From 2ddd8ef0a3e98c72881e6d349756a8f68271d09d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Sch=C3=BCrmann?= <daniel@schuermann.dev>
Date: Fri, 25 Jul 2025 09:34:51 +0200
Subject: [PATCH] aco/ra: don't optimize encodings on precolor affinity
 mismatch

Totals from 238 (0.30% of 79839) affected shaders: (Navi48)
Instrs: 137836 -> 137176 (-0.48%); split: -0.50%, +0.02%
CodeSize: 728616 -> 728668 (+0.01%); split: -0.06%, +0.07%
Latency: 1503248 -> 1500202 (-0.20%); split: -0.56%, +0.36%
InvThroughput: 297725 -> 296715 (-0.34%); split: -0.70%, +0.36%
Copies: 9390 -> 8825 (-6.02%); split: -6.33%, +0.31%
VALU: 89861 -> 89296 (-0.63%); split: -0.66%, +0.03%
SALU: 13166 -> 13167 (+0.01%); split: -0.05%, +0.06%

Suggested-by: Georg Lehmann <dadschoorse@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36345>
---
 src/amd/compiler/aco_register_allocation.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/amd/compiler/aco_register_allocation.cpp b/src/amd/compiler/aco_register_allocation.cpp
index d004f07dfa2..688b21798b2 100644
--- a/src/amd/compiler/aco_register_allocation.cpp
+++ b/src/amd/compiler/aco_register_allocation.cpp
@@ -3231,6 +3231,9 @@ optimize_encoding_vop2(ra_ctx& ctx, RegisterFile& register_file, aco_ptr<Instruc
            std::any_of(instr->operands.begin(), instr->operands.end(), [&](Operand op)
                        { return op.isKillBeforeDef() && op.physReg() == affinity.reg; })))
          return;
+   } else if (ctx.assignments[def_id].precolor_affinity) {
+      if (ctx.assignments[def_id].reg != instr->operands[2].physReg())
+         return;
    }
 
    if (!instr->operands[1].isOfType(RegType::vgpr))
@@ -3276,11 +3279,14 @@ optimize_encoding_sopk(ra_ctx& ctx, RegisterFile& register_file, aco_ptr<Instruc
    unsigned def_id = instr->definitions[0].tempId();
    if (ctx.assignments[def_id].affinity) {
       assignment& affinity = ctx.assignments[ctx.assignments[def_id].affinity];
-      if (affinity.assigned && affinity.reg != instr->operands[!literal_idx].physReg() &&
+      if (affinity.assigned && affinity.reg != op_reg &&
           (!register_file.test(affinity.reg, instr->operands[!literal_idx].bytes()) ||
            std::any_of(instr->operands.begin(), instr->operands.end(), [&](Operand op)
                        { return op.isKillBeforeDef() && op.physReg() == affinity.reg; })))
          return;
+   } else if (ctx.assignments[def_id].precolor_affinity) {
+      if (ctx.assignments[def_id].reg != op_reg)
+         return;
    }
 
    instr->format = Format::SOPK;