Basically, ALIGN1 mode will ignore swizzles on the input vectors so we don't
want the copy propagation pass to mess with them.
---
.../drivers/dri/i965/brw_vec4_copy_propagation.cpp | 24 ++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
b/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
index 8faa241..56c0dbb 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
@@ -281,6 +281,22 @@ try_constant_propagate(const struct brw_device_info
*devinfo,
}
static bool
+is_align1_opcode(unsigned opcode)
+{
+ switch (opcode) {
+ case VEC4_OPCODE_DOUBLE_TO_FLOAT:
+ case VEC4_OPCODE_FLOAT_TO_DOUBLE:
+ case VEC4_OPCODE_PICK_LOW_32BIT:
+ case VEC4_OPCODE_PICK_HIGH_32BIT:
+ case VEC4_OPCODE_SET_LOW_32BIT:
+ case VEC4_OPCODE_SET_HIGH_32BIT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool
try_copy_propagate(const struct brw_device_info *devinfo,
vec4_instruction *inst, int arg,
const copy_entry *entry, int attributes_per_reg)
@@ -324,6 +340,14 @@ try_copy_propagate(const struct brw_device_info *devinfo,
unsigned composed_swizzle = brw_compose_swizzle(inst->src[arg].swizzle,
value.swizzle);
+
+ /* Instructions that operate on vectors in ALIGN1 mode will ignore swizzles
+ * so copy-propagation won't be safe if the composed swizzle is anything
+ * other than the identity.
+ */
+ if (is_align1_opcode(inst->opcode) && composed_swizzle != BRW_SWIZZLE_XYZW)
+ return false;
+
if (inst->is_3src(devinfo) &&
(value.file == UNIFORM ||
(value.file == ATTR && attributes_per_reg != 1)) &&
--
2.7.4
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