if s.NoFrame() {
		return
	}

	// This implementation expects the following function prologue layout:
	// - Stack split code (optional)
	// - PUSHQ	BP
	// - MOVQ	SP,	BP
	//
	// If the prologue layout change, the unwind information should be updated
	// accordingly.

	// Search for the PUSHQ BP instruction inside the prologue.
	var pushbp *obj.Prog
	for p := s.Func().Text; p != nil; p = p.Link {

	RET

On arm64, functions in Go are aligned to 16 bytes by default, we can also use PCALIGN to set the
function alignment. The functions that need to be aligned are preferably using NOFRAME and NOSPLIT
to avoid the impact of the prologues inserted by the assembler, so that the function address will
have the same alignment as the first hand-written instruction.

In the following example, PCALIGN at the entry of the function Add will align its address to 2048 bytes.

// goroutine with minimal space, and to precisely scan a goroutine's
// stack.
//
// Synchronous safe-points are implemented by overloading the stack
// bound check in function prologues. To preempt a goroutine at the
// next synchronous safe-point, the runtime poisons the goroutine's
// stack bound to a value that will cause the next stack bound check
// to fail and enter the stack growth implementation, which will

// unsafe-points.
func IsUnsafe(f *ssa.Func) bool {
	// The runtime assumes the only safe-points are function
	// prologues (because that's how it used to be). We could and
	// should improve that, but for now keep consider all points
	// in the runtime unsafe. obj will add prologues and their
	// safe-points.
	//
	// go:nosplit functions are similar. Since safe points used to

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package runtime

func XTestSPWrite(t TestingT) {
	// Test that we can traceback from the stack check prologue of a function
	// that writes to SP. See #62326.

	// Start a goroutine to minimize the initial stack and ensure we grow the stack.
	done := make(chan bool)
	go func() {
		testSPWrite() // Defined in assembly

// run

// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Issue 8155.
// Alignment of stack prologue zeroing was wrong on 64-bit Native Client
// (because of 32-bit pointers).

package main

import "runtime"

func bad(b bool) uintptr {
	var p **int
	var x1 uintptr
	x1 = 1
	if b {
		var x [11]*int
		p = &x[0]

		// Insert stack adjustment.
		prologue = obj.Appendp(prologue, newprog)
		prologue.As = AADDI
		prologue.From = obj.Addr{Type: obj.TYPE_CONST, Offset: -stacksize}
		prologue.Reg = REG_SP
		prologue.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_SP}
		prologue.Spadj = int32(stacksize)

		prologue = ctxt.EndUnsafePoint(prologue, newprog, -1)

//	X=(-{gc,asm}flags={runtime/...,reflect,sync}=-d=maymorestack=runtime.mayMoreStackPreempt) GOFLAGS=${X[@]}
//
// This must be deeply nosplit because it is called from a function
// prologue before the stack is set up and because the compiler will
// call it from any splittable prologue (leading to infinite
// recursion).
//
// Ideally it should also use very little stack because the linker
// doesn't currently account for this in nosplit stack depth checking.

}

func main() {
	x, e := A(0, 0)
	for j := 0; j < 4; j++ { // j controls amount of B's stack dribble
		for i := 0; i < 1000; i++ { // try more and more recursion until stack growth occurs in newobject in prologue
			x, e = A(int64(i), int64(j))
		}
	}
	_, _ = x, e

	MOVD	$__asan_register_globals_go(SB), FARG
	BR	asancall<>(SB)

// Switches SP to g0 stack and calls (FARG). Arguments already set.
TEXT	asancall<>(SB), NOSPLIT, $0-0
	// LR saved in generated prologue
	// Get info from the current goroutine
	MOVD	runtime·tls_g(SB), R10  // g offset in TLS
	MOVD	0(R10), g
	MOVD	g_m(g), R7		// m for g
	MOVD	R1, R16			// callee-saved, preserved across C call