[clang] [Clang] Add support for fp when using min_fetch/max_fetch atomics (PR #160330)

[via cfe-commits]

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@@ -507,20 +507,35 @@ static llvm::Value *EmitPostAtomicMinMax(CGBuilderTy &Builder,
                                          bool IsSigned,
                                          llvm::Value *OldVal,
                                          llvm::Value *RHS) {
+  llvm::Type *ValTy = OldVal->getType();
+
   llvm::CmpInst::Predicate Pred;
+  bool IsFP = ValTy->isFloatingPointTy();
+
   switch (Op) {
   default:
     llvm_unreachable("Unexpected min/max operation");
+
   case AtomicExpr::AO__atomic_max_fetch:
   case AtomicExpr::AO__scoped_atomic_max_fetch:
-    Pred = IsSigned ? llvm::CmpInst::ICMP_SGT : llvm::CmpInst::ICMP_UGT;
+    Pred = IsFP
+               ? llvm::CmpInst::FCMP_OGT
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CarolineConcatto wrote:

Ok, I saw now that using llvm.maximum and llvm.minimum we can still lower to atomic instructions. I did know that before.

https://github.com/llvm/llvm-project/pull/160330