[PATCH] D72820: [FPEnv] Add pragma FP_CONTRACT support under strict FP.

[Phoebe Wang via Phabricator via cfe-commits]

pengfei added inline comments.


================
Comment at: clang/lib/CodeGen/CGExprScalar.cpp:3386
+    FMulAdd = Builder.CreateConstrainedFPCall(
+        CGF.CGM.getIntrinsic(llvm::Intrinsic::experimental_constrained_fmuladd,
+                             Addend->getType()),
----------------
Allen wrote:
> Sorry, I'm not familiar with the optimization of the clang front end. 
> I'd like to ask, is this optimization supposed to assume that all the backends have instructions like Fmuladd?
No, it is a flexible intrinsic, which allows backends to choose their best approach. It can be either interpretered as mul + add or fma. It represents user doesn't care the differece between them.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72820/new/

https://reviews.llvm.org/D72820