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| author | Brian Kessler <brian.m.kessler@gmail.com> | 2018-10-23 20:54:56 -0600 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2018-11-27 05:04:25 +0000 |
| commit | 319787a528284aefe23424056a19bda71f7cc2b1 (patch) | |
| tree | 999010b57fa235c0f78489bb1a8ed972176921e7 /test/codegen/mathbits.go | |
| parent | ead5d1e316873a63471de31f3d70f97aeb7969f5 (diff) | |
| download | go-319787a528284aefe23424056a19bda71f7cc2b1.tar.xz | |
cmd/compile: intrinsify math/bits.Div on amd64
Note that the intrinsic implementation panics separately for overflow and
divide by zero, which matches the behavior of the pure go implementation.
There is a modest performance improvement after intrinsic implementation.
name old time/op new time/op delta
Div-4 53.0ns ± 1% 47.0ns ± 0% -11.28% (p=0.008 n=5+5)
Div32-4 18.4ns ± 0% 18.5ns ± 1% ~ (p=0.444 n=5+5)
Div64-4 53.3ns ± 0% 47.5ns ± 4% -10.77% (p=0.008 n=5+5)
Updates #28273
Change-Id: Ic1688ecc0964acace2e91bf44ef16f5fb6b6bc82
Reviewed-on: https://go-review.googlesource.com/c/144378
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'test/codegen/mathbits.go')
| -rw-r--r-- | test/codegen/mathbits.go | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/test/codegen/mathbits.go b/test/codegen/mathbits.go index 85d5bdea33..44ab2c02b7 100644 --- a/test/codegen/mathbits.go +++ b/test/codegen/mathbits.go @@ -465,3 +465,17 @@ func Mul64(x, y uint64) (hi, lo uint64) { // ppc64le:"MULHDU","MULLD" return bits.Mul64(x, y) } + +// --------------- // +// bits.Div* // +// --------------- // + +func Div(hi, lo, x uint) (q, r uint) { + // amd64:"DIVQ" + return bits.Div(hi, lo, x) +} + +func Div64(hi, lo, x uint64) (q, r uint64) { + // amd64:"DIVQ" + return bits.Div64(hi, lo, x) +} |