cmd/compile: math.Trunc produces incorrect result on riscv64 in Go 1.23rc1 #68322
Description
Go version
go version go1.23rc1 darwin/arm64
Output of go env in your module/workspace:
GO111MODULE='on'
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/mathetake/Library/Caches/go-build'
GOENV='/Users/mathetake/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/mathetake/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/mathetake/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/mathetake/sdk/go1.23rc1'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/mathetake/sdk/go1.23rc1/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.23rc1'
GODEBUG=''
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/mathetake/Library/Application Support/go/telemetry'
GCCGO='gccgo'
GOARM64='v8.0'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/Users/mathetake/wazero/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/zv/cj1015lx5bndpw3n_qsx9mh40000gn/T/go-build971855478=/tmp/go-build -gno-record-gcc-switches -fno-common'What did you do?
I created the following reproducer
func TestRISCVTruncIncorrect(t *testing.T) {
if math.Trunc(18446744073709549568.0) != 18446744073709549568.0 {
t.Fatalf("math.Trunc(18446744073709549568.0) = %f, want 18446744073709549568.0", math.Trunc(18446744073709549568.0))
}
}
What did you see happen?
I cross compiled the test with GOOS=linux GOARCH=riscv64, and run it in the qemu environment. Then the test passed with Go 1.22 but was failing with Go 1.23rc1.
What did you expect to see?
The test passes.