Paul Brook - Re: [gfortran,patch] FPE options, once again (original) (raw)

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• From: Paul Brook
• To: fortran at gcc dot gnu dot org
• Cc: FX Coudert ,patch
• Date: Thu, 8 Sep 2005 17:50:11 +0100
• Subject: Re: [gfortran,patch] FPE options, once again
• References: <431768A9.9050409@gmail.com>

On Thursday 01 September 2005 21:46, FX Coudert wrote:

This is the new version of the FPE patch for gfortran, using glibc-specific code on systems where it is available, and runtime detection of SSE units.

I think the code itself is now in pretty good shape, although i'm a bit worried of having heard no word from other gfortran developpers about things such as the option name and the need/convenience of having environment variables.

I thought the last time this was discussed (for a different option), the conclusion was that environment variables were more trouble that they were worth. Applications are liable to mysteriously break because a user didn't have the exact same combination of magic environment variables set.

My preference is for a commandline switch (like you implemented), and maybe a new intrinsic procedure so an application can control the setting at runtime.

Regtested on i686-linux. Testing in progress on i686-freebsd, x86_64-linux and i386-openbsd (no glibc, no SSE).

OK for mainline? Do we want this on 4.0?

• ?int invalid = exceptions & 0x01;
• ?int denormal = exceptions & 0x02;
• ?int zero = exceptions & 0x04;
• ?int overflow = exceptions & 0x08;
• ?int underflow = exceptions & 0x10;
• ?int precision = exceptions & 0x20; ...
• ?gfc_option.fpe_invalid = 0;
• ?gfc_option.fpe_denormal = 0;
• ?gfc_option.fpe_zero = 0;
• ?gfc_option.fpe_overflow = 0;
• ?gfc_option.fpe_underflow = 0;
• ?gfc_option.fpe_precision = 0; [etc]

I agree with RTHs comment that there's no point having all there as separate variables. We convert to/from a bitmap anyway, so we may as well just use that bitmap all the time. Also make the bitmasks into #defines so we don't have hardcoded values in multiple places.

Paul

• Follow-Ups:
  • Re: [gfortran,patch] FPE options, once again
    * From: Richard Guenther
  • Re: [gfortran,patch] FPE options, once again
    * From: FX Coudert
• References:
  • [gfortran,patch] FPE options, once again
    * From: FX Coudert