From af974b5fe9b02be44445cea16665457e2c4b7229 Mon Sep 17 00:00:00 2001
From: Georg Lehmann <dadschoorse@gmail.com>
Date: Wed, 20 Nov 2024 17:26:22 +0100
Subject: [PATCH] nir/opt_undef: keep undefs used by partial undef vectors
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Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32249>
---
 src/compiler/nir/nir_opt_undef.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/src/compiler/nir/nir_opt_undef.c b/src/compiler/nir/nir_opt_undef.c
index a7ed879e767..6a0a202abab 100644
--- a/src/compiler/nir/nir_opt_undef.c
+++ b/src/compiler/nir/nir_opt_undef.c
@@ -181,15 +181,9 @@ visit_undef_use(nir_src *src, struct visit_info *info)
        */
       nir_alu_instr *alu = nir_instr_as_alu(instr);
 
-      /* Follow movs and vecs.
-       *
-       * Note that all vector component uses are followed and swizzles are
-       * ignored.
-       */
-      if (alu->op == nir_op_mov || nir_op_is_vec(alu->op)) {
-         nir_foreach_use_including_if(next_src, &alu->def) {
-            visit_undef_use(next_src, info);
-         }
+      /* opt_undef_vecN already copy propagated. */
+      if (nir_op_is_vec(alu->op)) {
+         info->must_keep_undef = true;
          return;
       }