From 00a9aebfe064ec252a95e0f3a38f4f6c967dadc4 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Thu, 9 Oct 2014 09:32:10 +0200 Subject: [PATCH] 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. --- src/gallium/drivers/vc4/vc4_opt_algebraic.c | 31 +++++++++++++++++++++ 1 file changed, 31 insertions(+) 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; } -- 2.30.2