On Mon, Oct 24, 2011 at 11:12:29PM -0400, David Miller wrote:
> While working on some test cases I noticed that the 'fsmuld'
> instruction on sparc was not being matched by the combiner for
> things like:
>
> double fsmuld (float a, float b)
> {
> return a * b;
> }
>
> Combine does try to match:
>
> (set x (float_extend:DF (mul:SF y z)))
That is correct. float a * float b is supposed to e.g. result in Inf
if the product overflows float (but would still fit into double).
I bet
double fsmuld (float a, float b)
{
return (double) a * b;
}
instead will match your pattern, then the operands are first extended
into double and then multiplied into a double product.
Jakub
