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Incorrect casting?
- From: Marcin BaczyÅski <marbacz at gmail dot com>
- To: gcc at gcc dot gnu dot org
- Date: Tue, 9 Mar 2010 19:16:27 +0100
- Subject: Incorrect casting?
Hi,
the following piece of code produces different output on svn trunk and
gcc-4_4-branch:
#include <stdio.h>
int main()
{
struct { unsigned bar:1; } foo;
foo.bar = 0x1;
printf("%08x\n", (unsigned char)(foo.bar * 0xfe));
printf("%08x\n", (unsigned char)(foo.bar * 0xff));
return 0;
}
monstter@yggdrasil /data/tmp $ gcc -v
Using built-in specs.
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-svn/configure --enable-stage1-languages-c
--enable-languages=c,c++
Thread model: posix
gcc version 4.4.4 20100309 (prerelease) (GCC)
monstter@yggdrasil /data/tmp $ ./a.out
000000fe
00000001
monstter@yggdrasil /data/tmp $ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/4.5.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-svn/configure --enable-stage1-languages-c
--enable-languages=c,c++
Thread model: posix
gcc version 4.5.0 20100309 (experimental) (GCC)
monstter@yggdrasil /data/tmp $ ./a.out
000000fe
000000ff
Is there something illegal in this code or is it a bug somewhere?
Thanks,
Marcin