diff --git a/include/asm-powerpc/bitops.h b/include/asm-powerpc/bitops.h index 36c8f3a43792..a99a74929475 100644 --- a/include/asm-powerpc/bitops.h +++ b/include/asm-powerpc/bitops.h @@ -312,7 +312,24 @@ static __inline__ int fls(unsigned int x) asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); return 32 - lz; } + +/* + * 64-bit can do this using one cntlzd (count leading zeroes doubleword) + * instruction; for 32-bit we use the generic version, which does two + * 32-bit fls calls. + */ +#ifdef __powerpc64__ +static __inline__ int fls64(__u64 x) +{ + int lz; + + asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x)); + return 64 - lz; +} +#else #include +#endif /* __powerpc64__ */ + #include #include