diff options
Diffstat (limited to 'intmath.c')
| -rw-r--r-- | intmath.c | 353 |
1 files changed, 3 insertions, 350 deletions
@@ -45,132 +45,6 @@ int int_max(int a, int b) { return (a > b) * a + (b >= a) * b; } -/* Returns `int x` floored to `unsigned int precision` as an `exp_notated` - * value with given `unsigned int base`. - * - * `unsigned int base` affects the precision. - */ -exp_notated int_floored_exponent_notation_base -( - int x, - unsigned int precision, - unsigned int base -) { - int original = x; - int sign = (x < 0) * -2 + 1; - x *= sign; - - int i = 0; - while (x >= int_pown(base, precision)) { - x /= base; - i++; - } - x += (sign == -1) && (original != -x * int_pown(base, i)); - if (x >= int_pown(base, precision)) { - x /= base; - i++; - } - x *= sign; - - exp_notated res = { - .mantissa = x, - .exponent = i, - .base = base - }; - return res; -} - -exp_notated int_floored_exponent_notation(int x, unsigned int precision) { - return int_floored_exponent_notation_base(x, precision, 10); -} - -exp_notated int_ceiled_exponent_notation_base( - int x, - unsigned int precision, - unsigned int base -) { - exp_notated res = int_floored_exponent_notation_base(-x, precision, base); - res.mantissa = -res.mantissa; - return res; -} - -exp_notated int_ceiled_exponent_notation(int x, unsigned int precision) { - return int_ceiled_exponent_notation_base(x, precision, 10); -} - -int exp_notated_to_int(exp_notated x) { - return x.mantissa * int_pown(x.base, x.exponent); -} - -/* Returns the appropriate binary prefix for `exp_notated x`. `x` must have - * `1024` as its base, it should not be greater than `1023*1024^10` and it - * should be floored/ceiled (ie. the mantissa should not be further away from - * zero than `1023`). Failing to meet these conditions results in the function - * returning `NULL`. - */ -const char* binary_prefix(exp_notated x) { - if ( - (x.base != 1024) || - (x.exponent > 10) || - (x.mantissa > 1023) || - (x.mantissa < -1023) - ) { - return NULL; - } - - switch (x.exponent) { - case 0: - return ""; - case 1: - return "Ki"; - case 2: - return "Mi"; - case 3: - return "Gi"; - case 4: - return "Ti"; - case 5: - return "Pi"; - case 6: - return "Ei"; - case 7: - return "Zi"; - case 8: - return "Yi"; - case 9: - return "Ri"; - default: - return "Qi"; - } -} - -/* Returns the a string describing the argument `int x` floored to the - * appropriate multiple of 1024 followed with a binary prefix (Ki, Mi, Gi...). - * The string is dynamically allocated and should be free'd. - * - * Returns NULL on malloc error. - */ -char* int_floored_with_binary_prefix(int x) { - exp_notated x_exp = int_floored_exponent_notation_base(x, 1, 1024); - if (x_exp.exponent > 10) /* quebi-=1024^10 greatest defined prefix */ - x_exp.mantissa *= int_pow10(x_exp.exponent - 10); - - const char* prefix = binary_prefix(x_exp); - - size_t bufsize = - 5 + /* len("-1024") */ - int_max(0, x_exp.exponent - 10) + /* length of possible zeros */ - 4; /* len(" Gi\0") */ - char* res = malloc(bufsize); - if (res == NULL) return NULL; - sprintf(res, "%d", x_exp.mantissa); - if (strcmp(prefix, "") != 0) - strcat(res, " "); - strcat(res, prefix); - - return res; -} - char* test_pown() { mt_assert_eq(int_pown(2, 5), 32); mt_assert_eq(int_pown(3, 3), 27); @@ -205,231 +79,14 @@ char* test_ceil() { char* test_min() { mt_assert_eq(int_min(2, 6), 2); mt_assert_eq(int_min(4, 1), 1); - mt_assert_eq(int_min(10, 10), 1); + mt_assert_eq(int_min(10, 10), 10); return 0; } char* test_max() { mt_assert_eq(int_max(3, 7), 7); - mt_assert_eq(int_min(4, 1), 4); - mt_assert_eq(int_min(10, 10), 10); - return 0; -} - -char* test_floored_exponent_notation() { - const size_t bufsize = 128; - char* msg = malloc(bufsize); - - exp_notated res = int_floored_exponent_notation(9489345, 3); - snprintf(msg, bufsize, - "int_floored_exponent_notation(9489345, 3): expected 948*10^4, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == 948 && - res.base == 10 && - res.exponent == 4 - , msg); - - res = int_floored_exponent_notation(-88, 1); - snprintf(msg, bufsize, - "int_floored_exponent_notation(-88, 1): expected -9*10^1, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -9 && - res.base == 10 && - res.exponent == 1 - , msg); - - res = int_floored_exponent_notation(-99, 1); - snprintf(msg, bufsize, - "int_floored_exponent_notation(-99, 1): expected -1*10^2, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -1 && - res.base == 10 && - res.exponent == 2 - , msg); - - res = int_floored_exponent_notation_base(3145733, 1, 1024); - snprintf(msg, bufsize, - "int_floored_exponent_notation_base(3145733, 1, 1024): expected 3*1024^2, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == 3 && - res.base == 1024 && - res.exponent == 2 - , msg); - - res = int_floored_exponent_notation_base(-1022, 1, 1024); - snprintf(msg, bufsize, - "int_floored_exponent_notation(-1022, 1, 1024): expected -1022*1024^0, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -1022 && - res.base == 1024 && - res.exponent == 0 - , msg); - - res = int_floored_exponent_notation_base(-1023, 1, 1024); - snprintf(msg, bufsize, - "int_floored_exponent_notation(-1023, 1, 1024): expected -1023*1024^0, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -1023 && - res.base == 1024 && - res.exponent == 0 - , msg); - - res = int_floored_exponent_notation_base(-1024, 1, 1024); - snprintf(msg, bufsize, - "int_floored_exponent_notation(-1024, 1, 1024): expected -1*1024^1, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -1 && - res.base == 1024 && - res.exponent == 1 - , msg); - - free(msg); - return 0; -} - -char* test_ceiled_exponent_notation() { - const size_t bufsize = 128; - char* msg = malloc(bufsize); - - exp_notated res = int_ceiled_exponent_notation(9489345, 3); - snprintf(msg, bufsize, - "int_ceiled_exponent_notation(9489345, 3): expected 949*10^4, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == 949 && - res.base == 10 && - res.exponent == 4 - , msg); - - res = int_ceiled_exponent_notation(-99, 1); - snprintf(msg, bufsize, - "int_ceiled_exponent_notation(-99, 1): expected -9*10^1, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -9 && - res.base == 10 && - res.exponent == 1 - , msg); - - res = int_ceiled_exponent_notation(-100, 1); - snprintf(msg, bufsize, - "int_ceiled_exponent_notation(-100, 1): expected -1*10^2, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -1 && - res.base == 10 && - res.exponent == 2 - , msg); - - res = int_ceiled_exponent_notation_base(3145733, 1, 1024); - snprintf(msg, bufsize, - "int_ceiled_exponent_notation_base(3145733, 1, 1024): expected 4*1024^2, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == 4 && - res.base == 1024 && - res.exponent == 2 - , msg); - - res = int_ceiled_exponent_notation_base(-1023, 1, 1024); - snprintf(msg, bufsize, - "int_ceiled_exponent_notation(-1023, 1, 1024): expected -1023*1024^0, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -1023 && - res.base == 1024 && - res.exponent == 0 - , msg); - - res = int_ceiled_exponent_notation_base(-1024, 1, 1024); - snprintf(msg, bufsize, - "int_ceiled_exponent_notation(-1024, 1, 1024): expected -1*1024^1, got %d*%d^%d", - res.mantissa, res.base, res.exponent - ); - mt_assert( - res.mantissa == -1 && - res.base == 1024 && - res.exponent == 1 - , msg); - - free(msg); - return 0; -} - -char* test_exponent_notated_to_int() { - exp_notated x = { - .mantissa = 3, - .exponent = 2, - .base = 10 - }; - mt_assert_eq(300, exp_notated_to_int(x)); - return 0; -} - -char* test_floored_with_binary_prefix() { - const size_t bufsize = 64; - char* msg = malloc(bufsize); - - char* res = int_floored_with_binary_prefix(1026); - snprintf(msg, bufsize, "1026 yielded `%s` instead of `1 Ki`", res); - mt_assert(strcmp( - res, - "1 Ki" - ) == 0, msg); - free(res); - - res = int_floored_with_binary_prefix(-1023); - snprintf(msg, bufsize, "-1023 yielded `%s` instead of `-1023`", res); - mt_assert(strcmp( - res, - "-1023" - ) == 0, msg); - free(res); - - res = int_floored_with_binary_prefix(-1026); - snprintf(msg, bufsize, "-1026 yielded `%s` instead of `-2 Ki`", res); - mt_assert(strcmp( - res, - "-2 Ki" - ) == 0, msg); - free(res); - - res = int_floored_with_binary_prefix(1049088); - snprintf(msg, bufsize, "1049088 yielded `%s` instead of `1 Mi`", res); - mt_assert(strcmp( - res, - "1 Mi" - ) == 0, msg); - free(res); - - res = int_floored_with_binary_prefix(5243392); - snprintf(msg, bufsize, "5243392 yielded `%s` instead of `5 Mi`", res); - mt_assert(strcmp( - res, - "5 Mi" - ) == 0, msg); - free(res); - - free(msg); + mt_assert_eq(int_max(4, 1), 4); + mt_assert_eq(int_max(10, 10), 10); return 0; } @@ -440,8 +97,4 @@ void intmath_tests() { mt_run_test(test_ceil); mt_run_test(test_min); mt_run_test(test_max); - mt_run_test(test_floored_exponent_notation); - mt_run_test(test_ceiled_exponent_notation); - mt_run_test(test_exponent_notated_to_int); - mt_run_test(test_floored_with_binary_prefix); } |