diff options
Diffstat (limited to 'subprojects/exess/src/int_math.h')
-rw-r--r-- | subprojects/exess/src/int_math.h | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/subprojects/exess/src/int_math.h b/subprojects/exess/src/int_math.h new file mode 100644 index 00000000..a4a57140 --- /dev/null +++ b/subprojects/exess/src/int_math.h @@ -0,0 +1,72 @@ +/* + Copyright 2019-2021 David Robillard <d@drobilla.net> + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#ifndef EXESS_INTMATH_H +#define EXESS_INTMATH_H + +#include "attributes.h" + +#include <stdint.h> + +static const int uint64_digits10 = 19; + +static const uint64_t POW10[] = {1ull, + 10ull, + 100ull, + 1000ull, + 10000ull, + 100000ull, + 1000000ull, + 10000000ull, + 100000000ull, + 1000000000ull, + 10000000000ull, + 100000000000ull, + 1000000000000ull, + 10000000000000ull, + 100000000000000ull, + 1000000000000000ull, + 10000000000000000ull, + 100000000000000000ull, + 1000000000000000000ull, + 10000000000000000000ull}; + +/// Return the number of leading zeros in `i` +EXESS_I_CONST_FUNC +unsigned +exess_clz32(uint32_t i); + +/// Return the number of leading zeros in `i` +EXESS_I_CONST_FUNC +unsigned +exess_clz64(uint64_t i); + +/// Return the log base 2 of `i` +EXESS_I_CONST_FUNC +uint64_t +exess_ilog2(uint64_t i); + +/// Return the log base 10 of `i` +EXESS_I_CONST_FUNC +uint64_t +exess_ilog10(uint64_t i); + +/// Return the number of decimal digits required to represent `i` +EXESS_I_CONST_FUNC +uint8_t +exess_num_digits(uint64_t i); + +#endif // EXESS_INTMATH_H |