File: chkstk.S

package info (click to toggle)
llvm-toolchain-17 1%3A17.0.6-22
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 1,799,624 kB
  • sloc: cpp: 6,428,607; ansic: 1,383,196; asm: 793,408; python: 223,504; objc: 75,364; f90: 60,502; lisp: 33,869; pascal: 15,282; sh: 9,684; perl: 7,453; ml: 4,937; awk: 3,523; makefile: 2,889; javascript: 2,149; xml: 888; fortran: 619; cs: 573
file content (35 lines) | stat: -rw-r--r-- 1,044 bytes parent folder | download | duplicates (30) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
 
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#include "../assembly.h"

// __chkstk routine
// This routine is windows specific.
// http://msdn.microsoft.com/en-us/library/ms648426.aspx

// This clobbers the register r12, and the condition codes, and uses r5 and r6
// as temporaries by backing them up and restoring them afterwards.
// Does not modify any memory or the stack pointer.

//      movw    r4,  #256 // Number of bytes of stack, in units of 4 byte
//      bl      __chkstk
//      sub.w   sp, sp, r4

#define PAGE_SIZE 4096

        .p2align 2
DEFINE_COMPILERRT_FUNCTION(__chkstk)
        lsl    r4,  r4,  #2
        mov    r12, sp
        push   {r5, r6}
        mov    r5,  r4
1:
        sub    r12, r12, #PAGE_SIZE
        subs   r5,  r5,  #PAGE_SIZE
        ldr    r6,  [r12]
        bgt    1b

        pop    {r5, r6}
        bx     lr
END_COMPILERRT_FUNCTION(__chkstk)