| /* |
| * 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_vpm.c |
| * |
| * This modifies instructions that exclusively consume a value read from the |
| * VPM to directly read the VPM if other operands allow it. |
| */ |
| |
| #include "vc4_qir.h" |
| |
| bool |
| qir_opt_vpm(struct vc4_compile *c) |
| { |
| if (c->stage == QSTAGE_FRAG) |
| return false; |
| |
| /* For now, only do this pass when we don't have control flow. */ |
| struct qblock *block = qir_entry_block(c); |
| if (block != qir_exit_block(c)) |
| return false; |
| |
| bool progress = false; |
| uint32_t use_count[c->num_temps]; |
| memset(&use_count, 0, sizeof(use_count)); |
| |
| qir_for_each_inst_inorder(inst, c) { |
| for (int i = 0; i < qir_get_nsrc(inst); i++) { |
| if (inst->src[i].file == QFILE_TEMP) { |
| uint32_t temp = inst->src[i].index; |
| use_count[temp]++; |
| } |
| } |
| } |
| |
| /* For instructions reading from a temporary that contains a VPM read |
| * result, try to move the instruction up in place of the VPM read. |
| */ |
| qir_for_each_inst_inorder(inst, c) { |
| if (!inst) |
| continue; |
| |
| if (qir_depends_on_flags(inst) || inst->sf) |
| continue; |
| |
| if (qir_has_side_effects(c, inst) || |
| qir_has_side_effect_reads(c, inst) || |
| qir_is_tex(inst)) |
| continue; |
| |
| for (int j = 0; j < qir_get_nsrc(inst); j++) { |
| if (inst->src[j].file != QFILE_TEMP || |
| inst->src[j].pack) |
| continue; |
| |
| uint32_t temp = inst->src[j].index; |
| |
| /* Since VPM reads pull from a FIFO, we only get to |
| * read each VPM entry once (unless we reset the read |
| * pointer). That means we can't copy-propagate a VPM |
| * read to multiple locations. |
| */ |
| if (use_count[temp] != 1) |
| continue; |
| |
| struct qinst *mov = c->defs[temp]; |
| if (!mov || |
| (mov->op != QOP_MOV && |
| mov->op != QOP_FMOV && |
| mov->op != QOP_MMOV) || |
| mov->src[0].file != QFILE_VPM) { |
| continue; |
| } |
| |
| uint32_t temps = 0; |
| for (int k = 0; k < qir_get_nsrc(inst); k++) { |
| if (inst->src[k].file == QFILE_TEMP) |
| temps++; |
| } |
| |
| /* The instruction is safe to reorder if its other |
| * sources are independent of previous instructions |
| */ |
| if (temps == 1) { |
| inst->src[j] = mov->src[0]; |
| |
| list_del(&inst->link); |
| list_addtail(&inst->link, &mov->link); |
| qir_remove_instruction(c, mov); |
| |
| progress = true; |
| break; |
| } |
| } |
| } |
| |
| return progress; |
| } |