summaryrefslogtreecommitdiffstats
path: root/src/glsl/nir
diff options
context:
space:
mode:
Diffstat (limited to 'src/glsl/nir')
-rw-r--r--src/glsl/nir/nir_opt_peephole_ffma.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/src/glsl/nir/nir_opt_peephole_ffma.c b/src/glsl/nir/nir_opt_peephole_ffma.c
index 798506b7595..a823adbb465 100644
--- a/src/glsl/nir/nir_opt_peephole_ffma.c
+++ b/src/glsl/nir/nir_opt_peephole_ffma.c
@@ -76,6 +76,7 @@ static nir_alu_instr *
get_mul_for_src(nir_alu_src *src, int num_components,
uint8_t swizzle[4], bool *negate, bool *abs)
{
+ uint8_t swizzle_tmp[4];
assert(src->src.is_ssa && !src->abs && !src->negate);
nir_instr *instr = src->src.ssa->parent_instr;
@@ -116,8 +117,18 @@ get_mul_for_src(nir_alu_src *src, int num_components,
if (!alu)
return NULL;
+ /* Copy swizzle data before overwriting it to avoid setting a wrong swizzle.
+ *
+ * Example:
+ * Former swizzle[] = xyzw
+ * src->swizzle[] = zyxx
+ *
+ * Expected output swizzle = zyxx
+ * If we reuse swizzle in the loop, then output swizzle would be zyzz.
+ */
+ memcpy(swizzle_tmp, swizzle, 4*sizeof(uint8_t));
for (unsigned i = 0; i < num_components; i++)
- swizzle[i] = swizzle[src->swizzle[i]];
+ swizzle[i] = swizzle_tmp[src->swizzle[i]];
return alu;
}