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Date: Wed, 21 Nov 2012 21:57:00 -0000
From: Richard Henderson <rth@twiddle.net>
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To: "Joseph S. Myers" <joseph@codesourcery.com>
CC: libc-ports@sourceware.org
Subject: Re: Make ARM fesetenv (FE_NOMASK_ENV) detect failure (bug 14866)
References: <Pine.LNX.4.64.1211212027330.11924@digraph.polyomino.org.uk>
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On 11/21/2012 12:28 PM, Joseph S. Myers wrote:
> +      if (envp == FE_NOMASK_ENV)
> +	{
> +	  /* VFPv3 and VFPv4 do not support trapping exceptions, so
> +	     test whether the relevant bits were set and fail if
> +	     not.  */
> +	  _FPU_GETCW (temp);
> +	  if ((temp & _FPU_IEEE) != _FPU_IEEE)
> +	    return 1;
> +	}

Why test vs FE_NOMASK_ENV explicitly?  In theory the exception value
could have come from just about anywhere.

This would seem to do the same thing with fewer assumptions:

  if (temp & _FPU_IEEE)
    {
      unsigned temp2;
      _FPU_GETCW (temp2);
      if (temp != temp2)
        return 1;
    }


r~