diff options
Diffstat (limited to 'src/include/lib.h')
| -rw-r--r-- | src/include/lib.h | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/src/include/lib.h b/src/include/lib.h index 7ad33dd552..b81b1b18bb 100644 --- a/src/include/lib.h +++ b/src/include/lib.h @@ -24,12 +24,6 @@ #include <stdint.h> #include <types.h> -#if !defined(__ROMCC__) /* Conflicts with inline function in arch/io.h */ -/* Defined in src/lib/clog2.c */ -unsigned long log2(unsigned long x); -#endif -unsigned long log2_ceil(unsigned long x); - /* Defined in src/lib/lzma.c */ unsigned long ulzma(unsigned char *src, unsigned char *dst); @@ -49,4 +43,16 @@ int checkstack(void *top_of_stack, int core); void hexdump(const void *memory, size_t length); void hexdump32(char LEVEL, const void *d, size_t len); +#if !defined(__ROMCC__) +/* Count Leading Zeroes: clz(0) == 32, clz(0xf) == 28, clz(1 << 31) == 0 */ +static inline int clz(u32 x) { return x ? __builtin_clz(x) : sizeof(x) * 8; } +/* Integer binary logarithm (rounding down): log2(0) == -1, log2(5) == 2 */ +static inline int log2(u32 x) { return sizeof(x) * 8 - clz(x) - 1; } +/* Find First Set: __ffs(1) == 0, __ffs(0) == -1, __ffs(1<<31) == 31 */ +static inline int __ffs(u32 x) { return log2(x & (u32)(-(s32)x)); } +#endif + +/* Integer binary logarithm (rounding up): log2_ceil(0) == -1, log2(5) == 3 */ +static inline int log2_ceil(u32 x) { return (x == 0) ? -1 : log2(x * 2 - 1); } + #endif /* __LIB_H__ */ |