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Date: | Wed, 19 Dec 2012 08:03:46 +0100 |
From: | marco atzeri <marco DOT atzeri AT gmail DOT com> |
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To: | cygwin AT cygwin DOT com |
Subject: | Re: Bug in Cygwin strtod() |
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On 12/19/2012 2:30 AM, KHMan wrote: > On 12/19/2012 8:54 AM, Cary R. wrote: >> The following code demonstrates a subtle bug in the Cygwin version of >> strtod(). The value it generates is slightly different than the value >> when using the math header files. This used to work correctly some >> time ago (months). I just took the time to track the problem down in >> our regression suite. >> >> #include<math.h> >> #include<stdio.h> >> #include<stdlib.h> >> >> int main() >> { >> double value = M_LN10; >> >> printf("generate const. - value: %0.15f.\n", value); >> printf("expected const. - value: 2.302585092994046.\n"); >> >> printf("\n"); >> value = strtod("2.30258509299404568402", 0); >> >> /* Note: the last digit is incorrect. */ >> printf("generate strtod - value: %0.15f.\n", value); >> printf("expected strtod - value: 2.302585092994046.\n"); >> >> return 0; >> } > > Yep, looks like the significand misses its mark by 1. > strtod is from newlib. the last change in the code is one year and half ago http://sourceware.org/cgi-bin/cvsweb.cgi/src/newlib/libc/stdlib/strtod.c.diff?r1=1.17&r2=1.18&cvsroot=src -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
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