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authorEric Anholt <[email protected]>2014-10-09 09:32:10 +0200
committerEric Anholt <[email protected]>2014-10-09 11:01:18 +0200
commit00a9aebfe064ec252a95e0f3a38f4f6c967dadc4 (patch)
treeae37c1b3453d8159d7881058b3bc5c859537143f /src
parent67aea92964ed06f10097271822f4a16378138be5 (diff)
vc4: Add some optimization of FADD(FSUB(0, x)).
This is a common production of st_glsl_to_tgsi, which uses negate flags on source arguments to handle subtraction.
Diffstat (limited to 'src')
-rw-r--r--src/gallium/drivers/vc4/vc4_opt_algebraic.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/src/gallium/drivers/vc4/vc4_opt_algebraic.c b/src/gallium/drivers/vc4/vc4_opt_algebraic.c
index f88a5c17d2a..4155e72fd21 100644
--- a/src/gallium/drivers/vc4/vc4_opt_algebraic.c
+++ b/src/gallium/drivers/vc4/vc4_opt_algebraic.c
@@ -128,6 +128,37 @@ qir_opt_algebraic(struct vc4_compile *c)
}
break;
+ case QOP_FADD:
+ /* FADD(a, FSUB(0, b)) -> FSUB(a, b) */
+ if (inst->src[1].file == QFILE_TEMP &&
+ defs[inst->src[1].index]->op == QOP_FSUB) {
+ struct qinst *fsub = defs[inst->src[1].index];
+ if (is_zero(c, defs, fsub->src[0])) {
+ dump_from(c, inst);
+ inst->op = QOP_FSUB;
+ inst->src[1] = fsub->src[1];
+ progress = true;
+ dump_to(c, inst);
+ break;
+ }
+ }
+
+ /* FADD(FSUB(0, b), a) -> FSUB(a, b) */
+ if (inst->src[0].file == QFILE_TEMP &&
+ defs[inst->src[0].index]->op == QOP_FSUB) {
+ struct qinst *fsub = defs[inst->src[0].index];
+ if (is_zero(c, defs, fsub->src[0])) {
+ dump_from(c, inst);
+ inst->op = QOP_FSUB;
+ inst->src[0] = inst->src[1];
+ inst->src[1] = fsub->src[1];
+ dump_to(c, inst);
+ progress = true;
+ break;
+ }
+ }
+ break;
+
default:
break;
}