cmd/compile: intrinsify math.Sqrt on 386
It seems like all the pieces were already there, it only needed the
final plumbing.
Before:
0x001b 00027 (test.go:9) MOVSD X0, (SP)
0x0020 00032 (test.go:9) CALL math.Sqrt(SB)
0x0025 00037 (test.go:9) MOVSD 8(SP), X0
After:
0x0018 00024 (test.go:9) SQRTSD X0, X0
name old time/op new time/op delta
Sqrt-4 4.60ns ± 2% 0.45ns ± 1% -90.33% (p=0.000 n=10+10)
Change-Id: I0f623958e19e726840140bf9b495d3f3a9184b9d
Reviewed-on: https://go-review.googlesource.com/96615
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>