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Re: [PATCH][ARM] NEON DImode neg


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


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