diff options
Diffstat (limited to 'gcc/hwint.h')
| -rw-r--r-- | gcc/hwint.h | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/gcc/hwint.h b/gcc/hwint.h index 6b4d53737a2..ea87b2158b1 100644 --- a/gcc/hwint.h +++ b/gcc/hwint.h @@ -134,6 +134,31 @@ typedef HOST_WIDE_INT __gcc_host_wide_int__; #endif /* Inline functions operating on HOST_WIDE_INT. */ + +/* Return X with all but the lowest bit masked off. */ + +static inline unsigned HOST_WIDE_INT +least_bit_hwi (unsigned HOST_WIDE_INT x) +{ + return (x & -x); +} + +/* True if X is zero or a power of two. */ + +static inline bool +pow2_or_zerop (unsigned HOST_WIDE_INT x) +{ + return least_bit_hwi (x) == x; +} + +/* True if X is a power of two. */ + +static inline bool +pow2p_hwi (unsigned HOST_WIDE_INT x) +{ + return x && pow2_or_zerop (x); +} + #if GCC_VERSION < 3004 extern int clz_hwi (unsigned HOST_WIDE_INT x); @@ -222,7 +247,7 @@ ceil_log2 (unsigned HOST_WIDE_INT x) static inline int exact_log2 (unsigned HOST_WIDE_INT x) { - return x == (x & -x) && x ? ctz_hwi (x) : -1; + return pow2p_hwi (x) ? ctz_hwi (x) : -1; } #endif /* GCC_VERSION >= 3004 */ @@ -238,6 +263,14 @@ extern HOST_WIDE_INT pos_mul_hwi (HOST_WIDE_INT, HOST_WIDE_INT); extern HOST_WIDE_INT mul_hwi (HOST_WIDE_INT, HOST_WIDE_INT); extern HOST_WIDE_INT least_common_multiple (HOST_WIDE_INT, HOST_WIDE_INT); +/* Like ctz_hwi, except 0 when x == 0. */ + +static inline int +ctz_or_zero (unsigned HOST_WIDE_INT x) +{ + return ffs_hwi (x) - 1; +} + /* Sign extend SRC starting from PREC. */ static inline HOST_WIDE_INT |