1 | //===------- bswapsi2 - Implement bswapsi2 --------------------------------===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #include "../assembly.h" |
10 | |
11 | .syntax unified |
12 | .text |
13 | DEFINE_CODE_STATE |
14 | |
15 | // |
16 | // extern uint32_t __bswapsi2(uint32_t); |
17 | // |
18 | // Reverse all the bytes in a 32-bit integer. |
19 | // |
20 | .p2align 2 |
21 | DEFINE_COMPILERRT_FUNCTION(__bswapsi2) |
22 | #if __ARM_ARCH < 6 |
23 | // before armv6 does not have "rev" instruction |
24 | eor r1, r0, r0, ror #16 |
25 | bic r1, r1, #0xff0000 |
26 | mov r1, r1, lsr #8 |
27 | eor r0, r1, r0, ror #8 |
28 | #else |
29 | rev r0, r0 |
30 | #endif |
31 | JMP(lr) |
32 | END_COMPILERRT_FUNCTION(__bswapsi2) |
33 | |
34 | NO_EXEC_STACK_DIRECTIVE |
35 | |
36 | |