From 1b11113efa817b6fb642a92a4165f3e5a2fe408f Mon Sep 17 00:00:00 2001
From: Jesse Natalie <jenatali@microsoft.com>
Date: Fri, 4 Feb 2022 08:23:42 -0800
Subject: [PATCH] d3d12: Don't force a GS to be added for 'flat' sysvals

Reviewed-by: Sil Vilerino <sivileri@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14881>
---
 src/gallium/drivers/d3d12/d3d12_compiler.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/d3d12/d3d12_compiler.cpp b/src/gallium/drivers/d3d12/d3d12_compiler.cpp
index 747c8805c11..754a1783310 100644
--- a/src/gallium/drivers/d3d12/d3d12_compiler.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_compiler.cpp
@@ -475,7 +475,10 @@ has_flat_varyings(struct d3d12_context *ctx)
 
    nir_foreach_variable_with_modes(input, fs->current->nir,
                                    nir_var_shader_in) {
-      if (input->data.interpolation == INTERP_MODE_FLAT)
+      if (input->data.interpolation == INTERP_MODE_FLAT &&
+          /* Disregard sysvals */
+          (input->data.location >= VARYING_SLOT_VAR0 ||
+             input->data.location <= VARYING_SLOT_TEX7))
          return true;
    }