cmd/compile: shallow copy of a struct does not always compile as MOVL #53810
Description
type Example struct {
a, b int32
}
x := Example{x:1, y:1}
y := xthe y:=x will be compiled to two movl while the x:=Example{x:1, y:1} compiled to single movq.
it confuse me about the memory bevavior, assumpt we have one routine write x=Example{x:1, y:1} and another write x=Example{x:2, y:2}, according to the memory model, x will either be x:1,y:1 or x:2, y:2. how ever if we do
y:=x
fmt.Println(y.a, y.b)then, we could get x:1, y:2 !!!