nir: Don't lower the local work group size if it's variable.

If the local work group size is variable it won't be available
at compile time so we can't lower it in nir_lower_system_values().

Signed-off-by: Plamena Manolova <[email protected]>

Reviewed-by: Jason Ekstrand <[email protected]>
Reviewed-by: Karol Herbst <[email protected]>

1 files changed, 18 insertions, 6 deletions

diff --git a/src/compiler/nir/nir_lower_system_values.c b/src/compiler/nir/nir_lower_system_values.c
index bde7eb11801..fbc40573579 100644
--- a/src/compiler/nir/nir_lower_system_values.c
+++ b/src/compiler/nir/nir_lower_system_values.c
@@ -31,12 +31,24 @@
 static nir_ssa_def*
 build_local_group_size(nir_builder *b)
 {
-   nir_const_value local_size;
-   memset(&local_size, 0, sizeof(local_size));
-   local_size.u32[0] = b->shader->info.cs.local_size[0];
-   local_size.u32[1] = b->shader->info.cs.local_size[1];
-   local_size.u32[2] = b->shader->info.cs.local_size[2];
-   return nir_build_imm(b, 3, 32, local_size);
+   nir_ssa_def *local_size;
+
+   /*
+    * If the local work group size is variable it can't be lowered at this
+    * point, but its intrinsic can still be used.
+    */
+   if (b->shader->info.cs.local_size_variable) {
+      local_size = nir_load_local_group_size(b);
+   } else {
+      nir_const_value local_size_const;
+      memset(&local_size_const, 0, sizeof(local_size_const));
+      local_size_const.u32[0] = b->shader->info.cs.local_size[0];
+      local_size_const.u32[1] = b->shader->info.cs.local_size[1];
+      local_size_const.u32[2] = b->shader->info.cs.local_size[2];
+      local_size = nir_build_imm(b, 3, 32, local_size_const);
+   }
+
+   return local_size;
 }
 
 static bool