mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
e75ffde09e
You can now build Cosmopolitan with Clang:
make -j8 MODE=llvm
o/llvm/examples/hello.com
The assembler and linker code is now friendly to LLVM too.
So it's not needed to configure Clang to use binutils under
the hood. If you love LLVM then you can now use pure LLVM.
46 lines
1.5 KiB
ArmAsm
46 lines
1.5 KiB
ArmAsm
// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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#include "third_party/compiler_rt/assembly.h"
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#ifdef __x86_64__
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.section .yoink
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nopl huge_compiler_rt_license(%rip)
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.previous
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// _chkstk (_alloca) routine - probe stack between %rsp and (%rsp-%rax) in 4k increments,
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// then decrement %rsp by %rax. Preserves all registers except %rsp and flags.
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// This routine is windows specific
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// http://msdn.microsoft.com/en-us/library/ms648426.aspx
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.text
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.balign 4
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DEFINE_COMPILERRT_FUNCTION(__alloca)
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mov %rcx,%rax // x64 _alloca is a normal function with parameter in rcx
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// fallthrough
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DEFINE_COMPILERRT_FUNCTION(___chkstk)
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push %rcx
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cmp $0x1000,%rax
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lea 16(%rsp),%rcx // rsp before calling this routine -> rcx
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jb 1f
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2:
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sub $0x1000,%rcx
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test %rcx,(%rcx)
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sub $0x1000,%rax
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cmp $0x1000,%rax
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ja 2b
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1:
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sub %rax,%rcx
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test %rcx,(%rcx)
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lea 8(%rsp),%rax // load pointer to the return address into rax
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mov %rcx,%rsp // install the new top of stack pointer into rsp
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mov -8(%rax),%rcx // restore rcx
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push (%rax) // push return address onto the stack
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sub %rsp,%rax // restore the original value in rax
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ret
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END_COMPILERRT_FUNCTION(___chkstk)
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END_COMPILERRT_FUNCTION(__alloca)
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#endif // __x86_64__
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