| 1 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
|---|---|
| 2 | // See https://llvm.org/LICENSE.txt for license information. |
| 3 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 4 | |
| 5 | #include "../assembly.h" |
| 6 | |
| 7 | // __chkstk routine |
| 8 | // This routine is windows specific. |
| 9 | // http://msdn.microsoft.com/en-us/library/ms648426.aspx |
| 10 | |
| 11 | // This clobbers registers x16 and x17. |
| 12 | // Does not modify any memory or the stack pointer. |
| 13 | |
| 14 | // mov x15, #256 // Number of bytes of stack, in units of 16 byte |
| 15 | // bl __chkstk |
| 16 | // sub sp, sp, x15, lsl #4 |
| 17 | |
| 18 | #ifdef __aarch64__ |
| 19 | |
| 20 | #define PAGE_SIZE 4096 |
| 21 | |
| 22 | .p2align 2 |
| 23 | DEFINE_COMPILERRT_FUNCTION(__chkstk) |
| 24 | lsl x16, x15, #4 |
| 25 | mov x17, sp |
| 26 | 1: |
| 27 | sub x17, x17, #PAGE_SIZE |
| 28 | subs x16, x16, #PAGE_SIZE |
| 29 | ldr xzr, [x17] |
| 30 | b.gt 1b |
| 31 | |
| 32 | ret |
| 33 | END_COMPILERRT_FUNCTION(__chkstk) |
| 34 | |
| 35 | #endif // __aarch64__ |
| 36 |