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// 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"
// __chkstk routine
// This routine is windows specific.
// http://msdn.microsoft.com/en-us/library/ms648426.aspx
// This clobbers the register r12, and the condition codes, and uses r5 and r6
// as temporaries by backing them up and restoring them afterwards.
// Does not modify any memory or the stack pointer.
// movw r4, #256 // Number of bytes of stack, in units of 4 byte
// bl __chkstk
// sub.w sp, sp, r4
#define PAGE_SIZE 4096
.p2align 2
DEFINE_COMPILERRT_FUNCTION(__chkstk)
lsl r4, r4, #2
mov r12, sp
push {r5, r6}
mov r5, r4
1:
sub r12, r12, #PAGE_SIZE
subs r5, r5, #PAGE_SIZE
ldr r6, [r12]
bgt 1b
pop {r5, r6}
bx lr
END_COMPILERRT_FUNCTION(__chkstk)
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