[Mesa-dev] [PATCH] spirv: Relax the validation conditions of OpSelect

[Jason Ekstrand]

The Talos Principle contains shaders with an OpSelect between two
vectors where the condition is a scalar boolean.  This is technically
against the spec bout nir_builder gracefully handles it by splatting
out the condition to all the channels.  So long as the condition is a
boolean, just emit a warning instead of failing.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104246
---
 src/compiler/spirv/spirv_to_nir.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/compiler/spirv/spirv_to_nir.c b/src/compiler/spirv/spirv_to_nir.c
index 0493dd3..f0476b2 100644
--- a/src/compiler/spirv/spirv_to_nir.c
+++ b/src/compiler/spirv/spirv_to_nir.c
@@ -3511,10 +3511,20 @@ vtn_handle_body_instruction(struct vtn_builder *b, SpvOp opcode,
          vtn_fail("Result type of OpSelect must be a scalar, vector, or pointer");
       }
 
-      vtn_fail_if(sel_val->type->type != sel_type,
-                  "Condition type of OpSelect must be a scalar or vector of "
-                  "Boolean type. It must have the same number of components "
-                  "as Result Type");
+      if (unlikely(sel_val->type->type != sel_type)) {
+         if (sel_val->type->type == glsl_bool_type()) {
+            /* This case is illegal but some versions of GLSLang produce it.
+             * That's fine, nir_builder will just splat the condition out
+             * which is most likely what the client wanted anyway.
+             */
+            vtn_warn("Condition type of OpSelect must have the same number "
+                     "of components as Result Type");
+         } else {
+            vtn_fail("Condition type of OpSelect must be a scalar or vector "
+                     "of Boolean type. It must have the same number of "
+                     "components as Result Type");
+         }
+      }
 
       vtn_fail_if(obj1_val->type != res_val->type ||
                   obj2_val->type != res_val->type,
-- 
2.5.0.400.gff86faf