1/* 2 * Copyright © 2014 Broadcom 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 */ 23 24/** 25 * @file vc4_opt_coalesce_ff_writes.c 26 * 27 * This modifies instructions that generate the value consumed by a VPM or TMU 28 * coordinate write to write directly into the VPM or TMU. 29 */ 30 31#include "vc4_qir.h" 32 33bool 34qir_opt_coalesce_ff_writes(struct vc4_compile *c) 35{ 36 /* For now, only do this pass when we don't have control flow. */ 37 struct qblock *block = qir_entry_block(c); 38 if (block != qir_exit_block(c)) 39 return false; 40 41 bool progress = false; 42 uint32_t use_count[c->num_temps]; 43 memset(&use_count, 0, sizeof(use_count)); 44 45 qir_for_each_inst_inorder(inst, c) { 46 for (int i = 0; i < qir_get_nsrc(inst); i++) { 47 if (inst->src[i].file == QFILE_TEMP) { 48 uint32_t temp = inst->src[i].index; 49 use_count[temp]++; 50 } 51 } 52 } 53 54 qir_for_each_inst_inorder(mov_inst, c) { 55 if (!qir_is_raw_mov(mov_inst) || mov_inst->sf) 56 continue; 57 if (mov_inst->src[0].file != QFILE_TEMP) 58 continue; 59 60 if (!(mov_inst->dst.file == QFILE_VPM || qir_is_tex(mov_inst))) 61 continue; 62 63 uint32_t temp = mov_inst->src[0].index; 64 if (use_count[temp] != 1) 65 continue; 66 67 struct qinst *inst = c->defs[temp]; 68 if (!inst) 69 continue; 70 71 /* Don't bother trying to fold in an ALU op using a uniform to 72 * a texture op, as we'll just have to lower the uniform back 73 * out. 74 */ 75 if (qir_is_tex(mov_inst) && qir_has_uniform_read(inst)) 76 continue; 77 78 if (qir_depends_on_flags(inst) || inst->sf) 79 continue; 80 81 if (qir_has_side_effects(c, inst) || 82 qir_has_side_effect_reads(c, inst) || 83 inst->op == QOP_VARY_ADD_C) { 84 continue; 85 } 86 87 /* Move the generating instruction into the position of the FF 88 * write. 89 */ 90 c->defs[inst->dst.index] = NULL; 91 inst->dst.file = mov_inst->dst.file; 92 inst->dst.index = mov_inst->dst.index; 93 if (qir_has_implicit_tex_uniform(mov_inst)) { 94 inst->src[qir_get_tex_uniform_src(inst)] = 95 mov_inst->src[qir_get_tex_uniform_src(mov_inst)]; 96 } 97 98 list_del(&inst->link); 99 list_addtail(&inst->link, &mov_inst->link); 100 101 qir_remove_instruction(c, mov_inst); 102 103 progress = true; 104 } 105 106 return progress; 107} 108