xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/arm/bswapsi2.S (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric//===------- bswapsi2 - Implement bswapsi2 --------------------------------===//
2*0b57cec5SDimitry Andric//
3*0b57cec5SDimitry Andric// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*0b57cec5SDimitry Andric// See https://llvm.org/LICENSE.txt for license information.
5*0b57cec5SDimitry Andric// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*0b57cec5SDimitry Andric//
7*0b57cec5SDimitry Andric//===----------------------------------------------------------------------===//
8*0b57cec5SDimitry Andric
9*0b57cec5SDimitry Andric#include "../assembly.h"
10*0b57cec5SDimitry Andric
11*0b57cec5SDimitry Andric	.syntax unified
12*0b57cec5SDimitry Andric	.text
13*0b57cec5SDimitry Andric	DEFINE_CODE_STATE
14*0b57cec5SDimitry Andric
15*0b57cec5SDimitry Andric//
16*0b57cec5SDimitry Andric// extern uint32_t __bswapsi2(uint32_t);
17*0b57cec5SDimitry Andric//
18*0b57cec5SDimitry Andric// Reverse all the bytes in a 32-bit integer.
19*0b57cec5SDimitry Andric//
20*0b57cec5SDimitry Andric	.p2align 2
21*0b57cec5SDimitry AndricDEFINE_COMPILERRT_FUNCTION(__bswapsi2)
22*0b57cec5SDimitry Andric#if __ARM_ARCH < 6
23*0b57cec5SDimitry Andric    // before armv6 does not have "rev" instruction
24*0b57cec5SDimitry Andric 	eor	r1, r0, r0, ror #16
25*0b57cec5SDimitry Andric 	bic	r1, r1, #0xff0000
26*0b57cec5SDimitry Andric 	mov	r1, r1, lsr #8
27*0b57cec5SDimitry Andric 	eor	r0, r1, r0, ror #8
28*0b57cec5SDimitry Andric#else
29*0b57cec5SDimitry Andric    rev r0, r0
30*0b57cec5SDimitry Andric#endif
31*0b57cec5SDimitry Andric    JMP(lr)
32*0b57cec5SDimitry AndricEND_COMPILERRT_FUNCTION(__bswapsi2)
33*0b57cec5SDimitry Andric
34*0b57cec5SDimitry AndricNO_EXEC_STACK_DIRECTIVE
35*0b57cec5SDimitry Andric
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