From ec9da314baf11bea57f315346091ae941ac4f662 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Fri, 4 Jul 2014 10:59:42 -0700 Subject: [PATCH] vc4: Add copy propagation between temps. We put in a bunch of extra MOVs for program outputs, and this can clean those up. We should do uniforms, too, though. v2: Fix missing flagging of progress when we actually optimize. Caught by Aaron Watry. --- src/gallium/drivers/vc4/Makefile.sources | 1 + .../drivers/vc4/vc4_opt_copy_propagation.c | 78 +++++++++++++++++++ src/gallium/drivers/vc4/vc4_qir.c | 1 + src/gallium/drivers/vc4/vc4_qir.h | 1 + 4 files changed, 81 insertions(+) create mode 100644 src/gallium/drivers/vc4/vc4_opt_copy_propagation.c diff --git a/src/gallium/drivers/vc4/Makefile.sources b/src/gallium/drivers/vc4/Makefile.sources index 6977a067bd7..b4e499b7d6c 100644 --- a/src/gallium/drivers/vc4/Makefile.sources +++ b/src/gallium/drivers/vc4/Makefile.sources @@ -5,6 +5,7 @@ C_SOURCES := \ vc4_draw.c \ vc4_emit.c \ vc4_opt_algebraic.c \ + vc4_opt_copy_propagation.c \ vc4_opt_dead_code.c \ vc4_program.c \ vc4_qir.c \ diff --git a/src/gallium/drivers/vc4/vc4_opt_copy_propagation.c b/src/gallium/drivers/vc4/vc4_opt_copy_propagation.c new file mode 100644 index 00000000000..dc4b5bc3c38 --- /dev/null +++ b/src/gallium/drivers/vc4/vc4_opt_copy_propagation.c @@ -0,0 +1,78 @@ +/* + * 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_copy_propagation.c + * + * This implements simple copy propagation for QIR without control flow. + * + * For each temp, it keeps a qreg of which source it was MOVed from, if it + * was. If we see that used later, we can just reuse the source value, since + * we know we don't have control flow, and we have SSA for our values so + * there's no killing to worry about. + */ + +#include +#include +#include "vc4_qir.h" + +bool +qir_opt_copy_propagation(struct qcompile *c) +{ + bool progress = false; + struct simple_node *node; + bool debug = false; + struct qreg *movs = calloc(c->num_temps, sizeof(struct qreg)); + + foreach(node, &c->instructions) { + struct qinst *inst = (struct qinst *)node; + + for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) { + int index = inst->src[i].index; + if (inst->src[i].file == QFILE_TEMP && + movs[index].file == QFILE_TEMP) { + if (debug) { + fprintf(stderr, "Copy propagate: "); + qir_dump_inst(inst); + fprintf(stderr, "\n"); + } + + inst->src[i] = movs[index]; + + if (debug) { + fprintf(stderr, "to: "); + qir_dump_inst(inst); + fprintf(stderr, "\n"); + } + + progress = true; + } + } + + if (inst->op == QOP_MOV && inst->dst.file == QFILE_TEMP) + movs[inst->dst.index] = inst->src[0]; + } + + free(movs); + return progress; +} diff --git a/src/gallium/drivers/vc4/vc4_qir.c b/src/gallium/drivers/vc4/vc4_qir.c index 13714115214..71f6e87578d 100644 --- a/src/gallium/drivers/vc4/vc4_qir.c +++ b/src/gallium/drivers/vc4/vc4_qir.c @@ -241,6 +241,7 @@ qir_optimize(struct qcompile *c) bool progress = false; OPTPASS(qir_opt_algebraic); + OPTPASS(qir_opt_copy_propagation); OPTPASS(qir_opt_dead_code); if (!progress) diff --git a/src/gallium/drivers/vc4/vc4_qir.h b/src/gallium/drivers/vc4/vc4_qir.h index c6c2a6476c4..5332478039a 100644 --- a/src/gallium/drivers/vc4/vc4_qir.h +++ b/src/gallium/drivers/vc4/vc4_qir.h @@ -155,6 +155,7 @@ const char *qir_get_stage_name(enum qstage stage); void qir_optimize(struct qcompile *c); bool qir_opt_algebraic(struct qcompile *c); +bool qir_opt_copy_propagation(struct qcompile *c); bool qir_opt_dead_code(struct qcompile *c); #define QIR_ALU1(name) \ -- 2.30.2