| /* |
| * Copyright (c) 2016 Jean-Paul Etienne <fractalclone@gmail.com> |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #ifndef _ASM_INLINE_GCC_H |
| #define _ASM_INLINE_GCC_H |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* |
| * The file must not be included directly |
| * Include arch/cpu.h instead |
| * NOTE: only pulpino-specific NOT RISCV32 |
| */ |
| |
| #ifndef _ASMLANGUAGE |
| |
| #include <toolchain.h> |
| |
| /* |
| * Account for pulpino-specific bit manipulation opcodes only when |
| * CONFIG_RISCV_GENERIC_TOOLCHAIN is not set |
| */ |
| |
| #ifndef CONFIG_RISCV_GENERIC_TOOLCHAIN |
| /** |
| * |
| * @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) |
| { |
| unsigned int ret; |
| |
| if (!op) |
| return 0; |
| |
| __asm__ volatile ("p.ff1 %[d], %[a]" |
| : [d] "=r" (ret) |
| : [a] "r" (op)); |
| |
| return ret + 1; |
| } |
| |
| /** |
| * |
| * @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) |
| { |
| unsigned int ret; |
| |
| if (!op) |
| return 0; |
| |
| __asm__ volatile ("p.fl1 %[d], %[a]" |
| : [d] "=r" (ret) |
| : [a] "r" (op)); |
| |
| return ret + 1; |
| } |
| |
| #else /* CONFIG_RISCV_GENERIC_TOOLCHAIN */ |
| |
| /* |
| * When compiled with a riscv32 generic toolchain, use |
| * __builtin_ffs and __builtin_clz to handle respectively |
| * find_lsb_set and find_msb_set. |
| */ |
| static ALWAYS_INLINE unsigned int find_lsb_set(u32_t op) |
| { |
| return __builtin_ffs(op); |
| } |
| |
| static ALWAYS_INLINE unsigned int find_msb_set(u32_t op) |
| { |
| if (!op) |
| return 0; |
| |
| return 32 - __builtin_clz(op); |
| } |
| |
| #endif /* CONFIG_RISCV_GENERIC_TOOLCHAIN */ |
| |
| #endif /* _ASMLANGUAGE */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* _ASM_INLINE_GCC_PUBLIC_GCC_H */ |