From 17cb76c4d58fb26fbb941a8bb6e51ee582dbd4c5 Mon Sep 17 00:00:00 2001
From: Gert Wollny <gert.wollny@collabora.com>
Date: Mon, 31 Jul 2023 09:36:18 +0200
Subject: [PATCH] r600/sfn: Don't try to propagate to vec4 with more than one
 use

Otherwise we end up with weird dependencies that make the scheduler
choke.

Fixes: 18a8d148d862d4a0f5b83f4385f00cf8a4a71b6d
    r600/sfn: Cleanup copy-prop into vec4 source values

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24393>
(cherry picked from commit 618fc13db78b4b8a270daf8fe719910906e49922)
---
 .pick_status.json                              | 2 +-
 src/gallium/drivers/r600/sfn/sfn_optimizer.cpp | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

#diff --git a/.pick_status.json b/.pick_status.json
#index d66b84ffc0c6..2af1876f9c11 100644
#--- a/.pick_status.json
#+++ b/.pick_status.json
#@@ -1210,7 +1210,7 @@
#         "description": "r600/sfn: Don't try to propagate to vec4 with more than one use",
#         "nominated": true,
#         "nomination_type": 1,
#-        "resolution": 0,
#+        "resolution": 1,
#         "main_sha": null,
#         "because_sha": "18a8d148d862d4a0f5b83f4385f00cf8a4a71b6d"
#     },
diff --git a/src/gallium/drivers/r600/sfn/sfn_optimizer.cpp b/src/gallium/drivers/r600/sfn/sfn_optimizer.cpp
index 2e05c2c7af34..767025b747bc 100644
--- a/src/gallium/drivers/r600/sfn/sfn_optimizer.cpp
+++ b/src/gallium/drivers/r600/sfn/sfn_optimizer.cpp
@@ -469,6 +469,9 @@ CopyPropFwdVisitor::propagate_to(RegisterVec4& value, Instr *instr)
          if (value[i]->parents().empty())
             return;
 
+         if (value[i]->uses().size() > 1)
+            return;
+
          assert(value[i]->parents().size() == 1);
          parents[i] = (*value[i]->parents().begin())->as_alu();
 
@@ -477,6 +480,7 @@ CopyPropFwdVisitor::propagate_to(RegisterVec4& value, Instr *instr)
 			if (!parents[i])
 				return; 
 
+
          if ((parents[i]->opcode() != op1_mov) ||
              parents[i]->has_alu_flag(alu_src0_neg) ||
              parents[i]->has_alu_flag(alu_src0_abs) ||
-- 
2.41.0