zephyr/include/arch/riscv32/riscv-privilege/asm_inline_gcc.h

66 lines
1.5 KiB
C

/*
* Copyright (c) 2017 Jean-Paul Etienne <fractalclone@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_ARCH_RISCV32_RISCV_PRIVILEGE_ASM_INLINE_GCC_H_
#define ZEPHYR_INCLUDE_ARCH_RISCV32_RISCV_PRIVILEGE_ASM_INLINE_GCC_H_
#ifdef __cplusplus
extern "C" {
#endif
/*
* The file must not be included directly
* Include arch/cpu.h instead
* TEMPORARY
*/
#ifndef _ASMLANGUAGE
#include <toolchain.h>
/**
*
* @brief find least significant bit set in a 32-bit word
*
* This routine finds the first bit set starting from the least significant bit
* in the argument passed in and returns the index of that bit. Bits are
* numbered starting at 1 from the least significant bit. A return value of
* zero indicates that the value passed is zero.
*
* @return least significant bit set, 0 if @a op is 0
*/
static ALWAYS_INLINE unsigned int find_lsb_set(u32_t op)
{
return __builtin_ffs(op);
}
/**
*
* @brief find most significant bit set in a 32-bit word
*
* This routine finds the first bit set starting from the most significant bit
* in the argument passed in and returns the index of that bit. Bits are
* numbered starting at 1 from the least significant bit. A return value of
* zero indicates that the value passed is zero.
*
* @return most significant bit set, 0 if @a op is 0
*/
static ALWAYS_INLINE unsigned int find_msb_set(u32_t op)
{
if (!op)
return 0;
return 32 - __builtin_clz(op);
}
#endif /* _ASMLANGUAGE */
#ifdef __cplusplus
}
#endif
#endif /* ZEPHYR_INCLUDE_ARCH_RISCV32_RISCV_PRIVILEGE_ASM_INLINE_GCC_H_ */