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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-exception4 5#include "../assembly.h"6 7// _chkstk routine8// This routine is windows specific9// http://msdn.microsoft.com/en-us/library/ms648426.aspx10 11// Notes from r22751912// MSVC x64s __chkstk and cygmings ___chkstk_ms do not adjust %rsp13// themselves. It also does not clobber %rax so we can reuse it when14// adjusting %rsp.15 16#ifdef __x86_64__17 18.text19.balign 420DEFINE_COMPILERRT_FUNCTION(___chkstk_ms)21 push %rcx22 push %rax23 cmp $0x1000,%rax24 lea 24(%rsp),%rcx25 jb 1f262:27 sub $0x1000,%rcx28 test %rcx,(%rcx)29 sub $0x1000,%rax30 cmp $0x1000,%rax31 ja 2b321:33 sub %rax,%rcx34 test %rcx,(%rcx)35 pop %rax36 pop %rcx37 ret38END_COMPILERRT_FUNCTION(___chkstk_ms)39 40#endif // __x86_64__41