diff options
Diffstat (limited to 'compiler-rt/lib/builtins/arm/bswapsi2.S')
| -rw-r--r-- | compiler-rt/lib/builtins/arm/bswapsi2.S | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/arm/bswapsi2.S b/compiler-rt/lib/builtins/arm/bswapsi2.S new file mode 100644 index 000000000000..07cc3d89190e --- /dev/null +++ b/compiler-rt/lib/builtins/arm/bswapsi2.S @@ -0,0 +1,35 @@ +//===------- bswapsi2 - Implement bswapsi2 --------------------------------===// +// +// 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 uint32_t __bswapsi2(uint32_t); +// +// Reverse all the bytes in a 32-bit integer. +// + .p2align 2 +DEFINE_COMPILERRT_FUNCTION(__bswapsi2) +#if __ARM_ARCH < 6 + // before armv6 does not have "rev" instruction + eor r1, r0, r0, ror #16 + bic r1, r1, #0xff0000 + mov r1, r1, lsr #8 + eor r0, r1, r0, ror #8 +#else + rev r0, r0 +#endif + JMP(lr) +END_COMPILERRT_FUNCTION(__bswapsi2) + +NO_EXEC_STACK_DIRECTIVE + |