cmd/compile: pgo after CL 449477 cause worse performance on benchmark #68974
Description
Go version
go version devel go1.24-f428c7b7 Sat Aug 3 05:06:40 2024 +0000 windows/amd64
Output of go env in your module/workspace:
set GO111MODULE=auto
set GOARCH=amd64
set GOBIN=
set GOCACHE=D:\file\go-build
set GOENV=C:\Users\26454\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=D:\file\gofile\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=D:\file\gofile
set GOPRIVATE=
set GOPROXY=https://goproxy.cn,direct
set GOROOT=C:\Users\26454\.go\current
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLCHAIN=local
set GOTOOLDIR=C:\Users\26454\.go\current\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=devel go1.24-f428c7b7 Sat Aug 3 05:06:40 2024 +0000
set GODEBUG=
set GOTELEMETRY=on
set GOTELEMETRYDIR=C:\Users\26454\AppData\Roaming\go\telemetry
set GCCGO=gccgo
set GOAMD64=v3
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
go: stripping unprintable or unescapable characters from %"GOMOD"%
set GOMOD=D:\file\gofile\U������\u\u-language\ucom\go.mod
set GOWORK=
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=C:\Users\26454\AppData\Local\Temp\go-build1658404967=/tmp/go-build -gno-record-gcc-switchesWhat did you do?
Repeat step:
git clone https://gitee.com/u-language/u-language.git -b pgo2024-8-20
cd u-language
Set environment variable URoot to the current path
cd ucom
go test -run=ssss -bench="ComplierToCBuildMode2/多文件" -count=10 -pgo off > new.txt && sleep 20 && go test -run=ssss -bench="ComplierToCBuildMode2/多文件" -count=10 -pgo default.pgo > pgo.txt && benchstat new.txt pgo.txt
What did you see happen?
pgo does not cause performance degradation
What did you expect to see?
│ new.txt │ pgo.txt │
│ sec/op │ sec/op vs base │
ComplierToCBuildMode2/多文件-16 177.0µ ± 1% 202.8µ ± 1% +14.58% (p=0.000 n=10)
│ new.txt │
│ B/s │
ComplierToCBuildMode2/多文件-16 9.766Ki ± 0%
│ new.txt │ pgo.txt │
│ B/op │ B/op vs base │
ComplierToCBuildMode2/多文件-16 32.64Ki ± 0% 32.51Ki ± 0% -0.38% (p=0.000 n=10)
│ new.txt │ pgo.txt │
│ allocs/op │ allocs/op vs base │
ComplierToCBuildMode2/多文件-16 498.0 ± 0% 495.0 ± 0% -0.60% (p=0.000 n=10)
│ pgo.txt │
│ MB/s │
ComplierToCBuildMode2/多文件-16 0.000 ± 0%
I tried tip,happen pgo cause worse performance on benchmark.
I tried 4b43b74 , no happen pgo cause worse performance on benchmark.
git bisect to 1b03568