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Subject: [Bug math/14803] Different ULPs depending on size of long int in GCC
Date: Sun, 04 Nov 2012 22:54:00 -0000
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http://sourceware.org/bugzilla/show_bug.cgi?id=14803

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2012-11-04 22:54:25 UTC ---
(In reply to comment #1)

> But since GCC uses 160 bits internally, getting different results for a 
> 64-bit mantissa is a bit surprising unless one of the constants is 
> extremely close to a half-way value.

I believe it is the case here.

> > /export/build/gnu/glibc-test/build-x86_64-linx/math/test-ildoubl.out
> > testing long double (inline functions)
> 
> We can of course also update libm-test-ulps to include these ulps, though

Since libm-test-ulps can be auto-generated, we need to collect x86-64 ULPs
from both 32-bit long GCC and 64-bit long GCC.

> preferably all computed constants in libm sources would be hex float to 
> make unambiguous exactly what floating-point number is intended.

This would be ideal.

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