[llvm-branch-commits] [llvm] InstCombine: Use SimplifyDemandedFPClass epilog helper function for fma (PR #176017)

[Matt Arsenault via llvm-branch-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/176017

NFC refactor to use shared code for fold to constant or set fast math
flags.

>From 25760c21d712c64df47169ad5b50acefd6216793 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Wed, 14 Jan 2026 20:37:45 +0100
Subject: [PATCH] InstCombine: Use SimplifyDemandedFPClass epilog helper
 function for fma

NFC refactor to use shared code for fold to constant or set fast math
flags.
---
 .../InstCombine/InstCombineSimplifyDemanded.cpp  | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index b198e5e824f1f..ce9dec699b06f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -2582,20 +2582,8 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(Instruction *I,
         Known = KnownFPClass::fma(KnownSrc[0], KnownSrc[1], KnownSrc[2], Mode);
       }
 
-      FPClassTest ValidResults = DemandedMask & Known.KnownFPClasses;
-      if (Constant *SingleVal =
-              getFPClassConstant(VTy, ValidResults, /*IsCanonicalizing=*/true))
-        return SingleVal;
-
-      FastMathFlags InferredFMF =
-          inferFastMathValueFlags(FMF, ValidResults, KnownSrc);
-      if (InferredFMF != FMF) {
-        CI->dropUBImplyingAttrsAndMetadata();
-        CI->setFastMathFlags(InferredFMF);
-        return I;
-      }
-
-      break;
+      return simplifyDemandedFPClassResult(CI, FMF, DemandedMask, Known,
+                                           {KnownSrc});
     }
     case Intrinsic::maximum:
     case Intrinsic::minimum: