[llvm-branch-commits] [llvm] [AMDGPU] Factor the AsmParser match-specificity comparison into a helper, NFC (PR #221987)

[Valery Pykhtin via llvm-branch-commits]

https://github.com/vpykhtin created https://github.com/llvm/llvm-project/pull/221987

Extract the "keep the most specific match status" comparison in
matchAndEmitInstruction into an atLeastAsSpecific() lambda ranking
Match_MnemonicFail < Match_InvalidOperand < Match_MissingFeature. No
functional change.

>From 5c471f0f48598196feba7d480674fa42f004a3e0 Mon Sep 17 00:00:00 2001
From: Valery Pykhtin <valery.pykhtin at amd.com>
Date: Mon, 24 Aug 2026 22:43:49 +0000
Subject: [PATCH] [AMDGPU] Factor the AsmParser match-specificity comparison
 into a helper, NFC

Extract the "keep the most specific match status" comparison in
matchAndEmitInstruction into an atLeastAsSpecific() lambda ranking
Match_MnemonicFail < Match_InvalidOperand < Match_MissingFeature. No
functional change.
---
 .../AMDGPU/AsmParser/AMDGPUAsmParser.cpp      | 22 +++++++++++++------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
index 46284628ae0c7..f0719a4dabf6b 100644
--- a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
+++ b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
@@ -5888,17 +5888,25 @@ bool AMDGPUAsmParser::matchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
   MCInst Inst;
   Inst.setLoc(IDLoc);
   unsigned Result = Match_Success;
+
+  // Order match statuses from least to most specific and keep the most
+  // specific one:
+  //   Match_MnemonicFail < Match_InvalidOperand < Match_MissingFeature
+  auto atLeastAsSpecific = [](unsigned New, unsigned Cur) {
+    auto rank = [](unsigned M) {
+      return M == Match_MnemonicFail     ? 1
+             : M == Match_InvalidOperand ? 2
+             : M == Match_MissingFeature ? 3
+                                         : 0; // Match_Success sentinel
+    };
+    return rank(New) >= rank(Cur);
+  };
+
   for (auto Variant : getMatchedVariants()) {
     uint64_t EI;
     auto R =
         MatchInstructionImpl(Operands, Inst, EI, MatchingInlineAsm, Variant);
-    // We order match statuses from least to most specific. We use most specific
-    // status as resulting
-    // Match_MnemonicFail < Match_InvalidOperand < Match_MissingFeature
-    if (R == Match_Success || R == Match_MissingFeature ||
-        (R == Match_InvalidOperand && Result != Match_MissingFeature) ||
-        (R == Match_MnemonicFail && Result != Match_InvalidOperand &&
-         Result != Match_MissingFeature)) {
+    if (R == Match_Success || atLeastAsSpecific(R, Result)) {
       Result = R;
       ErrorInfo = EI;
     }