diff options
Diffstat (limited to 'src/data.c')
| -rw-r--r-- | src/data.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/data.c b/src/data.c index ef7210fbfa0..00d1eb43033 100644 --- a/src/data.c +++ b/src/data.c @@ -3069,6 +3069,22 @@ usage: (logxor &rest INTS-OR-MARKERS) */) return arith_driver (Alogxor, nargs, args); } +DEFUN ("logcount", Flogcount, Slogcount, 1, 1, 0, + doc: /* Return population count of VALUE. +This is the number of one bits in the two's complement representation +of VALUE. If VALUE is negative, return the number of zero bits in the +representation. */) + (Lisp_Object value) +{ + CHECK_NUMBER (value); + EMACS_INT v = XINT (value) < 0 ? -1 - XINT (value) : XINT (value); + return make_number (EMACS_UINT_WIDTH <= UINT_WIDTH + ? count_one_bits (v) + : EMACS_UINT_WIDTH <= ULONG_WIDTH + ? count_one_bits_l (v) + : count_one_bits_ll (v)); +} + static Lisp_Object ash_lsh_impl (Lisp_Object value, Lisp_Object count, bool lsh) { @@ -3856,6 +3872,7 @@ syms_of_data (void) defsubr (&Slogand); defsubr (&Slogior); defsubr (&Slogxor); + defsubr (&Slogcount); defsubr (&Slsh); defsubr (&Sash); defsubr (&Sadd1); |