1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
2// See https://llvm.org/LICENSE.txt for license information.
3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
4
5#include "../assembly.h"
6
7// _chkstk routine
8// This routine is windows specific
9// http://msdn.microsoft.com/en-us/library/ms648426.aspx
10
11// Notes from r227519
12// MSVC x64s __chkstk and cygmings ___chkstk_ms do not adjust %rsp
13// themselves. It also does not clobber %rax so we can reuse it when
14// adjusting %rsp.
15
16#ifdef __x86_64__
17
18.text
19.balign 4
20DEFINE_COMPILERRT_FUNCTION(___chkstk_ms)
21DEFINE_COMPILERRT_FUNCTION(__chkstk)
22        push   %rcx
23        push   %rax
24        cmp    $0x1000,%rax
25        lea    24(%rsp),%rcx
26        jb     1f
272:
28        sub    $0x1000,%rcx
29        test   %rcx,(%rcx)
30        sub    $0x1000,%rax
31        cmp    $0x1000,%rax
32        ja     2b
331:
34        sub    %rax,%rcx
35        test   %rcx,(%rcx)
36        pop    %rax
37        pop    %rcx
38        ret
39END_COMPILERRT_FUNCTION(__chkstk)
40END_COMPILERRT_FUNCTION(___chkstk_ms)
41
42#endif // __x86_64__
43