diff options
Diffstat (limited to 'source')
| -rw-r--r-- | source/kit/bigint.h | 126 | ||||
| -rw-r--r-- | source/test/unittests/bigint.test.c | 22 |
2 files changed, 133 insertions, 15 deletions
diff --git a/source/kit/bigint.h b/source/kit/bigint.h index b2fa49f..e6222c5 100644 --- a/source/kit/bigint.h +++ b/source/kit/bigint.h @@ -50,6 +50,32 @@ static kit_bigint_t kit_bi_uint64(uint64_t const x) { return z; } +static kit_bigint_t kit_bi_int32(int32_t const x) { + kit_bigint_t z; + memset(&z, x < 0 ? -1 : 0, sizeof z); + z.v[0] = x; + return z; +} + +static kit_bigint_t kit_bi_int64(int64_t const x) { + kit_bigint_t z; + memset(&z, x < 0 ? -1 : 0, sizeof z); + z.v[0] = (uint32_t) (((uint64_t) x) & 0xffffffff); + z.v[1] = (uint32_t) (((uint64_t) x) >> 32); + return z; +} + +static int kit_bi_is_zero(kit_bigint_t const x) { + for (ptrdiff_t i = 0; i < KIT_BIGINT_SIZE / 4; i++) + if (x.v[i] != 0) + return 0; + return 1; +} + +static int kit_bi_is_neg(kit_bigint_t const x) { + return (x.v[KIT_BIGINT_SIZE / 4 - 1] & 0x80000000) != 0; +} + static int kit_bi_equal(kit_bigint_t const x, kit_bigint_t const y) { return kit_ar_equal_bytes(1, KIT_BIGINT_SIZE, x.v, 1, KIT_BIGINT_SIZE, y.v); @@ -181,6 +207,36 @@ static kit_bit_t kit_bi_carry(uint32_t const x, uint32_t const y, return 0xffffffffu - x < y || 0xffffffffu - x - y < carry ? 1 : 0; } +/* Increment. + */ +static kit_bigint_t kit_bi_inc(kit_bigint_t const x) { + kit_bigint_t z; + kit_bit_t carry = 1; + + for (ptrdiff_t i = 0; i < KIT_BIGINT_SIZE / 4; i++) { + z.v[i] = x.v[i] + carry; + carry = kit_bi_carry(x.v[i], 0, carry); + } + + return z; +} + +/* Decrement + */ +static kit_bigint_t kit_bi_dec(kit_bigint_t const x) { + kit_bigint_t z; + kit_bit_t carry = 0; + + for (ptrdiff_t i = 0; i < KIT_BIGINT_SIZE / 4; i++) { + z.v[i] = x.v[i] + 0xffffffff + carry; + carry = kit_bi_carry(x.v[i], 0xffffffff, carry); + } + + return z; +} + +/* Addition. + */ static kit_bigint_t kit_bi_add(kit_bigint_t const x, kit_bigint_t const y) { kit_bigint_t z; @@ -194,6 +250,8 @@ static kit_bigint_t kit_bi_add(kit_bigint_t const x, return z; } +/* Negation. + */ static kit_bigint_t kit_bi_neg(kit_bigint_t const x) { kit_bigint_t y; kit_bit_t carry = 1; @@ -206,6 +264,8 @@ static kit_bigint_t kit_bi_neg(kit_bigint_t const x) { return y; } +/* Subtraction. + */ static kit_bigint_t kit_bi_sub(kit_bigint_t const x, kit_bigint_t const y) { kit_bigint_t z; @@ -242,6 +302,8 @@ static kit_bigint_t kit_bi_mul_uint32(kit_bigint_t const x, return z; } +/* Multiplication. + */ static kit_bigint_t kit_bi_mul(kit_bigint_t const x, kit_bigint_t const y) { kit_bigint_t z; @@ -275,8 +337,10 @@ typedef struct { kit_bigint_t remainder; } kit_bi_division_t; -static kit_bi_division_t kit_bi_div(kit_bigint_t const x, - kit_bigint_t y) { +/* Unsigned division. + */ +static kit_bi_division_t kit_bi_udiv(kit_bigint_t const x, + kit_bigint_t y) { kit_bi_division_t result; memset(&result, 0, sizeof result); @@ -308,6 +372,34 @@ static kit_bi_division_t kit_bi_div(kit_bigint_t const x, return result; } +/* Signed division. + * + * Remainder is always a non-negative value less than absolute value + * of y. + */ +static kit_bi_division_t kit_bi_div(kit_bigint_t const x, + kit_bigint_t const y) { + int const x_neg = kit_bi_is_neg(x); + int const y_neg = kit_bi_is_neg(y); + + if (!x_neg && !y_neg) + return kit_bi_udiv(x, y); + if (x_neg && y_neg) + return kit_bi_udiv(kit_bi_neg(x), kit_bi_neg(y)); + + kit_bigint_t const x_abs = x_neg ? kit_bi_neg(x) : x; + kit_bigint_t const y_abs = y_neg ? kit_bi_neg(y) : y; + + kit_bi_division_t z = kit_bi_udiv(x_abs, y_abs); + + if (!kit_bi_is_zero(z.remainder) && !y_neg) + z.quotient = kit_bi_dec(kit_bi_neg(z.quotient)); + else + z.quotient = kit_bi_neg(z.quotient); + + return z; +} + static void kit_bi_serialize(kit_bigint_t const in, uint8_t *const out) { for (ptrdiff_t i = 0; i < KIT_BIGINT_SIZE / 4; i++) { @@ -332,7 +424,7 @@ static uint8_t kit_bin_digit(char const hex) { return hex == '1' ? 1 : 0; } -static kit_bigint_t kit_bi_bin(kit_str_t const bin) { +static kit_bigint_t kit_bi_from_bin(kit_str_t const bin) { kit_bigint_t z; memset(&z, 0, sizeof z); @@ -349,7 +441,7 @@ static uint8_t kit_dec_digit(char const c) { return c >= '0' && c <= '9' ? (uint8_t) (c - '0') : 0; } -static kit_bigint_t kit_bi_dec(kit_str_t const dec) { +static kit_bigint_t kit_bi_from_dec(kit_str_t const dec) { kit_bigint_t z = kit_bi_uint32(0); kit_bigint_t factor = kit_bi_uint32(1); @@ -373,7 +465,7 @@ static uint8_t kit_hex_digit(char const hex) { return 0; } -static kit_bigint_t kit_bi_hex(kit_str_t const hex) { +static kit_bigint_t kit_bi_from_hex(kit_str_t const hex) { kit_bigint_t z; memset(&z, 0, sizeof z); @@ -402,7 +494,7 @@ static uint8_t kit_base32_digit(char const c) { : 0; } -static kit_bigint_t kit_bi_base32(kit_str_t const base32) { +static kit_bigint_t kit_bi_from_base32(kit_str_t const base32) { kit_bigint_t z; memset(&z, 0, sizeof z); @@ -435,7 +527,7 @@ static uint8_t kit_base58_digit(char const c) { : 0; } -static kit_bigint_t kit_bi_base58(kit_str_t const base58) { +static kit_bigint_t kit_bi_from_base58(kit_str_t const base58) { kit_bigint_t z = kit_bi_uint32(0); kit_bigint_t factor = kit_bi_uint32(1); @@ -455,26 +547,33 @@ static kit_bigint_t kit_bi_base58(kit_str_t const base58) { #endif #define KIT_BIN(static_str_) \ - kit_bi_bin(kit_str(sizeof(static_str_) - 1, (static_str_))) + kit_bi_from_bin(kit_str(sizeof(static_str_) - 1, (static_str_))) #define KIT_DEC(static_str_) \ - kit_bi_dec(kit_str(sizeof(static_str_) - 1, (static_str_))) + kit_bi_from_dec(kit_str(sizeof(static_str_) - 1, (static_str_))) #define KIT_HEX(static_str_) \ - kit_bi_hex(kit_str(sizeof(static_str_) - 1, (static_str_))) + kit_bi_from_hex(kit_str(sizeof(static_str_) - 1, (static_str_))) #define KIT_BASE32(static_str_) \ - kit_bi_base32(kit_str(sizeof(static_str_) - 1, (static_str_))) + kit_bi_from_base32(kit_str(sizeof(static_str_) - 1, (static_str_))) #define KIT_BASE58(static_str_) \ - kit_bi_base58(kit_str(sizeof(static_str_) - 1, (static_str_))) + kit_bi_from_base58(kit_str(sizeof(static_str_) - 1, (static_str_))) #ifndef KIT_DISABLE_SHORT_NAMES # define bigint_t kit_bigint_t # define bi_uint32 kit_bi_uint32 # define bi_uint64 kit_bi_uint64 +# define bi_int32 kit_bi_int32 +# define bi_int64 kit_bi_int64 +# define bi_is_zero kit_bi_is_zero +# define bi_is_neg kit_bi_is_neg # define bi_equal kit_bi_equal +# define bi_compare kit_bi_compare # define bi_carry kit_bi_carry +# define bi_inc kit_bi_inc +# define bi_dec kit_bi_dec # define bi_add kit_bi_add # define bi_neg kit_bi_neg # define bi_sub kit_bi_sub @@ -482,9 +581,6 @@ static kit_bigint_t kit_bi_base58(kit_str_t const base58) { # define bi_div kit_bi_div # define bi_serialize kit_bi_serialize # define bi_deserialize kit_bi_deserialize -# define hex_digit kit_hex_digit -# define bi_hex kit_bi_hex -# define bi_base58 kit_bi_base58 # define BIN KIT_BIN # define DEC KIT_DEC # define HEX KIT_HEX diff --git a/source/test/unittests/bigint.test.c b/source/test/unittests/bigint.test.c index 0b45d7b..048bcca 100644 --- a/source/test/unittests/bigint.test.c +++ b/source/test/unittests/bigint.test.c @@ -56,6 +56,28 @@ TEST("bigint base58 mul") { } TEST("bigint div") { + REQUIRE(bi_equal(bi_div(bi_int32(-1), bi_int32(-1)).quotient, + bi_int32(1))); + REQUIRE(bi_equal(bi_div(bi_int32(-1), bi_int32(-1)).remainder, + bi_int32(0))); + REQUIRE(bi_equal(bi_div(bi_int32(-3), bi_int32(2)).quotient, + bi_int32(-2))); + REQUIRE(bi_equal(bi_div(bi_int32(-3), bi_int32(2)).remainder, + bi_int32(1))); + REQUIRE(bi_equal(bi_div(bi_int32(3), bi_int32(-2)).quotient, + bi_int32(-1))); + REQUIRE(bi_equal(bi_div(bi_int32(3), bi_int32(-2)).remainder, + bi_int32(1))); + REQUIRE(bi_equal(bi_div(bi_int32(-3), bi_int32(4)).quotient, + bi_int32(-1))); + REQUIRE(bi_equal(bi_div(bi_int32(-3), bi_int32(4)).remainder, + bi_int32(3))); + REQUIRE(bi_equal(bi_div(bi_int32(3), bi_int32(-4)).quotient, + bi_int32(0))); + REQUIRE(bi_equal(bi_div(bi_int32(3), bi_int32(-4)).remainder, + bi_int32(3))); + + REQUIRE( bi_equal(bi_div(HEX("100"), HEX("10")).quotient, HEX("10"))); |