Re: [PATCH 1/3] Add rtx costs for sse integer ops

On 06/27/2012 10:08 AM, Igor Zamyatin wrote:
> On Wed, Jun 27, 2012 at 9:00 PM, Richard Henderson <rth <at> redhat.com> wrote:
>> > On 06/27/2012 09:07 AM, Igor Zamyatin wrote:
>>> >> May I ask about the purpose of the following piece of change? Doesn't
>>> >> it affect non-sse cases either?
>> >
>> > Err, no, it doesn't affect non-sse cases.  All MODE_VECTOR_INT
>> > cases will be implemented in the xmm registers (ignoring the
>> > deprecated and largely ignored mmx case).
> Probably I misunderstand something... This condition - GET_MODE_SIZE
> (mode) < UNITS_PER_WORD - is outside the check for MODE_VECTOR_INT.

Of course.

We currently have

	if (vector mode)
	else if (mode <= word size)
	else /* scalar mode > word size */

We could no doubt legitimately rearrange this to

	if (mode < word size)
	else if (vector mode)
	else /* scalar mode > word size */

but I don't see how that's any clearer.  We certainly
can't eliminate any tests, since there are in fact
three different possibilities.

r~