Closed
Description
$ gotip version
go version devel +e92be18fd8 Wed Jun 10 14:56:01 2020 +0000 linux/amd64
The following program:
package p
func f() {
if len([]int{})-1 < len([]int{}) {
}
var st struct {
i int
}
g := func() string {
return ""
}
h := func(string) string {
return g() + g()
}
s, i := "", 0
st.i = len(s)
i = len(h(s[i+0:i+1])) + len(s[len(s)+1:i+1])
s = s[(len(s[i+1:len(s)+1])+1):len(h(""))+1] + (s[i+1 : len([]int{})+i])
i = 1 + len([]int{len([]string{s[i+len([]int{}) : len(s)+i]})})
var ch chan int
ch <- len(h("")) - len(s)
}
Crashes the tip compiler when built for arm or arm64:
$ GOARCH=arm gotip tool compile crash.go
crash.go:4:20: internal compiler error: 'f': Flag* ops should never make it to codegen v294 = FlagLT_ULT <flags>
goroutine 1 [running]:
runtime/debug.Stack(0xd4bb80, 0xc0000b8008, 0x0)
/home/alberto/go/src/runtime/debug/stack.go:24 +0x9f
cmd/compile/internal/gc.Fatalf(0xc000018180, 0x32, 0xc00000c0c0, 0x2, 0x2)
/home/alberto/go/src/cmd/compile/internal/gc/subr.go:199 +0x1b0
cmd/compile/internal/gc.(*ssafn).Fatalf(0xc0003ca510, 0x414000000002, 0xc61cd5, 0x2c, 0xc000044040, 0x1, 0x1)
/home/alberto/go/src/cmd/compile/internal/gc/ssa.go:6844 +0x1a5
cmd/compile/internal/ssa.(*Value).Fatalf(...)
/home/alberto/go/src/cmd/compile/internal/ssa/value.go:384
cmd/compile/internal/arm.ssaGenValue(0xc0003eb400, 0xc0004080a0)
/home/alberto/go/src/cmd/compile/internal/arm/ssa.go:865 +0x2b3d
cmd/compile/internal/gc.genssa(0xc00010cc60, 0xc0003eb380)
/home/alberto/go/src/cmd/compile/internal/gc/ssa.go:6071 +0x702
cmd/compile/internal/gc.compileSSA(0xc00010c2c0, 0x0)
/home/alberto/go/src/cmd/compile/internal/gc/pgen.go:327 +0x3a5
cmd/compile/internal/gc.compile(0xc00010c2c0)
/home/alberto/go/src/cmd/compile/internal/gc/pgen.go:275 +0x345
cmd/compile/internal/gc.funccompile(0xc00010c2c0)
/home/alberto/go/src/cmd/compile/internal/gc/pgen.go:220 +0xc5
cmd/compile/internal/gc.Main(0xc6e018)
/home/alberto/go/src/cmd/compile/internal/gc/main.go:747 +0x344f
main.main()
/home/alberto/go/src/cmd/compile/main.go:52 +0xb1
It compiles fine on go1.14.4, so this is a tip regression in two First Class Ports. I'm tentatively labelling this as a release-blocker, but leaving to you to decide if this is fine.