On Sat, Sep 15, 2007 at 05:59:06PM -0400, Kamaraju S Kusumanchi wrote: > I am trying to understand why guile 1.8.2 FTBFS on alpha architecture. > The corresponding build log is at > http://buildd.debian.org/fetch.cgi?&pkg=guile-1.8&ver=1.8.2%2B1-2&arch=alpha&stamp=1188100514&file=log
> I looked at the source guile-1.8-1.8.2+1/test-suite/standalone/test-round.c > and the lines where the build fails is > /* 2^DBL_MANT_DIG-1 > In the past scm_c_round had incorrectly incremented this value, due > to the way that x+0.5 would round upwards (in the usual default > nearest-even mode on most systems). */ > x = ldexp (1.0, DBL_MANT_DIG) - 1.0; > assert (x == floor (x)); /* should be an integer already */ > assert (scm_c_round (x) == x); /* scm_c_round should return it > unchanged */ > I do not have access to an alpha machine, so the only way I can debug the > problem is by looking at the source code. I gather that the above test > should not fail provided IEEE 745 standard is followed for performing > floating point arithmetic. What is the status of this on various > architectures (especially on alpha)? Here's the problem: value: 9007199254740991.000000, floor: 9007199254740990.000000 This is evidently a bug in glibc, calculating the floor() value wrong on alpha. -- Steve Langasek Give me a lever long enough and a Free OS Debian Developer to set it on, and I can move the world. [EMAIL PROTECTED] http://www.debian.org/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
