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Re: Vector comparison
On Sun, Aug 15, 2010 at 8:56 PM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> On Sun, Aug 15, 2010 at 8:38 PM, Artem Shinkarov
> <artyom.shinkaroff@gmail.com> wrote:
>>> Please consider using tree codes all the way through the gimple IR if
>>> the target supports expansion and doing the expansion only at expand
>>> time. ?Building a call expression is expensive and really you could
>>> use opcodes and not worry about a target hook. ?I think opcodes it is
>>> a much easier way allowing for targets to add support rather than
>>> adding more and more target hooks.
>>
>> The hook approach was approved by Richard,
>
> Hmm, it's unfortunate that this wasn't brought up earlier on the gcc
> list. I agree with pinski that using new codes here seems like the
> better approach.
New codes for what? If you want to delay expansion to expand instead
of vector lowering you could do that by just keeping the comparison as it is.
>> so let's wait what he is
>> going to tell.
>
> Right. Perhaps Richi had good reasons to not use new codes.
Lowering vector comparisons to either piecewise operations (as veclower
usually does) or to target specific code is easier on gimple. It's easier
to develop and grok to have it in one place (instead of lowering only what
we can't handle directly).
But well - maybe you can clarify what new tree codes you are thinking of?
Certainly not a new tree code for every possible target builtin we have?
Richard.
> Ciao!
> Steven
>