cmd/compile: miscompile of shift on GOOS=arm #64715
Description
Go version
go version devel go1.22-f2d243db8f Wed Dec 13 16:20:09 2023 +0000 linux/amd64
What operating system and processor architecture are you using (go env)?
linux/armWhat did you do?
NB: filing this issue on behalf of Jan Mercl, who discovered and reported the problem here
Run this program on a GOOS=linux GOARCH=arm machine:
package main
func boolInt32(b bool) int32 {
if b {
return 1
}
return 0
}
func f(left uint16, right int32) (r uint16) {
return left >> right
}
var n = uint16(65535)
func main() {
println(f(n, boolInt32(int64(n^n) > 1)))
}
What did you expect to see?
Expected:
$ go run prog.go
65535
$
What did you see instead?
Got instead:
$ go run prog.go
0
$
Also worth noting that building with -gcflags="-l -N" makes the problem go away.