internal/runtime/maps: hash copy of key instead of key itself makes map run slowly #76083
Description
Go version
go version go1.24.6 linux/arm64
Output of go env in your module/workspace:
AR='ar' CC='gcc' CGO_CFLAGS='-O2 -g' CGO_CPPFLAGS='' CGO_CXXFLAGS='-O2 -g' CGO_ENABLED='1' CGO_FFLAGS='-O2 -g' CGO_LDFLAGS='-O2 -g' CXX='g++' GCCGO='gccgo' GO111MODULE='' GOARCH='arm64' GOARM64='v8.0' GOAUTH='netrc' GOBIN='' GOCACHE='/root/.cache/go-build' GOCACHEPROG='' GODEBUG='' GOENV='/root/.config/go/env' GOEXE='' GOEXPERIMENT='' GOFIPS140='off' GOFLAGS='' GOGCCFLAGS='-fPIC -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1461831740=/tmp/go-build -gno-record-gcc-switches' GOHOSTARCH='arm64' GOHOSTOS='linux' GOINSECURE='' GOMOD='/home/spy/gomapbench/go.mod' GOMODCACHE='/root/go/pkg/mod' GONOPROXY='' GONOSUMDB='' GOOS='linux' GOPATH='/root/go' GOPRIVATE='' GOPROXY='https://goproxy.cn,direct' GOROOT='/home/spy/golang' GOSUMDB='sum.golang.org' GOTELEMETRY='local' GOTELEMETRYDIR='/root/.config/go/telemetry' GOTMPDIR='' GOTOOLCHAIN='auto' GOTOOLDIR='/home/spy/golang/pkg/tool/linux_arm64' GOVCS='' GOVERSION='go1.24.2' GOWORK='' PKG_CONFIG='pkg-config'What did you do?
Run a benchmark with gomapbench zhangyunhao116/gomapbench, then revert commit d13e6d0b089b72d666d0dd46f4965660ab10b712 and run the benchmark again.
What did you see happen?
Here are the result on arm64 platform:
name old time/op new time/op delta MapIter/Int/6-4 67.1ns ± 0% 67.2ns ± 1% +0.15% (p=0.085 n=10+10) MapIter/Int/12-4 161ns ±11% 156ns ± 8% -3.05% (p=0.306 n=10+10) MapIter/Int/18-4 236ns ± 8% 234ns ±11% -0.97% (p=0.957 n=10+10) MapIter/Int/24-4 274ns ± 8% 274ns ± 6% +0.06% (p=0.730 n=9+9) MapIter/Int/30-4 383ns ± 7% 387ns ±10% +1.02% (p=0.853 n=10+10) MapIter/Int/64-4 746ns ± 5% 760ns ± 9% +1.87% (p=0.280 n=10+10) MapIter/Int/128-4 1.51μs ± 6% 1.48μs ± 1% -2.12% (p=0.133 n=10+9) MapIter/Int/256-4 2.89μs ± 2% 2.88μs ± 3% -0.47% (p=0.677 n=10+9) MapIter/Int/512-4 5.64μs ± 3% 5.73μs ± 3% +1.51% (p=0.037 n=10+10) MapIter/Int/1024-4 11.8μs ± 1% 11.8μs ± 2% -0.49% (p=0.356 n=10+9) MapIter/Int/2048-4 23.9μs ± 1% 23.9μs ± 1% +0.17% (p=0.684 n=10+10) MapIter/Int/4096-4 48.4μs ± 1% 48.4μs ± 1% +0.03% (p=0.853 n=10+10) MapIter/Int/8192-4 96.7μs ± 1% 96.9μs ± 1% +0.27% (p=0.165 n=10+10) MapIter/Int/65536-4 776μs ± 0% 776μs ± 0% -0.03% (p=0.863 n=9+9) MapAccessHit/Int64/6-4 3.91ns ± 0% 4.45ns ± 0% +13.75% (p=0.000 n=10+9) MapAccessHit/Int64/12-4 8.36ns ± 1% 8.99ns ±14% +7.54% (p=0.483 n=9+10) MapAccessHit/Int64/18-4 8.34ns ± 1% 8.21ns ± 0% -1.60% (p=0.000 n=10+10) MapAccessHit/Int64/24-4 8.96ns ±15% 8.71ns ± 8% -2.79% (p=0.160 n=10+10) MapAccessHit/Int64/30-4 8.40ns ± 0% 8.20ns ± 0% -2.35% (p=0.000 n=9+10) MapAccessHit/Int64/64-4 8.39ns ± 0% 8.19ns ± 1% -2.45% (p=0.000 n=9+8) MapAccessHit/Int64/128-4 8.40ns ± 0% 8.20ns ± 0% -2.37% (p=0.001 n=6+8) MapAccessHit/Int64/256-4 8.36ns ± 1% 8.19ns ± 0% -2.09% (p=0.000 n=10+10) MapAccessHit/Int64/512-4 8.54ns ± 2% 8.35ns ± 1% -2.21% (p=0.000 n=10+10) MapAccessHit/Int64/1024-4 10.0ns ± 1% 9.8ns ± 2% -1.74% (p=0.002 n=9+10) MapAccessHit/Int64/2048-4 10.1ns ± 1% 10.0ns ± 2% -1.12% (p=0.009 n=10+10) MapAccessHit/Int64/4096-4 11.0ns ± 1% 10.8ns ± 2% -1.70% (p=0.000 n=10+10) MapAccessHit/Int64/8192-4 11.6ns ± 1% 11.4ns ± 1% -1.81% (p=0.000 n=10+10) MapAccessHit/Int64/65536-4 16.0ns ± 2% 15.9ns ± 2% -0.11% (p=0.795 n=10+9) MapAccessHit/Int32/6-4 3.96ns ± 0% 4.54ns ± 1% +14.70% (p=0.000 n=10+10) MapAccessHit/Int32/12-4 9.07ns ±19% 9.33ns ±13% +2.83% (p=0.424 n=10+10) MapAccessHit/Int32/18-4 8.38ns ± 1% 8.28ns ± 1% -1.22% (p=0.000 n=8+10) MapAccessHit/Int32/24-4 8.91ns ±16% 9.07ns ±13% +1.72% (p=0.579 n=10+10) MapAccessHit/Int32/30-4 8.39ns ± 1% 8.26ns ± 0% -1.57% (p=0.000 n=10+9) MapAccessHit/Int32/64-4 8.39ns ± 1% 8.28ns ± 0% -1.36% (p=0.000 n=9+8) MapAccessHit/Int32/128-4 8.48ns ± 1% 8.27ns ± 0% -2.46% (p=0.000 n=7+8) MapAccessHit/Int32/256-4 8.41ns ± 1% 8.25ns ± 0% -1.92% (p=0.000 n=10+10) MapAccessHit/Int32/512-4 8.51ns ± 1% 8.43ns ± 1% -0.93% (p=0.011 n=9+10) MapAccessHit/Int32/1024-4 10.1ns ± 1% 10.0ns ± 2% -0.98% (p=0.004 n=10+10) MapAccessHit/Int32/2048-4 10.2ns ± 1% 10.1ns ± 1% -1.01% (p=0.000 n=10+10) MapAccessHit/Int32/4096-4 11.1ns ± 0% 11.0ns ± 1% -0.81% (p=0.000 n=10+10) MapAccessHit/Int32/8192-4 11.7ns ± 0% 11.6ns ± 0% -1.06% (p=0.000 n=8+10) MapAccessHit/Int32/65536-4 16.2ns ± 1% 15.4ns ± 1% -4.70% (p=0.000 n=9+8) MapAccessHit/Str/6-4 16.7ns ± 2% 17.9ns ± 1% +6.98% (p=0.000 n=10+9) MapAccessHit/Str/12-4 25.1ns ± 3% 14.1ns ±16% -43.56% (p=0.000 n=9+10) MapAccessHit/Str/18-4 24.0ns ± 0% 13.2ns ± 0% -45.14% (p=0.000 n=8+8) MapAccessHit/Str/24-4 24.7ns ± 6% 14.3ns ±13% -41.95% (p=0.000 n=10+10) MapAccessHit/Str/30-4 24.0ns ± 0% 13.4ns ± 8% -43.94% (p=0.000 n=8+9) MapAccessHit/Str/64-4 24.0ns ± 1% 12.6ns ± 8% -47.46% (p=0.000 n=9+10) MapAccessHit/Str/128-4 24.2ns ± 1% 12.6ns ± 5% -48.02% (p=0.000 n=10+10) MapAccessHit/Str/256-4 24.9ns ± 1% 12.8ns ± 3% -48.66% (p=0.000 n=10+10) MapAccessHit/Str/512-4 25.2ns ± 1% 13.0ns ± 2% -48.33% (p=0.000 n=9+10) MapAccessHit/Str/1024-4 29.5ns ± 0% 14.8ns ± 1% -49.92% (p=0.000 n=9+10) MapAccessHit/Str/2048-4 30.8ns ± 0% 15.9ns ± 1% -48.52% (p=0.000 n=10+10) MapAccessHit/Str/4096-4 32.5ns ± 0% 16.7ns ± 1% -48.52% (p=0.000 n=10+10) MapAccessHit/Str/8192-4 33.4ns ± 0% 17.2ns ± 1% -48.45% (p=0.000 n=9+10) MapAccessHit/Str/65536-4 53.2ns ± 3% 28.6ns ± 3% -46.23% (p=0.000 n=10+10) MapAccessMiss/Int64/6-4 5.19ns ± 0% 5.58ns ± 0% +7.60% (p=0.000 n=10+10) MapAccessMiss/Int64/12-4 11.8ns ±39% 15.8ns ± 1% +33.78% (p=1.000 n=10+8) MapAccessMiss/Int64/18-4 10.2ns ±30% 6.9ns ± 1% -32.58% (p=0.000 n=10+8) MapAccessMiss/Int64/24-4 12.6ns ± 1% 11.8ns ± 0% -6.43% (p=0.000 n=9+8) MapAccessMiss/Int64/30-4 7.03ns ± 1% 6.77ns ± 1% -3.62% (p=0.000 n=8+8) MapAccessMiss/Int64/64-4 7.89ns ±20% 7.55ns ±19% -4.37% (p=0.218 n=10+10) MapAccessMiss/Int64/128-4 7.38ns ±11% 7.37ns ±12% -0.13% (p=0.897 n=10+10) MapAccessMiss/Int64/256-4 7.05ns ± 0% 6.89ns ± 3% -2.27% (p=0.062 n=9+10) MapAccessMiss/Int64/512-4 7.11ns ± 3% 6.87ns ± 2% -3.40% (p=0.000 n=10+9) MapAccessMiss/Int64/1024-4 8.74ns ± 4% 8.49ns ± 6% -2.85% (p=0.029 n=10+10) MapAccessMiss/Int64/2048-4 9.07ns ± 3% 8.74ns ± 3% -3.65% (p=0.004 n=10+10) MapAccessMiss/Int64/4096-4 9.86ns ± 2% 9.56ns ± 3% -3.08% (p=0.000 n=10+10) MapAccessMiss/Int64/8192-4 10.4ns ± 2% 10.1ns ± 1% -3.13% (p=0.000 n=10+10) MapAccessMiss/Int64/65536-4 13.6ns ± 1% 13.3ns ± 2% -2.34% (p=0.000 n=10+10) MapAccessMiss/Int32/6-4 5.18ns ± 0% 5.59ns ± 1% +7.95% (p=0.000 n=10+10) MapAccessMiss/Int32/12-4 16.4ns ± 1% 15.8ns ± 0% -3.99% (p=0.000 n=8+8) MapAccessMiss/Int32/18-4 9.09ns ±32% 10.18ns ±32% +12.00% (p=0.565 n=10+10) MapAccessMiss/Int32/24-4 14.2ns ±42% 11.8ns ± 1% -17.41% (p=0.000 n=10+9) MapAccessMiss/Int32/30-4 7.04ns ± 1% 6.78ns ± 0% -3.72% (p=0.000 n=9+10) MapAccessMiss/Int32/64-4 7.49ns ± 9% 7.22ns ± 9% -3.58% (p=0.050 n=10+10) MapAccessMiss/Int32/128-4 7.37ns ± 5% 7.07ns ± 5% -4.09% (p=0.063 n=10+10) MapAccessMiss/Int32/256-4 7.10ns ± 1% 6.83ns ± 0% -3.85% (p=0.000 n=9+8) MapAccessMiss/Int32/512-4 7.22ns ± 4% 6.88ns ± 2% -4.74% (p=0.000 n=10+9) MapAccessMiss/Int32/1024-4 8.88ns ± 7% 8.39ns ± 5% -5.48% (p=0.001 n=10+10) MapAccessMiss/Int32/2048-4 9.17ns ± 2% 8.74ns ± 4% -4.70% (p=0.000 n=9+10) MapAccessMiss/Int32/4096-4 9.95ns ± 2% 9.42ns ± 1% -5.32% (p=0.000 n=10+9) MapAccessMiss/Int32/8192-4 10.4ns ± 2% 10.0ns ± 2% -3.30% (p=0.000 n=10+10) MapAccessMiss/Int32/65536-4 13.5ns ± 2% 13.2ns ± 1% -2.11% (p=0.000 n=10+10) MapAccessMiss/Str/6-4 16.3ns ± 1% 20.0ns ± 1% +22.79% (p=0.000 n=10+10) MapAccessMiss/Str/12-4 23.1ns ± 1% 14.3ns ± 6% -38.19% (p=0.000 n=9+10) MapAccessMiss/Str/18-4 22.1ns ± 0% 10.4ns ± 0% -53.05% (p=0.000 n=9+9) MapAccessMiss/Str/24-4 23.2ns ± 5% 13.7ns ±16% -41.28% (p=0.000 n=10+10) MapAccessMiss/Str/30-4 21.9ns ± 5% 11.1ns ±11% -49.15% (p=0.000 n=10+10) MapAccessMiss/Str/64-4 21.8ns ± 4% 11.2ns ±13% -48.66% (p=0.000 n=9+10) MapAccessMiss/Str/128-4 22.4ns ± 6% 10.8ns ± 7% -51.74% (p=0.000 n=10+9) MapAccessMiss/Str/256-4 21.5ns ± 3% 10.8ns ± 9% -49.53% (p=0.000 n=10+9) MapAccessMiss/Str/512-4 21.4ns ± 4% 10.7ns ± 4% -50.22% (p=0.000 n=10+10) MapAccessMiss/Str/1024-4 24.7ns ± 2% 12.2ns ± 3% -50.78% (p=0.000 n=10+10) MapAccessMiss/Str/2048-4 26.1ns ± 1% 12.8ns ± 3% -51.10% (p=0.000 n=10+10) MapAccessMiss/Str/4096-4 27.4ns ± 1% 13.6ns ± 1% -50.35% (p=0.000 n=10+9) MapAccessMiss/Str/8192-4 28.3ns ± 1% 14.0ns ± 1% -50.45% (p=0.000 n=10+10) MapAccessMiss/Str/65536-4 35.6ns ± 1% 18.4ns ± 2% -48.17% (p=0.000 n=10+10) MapAssignGrow/Int64/6-4 69.8ns ± 0% 69.4ns ± 0% -0.60% (p=0.000 n=8+10) MapAssignGrow/Int64/12-4 463ns ± 1% 459ns ± 1% -0.85% (p=0.005 n=10+10) MapAssignGrow/Int64/18-4 1.04μs ± 0% 1.02μs ± 0% -1.11% (p=0.000 n=10+10) MapAssignGrow/Int64/24-4 1.14μs ± 1% 1.12μs ± 0% -1.39% (p=0.000 n=10+10) MapAssignGrow/Int64/30-4 2.13μs ± 0% 2.12μs ± 0% -0.65% (p=0.000 n=10+10) MapAssignGrow/Int64/64-4 4.24μs ± 0% 4.16μs ± 0% -1.97% (p=0.000 n=10+10) MapAssignGrow/Int64/128-4 8.26μs ± 0% 7.99μs ± 0% -3.21% (p=0.000 n=10+10) MapAssignGrow/Int64/256-4 15.6μs ± 0% 15.2μs ± 0% -2.20% (p=0.000 n=10+10) MapAssignGrow/Int64/512-4 29.8μs ± 1% 29.2μs ± 0% -1.84% (p=0.000 n=10+9) MapAssignGrow/Int64/1024-4 62.7μs ± 0% 60.7μs ± 0% -3.08% (p=0.000 n=10+10) MapAssignGrow/Int64/2048-4 130μs ± 0% 127μs ± 0% -2.67% (p=0.000 n=10+10) MapAssignGrow/Int64/4096-4 269μs ± 0% 263μs ± 0% -2.25% (p=0.000 n=10+10) MapAssignGrow/Int64/8192-4 551μs ± 0% 540μs ± 1% -1.94% (p=0.000 n=10+9) MapAssignGrow/Int64/65536-4 4.90ms ± 0% 4.84ms ± 0% -1.13% (p=0.000 n=10+10) MapAssignGrow/Int32/6-4 69.9ns ± 1% 70.4ns ± 0% +0.61% (p=0.010 n=10+9) MapAssignGrow/Int32/12-4 462ns ± 1% 461ns ± 1% -0.16% (p=0.424 n=10+10) MapAssignGrow/Int32/18-4 1.04μs ± 0% 1.03μs ± 0% -0.48% (p=0.003 n=10+10) MapAssignGrow/Int32/24-4 1.14μs ± 0% 1.13μs ± 0% -0.83% (p=0.000 n=10+10) MapAssignGrow/Int32/30-4 2.14μs ± 0% 2.13μs ± 0% -0.63% (p=0.000 n=10+10) MapAssignGrow/Int32/64-4 4.25μs ± 0% 4.17μs ± 0% -1.95% (p=0.000 n=10+8) MapAssignGrow/Int32/128-4 8.29μs ± 0% 7.99μs ± 0% -3.56% (p=0.000 n=10+10) MapAssignGrow/Int32/256-4 15.7μs ± 0% 15.2μs ± 0% -3.13% (p=0.000 n=10+10) MapAssignGrow/Int32/512-4 29.8μs ± 0% 29.3μs ± 0% -1.80% (p=0.000 n=9+10) MapAssignGrow/Int32/1024-4 62.4μs ± 0% 60.5μs ± 0% -2.97% (p=0.000 n=9+10) MapAssignGrow/Int32/2048-4 130μs ± 0% 126μs ± 0% -2.83% (p=0.000 n=10+9) MapAssignGrow/Int32/4096-4 268μs ± 0% 262μs ± 0% -2.39% (p=0.000 n=9+9) MapAssignGrow/Int32/8192-4 550μs ± 0% 538μs ± 0% -2.18% (p=0.000 n=9+9) MapAssignGrow/Int32/65536-4 4.94ms ± 0% 4.88ms ± 1% -1.20% (p=0.000 n=9+10) MapAssignGrow/Str/6-4 89.9ns ± 0% 88.4ns ± 0% -1.60% (p=0.000 n=10+10) MapAssignGrow/Str/12-4 549ns ± 0% 552ns ± 0% +0.50% (p=0.000 n=10+10) MapAssignGrow/Str/18-4 1.26μs ± 1% 1.29μs ± 1% +2.14% (p=0.000 n=10+10) MapAssignGrow/Str/24-4 1.39μs ± 0% 1.42μs ± 1% +1.61% (p=0.000 n=10+10) MapAssignGrow/Str/30-4 2.56μs ± 0% 2.61μs ± 0% +1.93% (p=0.000 n=9+10) MapAssignGrow/Str/64-4 5.16μs ± 0% 5.18μs ± 0% +0.39% (p=0.001 n=7+9) MapAssignGrow/Str/128-4 10.0μs ± 0% 10.1μs ± 2% +0.56% (p=0.118 n=10+10) MapAssignGrow/Str/256-4 20.0μs ± 1% 19.9μs ± 1% -0.38% (p=0.149 n=10+10) MapAssignGrow/Str/512-4 38.7μs ± 1% 38.0μs ± 0% -1.68% (p=0.000 n=10+9) MapAssignGrow/Str/1024-4 79.1μs ± 0% 78.1μs ± 0% -1.26% (p=0.000 n=10+9) MapAssignGrow/Str/2048-4 165μs ± 0% 163μs ± 0% -1.07% (p=0.000 n=10+10) MapAssignGrow/Str/4096-4 339μs ± 0% 335μs ± 0% -1.18% (p=0.000 n=10+10) MapAssignGrow/Str/8192-4 715μs ± 0% 708μs ± 0% -1.00% (p=0.000 n=10+10) MapAssignGrow/Str/65536-4 8.32ms ± 1% 8.28ms ± 0% -0.42% (p=0.006 n=10+8) MapAssignPreAllocate/Pointer/6-4 142ns ± 1% 143ns ± 1% +0.34% (p=0.099 n=10+10) MapAssignPreAllocate/Pointer/12-4 491ns ± 0% 487ns ± 1% -0.64% (p=0.001 n=9+10) MapAssignPreAllocate/Pointer/18-4 703ns ± 1% 701ns ± 1% -0.22% (p=0.353 n=10+10) MapAssignPreAllocate/Pointer/24-4 857ns ± 1% 856ns ± 1% -0.15% (p=0.566 n=10+10) MapAssignPreAllocate/Pointer/30-4 1.08μs ± 1% 1.07μs ± 1% -0.89% (p=0.000 n=10+10) MapAssignPreAllocate/Pointer/64-4 2.03μs ± 0% 2.02μs ± 1% -0.38% (p=0.003 n=10+10) MapAssignPreAllocate/Pointer/128-4 3.91μs ± 0% 3.87μs ± 0% -0.95% (p=0.000 n=10+9) MapAssignPreAllocate/Pointer/256-4 7.52μs ± 0% 7.46μs ± 0% -0.78% (p=0.000 n=10+10) MapAssignPreAllocate/Pointer/512-4 14.8μs ± 0% 14.7μs ± 0% -0.41% (p=0.003 n=10+10) MapAssignPreAllocate/Pointer/1024-4 32.9μs ± 0% 31.2μs ± 0% -5.13% (p=0.000 n=10+10) MapAssignPreAllocate/Pointer/2048-4 66.0μs ± 0% 64.1μs ± 1% -2.82% (p=0.000 n=9+9) MapAssignPreAllocate/Pointer/4096-4 140μs ± 0% 136μs ± 1% -2.71% (p=0.000 n=9+10) MapAssignPreAllocate/Pointer/8192-4 294μs ± 1% 285μs ± 0% -2.98% (p=0.000 n=10+10) MapAssignPreAllocate/Pointer/65536-4 3.00ms ± 1% 2.88ms ± 1% -4.24% (p=0.000 n=10+9) MapAssignPreAllocate/Int64/6-4 73.8ns ± 1% 73.1ns ± 1% -0.93% (p=0.000 n=8+10) MapAssignPreAllocate/Int64/12-4 306ns ± 1% 304ns ± 1% -0.87% (p=0.000 n=9+10) MapAssignPreAllocate/Int64/18-4 419ns ± 1% 413ns ± 1% -1.37% (p=0.000 n=10+10) MapAssignPreAllocate/Int64/24-4 489ns ± 1% 481ns ± 1% -1.70% (p=0.000 n=10+10) MapAssignPreAllocate/Int64/30-4 643ns ± 0% 631ns ± 1% -1.86% (p=0.000 n=9+10) MapAssignPreAllocate/Int64/64-4 1.12μs ± 0% 1.09μs ± 0% -2.26% (p=0.000 n=9+10) MapAssignPreAllocate/Int64/128-4 2.06μs ± 0% 2.02μs ± 0% -2.15% (p=0.000 n=10+10) MapAssignPreAllocate/Int64/256-4 3.79μs ± 0% 3.71μs ± 0% -2.12% (p=0.000 n=9+9) MapAssignPreAllocate/Int64/512-4 7.45μs ± 2% 7.22μs ± 0% -3.09% (p=0.000 n=10+10) MapAssignPreAllocate/Int64/1024-4 16.6μs ± 0% 15.5μs ± 0% -6.95% (p=0.000 n=9+9) MapAssignPreAllocate/Int64/2048-4 33.6μs ± 0% 31.2μs ± 0% -7.04% (p=0.000 n=10+9) MapAssignPreAllocate/Int64/4096-4 71.1μs ± 1% 65.9μs ± 0% -7.28% (p=0.000 n=9+8) MapAssignPreAllocate/Int64/8192-4 150μs ± 0% 139μs ± 1% -7.03% (p=0.000 n=10+10) MapAssignPreAllocate/Int64/65536-4 1.65ms ± 2% 1.62ms ± 1% -2.38% (p=0.000 n=10+9) MapAssignPreAllocate/Int32/6-4 74.0ns ± 0% 73.5ns ± 1% -0.67% (p=0.013 n=7+10) MapAssignPreAllocate/Int32/12-4 307ns ± 1% 314ns ± 0% +2.22% (p=0.000 n=10+9) MapAssignPreAllocate/Int32/18-4 419ns ± 1% 426ns ± 0% +1.64% (p=0.000 n=9+9) MapAssignPreAllocate/Int32/24-4 491ns ± 1% 496ns ± 0% +0.97% (p=0.000 n=10+9) MapAssignPreAllocate/Int32/30-4 643ns ± 0% 645ns ± 0% +0.42% (p=0.000 n=9+10) MapAssignPreAllocate/Int32/64-4 1.12μs ± 0% 1.12μs ± 0% -0.06% (p=0.528 n=9+9) MapAssignPreAllocate/Int32/128-4 2.06μs ± 1% 2.06μs ± 0% -0.00% (p=0.897 n=10+10) MapAssignPreAllocate/Int32/256-4 3.80μs ± 1% 3.79μs ± 1% -0.34% (p=0.056 n=10+9) MapAssignPreAllocate/Int32/512-4 7.37μs ± 0% 7.42μs ± 1% +0.58% (p=0.000 n=10+10) MapAssignPreAllocate/Int32/1024-4 16.6μs ± 0% 15.9μs ± 0% -4.14% (p=0.000 n=10+10) MapAssignPreAllocate/Int32/2048-4 33.6μs ± 0% 31.8μs ± 2% -5.32% (p=0.000 n=10+10) MapAssignPreAllocate/Int32/4096-4 71.2μs ± 0% 66.0μs ± 0% -7.23% (p=0.000 n=8+10) MapAssignPreAllocate/Int32/8192-4 151μs ± 1% 141μs ± 1% -7.04% (p=0.000 n=10+10) MapAssignPreAllocate/Int32/65536-4 1.62ms ± 1% 1.59ms ± 3% -2.42% (p=0.007 n=10+10) MapAssignPreAllocate/Str/6-4 93.2ns ± 0% 89.6ns ± 1% -3.87% (p=0.000 n=10+10) MapAssignPreAllocate/Str/12-4 410ns ± 0% 413ns ± 0% +0.68% (p=0.000 n=10+10) MapAssignPreAllocate/Str/18-4 576ns ± 0% 597ns ± 0% +3.64% (p=0.000 n=9+10) MapAssignPreAllocate/Str/24-4 682ns ± 0% 702ns ± 0% +2.94% (p=0.000 n=10+9) MapAssignPreAllocate/Str/30-4 841ns ± 1% 861ns ± 0% +2.36% (p=0.000 n=10+10) MapAssignPreAllocate/Str/64-4 1.53μs ± 0% 1.52μs ± 1% -0.20% (p=0.254 n=10+10) MapAssignPreAllocate/Str/128-4 2.83μs ± 0% 2.74μs ± 0% -3.22% (p=0.000 n=10+9) MapAssignPreAllocate/Str/256-4 5.53μs ± 1% 5.30μs ± 0% -4.06% (p=0.000 n=10+8) MapAssignPreAllocate/Str/512-4 10.7μs ± 1% 10.2μs ± 1% -4.66% (p=0.000 n=10+10) MapAssignPreAllocate/Str/1024-4 23.4μs ± 0% 22.5μs ± 1% -4.04% (p=0.000 n=10+10) MapAssignPreAllocate/Str/2048-4 49.9μs ± 2% 48.0μs ± 2% -3.73% (p=0.000 n=10+10) MapAssignPreAllocate/Str/4096-4 104μs ± 1% 101μs ± 1% -3.46% (p=0.000 n=10+9) MapAssignPreAllocate/Str/8192-4 232μs ± 1% 222μs ± 1% -4.23% (p=0.000 n=10+9) MapAssignPreAllocate/Str/65536-4 3.31ms ± 3% 3.21ms ± 3% -2.95% (p=0.000 n=10+10) MapAssignReuse/Pointer/6-4 162ns ± 1% 164ns ± 1% +0.71% (p=0.000 n=10+10) MapAssignReuse/Pointer/12-4 338ns ± 0% 335ns ± 0% -1.03% (p=0.000 n=10+9) MapAssignReuse/Pointer/18-4 501ns ± 0% 491ns ± 0% -1.90% (p=0.000 n=10+9) MapAssignReuse/Pointer/24-4 663ns ± 1% 651ns ± 1% -1.83% (p=0.000 n=10+10) MapAssignReuse/Pointer/30-4 831ns ± 1% 818ns ± 1% -1.62% (p=0.000 n=10+9) MapAssignReuse/Pointer/64-4 1.75μs ± 0% 1.72μs ± 0% -1.79% (p=0.000 n=9+10) MapAssignReuse/Pointer/128-4 3.45μs ± 1% 3.41μs ± 1% -1.06% (p=0.001 n=10+10) MapAssignReuse/Pointer/256-4 6.87μs ± 0% 6.72μs ± 1% -2.19% (p=0.000 n=10+10) MapAssignReuse/Pointer/512-4 13.7μs ± 1% 13.5μs ± 1% -1.48% (p=0.000 n=10+10) MapAssignReuse/Pointer/1024-4 30.6μs ± 0% 28.7μs ± 1% -5.97% (p=0.000 n=10+10) MapAssignReuse/Pointer/2048-4 62.5μs ± 0% 59.0μs ± 1% -5.60% (p=0.000 n=10+10) MapAssignReuse/Pointer/4096-4 132μs ± 0% 124μs ± 1% -5.57% (p=0.000 n=10+10) MapAssignReuse/Pointer/8192-4 273μs ± 0% 257μs ± 1% -5.60% (p=0.000 n=10+10) MapAssignReuse/Pointer/65536-4 3.34ms ± 1% 3.24ms ± 1% -3.00% (p=0.000 n=10+9) MapAssignReuse/Int64/6-4 79.8ns ± 0% 80.3ns ± 0% +0.66% (p=0.000 n=10+10) MapAssignReuse/Int64/12-4 168ns ± 0% 160ns ± 0% -4.55% (p=0.000 n=10+8) MapAssignReuse/Int64/18-4 250ns ± 0% 237ns ± 0% -5.04% (p=0.000 n=10+9) MapAssignReuse/Int64/24-4 329ns ± 0% 311ns ± 0% -5.31% (p=0.000 n=7+10) MapAssignReuse/Int64/30-4 404ns ± 0% 381ns ± 0% -5.60% (p=0.000 n=9+10) MapAssignReuse/Int64/64-4 863ns ± 0% 813ns ± 0% -5.86% (p=0.000 n=10+10) MapAssignReuse/Int64/128-4 1.66μs ± 0% 1.56μs ± 0% -6.18% (p=0.000 n=10+10) MapAssignReuse/Int64/256-4 3.28μs ± 0% 3.07μs ± 0% -6.38% (p=0.000 n=10+9) MapAssignReuse/Int64/512-4 6.51μs ± 0% 6.17μs ± 0% -5.28% (p=0.000 n=10+7) MapAssignReuse/Int64/1024-4 14.7μs ± 0% 13.4μs ± 0% -8.64% (p=0.000 n=10+10) MapAssignReuse/Int64/2048-4 29.6μs ± 0% 27.1μs ± 0% -8.38% (p=0.000 n=10+9) MapAssignReuse/Int64/4096-4 62.8μs ± 0% 57.4μs ± 0% -8.65% (p=0.000 n=9+10) MapAssignReuse/Int64/8192-4 131μs ± 0% 120μs ± 0% -8.96% (p=0.000 n=9+10) MapAssignReuse/Int64/65536-4 1.62ms ± 1% 1.46ms ± 1% -9.51% (p=0.000 n=9+10) MapAssignReuse/Int32/6-4 80.5ns ± 1% 80.4ns ± 0% -0.24% (p=0.016 n=9+10) MapAssignReuse/Int32/12-4 168ns ± 0% 160ns ± 0% -4.77% (p=0.000 n=8+10) MapAssignReuse/Int32/18-4 247ns ± 0% 237ns ± 0% -4.24% (p=0.000 n=10+10) MapAssignReuse/Int32/24-4 326ns ± 0% 312ns ± 0% -4.54% (p=0.000 n=9+10) MapAssignReuse/Int32/30-4 401ns ± 0% 382ns ± 0% -4.80% (p=0.000 n=10+10) MapAssignReuse/Int32/64-4 841ns ± 0% 814ns ± 0% -3.31% (p=0.000 n=10+10) MapAssignReuse/Int32/128-4 1.62μs ± 0% 1.56μs ± 0% -3.46% (p=0.000 n=10+9) MapAssignReuse/Int32/256-4 3.19μs ± 0% 3.07μs ± 0% -3.61% (p=0.000 n=10+10) MapAssignReuse/Int32/512-4 6.40μs ± 0% 6.18μs ± 0% -3.41% (p=0.000 n=10+9) MapAssignReuse/Int32/1024-4 14.6μs ± 0% 13.4μs ± 0% -8.41% (p=0.000 n=9+10) MapAssignReuse/Int32/2048-4 29.5μs ± 0% 27.1μs ± 0% -8.30% (p=0.000 n=8+9) MapAssignReuse/Int32/4096-4 62.8μs ± 0% 57.3μs ± 0% -8.63% (p=0.000 n=10+8) MapAssignReuse/Int32/8192-4 131μs ± 0% 120μs ± 0% -8.71% (p=0.000 n=10+10) MapAssignReuse/Int32/65536-4 1.59ms ± 0% 1.49ms ± 1% -6.20% (p=0.000 n=10+10) MapAssignReuse/Str/6-4 100ns ± 0% 97ns ± 0% -2.74% (p=0.000 n=8+10) MapAssignReuse/Str/12-4 224ns ± 1% 231ns ± 0% +3.05% (p=0.000 n=10+10) MapAssignReuse/Str/18-4 331ns ± 0% 347ns ± 0% +4.85% (p=0.000 n=10+10) MapAssignReuse/Str/24-4 441ns ± 0% 459ns ± 0% +4.00% (p=0.000 n=10+10) MapAssignReuse/Str/30-4 542ns ± 0% 561ns ± 0% +3.49% (p=0.000 n=9+10) MapAssignReuse/Str/64-4 1.12μs ± 0% 1.12μs ± 0% -0.43% (p=0.000 n=10+8) MapAssignReuse/Str/128-4 2.22μs ± 0% 2.16μs ± 0% -2.68% (p=0.000 n=9+9) MapAssignReuse/Str/256-4 4.44μs ± 0% 4.26μs ± 1% -4.12% (p=0.000 n=10+10) MapAssignReuse/Str/512-4 8.88μs ± 0% 8.50μs ± 0% -4.33% (p=0.000 n=10+10) MapAssignReuse/Str/1024-4 19.4μs ± 0% 20.3μs ± 9% +4.77% (p=1.000 n=10+10) MapAssignReuse/Str/2048-4 39.1μs ± 0% 37.6μs ± 1% -3.89% (p=0.000 n=10+10) MapAssignReuse/Str/4096-4 81.1μs ± 0% 78.1μs ± 1% -3.79% (p=0.000 n=10+9) MapAssignReuse/Str/8192-4 165μs ± 1% 160μs ± 1% -3.23% (p=0.000 n=10+10) MapAssignReuse/Str/65536-4 2.18ms ± 3% 2.14ms ± 1% -1.90% (p=0.000 n=9+10) [Geo mean] 812ns 746ns -8.13% What did you expect to see?
As you see in the result of the benchmark, time cost decreases a lot after revert the commit. So what's happened to the commit?