[InstSimplify] Check call for FMF instead of CtxI

[annamthomas]

This code was incorrectly checking that the CtxI has required FMF, but
the context instruction need not always be the instrinsic call.

Check that the intrinsic call has the required FMF.

Fixes PR71548.

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: None (annamthomas)

Changes

This code was incorrectly checking that the CtxI has required FMF, but
the context instruction need not always be the instrinsic call.

Check that the intrinsic call has the required FMF.

Fixes PR71548.

---

Full diff: https://github.com/llvm/llvm-project/pull/71585.diff

1 Files Affected:

• (modified) llvm/lib/Analysis/InstructionSimplify.cpp (+6-6)

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index ad51e163062012e..bec20d75f004422 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -6346,7 +6346,8 @@ static Value *foldMinimumMaximumSharedOp(Intrinsic::ID IID, Value *Op0,
 }
 
 static Value *simplifyBinaryIntrinsic(Function *F, Value *Op0, Value *Op1,
-                                      const SimplifyQuery &Q) {
+                                      const SimplifyQuery &Q,
+                                      const CallBase *Call) {
   Intrinsic::ID IID = F->getIntrinsicID();
   Type *ReturnType = F->getReturnType();
   unsigned BitWidth = ReturnType->getScalarSizeInBits();
@@ -6606,20 +6607,19 @@ static Value *simplifyBinaryIntrinsic(Function *F, Value *Op0, Value *Op1,
     // float, if the ninf flag is set.
     const APFloat *C;
     if (match(Op1, m_APFloat(C)) &&
-        (C->isInfinity() || (isa<FPMathOperator>(Q.CxtI) &&
-                             Q.CxtI->hasNoInfs() && C->isLargest()))) {
+        (C->isInfinity() || (Call->hasNoInfs() && C->isLargest()))) {
       // minnum(X, -inf) -> -inf
       // maxnum(X, +inf) -> +inf
       // minimum(X, -inf) -> -inf if nnan
       // maximum(X, +inf) -> +inf if nnan
-      if (C->isNegative() == IsMin && (!PropagateNaN || Q.CxtI->hasNoNaNs()))
+      if (C->isNegative() == IsMin && (!PropagateNaN || Call->hasNoNaNs()))
         return ConstantFP::get(ReturnType, *C);
 
       // minnum(X, +inf) -> X if nnan
       // maxnum(X, -inf) -> X if nnan
       // minimum(X, +inf) -> X
       // maximum(X, -inf) -> X
-      if (C->isNegative() != IsMin && (PropagateNaN || Q.CxtI->hasNoNaNs()))
+      if (C->isNegative() != IsMin && (PropagateNaN || Call->hasNoNaNs()))
         return Op0;
     }
 
@@ -6681,7 +6681,7 @@ static Value *simplifyIntrinsic(CallBase *Call, Value *Callee,
     return simplifyUnaryIntrinsic(F, Args[0], Q);
 
   if (NumOperands == 2)
-    return simplifyBinaryIntrinsic(F, Args[0], Args[1], Q);
+    return simplifyBinaryIntrinsic(F, Args[0], Args[1], Q, Call);
 
   // Handle intrinsics with 3 or more arguments.
   switch (IID) {

[nikic]

There are more cases like this inside simplifyUnaryIntrinsic().

[nikic]

LGTM