From d92463d5dc42aca09a54588c322fc60582cf9131 Mon Sep 17 00:00:00 2001 From: Paul Berry Date: Fri, 22 Jul 2011 14:05:52 -0700 Subject: [PATCH] i965: vs optimization fix: Check val.{negate,abs} in accumulator_contains() When emitting a MAC instruction in a vertex shader, brw_vs_emit() calls accumulator_contains() to determine whether the accumulator already contains the appropriate addend; if it does, then we can avoid emitting an unnecessary MOV instruction. However, accumulator_contains() wasn't checking the val.negate or val.abs flags. As a result, if the desired value was the negation, or the absolute value, of what was already in the accumulator, we would generate an incorrect shader. Fixes piglit test vs-refract-vec4-vec4-float. Tested on Gen5 and Gen6. Reviewed-by: Eric Anholt --- src/mesa/drivers/dri/i965/brw_vs_emit.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_vs_emit.c b/src/mesa/drivers/dri/i965/brw_vs_emit.c index d8cb0f7cb69..674a994bace 100644 --- a/src/mesa/drivers/dri/i965/brw_vs_emit.c +++ b/src/mesa/drivers/dri/i965/brw_vs_emit.c @@ -1821,6 +1821,9 @@ accumulator_contains(struct brw_vs_compile *c, struct brw_reg val) if (val.address_mode != BRW_ADDRESS_DIRECT) return GL_FALSE; + if (val.negate || val.abs) + return GL_FALSE; + switch (prev_insn->header.opcode) { case BRW_OPCODE_MOV: case BRW_OPCODE_MAC: -- 2.11.0