[llvm] ValueTracking: Fix wrong interested mask in SimplifyDemandedFPClass (PR #174072)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/174072

We are interested in the values that are still candidates, not ones
that have already been ruled out from the uses. Avoids regressions
when new uses are introduced.

>From 2368c97e82a0d262e956177a18d773387276ca7f Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Wed, 31 Dec 2025 08:56:37 +0100
Subject: [PATCH] ValueTracking: Fix wrong interested mask in
 SimplifyDemandedFPClass

We are interested in the values that are still candidates, not ones
that have already been ruled out from the uses. Avoids regressions
when new uses are introduced.
---
 llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 45fa8ee8b33a3..85672cdfe1377 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -2281,7 +2281,7 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(Value *V,
     break;
   }
   default:
-    Known = computeKnownFPClass(I, ~DemandedMask, CxtI, Depth + 1);
+    Known = computeKnownFPClass(I, DemandedMask, CxtI, Depth + 1);
     break;
   }