>
> You can get the RTL for these patterns when expanding stores like
>
> a = (b < c);
>
> In this case, GCC tries to avoid a conditional branch and (I suppose you are
> on GCC <4.5) instead of cmp<mode> and b<cond> you go through cmp<mode> and
> s<cond>. cmp<mode> does nothing but stashing away its operands, while
> s<cond> expands RTL for both the comparison and the above insn.
Thanks, and yes, I'm using GCC 4.4,
But gcc didn't work in this way for me, I tried piece of code like:
extern float a, b;
extern int c;
int main(void)
{
c = (a < b);
return 0;
}
after tracing cc1, found gcc would also do it with set/compare/jump/set code at
the end of function do_store_flag, i.e., unsing cmp<mode> and b<code> sequence.
--
Best Regards.
