/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/macros.internal.h"

//	Switches stack.
//
//	@param	rdi is new rsp, passed as malloc(size) + size
//	@param	rsi is function to call in new stack space
//	@param	rdx,rcx,r8,r9 get passed as args to rsi
//	@return	rax and happens on original stack
_setstack:
	push	%rbp
	mov	%rsp,%rbp
	push	%rbx
	mov	%rsp,%rbx
	mov	%rdi,%rsp
	push	16(%rbx)
	push	8(%rbx)
	mov	%rsi,%rax
	mov	%rdx,%rdi
	mov	%rcx,%rsi
	mov	%r8,%rdx
	mov	%r9,%rcx
	call	*%rax
	mov	%rbx,%rsp
	pop	%rbx
	pop	%rbp
	ret
	.endfn	_setstack,globl,hidden