aboutsummaryrefslogtreecommitdiff
path: root/contrib/compiler-rt/lib/builtins/arm/bswapsi2.S
blob: 1f6eed5c1bbf23676bac9798936bc28cd0e5b283 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
//===------- bswapsi2 - Implement bswapsi2 --------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "../assembly.h"

	.syntax unified
	.text
	DEFINE_CODE_STATE

//
// extern uint32_t __bswapsi2(uint32_t);
//
// Reverse all the bytes in a 32-bit integer.
//
	.p2align 2
DEFINE_COMPILERRT_FUNCTION(__bswapsi2)
#if __ARM_ARCH < 6
    // before armv6 does not have "rev" instruction
 	eor	r1, r0, r0, ror #16
 	bic	r1, r1, #0xff0000
 	mov	r1, r1, lsr #8
 	eor	r0, r1, r0, ror #8
#else
    rev r0, r0
#endif
    JMP(lr)
END_COMPILERRT_FUNCTION(__bswapsi2)

NO_EXEC_STACK_DIRECTIVE