove_unused(ir, so); |
| made_progress |= progress; |
| } while (progress); |
| |
| ralloc_free(mem_ctx); |
| |
| return made_progress; |
| } |