diff options
Diffstat (limited to 'compiler-rt/lib/builtins/x86_64/chkstk2.S')
| -rw-r--r-- | compiler-rt/lib/builtins/x86_64/chkstk2.S | 43 |
1 files changed, 0 insertions, 43 deletions
diff --git a/compiler-rt/lib/builtins/x86_64/chkstk2.S b/compiler-rt/lib/builtins/x86_64/chkstk2.S deleted file mode 100644 index 33d10d5b63be..000000000000 --- a/compiler-rt/lib/builtins/x86_64/chkstk2.S +++ /dev/null @@ -1,43 +0,0 @@ -// 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" - -#ifdef __x86_64__ - -// _chkstk (_alloca) routine - probe stack between %rsp and (%rsp-%rax) in 4k increments, -// then decrement %rsp by %rax. Preserves all registers except %rsp and flags. -// This routine is windows specific -// http://msdn.microsoft.com/en-us/library/ms648426.aspx - -.text -.balign 4 -DEFINE_COMPILERRT_FUNCTION(__alloca) - mov %rcx,%rax // x64 _alloca is a normal function with parameter in rcx - // fallthrough -DEFINE_COMPILERRT_FUNCTION(___chkstk) - push %rcx - cmp $0x1000,%rax - lea 16(%rsp),%rcx // rsp before calling this routine -> rcx - jb 1f -2: - sub $0x1000,%rcx - test %rcx,(%rcx) - sub $0x1000,%rax - cmp $0x1000,%rax - ja 2b -1: - sub %rax,%rcx - test %rcx,(%rcx) - - lea 8(%rsp),%rax // load pointer to the return address into rax - mov %rcx,%rsp // install the new top of stack pointer into rsp - mov -8(%rax),%rcx // restore rcx - push (%rax) // push return address onto the stack - sub %rsp,%rax // restore the original value in rax - ret -END_COMPILERRT_FUNCTION(___chkstk) -END_COMPILERRT_FUNCTION(__alloca) - -#endif // __x86_64__ |