xref: /aosp_15_r20/external/compiler-rt/lib/builtins/arm/bswapdi2.S (revision 7c3d14c8b49c529e04be81a3ce6f5cc23712e4c6)
1*7c3d14c8STreehugger Robot//===------- bswapdi2 - Implement bswapdi2 --------------------------------===//
2*7c3d14c8STreehugger Robot//
3*7c3d14c8STreehugger Robot//                     The LLVM Compiler Infrastructure
4*7c3d14c8STreehugger Robot//
5*7c3d14c8STreehugger Robot// This file is dual licensed under the MIT and the University of Illinois Open
6*7c3d14c8STreehugger Robot// Source Licenses. See LICENSE.TXT for details.
7*7c3d14c8STreehugger Robot//
8*7c3d14c8STreehugger Robot//===----------------------------------------------------------------------===//
9*7c3d14c8STreehugger Robot
10*7c3d14c8STreehugger Robot#include "../assembly.h"
11*7c3d14c8STreehugger Robot
12*7c3d14c8STreehugger Robot	.syntax unified
13*7c3d14c8STreehugger Robot	.text
14*7c3d14c8STreehugger Robot#if __ARM_ARCH_ISA_THUMB == 2
15*7c3d14c8STreehugger Robot	.thumb
16*7c3d14c8STreehugger Robot#endif
17*7c3d14c8STreehugger Robot
18*7c3d14c8STreehugger Robot//
19*7c3d14c8STreehugger Robot// extern uint64_t __bswapdi2(uint64_t);
20*7c3d14c8STreehugger Robot//
21*7c3d14c8STreehugger Robot// Reverse all the bytes in a 64-bit integer.
22*7c3d14c8STreehugger Robot//
23*7c3d14c8STreehugger Robot	.p2align 2
24*7c3d14c8STreehugger Robot#if __ARM_ARCH_ISA_THUMB == 2
25*7c3d14c8STreehugger RobotDEFINE_COMPILERRT_THUMB_FUNCTION(__bswapdi2)
26*7c3d14c8STreehugger Robot#else
27*7c3d14c8STreehugger RobotDEFINE_COMPILERRT_FUNCTION(__bswapdi2)
28*7c3d14c8STreehugger Robot#endif
29*7c3d14c8STreehugger Robot#if __ARM_ARCH < 6
30*7c3d14c8STreehugger Robot    // before armv6 does not have "rev" instruction
31*7c3d14c8STreehugger Robot    // r2 = rev(r0)
32*7c3d14c8STreehugger Robot    eor r2, r0, r0, ror #16
33*7c3d14c8STreehugger Robot    bic r2, r2, #0xff0000
34*7c3d14c8STreehugger Robot    mov r2, r2, lsr #8
35*7c3d14c8STreehugger Robot    eor r2, r2, r0, ror #8
36*7c3d14c8STreehugger Robot    // r0 = rev(r1)
37*7c3d14c8STreehugger Robot    eor r0, r1, r1, ror #16
38*7c3d14c8STreehugger Robot    bic r0, r0, #0xff0000
39*7c3d14c8STreehugger Robot    mov r0, r0, lsr #8
40*7c3d14c8STreehugger Robot    eor r0, r0, r1, ror #8
41*7c3d14c8STreehugger Robot#else
42*7c3d14c8STreehugger Robot    rev r2, r0  // r2 = rev(r0)
43*7c3d14c8STreehugger Robot    rev r0, r1  // r0 = rev(r1)
44*7c3d14c8STreehugger Robot#endif
45*7c3d14c8STreehugger Robot    mov r1, r2  // r1 = r2 = rev(r0)
46*7c3d14c8STreehugger Robot    JMP(lr)
47*7c3d14c8STreehugger RobotEND_COMPILERRT_FUNCTION(__bswapdi2)
48*7c3d14c8STreehugger Robot
49*7c3d14c8STreehugger RobotNO_EXEC_STACK_DIRECTIVE
50*7c3d14c8STreehugger Robot
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