[llvm-dev] Floating point semantic modes

[Cameron McInally via llvm-dev]

On Wed, Jan 29, 2020 at 1:51 PM Kaylor, Andrew <andrew.kaylor at intel.com> wrote:
>
> Yes, you’re probably right about this. I was originally thinking of FENV_ACCESS as a fully strict mode of operation, but what you’re suggesting aligns with what Cameron suggested and even some of my own reasoning on other points. So, let me amend my previous proposal to say:
>
>
>
> STDC FENV_ACCESS {ON|OFF}
>   Patch in progress. I think ON should force the following:
>
>     except_behavior { strict }
>     fenv_access { on }
>     rounding_mode { dynamic }
>   Other modes should be unchanged.

Does that apply to -ffp-model=strict too?

If FMFs are really orthogonal to -ffp-model=, then we shouldn't be
setting default values for the FMFs.

>------------------
>
>strict
>
>------------------
>
>except_behavior { strict }
>fenv_access { on }
>rounding_mode { dynamic }
>contract { off }
>denormal_fp_math { IEEE }
>denormal_fp32_math { IEEE }
>support_math_errno { on }
>no_honor_nans { off }
>no_honor_infinities { off }
>no_signed_zeros { off }
>allow_reciprocal { off }
>allow_approximate_fns { off }
>allow_reassociation { off }