[aarch64-port-dev ] RFR(XS): 8242070: AArch64: Fix a typo introduced by JDK-8238690

[Andrew Haley]

On 4/17/20 10:14 AM, Yang Zhang wrote:
> 
> Ping it again. Could you please help to review this?

Before:

Benchmark                    Mode  Cnt    Score   Error  Units
TestVect.testVectShift       avgt    5  141.027 ± 0.117  us/op

  0.41%    0x0000ffffa8c5fc40:   sbfiz	x15, x11, #1, #32
           0x0000ffffa8c5fc44:   add	x16, x18, x15               ;*saload {reexecute=0 rethrow=0 return_oop=0}
                                                                     ; - org.sample.TestVect::testVectShift at 16 (line 31)
           0x0000ffffa8c5fc48:   ldr	q16, [x16, #16]
  0.51%    0x0000ffffa8c5fc4c:   neg	v17.16b, v18.16b
           0x0000ffffa8c5fc50:   sshl	v16.8h, v16.8h, v17.8h
           0x0000ffffa8c5fc54:   add	x15, x17, x15


After:

Benchmark                    Mode  Cnt    Score   Error  Units
TestVect.testVectShift       avgt    5  143.021 ± 0.506  us/op

  0.46%    0x0000ffff78c61f00:   sbfiz	x13, x15, #1, #32
           0x0000ffff78c61f04:   add	x14, x17, x13               ;*saload {reexecute=0 rethrow=0 return_oop=0}
                                                                     ; - org.sample.TestVect::testVectShift at 16 (line 31)
           0x0000ffff78c61f08:   ldr	q16, [x14, #16]
  0.36%    0x0000ffff78c61f0c:   sshr	v16.8h, v16.8h, #2
           0x0000ffff78c61f10:   add	x13, x16, x13

So, at least on this thing it makes no difference. I'll grant you it's
less code, so OK.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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