1//===------- bswapsi2 - Implement bswapsi2 --------------------------------===// 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 uint32_t __bswapsi2(uint32_t); 20// 21// Reverse all the bytes in a 32-bit integer. 22// 23 .p2align 2 24DEFINE_COMPILERRT_FUNCTION(__bswapsi2) 25#if __ARM_ARCH < 6 26 // before armv6 does not have "rev" instruction 27 eor r1, r0, r0, ror #16 28 bic r1, r1, #0xff0000 29 mov r1, r1, lsr #8 30 eor r0, r1, r0, ror #8 31#else 32 rev r0, r0 33#endif 34 JMP(lr) 35END_COMPILERRT_FUNCTION(__bswapsi2) 36