nir: Stop whacking gl_FrontFacing to a system value

We have a cap bit for gallium and a GLSL compiler flag to control this.
Just trust what GLSL gives us and stop forcing it.  In order for this to
be safe, we have to advertise another cap in some of the gallium
drivers.

Reviewed-by: Alyssa Rosenzweig <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 2 insertions, 7 deletions

diff --git a/src/compiler/glsl/glsl_to_nir.cpp b/src/compiler/glsl/glsl_to_nir.cpp
index 7b454cab623..3238c65cd9c 100644
--- a/src/compiler/glsl/glsl_to_nir.cpp
+++ b/src/compiler/glsl/glsl_to_nir.cpp
@@ -460,13 +460,8 @@ nir_visitor::visit(ir_variable *ir)
       break;
 
    case ir_var_shader_in:
-      if (shader->info.stage == MESA_SHADER_FRAGMENT &&
-          ir->data.location == VARYING_SLOT_FACE) {
-         /* For whatever reason, GLSL IR makes gl_FrontFacing an input */
-         var->data.location = SYSTEM_VALUE_FRONT_FACE;
-         var->data.mode = nir_var_system_value;
-      } else if (shader->info.stage == MESA_SHADER_GEOMETRY &&
-                 ir->data.location == VARYING_SLOT_PRIMITIVE_ID) {
+      if (shader->info.stage == MESA_SHADER_GEOMETRY &&
+          ir->data.location == VARYING_SLOT_PRIMITIVE_ID) {
          /* For whatever reason, GLSL IR makes gl_PrimitiveIDIn an input */
          var->data.location = SYSTEM_VALUE_PRIMITIVE_ID;
          var->data.mode = nir_var_system_value;