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[Bug libc/13524] New: glibc 32: sscanf get wrong result for long double at 4e-28 and 8e-28 at Linux on Power
- From: "guojiufu at gmail dot com" <sourceware-bugzilla at sourceware dot org>
- To: glibc-bugs at sources dot redhat dot com
- Date: Wed, 21 Dec 2011 02:58:00 +0000
- Subject: [Bug libc/13524] New: glibc 32: sscanf get wrong result for long double at 4e-28 and 8e-28 at Linux on Power
- Auto-submitted: auto-generated
http://sourceware.org/bugzilla/show_bug.cgi?id=13524
Bug #: 13524
Summary: glibc 32: sscanf get wrong result for long double at
4e-28 and 8e-28 at Linux on Power
Product: glibc
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: libc
AssignedTo: drepper.fsp@gmail.com
ReportedBy: guojiufu@gmail.com
Classification: Unclassified
Hardware >POWER5+
software
---
#include<stdio.h>
#include<math.h>
union U { long double ld; int d[sizeof(long double)/sizeof(int)];};
void Print(long double data) {
union U u;
u.ld=data;
printf("long double:%Lg\t hex:" ,u.ld);
int i;
for(i = 0; i < sizeof(long double)/sizeof(int);++i) printf("%0x ",u.d[i]);
printf("\n");
}
void foo(char * str,long double b){
long double a ;
(void)sscanf(str, "%Le", &a);
Print(b);
Print(a);
Print(a-b);
}
int main()
{
foo("4e-28L",+4e-28L);
foo("8e-28L",+8e-28L);
return 0 ;
}
-----------
gcc t.c -m32;./a.out
long double:4e-28 hex:3a3fb0f6 be506019 36d06c5e 54eb70c4
long double:4e-28 hex:3a3fb0f6 be506019 36d06c5e 54eb70e4
long double:7.96546e-59 hex:33e00000 0 0 0
long double:8e-28 hex:3a4fb0f6 be506019 36e06c5e 54eb70c4
long double:8e-28 hex:3a4fb0f6 be506019 36e06c5e 54eb70d4
long double:7.96546e-59 hex:33e00000 0 0 0
--
gcc t.c -m64;./a.out
long double:4e-28 hex:3a3fb0f6 be506019 36d06c5e 54eb70c4
long double:4e-28 hex:3a3fb0f6 be506019 36d06c5e 54eb70c4
long double:0 hex:0 0 0 0
long double:8e-28 hex:3a4fb0f6 be506019 36e06c5e 54eb70c4
long double:8e-28 hex:3a4fb0f6 be506019 36e06c5e 54eb70c4
long double:0 hex:0 0 0 0
--
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