[Mesa-dev] [PATCH] i965/vec4: fix splitting of interleaved attributes

[Iago Toral Quiroga]

Whe we split an instruction that reads a uniform value
(vstride 0) we need to respect the vstride on the second
half of the instruction (that is, the second half should
read the same region as the first).

We were doing this already, but we didn't account for
stages that have interleaved input attributes which also
have a vstride of 0 and need the same treatment.

Fixes the following on Haswell:
KHR-GL45.enhanced_layouts.varying_locations
KHR-GL45.enhanced_layouts.varying_array_locations
KHR-GL45.enhanced_layouts.varying_structure_locations
---
 src/intel/compiler/brw_vec4.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/intel/compiler/brw_vec4.cpp b/src/intel/compiler/brw_vec4.cpp
index bbe4585e0c..73c40ad600 100644
--- a/src/intel/compiler/brw_vec4.cpp
+++ b/src/intel/compiler/brw_vec4.cpp
@@ -2238,7 +2238,12 @@ vec4_visitor::lower_simd_width()
             if (linst->src[i].file == BAD_FILE)
                continue;
 
-            if (!is_uniform(linst->src[i]))
+            bool is_interleaved_attr =
+               linst->src[i].file == ATTR &&
+               stage_uses_interleaved_attributes(stage,
+                                                 prog_data->dispatch_mode);
+
+            if (!is_uniform(linst->src[i]) && !is_interleaved_attr)
                linst->src[i] = horiz_offset(linst->src[i], channel_offset);
          }
 
-- 
2.11.0