https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112112
Thomas Koenig <tkoenig at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |tkoenig at gcc dot gnu.org
--- Comment #5 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
(In reply to κΉλμ from comment #4)
> From your perspective, do you think this could be a compiler bug? When
> tested with various compiler options following the GCC bug reporting
> guidelines, the binary compiles without any warnings, yet exhibits these
> behaviors
It definitely sounds wrong, there should be consistent results.
Just to make the effect of the signs clear: Could you maybe run the
program
$ cat a.c
#include <stdio.h>
SIGN char v1 = -1;
short v2 = 1;
int main()
{
printf("result for " OPT " \"" STR "\" = %d\n", v1 <= v2);
return 0;
}
with the shell script
$ cat do_all.sh
for s in signed unsigned ""
do
for o in -O0 -O1 -O2 -O3
do
gcc $o -DOPT='"'$o'"' -DSTR='"'$s'"' -DSIGN=$s a.c && ./a.out
done
done
and post the results? For reference, on x86_64 (which has signed
chars) this gets
result for -O0 "signed" = 1
result for -O1 "signed" = 1
result for -O2 "signed" = 1
result for -O3 "signed" = 1
result for -O0 "unsigned" = 0
result for -O1 "unsigned" = 0
result for -O2 "unsigned" = 0
result for -O3 "unsigned" = 0
result for -O0 "" = 1
result for -O1 "" = 1
result for -O2 "" = 1
result for -O3 "" = 1
