aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/cxxsupp/builtins/arm/bswapdi2.S
blob: 86f3bba8c2902d5b9b07a66ef9164205f7125382 (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
37
38
39
40
41
42
43
44
45
46
47
//===------- bswapdi2 - Implement bswapdi2 --------------------------------===//
//
//                     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
#if __ARM_ARCH_ISA_THUMB == 2
	.thumb
#endif

//
// extern uint64_t __bswapdi2(uint64_t);
//
// Reverse all the bytes in a 64-bit integer.
//
	.p2align 2
#if __ARM_ARCH_ISA_THUMB == 2
DEFINE_COMPILERRT_THUMB_FUNCTION(__bswapdi2)
#else
DEFINE_COMPILERRT_FUNCTION(__bswapdi2)
#endif
#if __ARM_ARCH < 6
    // before armv6 does not have "rev" instruction
    // r2 = rev(r0)
    eor r2, r0, r0, ror #16
    bic r2, r2, #0xff0000
    mov r2, r2, lsr #8
    eor r2, r2, r0, ror #8
    // r0 = rev(r1)
    eor r0, r1, r1, ror #16
    bic r0, r0, #0xff0000
    mov r0, r0, lsr #8
    eor r0, r0, r1, ror #8
#else
    rev r2, r0  // r2 = rev(r0)
    rev r0, r1  // r0 = rev(r1)
#endif
    mov r1, r2  // r1 = r2 = rev(r0)
    JMP(lr)
END_COMPILERRT_FUNCTION(__bswapdi2)