xref: /aosp_15_r20/external/compiler-rt/lib/builtins/x86_64/chkstk.S (revision 7c3d14c8b49c529e04be81a3ce6f5cc23712e4c6)
1*7c3d14c8STreehugger Robot// This file is dual licensed under the MIT and the University of Illinois Open
2*7c3d14c8STreehugger Robot// Source Licenses. See LICENSE.TXT for details.
3*7c3d14c8STreehugger Robot
4*7c3d14c8STreehugger Robot#include "../assembly.h"
5*7c3d14c8STreehugger Robot
6*7c3d14c8STreehugger Robot// _chkstk routine
7*7c3d14c8STreehugger Robot// This routine is windows specific
8*7c3d14c8STreehugger Robot// http://msdn.microsoft.com/en-us/library/ms648426.aspx
9*7c3d14c8STreehugger Robot
10*7c3d14c8STreehugger Robot// Notes from r227519
11*7c3d14c8STreehugger Robot// MSVC x64s __chkstk and cygmings ___chkstk_ms do not adjust %rsp
12*7c3d14c8STreehugger Robot// themselves. It also does not clobber %rax so we can reuse it when
13*7c3d14c8STreehugger Robot// adjusting %rsp.
14*7c3d14c8STreehugger Robot
15*7c3d14c8STreehugger Robot#ifdef __x86_64__
16*7c3d14c8STreehugger Robot
17*7c3d14c8STreehugger Robot.text
18*7c3d14c8STreehugger Robot.balign 4
19*7c3d14c8STreehugger RobotDEFINE_COMPILERRT_FUNCTION(___chkstk_ms)
20*7c3d14c8STreehugger Robot        push   %rcx
21*7c3d14c8STreehugger Robot        push   %rax
22*7c3d14c8STreehugger Robot        cmp    $0x1000,%rax
23*7c3d14c8STreehugger Robot        lea    24(%rsp),%rcx
24*7c3d14c8STreehugger Robot        jb     1f
25*7c3d14c8STreehugger Robot2:
26*7c3d14c8STreehugger Robot        sub    $0x1000,%rcx
27*7c3d14c8STreehugger Robot        test   %rcx,(%rcx)
28*7c3d14c8STreehugger Robot        sub    $0x1000,%rax
29*7c3d14c8STreehugger Robot        cmp    $0x1000,%rax
30*7c3d14c8STreehugger Robot        ja     2b
31*7c3d14c8STreehugger Robot1:
32*7c3d14c8STreehugger Robot        sub    %rax,%rcx
33*7c3d14c8STreehugger Robot        test   %rcx,(%rcx)
34*7c3d14c8STreehugger Robot        pop    %rax
35*7c3d14c8STreehugger Robot        pop    %rcx
36*7c3d14c8STreehugger Robot        ret
37*7c3d14c8STreehugger RobotEND_COMPILERRT_FUNCTION(___chkstk_ms)
38*7c3d14c8STreehugger Robot
39*7c3d14c8STreehugger Robot#endif // __x86_64__
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