1 files changed, 2 insertions, 19 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index de9fb7c524f..c3100dd9cc3 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -104,23 +104,6 @@ static bool hasUnaryFloatFn(const TargetLibraryInfo *TLI, Type *Ty,
   }
 }
 
-/// \brief Check whether we can use unsafe floating point math for
-/// the function passed as input.
-static bool canUseUnsafeFPMath(Function *F) {
-
-  // FIXME: For finer-grain optimization, we need intrinsics to have the same
-  // fast-math flag decorations that are applied to FP instructions. For now,
-  // we have to rely on the function-level unsafe-fp-math attribute to do this
-  // optimization because there's no other way to express that the call can be
-  // relaxed.
-  if (F->hasFnAttribute("unsafe-fp-math")) {
-    Attribute Attr = F->getFnAttribute("unsafe-fp-math");
-    if (Attr.getValueAsString() == "true")
-      return true;
-  }
-  return false;
-}
-
 /// \brief Returns whether \p F matches the signature expected for the
 /// string/memory copying library function \p Func.
 /// Acceptable functions are st[rp][n]?cpy, memove, memcpy, and memset.
@@ -2184,10 +2167,10 @@ Value *LibCallSimplifier::optimizeCall(CallInst *CI) {
   IRBuilder<> Builder(CI, /*FPMathTag=*/nullptr, OpBundles);
   bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
 
-  // Command-line parameter overrides function attribute.
+  // Command-line parameter overrides instruction attribute.
   if (EnableUnsafeFPShrink.getNumOccurrences() > 0)
     UnsafeFPShrink = EnableUnsafeFPShrink;
-  else if (canUseUnsafeFPMath(Callee))
+  else if (isa<FPMathOperator>(CI) && CI->hasUnsafeAlgebra())
     UnsafeFPShrink = true;
 
   // First, check for intrinsics.