From 13234a8a8aaa748eff27319c9d95ff11f2e165d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timur=20Krist=C3=B3f?= <timur.kristof@gmail.com>
Date: Fri, 13 Dec 2024 07:07:52 +0100
Subject: [PATCH] ac/nir: Only export parameters when they are actually
 varying.
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In AMD terminology, varying outputs are implemented by
parameter export instructions on GFX6-10.3 GPUs.

Only emit those when actually necessary.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Acked-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32640>
---
 src/amd/common/ac_nir.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/amd/common/ac_nir.c b/src/amd/common/ac_nir.c
index ccf3ac4ef9e..9c8fbb508d0 100644
--- a/src/amd/common/ac_nir.c
+++ b/src/amd/common/ac_nir.c
@@ -538,7 +538,7 @@ ac_nir_export_parameters(nir_builder *b,
       uint32_t write_mask = 0;
       for (int i = 0; i < 4; i++) {
          if (out->outputs[slot][i])
-            write_mask |= BITFIELD_BIT(i);
+            write_mask |= (out->infos[slot].as_varying_mask & BITFIELD_BIT(i));
       }
 
       /* no one set this output slot, we can skip the param export */