xref: /openbsd-src/gnu/llvm/compiler-rt/lib/builtins/arm/bswapsi2.S (revision 3cab2bb3f667058bece8e38b12449a63a9d73c4b)
1*3cab2bb3Spatrick//===------- bswapsi2 - Implement bswapsi2 --------------------------------===//
2*3cab2bb3Spatrick//
3*3cab2bb3Spatrick// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*3cab2bb3Spatrick// See https://llvm.org/LICENSE.txt for license information.
5*3cab2bb3Spatrick// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*3cab2bb3Spatrick//
7*3cab2bb3Spatrick//===----------------------------------------------------------------------===//
8*3cab2bb3Spatrick
9*3cab2bb3Spatrick#include "../assembly.h"
10*3cab2bb3Spatrick
11*3cab2bb3Spatrick	.syntax unified
12*3cab2bb3Spatrick	.text
13*3cab2bb3Spatrick	DEFINE_CODE_STATE
14*3cab2bb3Spatrick
15*3cab2bb3Spatrick//
16*3cab2bb3Spatrick// extern uint32_t __bswapsi2(uint32_t);
17*3cab2bb3Spatrick//
18*3cab2bb3Spatrick// Reverse all the bytes in a 32-bit integer.
19*3cab2bb3Spatrick//
20*3cab2bb3Spatrick	.p2align 2
21*3cab2bb3SpatrickDEFINE_COMPILERRT_FUNCTION(__bswapsi2)
22*3cab2bb3Spatrick#if __ARM_ARCH < 6
23*3cab2bb3Spatrick    // before armv6 does not have "rev" instruction
24*3cab2bb3Spatrick 	eor	r1, r0, r0, ror #16
25*3cab2bb3Spatrick 	bic	r1, r1, #0xff0000
26*3cab2bb3Spatrick 	mov	r1, r1, lsr #8
27*3cab2bb3Spatrick 	eor	r0, r1, r0, ror #8
28*3cab2bb3Spatrick#else
29*3cab2bb3Spatrick    rev r0, r0
30*3cab2bb3Spatrick#endif
31*3cab2bb3Spatrick    JMP(lr)
32*3cab2bb3SpatrickEND_COMPILERRT_FUNCTION(__bswapsi2)
33*3cab2bb3Spatrick
34*3cab2bb3SpatrickNO_EXEC_STACK_DIRECTIVE
35*3cab2bb3Spatrick
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