bit_rev.h

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/*
 * SPDX-FileCopyrightText: Copyright The Zephyr Project Contributors
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_ARCH_RISCV_BIT_REV_H_
#define ZEPHYR_INCLUDE_ARCH_RISCV_BIT_REV_H_
 
#ifndef _ASMLANGUAGE
 
#include <zephyr/types.h>
#include <zephyr/sys/util.h>
 
#ifdef __cplusplus
extern "C" {
#endif

 
#if defined(CONFIG_ARCH_HAS_BIT_REV) || defined(__DOXYGEN__)

static inline uint32_t arch_sys_bit_rev32(uint32_t x)
{
        unsigned long x_rev = x;
 
        __asm__("rev8 %0, %1\n"
                "brev8 %0, %0\n"
                : "=r"(x_rev)
                : "r"(x_rev));
 
        return x_rev >> (__riscv_xlen - 32);
}

static inline uint16_t arch_sys_bit_rev16(uint16_t x)
{
        return arch_sys_bit_rev32(x) >> 16;
}

static inline uint8_t arch_sys_bit_rev8(uint8_t x)
{
        __asm__("brev8 %0, %1\n" : "=r"(x) : "r"(x));
        return x;
}
 
#endif /* defined(CONFIG_ARCH_HAS_BIT_REV) || defined(__DOXYGEN__) */

 
#ifdef __cplusplus
}
#endif
 
#endif /* !_ASMLANGUAGE */
#endif /* ZEPHYR_INCLUDE_ARCH_RISCV_BIT_REV_H_ */