1//===------- bswapdi2 - Implement bswapdi2 --------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "../assembly.h"
11
12	.syntax unified
13	.text
14#if __ARM_ARCH_ISA_THUMB == 2
15	.thumb
16#endif
17
18//
19// extern uint64_t __bswapdi2(uint64_t);
20//
21// Reverse all the bytes in a 64-bit integer.
22//
23	.p2align 2
24DEFINE_COMPILERRT_FUNCTION(__bswapdi2)
25#if __ARM_ARCH < 6
26    // before armv6 does not have "rev" instruction
27    // r2 = rev(r0)
28    eor r2, r0, r0, ror #16
29    bic r2, r2, #0xff0000
30    mov r2, r2, lsr #8
31    eor r2, r2, r0, ror #8
32    // r0 = rev(r1)
33    eor r0, r1, r1, ror #16
34    bic r0, r0, #0xff0000
35    mov r0, r0, lsr #8
36    eor r0, r0, r1, ror #8
37#else
38    rev r2, r0  // r2 = rev(r0)
39    rev r0, r1  // r0 = rev(r1)
40#endif
41    mov r1, r2  // r1 = r2 = rev(r0)
42    JMP(lr)
43END_COMPILERRT_FUNCTION(__bswapdi2)
44