[Mesa-dev] [PATCH] intel/fs: Don't emit a des copy for image ops with has_dest == false

[Jason Ekstrand]

This was causing us to walk dest_components times over a thing with no
destination.  This happened to work because all of the image intrinsics
without a destination also happened to have dest_components == 0.  We
shouldn't be reading dest_components if has_dest == false.
---
 src/intel/compiler/brw_fs_nir.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
index f5d5399..8d1c387 100644
--- a/src/intel/compiler/brw_fs_nir.cpp
+++ b/src/intel/compiler/brw_fs_nir.cpp
@@ -3848,9 +3848,11 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
                                  get_image_atomic_op(instr->intrinsic, type));
 
       /* Assign the result. */
-      for (unsigned c = 0; c < info->dest_components; ++c)
-         bld.MOV(offset(retype(dest, base_type), bld, c),
-                 offset(tmp, bld, c));
+      if (nir_intrinsic_infos[instr->intrinsic].has_dest) {
+         for (unsigned c = 0; c < info->dest_components; ++c)
+            bld.MOV(offset(retype(dest, base_type), bld, c),
+                    offset(tmp, bld, c));
+      }
       break;
    }
 
-- 
2.5.0.400.gff86faf