Avoid overflows from long double functions using __kernel_standard

[Andreas Jaeger]

On 03/28/2012 03:03 AM, Joseph S. Myers wrote:
> Error handling for various libm functions involves the function
> __kernel_standard that provides support for errno setting and
> "matherr".
>
> This function takes double arguments; matherr is defined that way.
> This causes problems for long double functions when converting long
> double arguments to double causes overflow although the original
> function did not overflow.  This patch addresses that by adding a
> variant __kernel_standard_l that wraps __kernel_standard and reduces
> out-of-range arguments to DBL_MAX or DBL_MIN (or minus those values)
> to avoid spurious exceptions.
>
> Tested x86 and x86_64.  Cases where there were spurious or missing
> exceptions unrelated to this particular cause had appropriate comments
> put in the tests (pointing to existing or new bugs) and
> OVERFLOW_EXCEPTION_OK used to allow overflow exceptions to vary from
> the desired results, or where other exceptions were involved some
> tests were disabled for long double.
>
> Aurelien, this should make it particularly easy to provide testsuite
> coverage for your bug 13705 fix: simply remove ",
> OVERFLOW_EXCEPTION_OK" and the comment from the test with a comment
> pointing to bug 13705.
>
> (This is actually the next piece of attempting to sort out bug 369; I
> found too many of the new tests I added for that bug were failing for
> long double because of issues with using __kernel_standard, so it
> seemed appropriate to fix those issues first.)

This is fine, thanks a lot!

Andreas
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