On Nov 27, 2007 9:09 PM, Raymond Sheh <rsheh@xxxxxxxxxxxxxxx> wrote:
> whole thing goes random with -O3. Adding -fno-strict-aliasing makes it
> work again but compiling with only -fstrict-aliasing doesn't break it so
> it looks like a combination of things.
You don't see warnings with -fstrict-aliasing?
> float floatblah(float in)
> {
> unsigned long retval =
> byte_manipulation_function_that_happens_to_take_ulongs(*((unsigned
> long*)(&in)));
> return *((float*)(&retval));
> }
You realize of course, this is invalid for 64-bit since float is
32-bit and unsigned long is 64-bit on 64-bit linux.
Why can't you use the union for type-punning here?
union { float a; unsigned long b; };
a = in;
b = im_not_typing_that(b);
return a;
corey
