946a81f5b0
This function is available for linking in from kernel32.dll, but it's not allowed to link that function from there in Windows Store apps. Differential Revision: https://reviews.llvm.org/D49055 llvm-svn: 337313
35 lines
972 B
ArmAsm
35 lines
972 B
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 "../assembly.h"
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// __chkstk routine
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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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// This clobbers the register r12, and the condition codes, and uses r5 and r6
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// as temporaries by backing them up and restoring them afterwards.
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// Does not modify any memory or the stack pointer.
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// movw r4, #256 // Number of bytes of stack, in units of 4 byte
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// bl __chkstk
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// sub.w sp, sp, r4
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#define PAGE_SIZE 4096
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.p2align 2
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DEFINE_COMPILERRT_FUNCTION(__chkstk)
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lsl r4, r4, #2
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mov r12, sp
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push {r5, r6}
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mov r5, r4
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1:
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sub r12, r12, #PAGE_SIZE
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subs r5, r5, #PAGE_SIZE
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ldr r6, [r12]
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bgt 1b
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pop {r5, r6}
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bx lr
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END_COMPILERRT_FUNCTION(__chkstk)
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