/*
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* Copyright © 2015 Broadcom
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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/**
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* @file vc4_opt_constant_folding.c
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*
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* Simple constant folding pass to clean up operations on only constants,
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* which we might have generated within vc4_program.c.
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*/
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#include "vc4_qir.h"
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#include "util/u_math.h"
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static bool debug;
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static void
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dump_from(struct vc4_compile *c, struct qinst *inst)
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{
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if (!debug)
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return;
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fprintf(stderr, "optimizing: ");
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qir_dump_inst(c, inst);
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fprintf(stderr, "\n");
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}
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static void
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dump_to(struct vc4_compile *c, struct qinst *inst)
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{
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if (!debug)
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return;
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fprintf(stderr, "to: ");
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qir_dump_inst(c, inst);
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fprintf(stderr, "\n");
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}
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static bool
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constant_fold(struct vc4_compile *c, struct qinst *inst)
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{
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int nsrc = qir_get_nsrc(inst);
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uint32_t ui[nsrc];
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for (int i = 0; i < nsrc; i++) {
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struct qreg reg = inst->src[i];
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if (reg.file == QFILE_UNIF &&
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c->uniform_contents[reg.index] == QUNIFORM_CONSTANT) {
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ui[i] = c->uniform_data[reg.index];
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} else if (reg.file == QFILE_SMALL_IMM) {
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ui[i] = reg.index;
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} else {
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return false;
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}
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}
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uint32_t result = 0;
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switch (inst->op) {
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case QOP_SHR:
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result = ui[0] >> ui[1];
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break;
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default:
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return false;
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}
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dump_from(c, inst);
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inst->src[0] = qir_uniform_ui(c, result);
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for (int i = 1; i < nsrc; i++)
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inst->src[i] = c->undef;
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inst->op = QOP_MOV;
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dump_to(c, inst);
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return true;
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}
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bool
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qir_opt_constant_folding(struct vc4_compile *c)
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{
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bool progress = false;
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qir_for_each_inst_inorder(inst, c) {
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if (constant_fold(c, inst))
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progress = true;
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}
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return progress;
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}
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