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* [Bug math/13563] New: LoP asinl returns unexpected value on long double
@ 2012-01-05  6:56 guojiufu at gmail dot com
  2012-01-05  8:23 ` [Bug math/13563] " aj at suse dot de
                   ` (8 more replies)
  0 siblings, 9 replies; 10+ messages in thread
From: guojiufu at gmail dot com @ 2012-01-05  6:56 UTC (permalink / raw)
  To: glibc-bugs

http://sourceware.org/bugzilla/show_bug.cgi?id=13563

             Bug #: 13563
           Summary: LoP asinl returns unexpected value on long double
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: math
        AssignedTo: aj@suse.de
        ReportedBy: guojiufu@gmail.com
    Classification: Unclassified


#include <stdio.h>
#include <float.h>
#include <math.h>

typedef union { long double ld; struct{long l1, l2, l3, l4;} s; } U ;

int main(void) {
   U u ;
   long double arg = (1.L-((__extension__ 0x1p-105L))/(long double)2);
   long double a = asinl(arg);

   u.ld = arg ;
   printf("size of long double=%d long=%d\n", sizeof(long double),
sizeof(long));
   printf("%X %X %X %X\n", u.s.l1,u.s.l2,u.s.l3,u.s.l4);
   printf("%.30Lg\n",arg);
   printf("%.30Lg\n",a);

 return 0;
}

> gcc t.c -lm;./a.out

EXPECTED OUTPUT:

size of long double=8 long=4
3FF00000 0 FE97FF4 0
1
1.57079632679489655799898173427


ACTUAL OUTPUT:
size of long double=16 long=4
3FF00000 0 B9500000 0
1
nan   <-should be 1.570796326794....

This issue happens at Linux on Power system

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^ permalink raw reply	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2014-06-27 11:16 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-01-05  6:56 [Bug math/13563] New: LoP asinl returns unexpected value on long double guojiufu at gmail dot com
2012-01-05  8:23 ` [Bug math/13563] " aj at suse dot de
2012-01-05 14:45 ` sjmunroe at us dot ibm.com
2012-01-05 19:19 ` sjmunroe at us dot ibm.com
2012-01-24 21:03 ` dflahert at us dot ibm.com
2012-02-16 17:14 ` dflahert at us dot ibm.com
2012-03-02  0:59 ` jsm28 at gcc dot gnu.org
2012-05-06 14:44 ` azanella at linux dot vnet.ibm.com
2012-05-06 14:45 ` azanella at linux dot vnet.ibm.com
2014-06-27 11:16 ` fweimer at redhat dot com

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