1// Copyright 2023 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5//go:build amd64 || arm64
6
7package main
8
9import "unsafe"
10
11func init() {
12	register("FramePointerAdjust", FramePointerAdjust)
13}
14
15func FramePointerAdjust() { framePointerAdjust1(0) }
16
17//go:noinline
18func framePointerAdjust1(x int) {
19	argp := uintptr(unsafe.Pointer(&x))
20	fp := *getFP()
21	if !(argp-0x100 <= fp && fp <= argp+0x100) {
22		print("saved FP=", fp, " &x=", argp, "\n")
23		panic("FAIL")
24	}
25
26	// grow the stack
27	grow(10000)
28
29	// check again
30	argp = uintptr(unsafe.Pointer(&x))
31	fp = *getFP()
32	if !(argp-0x100 <= fp && fp <= argp+0x100) {
33		print("saved FP=", fp, " &x=", argp, "\n")
34		panic("FAIL")
35	}
36}
37
38func grow(n int) {
39	if n > 0 {
40		grow(n - 1)
41	}
42}
43
44func getFP() *uintptr
45