Re: [PATCH][ARM] NEON DImode neg

[Andrew Stubbs <ams@codesourcery.com>]

Ping.

On 26/03/12 11:14, Andrew Stubbs wrote:
> On 28/02/12 17:45, Andrew Stubbs wrote:
>> Hi all,
>>
>> This patch adds a DImode negate pattern for NEON.
>>
>> Unfortunately, the NEON vneg instruction only supports vectors, not
>> singletons, so there's no direct way to do it in DImode, and the
>> compiler ends up moving the value back to core registers, negating it,
>> and returning to NEON afterwards:
>>
>> fmrrd r2, r3, d16 @ int
>> negs r2, r2
>> sbc r3, r3, r3, lsl #1
>> fmdrr d16, r2, r3 @ int
>>
>> The new patch does it entirely in NEON:
>>
>> vmov.i32 d17, #0 @ di
>> vsub.i64 d16, d17, d16
>>
>> (Note that this is the result when combined with my recent patch for
>> NEON DImode immediates. Without that you get a constant pool load.)
>
> This updates fixes a bootstrap failure caused by an early clobber error.
> I've also got a native regression test running now.
>
> OK?
>
> Andrew