[PATCH] D80315: Fix CC1 command line options mapping into fast-math flags.

Wed May 27 23:24:55 PDT 2020

michele.scandale added a comment.

In D80315#2058914 <https://reviews.llvm.org/D80315#2058914>, @rjmccall wrote:

> In D80315#2058735 <https://reviews.llvm.org/D80315#2058735>, @michele.scandale wrote:
>
> > In D80315#2058549 <https://reviews.llvm.org/D80315#2058549>, @rjmccall wrote:
> >
> > > The code cleanups all seems reasonable.  The actual changes in code-generation changes are because we were failing to set these reliably?
> >
> >
> > Most of them yes.
> >
> > In the CUDA test we there is now `contract` because we honor the default contraction mode that for CUDA is set to fast.
>
>
> Right, and we weren't honoring that mode before?

Not in the setup of base fast-math flags inside `CodeGenFunction`. However when emitting code for expression with `FPOptions` stored in the AST nodes then `contract` was set correctly.

> 
> 
>> In `clang/test/CodeGen/complex-math.c` I've added `-ffp-contract=fast` to the command line option because `-ffast-math` at the CC1 level does not change the default contraction mode.
> 
> Oh, I see, makes sense.  So there was inconsistent treatment of the options, where one thing observed it but others didn't, and that's been fixed now.

Do you think we should handle `-ffast-math` as `-cl-fast-relaxed-math`, i.e. it implies the default contraction mode being "fast"?

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D80315/new/

https://reviews.llvm.org/D80315