Date: Thu, 5 Jan 2006 09:18:48 +0000 (UTC) From: Bruce Evans <bde@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/lib/msun/src s_cbrtf.c Message-ID: <200601050918.k059Inrv089729@repoman.freebsd.org>
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bde 2006-01-05 09:18:48 UTC
FreeBSD src repository
Modified files:
lib/msun/src s_cbrtf.c
Log:
Oops, on amd64 (and probably on all non-i386 systems), the previous
commit broke the 2**24 cases where |x| > DBL_MAX/2. There are exponent
range problems not just for denormals (underflow) but for large values
(overflow). Doubles have more than enough exponent range to avoid the
problems, but I forgot to convert enough terms to double, so there was
an x+x term which was sometimes evaluated in float precision.
Unfortunately, this is a pessimization with some combinations of systems
and compilers (it makes no difference on Athlon XP's, but on Athlon64's
it gives a 5% pessimization with gcc-3.4 but not with gcc-3.3).
Exlain the problem better in comments.
Revision Changes Path
1.16 +11 -6 src/lib/msun/src/s_cbrtf.c
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