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[Bug target/21642] New: wrong code with -O2
- From: "joerg dot richter at pdv-fs dot de" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 18 May 2005 10:01:18 -0000
- Subject: [Bug target/21642] New: wrong code with -O2
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
$ gcc -v
Reading specs from /pdv/.tools/pkg/gcc/3.4.3/bin/../lib/gcc/powerpc-ibm-
aix5.2.0.0/3.4.3/specs
Configured with: ../gcc-3.4.3/configure --prefix=/tools/pkg/gcc/3.4.3 --with-
ld=/bin/ld --with-as=/bin/as --disable-threads --enable-languages=c,c++
Thread model: aix
gcc version 3.4.3
// foo.c //
#include <stdio.h>
inline void
reverse( char* beg, char* end )
{
while( beg < --end )
{
char t = *end;
*end = *beg;
*beg++ = t;
}
}
void doIt( int* val )
{
reverse( (char*)val, (char*)val + sizeof( *val ) );
}
int main()
{
int d = 0x12345678;
printf( "%x\n", d );
doIt( &d );
printf( "%x\n", d );
return 0;
}
////
$ gcc -o foo foo.c -O2
$ foo
12345678
78345612
$ gcc -o foo foo.c
$ foo
12345678
78563412
Works with GCC 3.3.3
--
Summary: wrong code with -O2
Product: gcc
Version: 3.4.3
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: joerg dot richter at pdv-fs dot de
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: powerpc-ibm-aix5.2.0.0
GCC host triplet: powerpc-ibm-aix5.2.0.0
GCC target triplet: powerpc-ibm-aix5.2.0.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21642