Choosing the best multiplication

[Paulo J. Matos]

Paolo Bonzini <bonzini@gnu.org> writes:

> On 09/24/2010 10:10 AM, Paulo J. Matos wrote:
>
> You can use mul<mode>3 for non-widening multiplication, which would
> always use smult, and {u,}mul<mode1><mode2>3 for widening
> multiplication which has to use smult or umult for correctness.
> That's how i386 chooses between multi-operand imul (non-widening),
> single-operand imul (widening signed) and single-operand mul (widening
> unsigned).  Note that the i386 ISA lacks a non-widening unsigned
> multiplication exactly because it's pointless.
>
> Or are you already doing that?
>

No, I am not actually. I initially thought it wouldn't  work.
However, it makes sense. I just implemented it and it doesn work.

Thanks!

-- 
PMatos