int weird(float *fp){
// access an int as an int (see caller),
// so not an aliasing violation
return *(int*)fp;
}
int main(int argc, char *argv[]){
return weird((float*)&argc);
}
I just tried this code with gcc 4.4.5 on 32-bit powerpc using -O2 -W -Wall.
Assembly code for the weird function looks OK, both inlined and not, but
that certainly isn't proof that gcc will always tolerate such code.
I recall that there were problems handling this type of code. (never mind
any non-conformant callers that actually pass a pointer to a float -- not
that gcc would be able to see them in separately compiled files)
So, is it fixed now? (what gcc version?) If not, is it at least fixed
if I change "float" to "void" and/or "unsigned char"?
BTW, oddly it looks like gcc tolerates a genuine aliasing violation
as well now. (passing the value as a float) Of course, that may just
be my luck with the optimizer.
