| 0,0 → 1,161 |
|---|
| /* |
| * Copyright © 2014 Broadcom |
| * |
| * 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 vc4_opt_dead_code.c |
| * |
| * This is a simmple dead code eliminator for QIR with no control flow. |
| * |
| * It walks from the bottom of the instruction list, removing instructions |
| * with a destination that is never used, and marking the sources of non-dead |
| * instructions as used. |
| */ |
| |
| #include "vc4_qir.h" |
| |
| static bool debug; |
| |
| static void |
| dce(struct vc4_compile *c, struct qinst *inst) |
| { |
| if (debug) { |
| fprintf(stderr, "Removing: "); |
| qir_dump_inst(c, inst); |
| fprintf(stderr, "\n"); |
| } |
| assert(!inst->sf); |
| qir_remove_instruction(c, inst); |
| } |
| |
| static bool |
| has_nonremovable_reads(struct vc4_compile *c, struct qinst *inst) |
| { |
| for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) { |
| if (inst->src[i].file == QFILE_VPM) { |
| uint32_t attr = inst->src[i].index / 4; |
| uint32_t offset = (inst->src[i].index % 4) * 4; |
| |
| if (c->vattr_sizes[attr] != offset + 4) |
| return true; |
| |
| /* Can't get rid of the last VPM read, or the |
| * simulator (at least) throws an error. |
| */ |
| uint32_t total_size = 0; |
| for (uint32_t i = 0; i < ARRAY_SIZE(c->vattr_sizes); i++) |
| total_size += c->vattr_sizes[i]; |
| if (total_size == 4) |
| return true; |
| } |
| |
| if (inst->src[i].file == QFILE_VARY && |
| c->input_semantics[inst->src[i].index].semantic == 0xff) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| bool |
| qir_opt_dead_code(struct vc4_compile *c) |
| { |
| bool progress = false; |
| bool *used = calloc(c->num_temps, sizeof(bool)); |
| bool sf_used = false; |
| /* Whether we're eliminating texture setup currently. */ |
| bool dce_tex = false; |
| |
| struct simple_node *node, *t; |
| for (node = c->instructions.prev, t = node->prev; |
| &c->instructions != node; |
| node = t, t = t->prev) { |
| struct qinst *inst = (struct qinst *)node; |
| |
| if (inst->dst.file == QFILE_TEMP && |
| !used[inst->dst.index] && |
| !inst->sf && |
| (!qir_has_side_effects(c, inst) || |
| inst->op == QOP_TEX_RESULT) && |
| !has_nonremovable_reads(c, inst)) { |
| if (inst->op == QOP_TEX_RESULT) { |
| dce_tex = true; |
| c->num_texture_samples--; |
| } |
| |
| for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) { |
| if (inst->src[i].file != QFILE_VPM) |
| continue; |
| uint32_t attr = inst->src[i].index / 4; |
| uint32_t offset = (inst->src[i].index % 4) * 4; |
| |
| if (c->vattr_sizes[attr] == offset + 4) { |
| c->num_inputs--; |
| c->vattr_sizes[attr] -= 4; |
| } |
| } |
| |
| dce(c, inst); |
| progress = true; |
| continue; |
| } |
| |
| if (qir_depends_on_flags(inst)) |
| sf_used = true; |
| if (inst->sf) { |
| if (!sf_used) { |
| if (debug) { |
| fprintf(stderr, "Removing SF on: "); |
| qir_dump_inst(c, inst); |
| fprintf(stderr, "\n"); |
| } |
| |
| inst->sf = false; |
| progress = true; |
| } |
| sf_used = false; |
| } |
| |
| if (inst->op == QOP_TEX_RESULT) |
| dce_tex = false; |
| |
| if (dce_tex && (inst->op == QOP_TEX_S || |
| inst->op == QOP_TEX_T || |
| inst->op == QOP_TEX_R || |
| inst->op == QOP_TEX_B || |
| inst->op == QOP_TEX_DIRECT)) { |
| dce(c, inst); |
| progress = true; |
| continue; |
| } |
| |
| for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) { |
| if (inst->src[i].file == QFILE_TEMP) |
| used[inst->src[i].index] = true; |
| } |
| } |
| |
| free(used); |
| |
| return progress; |
| } |