解析go语言调用约定多返回值实现原理

package main
func vals(c, d int) (a int, b int) {
	e := 1
	f := 2
	a = c + d + e + f
	b = d * 2
	return
}
func testMutil() {
	i, j := vals(1, 2)
	i = i + 1
	j = j + 1
}
func main() {
	testMutil()
}

main_vals:
    sub     rsp, 18h
    mov     [rsp+18h+var_8], rbp
    lea     rbp, [rsp+18h+var_8]
    mov     [rsp+18h+arg_10], 0
    mov     [rsp+18h+arg_18], 0
    mov     [rsp+18h+var_10], 1
    mov     [rsp+18h+var_18], 2
    mov     rax, [rsp+18h+arg_0]
    add     rax, [rsp+18h+arg_8]
    add     rax, [rsp+18h+var_10]
    add     rax, 2
    mov     [rsp+18h+arg_10], rax
    mov     rax, [rsp+18h+arg_8]
    shl     rax, 1
    mov     [rsp+18h+arg_18], rax
    mov     rbp, [rsp+18h+var_8]
    add     rsp, 18h
    retn
main_vals endp
main_testMutil:
    mov     rcx, gs:28h
    mov     rcx, [rcx+0]
    cmp     rsp, [rcx+10h]
    jbe     short morestack_noctxt
    sub     rsp, 48h
    mov     [rsp+48h+var_8], rbp
    lea     rbp, [rsp+48h+var_8]
    mov     [rsp+48h+var_48], 1
    mov     [rsp+48h+var_40], 2
    call    main_vals
    mov     rax, [rsp+48h+var_38]
    mov     [rsp+48h+var_10], rax
    mov     rax, [rsp+48h+var_30]
    mov     [rsp+48h+var_18], rax
    mov     rax, [rsp+48h+var_10]
    mov     [rsp+48h+var_20], rax
    mov     rax, [rsp+48h+var_18]
    mov     [rsp+48h+var_28], rax
    mov     rax, [rsp+48h+var_20]
    inc     rax
    mov     [rsp+48h+var_20], rax
    mov     rax, [rsp+48h+var_28]
    inc     rax
    mov     [rsp+48h+var_28], rax
    mov     rbp, [rsp+48h+var_8]
    add     rsp, 48h
    retn
morestack_noctxt:
    call    runtime_morestack_noctxt
main_testMutil endp

sub     rsp, 18h
mov     [rsp+18h+var_8], rbp
...
mov     rbp, [rsp+18h+var_8]
add     rsp, 18h

mov     [rsp+18h+arg_10], rax
...
mov     [rsp+18h+arg_18], rax

mov     rax, [rsp+48h+var_38]
mov     [rsp+48h+var_10], rax
mov     rax, [rsp+48h+var_30]
mov     [rsp+48h+var_18], rax