cosmopolitan/libc/mem/realloc_in_place.S

54 lines
3.0 KiB
ArmAsm

/*-*- 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
This program is free software; you can redistribute it and/or modify │
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License. │
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of │
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software │
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/macros.h"
#include "libc/notice.inc"
.source __FILE__
/ Resizes the space allocated for p to size n, only if this can be
/ done without moving p (i.e., only if there is adjacent space
/ available if n is greater than p's current allocated size, or n is
/ less than or equal to p's size). This may be used instead of plain
/ realloc if an alternative allocation strategy is needed upon failure
/ to expand space, for example, reallocation of a buffer that must be
/ memory-aligned or cleared. You can use realloc_in_place to trigger
/ these alternatives only when needed.
/
/ @param rdi (p) is address of current allocation
/ @param rsi (newsize) is number of bytes needed
/ @return rax is result, or NULL w/ errno
/ @see dlrealloc_in_place()
realloc_in_place:
jmp *hook$realloc_in_place(%rip)
.endfn realloc_in_place,globl
.initbss 800,_init_realloc_in_place
hook$realloc_in_place:
.quad 0
.endobj hook$realloc_in_place,globl,hidden
.previous
.init.start 800,_init_realloc_in_place
.hidden dlrealloc_in_place
ezlea dlrealloc_in_place,ax
stosq
.init.end 800,_init_realloc_in_place
yoink free