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Date: Wed, 22 Mar 2023 15:26:13 +0300 (MSK)
From: Alexander Monakov <amonakov@ispras.ru>
To: Richard Biener <richard.guenther@gmail.com>
cc: Jeff Law <jeffreyalaw@gmail.com>, gcc-patches@gcc.gnu.org
Subject: Re: Should -ffp-contract=off the default on GCC?
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On Wed, 22 Mar 2023, Richard Biener wrote:

> I think it's even less realistic to expect users to know the details of
> floating-point math.  So I doubt any such sentence will be helpful
> besides spreading some FUD?

I think it's closer to "fundamental notions" rather than "details". For
users who bother to read the GCC manual there's a decent chance it wouldn't
be for naught.

For documentation, I was thinking

  Together with -fexcess-precision=standard, -ffp-contract=off
  is necessary to ensure that rounding of intermediate results to precision
  implied by the source code and the FLT_EVAL_METHOD macro is not
  omitted by the compiler.

Alexander