gccgo: double evaluation in interface field expression #26248
Description
What version of Go are you using (go version)?
go version go1.10.3 gccgo (GCC) 9.0.0 20180622 (experimental) linux/amd64
What did you do?
package main
type I interface{
M()
}
type T struct{}
func (T) M() {}
//go:noinline
func G() I {
println("XXX")
return T{}
}
//go:noinline
func G2(interface{}) {}
//go:noinline
func F() {
x := G().M
G2(x)
}
func main() {
F()
}
What did you expect to see?
$ go run -compiler=gc i.go
XXX
What did you see instead?
$ go run -compiler=gccgo i.go
XXX
XXX
It generates two calls to G in F, one in nil check, one in constructing the func value G().M.