[llvm] [AMDGPU] Use std::optional in InstCombine of amdgcn_fmed3. NFC. (PR #108223)

[Jay Foad via llvm-commits]

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@@ -353,23 +353,20 @@ bool GCNTTIImpl::canSimplifyLegacyMulToMul(const Instruction &I,
 }
 
 /// Match an fpext from half to float, or a constant we can convert.
-static bool matchFPExtFromF16(Value *Arg, Value *&FPExtSrc) {
-  if (match(Arg, m_OneUse(m_FPExt(m_Value(FPExtSrc)))))
-    return FPExtSrc->getType()->isHalfTy();
-
+static std::optional<Value *> matchFPExtFromF16(Value *Arg) {
+  Value *Src;
   ConstantFP *CFP;
-  if (match(Arg, m_ConstantFP(CFP))) {
+  if (match(Arg, m_OneUse(m_FPExt(m_Value(Src))))) {
+    if (Src->getType()->isHalfTy())
+      return Src;
+  } else if (match(Arg, m_ConstantFP(CFP))) {
     bool LosesInfo;
     APFloat Val(CFP->getValueAPF());
     Val.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &LosesInfo);
-    if (LosesInfo)
-      return false;
-
-    FPExtSrc = ConstantFP::get(Type::getHalfTy(Arg->getContext()), Val);
-    return true;
+    if (!LosesInfo)
+      return ConstantFP::get(Type::getHalfTy(Arg->getContext()), Val);
   }
-
-  return false;
+  return {};
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jayfoad wrote:

Done

https://github.com/llvm/llvm-project/pull/108223