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| author | Alberto Donizetti <alb.donizetti@gmail.com> | 2018-04-03 13:46:36 +0200 |
|---|---|---|
| committer | Alberto Donizetti <alb.donizetti@gmail.com> | 2018-04-03 17:45:28 +0000 |
| commit | 00c8e149b67da589f82b7a19df9735e4f03ec5ae (patch) | |
| tree | 6ed0c6b55a61d87bcb0eb7bb6d3d7e0705ddad58 /src/cmd/compile/internal/ssa/schedule.go | |
| parent | ee7dd810f9ca4e63ecfc1d3044869591783b8b74 (diff) | |
| download | go-00c8e149b67da589f82b7a19df9735e4f03ec5ae.tar.gz go-00c8e149b67da589f82b7a19df9735e4f03ec5ae.zip | |
cmd/compile: stack-allocate values worklist in schedule
Compiler instrumentation shows that the cap of the stores slice in the
storeOrder function is almost always 64 or less. Since the slice does
not escape, pre-allocating on the stack a 64-elements one greatly
reduces the number of allocations performed by the function.
name old time/op new time/op delta
Template 289ms ± 5% 283ms ± 3% -1.99% (p=0.000 n=19+20)
Unicode 140ms ± 6% 136ms ± 6% -2.61% (p=0.021 n=19+20)
GoTypes 915ms ± 2% 895ms ± 2% -2.24% (p=0.000 n=19+20)
Compiler 4.15s ± 1% 4.04s ± 2% -2.73% (p=0.000 n=20+20)
SSA 10.0s ± 1% 9.8s ± 2% -2.13% (p=0.000 n=20+20)
Flate 189ms ± 6% 186ms ± 4% -1.75% (p=0.028 n=19+20)
GoParser 229ms ± 5% 224ms ± 4% -2.25% (p=0.001 n=20+19)
Reflect 584ms ± 2% 573ms ± 3% -1.83% (p=0.000 n=18+20)
Tar 265ms ± 3% 261ms ± 3% -1.33% (p=0.021 n=20+20)
XML 328ms ± 2% 321ms ± 2% -2.11% (p=0.000 n=20+20)
name old user-time/op new user-time/op delta
Template 408ms ± 4% 400ms ± 4% -1.98% (p=0.006 n=19+20)
Unicode 216ms ± 9% 216ms ± 7% ~ (p=0.883 n=20+20)
GoTypes 1.25s ± 1% 1.23s ± 3% -1.32% (p=0.002 n=19+20)
Compiler 5.77s ± 1% 5.69s ± 2% -1.47% (p=0.000 n=18+19)
SSA 14.6s ± 5% 14.1s ± 4% -3.45% (p=0.000 n=20+20)
Flate 252ms ± 7% 251ms ± 7% ~ (p=0.659 n=20+20)
GoParser 314ms ± 5% 310ms ± 5% ~ (p=0.165 n=20+20)
Reflect 780ms ± 2% 769ms ± 3% -1.34% (p=0.004 n=19+18)
Tar 365ms ± 7% 367ms ± 5% ~ (p=0.841 n=20+20)
XML 439ms ± 4% 432ms ± 4% -1.45% (p=0.043 n=20+20)
name old alloc/op new alloc/op delta
Template 38.9MB ± 0% 38.8MB ± 0% -0.26% (p=0.000 n=19+20)
Unicode 29.0MB ± 0% 29.0MB ± 0% -0.02% (p=0.001 n=20+19)
GoTypes 115MB ± 0% 115MB ± 0% -0.31% (p=0.000 n=20+20)
Compiler 492MB ± 0% 490MB ± 0% -0.41% (p=0.000 n=20+19)
SSA 1.40GB ± 0% 1.39GB ± 0% -0.48% (p=0.000 n=20+20)
Flate 24.9MB ± 0% 24.9MB ± 0% -0.24% (p=0.000 n=20+20)
GoParser 30.9MB ± 0% 30.8MB ± 0% -0.39% (p=0.000 n=20+20)
Reflect 77.1MB ± 0% 76.8MB ± 0% -0.32% (p=0.000 n=17+20)
Tar 39.1MB ± 0% 39.0MB ± 0% -0.23% (p=0.000 n=20+20)
XML 44.7MB ± 0% 44.6MB ± 0% -0.30% (p=0.000 n=20+18)
name old allocs/op new allocs/op delta
Template 385k ± 0% 382k ± 0% -0.99% (p=0.000 n=20+19)
Unicode 336k ± 0% 336k ± 0% -0.08% (p=0.000 n=19+17)
GoTypes 1.20M ± 0% 1.18M ± 0% -1.11% (p=0.000 n=20+18)
Compiler 4.66M ± 0% 4.59M ± 0% -1.42% (p=0.000 n=19+20)
SSA 11.6M ± 0% 11.5M ± 0% -1.49% (p=0.000 n=20+20)
Flate 237k ± 0% 235k ± 0% -1.00% (p=0.000 n=20+19)
GoParser 319k ± 0% 315k ± 0% -1.12% (p=0.000 n=20+20)
Reflect 960k ± 0% 952k ± 0% -0.92% (p=0.000 n=18+20)
Tar 394k ± 0% 390k ± 0% -0.87% (p=0.000 n=20+20)
XML 418k ± 0% 413k ± 0% -1.18% (p=0.000 n=20+20)
Change-Id: I01b9f45b161379967d7a52e23f39ac30dd90edb0
Reviewed-on: https://go-review.googlesource.com/104415
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Diffstat (limited to 'src/cmd/compile/internal/ssa/schedule.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/schedule.go | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/ssa/schedule.go b/src/cmd/compile/internal/ssa/schedule.go index 8109908475..ff8bac8409 100644 --- a/src/cmd/compile/internal/ssa/schedule.go +++ b/src/cmd/compile/internal/ssa/schedule.go @@ -301,7 +301,11 @@ func storeOrder(values []*Value, sset *sparseSet, storeNumber []int32) []*Value f := values[0].Block.Func // find all stores - var stores []*Value // members of values that are store values + + // Members of values that are store values. + // A constant bound allows this to be stack-allocated. 64 is + // enough to cover almost every storeOrder call. + stores := make([]*Value, 0, 64) hasNilCheck := false sset.clear() // sset is the set of stores that are used in other values for _, v := range values { |