math: wrong result for Pow(±0, .5) contrary to documentation #23224
Description
Please answer these questions before submitting your issue. Thanks!
What version of Go are you using (go version)?
go version go1.9.2 linux/amd64
Does this issue reproduce with the latest release?
I believe go1.9.2 is the latest release.
What operating system and processor architecture are you using (go env)?
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/usr/local/google/home/majnemer/go"
GORACE=""
GOROOT="/usr/lib/google-golang"
GOTOOLDIR="/usr/lib/google-golang/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build846653371=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
What did you do?
I ran the following program: https://play.golang.org/p/_lUAaRG9D-P
What did you expect to see?
The documentation for math.Pow says the following:
Pow(±0, y) = +0 for finite y > 0 and not an odd integer
.5 is finite and not an odd integer which means math.Pow should give back +0.
What did you see instead?
math.Pow gave back -0.