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//===------- bswapdi2 - Implement bswapdi2 --------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "../assembly.h"
.syntax unified
.text
DEFINE_CODE_STATE
//
// extern uint64_t __bswapdi2(uint64_t);
//
// Reverse all the bytes in a 64-bit integer.
//
.p2align 2
DEFINE_COMPILERRT_FUNCTION(__bswapdi2)
#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)
NO_EXEC_STACK_DIRECTIVE
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