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cmd/compile: intrinsify math/bits.Add on amd64

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name             old time/op  new time/op  delta
Add-8            1.11ns ± 0%  1.18ns ± 0%   +6.31%  (p=0.029 n=4+4)
Add32-8          1.02ns ± 0%  1.02ns ± 1%     ~     (p=0.333 n=4+5)
Add64-8          1.11ns ± 1%  1.17ns ± 0%   +5.79%  (p=0.008 n=5+5)
Add64multiple-8  4.35ns ± 1%  0.86ns ± 0%  -80.22%  (p=0.000 n=5+4)

The individual ops are a bit slower (but still very fast).
Using the ops in carry chains is very fast.

Update #28273

Change-Id: Id975f76df2b930abf0e412911d327b6c5b1befe5
Reviewed-on: https://go-review.googlesource.com/c/144257
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This commit is contained in:
Keith Randall 2018-10-23 14:05:38 -07:00 • committed by Keith Randall
parent f6b554fec7
commit 899f3a2892
10 changed files with 493 additions and 12 deletions
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2
src/cmd/compile/internal/ssa/gen/genericOps.go
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@ -491,6 +491,8 @@ var genericOps = []opData{
{name: "Sub32carry", argLength: 2, typ: "(UInt32,Flags)"}, // arg0 - arg1, returns (value, carry)
{name: "Sub32withcarry", argLength: 3}, // arg0 - arg1 - arg2, arg2=carry (0 or 1)
{name: "Add64carry", argLength: 3, commutative: true, typ: "(UInt64,UInt64)"}, // arg0 + arg1 + arg2, arg2 must be 0 or 1. returns (value, value>>64)
{name: "Signmask", argLength: 1, typ: "Int32"}, // 0 if arg0 >= 0, -1 if arg0 < 0
{name: "Zeromask", argLength: 1, typ: "UInt32"}, // 0 if arg0 == 0, 0xffffffff if arg0 != 0
{name: "Slicemask", argLength: 1}, // 0 if arg0 == 0, -1 if arg0 > 0, undef if arg0<0. Type is native int size.