| 1 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 2 | // See https://llvm.org/LICENSE.txt for license information. |
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| 3 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 4 | |
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| 5 | #include "../assembly.h" |
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| 6 | |
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| 7 | // _chkstk routine |
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| 8 | // This routine is windows specific |
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| 9 | // http://msdn.microsoft.com/en-us/library/ms648426.aspx |
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| 10 | |
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| 11 | // Notes from r227519 |
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| 12 | // MSVC x64s __chkstk and cygmings ___chkstk_ms do not adjust %rsp |
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| 13 | // themselves. It also does not clobber %rax so we can reuse it when |
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| 14 | // adjusting %rsp. |
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| 15 | |
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| 16 | #ifdef __x86_64__ |
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| 17 | |
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| 18 | .text |
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| 19 | .balign 4 |
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| 20 | DEFINE_COMPILERRT_FUNCTION(___chkstk_ms) |
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| 21 | push %rcx |
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| 22 | push %rax |
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| 23 | cmp $0x1000,%rax |
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| 24 | lea 24(%rsp),%rcx |
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| 25 | jb 1f |
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| 26 | 2: |
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| 27 | sub $0x1000,%rcx |
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| 28 | test %rcx,(%rcx) |
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| 29 | sub $0x1000,%rax |
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| 30 | cmp $0x1000,%rax |
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| 31 | ja 2b |
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| 32 | 1: |
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| 33 | sub %rax,%rcx |
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| 34 | test %rcx,(%rcx) |
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| 35 | pop %rax |
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| 36 | pop %rcx |
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| 37 | ret |
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| 38 | END_COMPILERRT_FUNCTION(___chkstk_ms) |
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| 39 | |
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| 40 | #endif // __x86_64__ |
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| 41 | |
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