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author | David Robillard <d@drobilla.net> | 2021-02-25 10:27:59 -0500 |
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committer | David Robillard <d@drobilla.net> | 2021-03-08 23:23:05 -0500 |
commit | c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b (patch) | |
tree | a62995534f5f606ac2f8bae22d525532b824cb5e /subprojects/exess/src/bigint.h | |
parent | 6bcd18ae60482790b645a345f718e7099250f261 (diff) | |
download | serd-c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b.tar.gz serd-c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b.tar.bz2 serd-c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b.zip |
Add exess from git@gitlab.com:drobilla/exess.git 4638b1f
Diffstat (limited to 'subprojects/exess/src/bigint.h')
-rw-r--r-- | subprojects/exess/src/bigint.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/subprojects/exess/src/bigint.h b/subprojects/exess/src/bigint.h new file mode 100644 index 00000000..088052f6 --- /dev/null +++ b/subprojects/exess/src/bigint.h @@ -0,0 +1,118 @@ +/* + 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_BIGINT_H +#define EXESS_BIGINT_H + +#include "attributes.h" + +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> + +typedef uint32_t Bigit; + +/* We need enough precision for any double, the "largest" of which (using + absolute exponents) is the smallest subnormal ~= 5e-324. This is 1076 bits + long, but we need a bit more space for arithmetic. This is absurd, but such + is decimal. These are only used on the stack so it doesn't hurt too much. +*/ + +#define BIGINT_MAX_SIGNIFICANT_BITS 1280u +#define BIGINT_BIGIT_BITS 32u +#define BIGINT_MAX_BIGITS (BIGINT_MAX_SIGNIFICANT_BITS / BIGINT_BIGIT_BITS) + +typedef struct { + Bigit bigits[BIGINT_MAX_BIGITS]; + unsigned n_bigits; +} ExessBigint; + +void +exess_bigint_zero(ExessBigint* num); + +size_t +exess_bigint_print_hex(FILE* stream, const ExessBigint* num); + +void +exess_bigint_clamp(ExessBigint* num); + +void +exess_bigint_shift_left(ExessBigint* num, unsigned amount); + +void +exess_bigint_set(ExessBigint* num, const ExessBigint* value); + +void +exess_bigint_set_u32(ExessBigint* num, uint32_t value); + +void +exess_bigint_set_u64(ExessBigint* num, uint64_t value); + +void +exess_bigint_set_pow10(ExessBigint* num, unsigned exponent); + +void +exess_bigint_set_decimal_string(ExessBigint* num, const char* str); + +void +exess_bigint_set_hex_string(ExessBigint* num, const char* str); + +void +exess_bigint_multiply_u32(ExessBigint* num, uint32_t factor); + +void +exess_bigint_multiply_u64(ExessBigint* num, uint64_t factor); + +void +exess_bigint_multiply_pow10(ExessBigint* num, unsigned exponent); + +EXESS_I_PURE_FUNC +int +exess_bigint_compare(const ExessBigint* lhs, const ExessBigint* rhs); + +void +exess_bigint_add_u32(ExessBigint* lhs, uint32_t rhs); + +void +exess_bigint_add(ExessBigint* lhs, const ExessBigint* rhs); + +void +exess_bigint_subtract(ExessBigint* lhs, const ExessBigint* rhs); + +EXESS_I_PURE_FUNC +Bigit +exess_bigint_left_shifted_bigit(const ExessBigint* num, + unsigned amount, + unsigned index); + +/// Faster implementation of exess_bigint_subtract(lhs, rhs << amount) +void +exess_bigint_subtract_left_shifted(ExessBigint* lhs, + const ExessBigint* rhs, + unsigned amount); + +/// Faster implementation of exess_bigint_compare(l + p, c) +EXESS_I_PURE_FUNC +int +exess_bigint_plus_compare(const ExessBigint* l, + const ExessBigint* p, + const ExessBigint* c); + +/// Divide and set `lhs` to modulo +uint32_t +exess_bigint_divmod(ExessBigint* lhs, const ExessBigint* rhs); + +#endif // EXESS_BIGINT_H |