Move integer implementation details into separate header/C files, backed

by template headers that use an INT_BITS macro to redefine
implementations for different int sizes.

1 files changed, 548 insertions, 0 deletions

diff --git a/src/stdlib/bigint.c b/src/stdlib/bigint.c
new file mode 100644
index 00000000..3ed3f3cf
--- /dev/null
+++ b/src/stdlib/bigint.c
@@ -0,0 +1,548 @@
+// Integer type infos and methods
+
+#include <stdio.h> // Must be before gmp.h
+
+#include <ctype.h>
+#include <gc.h>
+#include <gmp.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "datatypes.h"
+#include "integers.h"
+#include "optionals.h"
+#include "print.h"
+#include "siphash.h"
+#include "text.h"
+#include "types.h"
+
+public
+int Int$print(FILE *f, Int_t i) {
+    if (likely(i.small & 1L)) {
+        return _print_int(f, (int64_t)((i.small) >> 2L));
+    } else {
+        return gmp_fprintf(f, "%Zd", *i.big);
+    }
+}
+
+static Text_t _int64_to_text(int64_t n) {
+    if (n == INT64_MIN) return Text("-9223372036854775808");
+
+    char buf[21] = {[20] = 0}; // Big enough for INT64_MIN + '\0'
+    char *p = &buf[19];
+    bool negative = n < 0;
+    if (negative) n = -n; // Safe to do because we checked for INT64_MIN earlier
+
+    do {
+        *(p--) = '0' + (n % 10);
+        n /= 10;
+    } while (n > 0);
+
+    if (negative) *(p--) = '-';
+
+    return Text$from_strn(p + 1, (size_t)(&buf[19] - p));
+}
+
+public
+Text_t Int$value_as_text(Int_t i) {
+    if (likely(i.small & 1L)) {
+        return _int64_to_text(i.small >> 2L);
+    } else {
+        char *str = mpz_get_str(NULL, 10, *i.big);
+        return Text$from_str(str);
+    }
+}
+
+public
+Text_t Int$as_text(const void *i, bool colorize, const TypeInfo_t *info) {
+    (void)info;
+    if (!i) return Text("Int");
+    Text_t text = Int$value_as_text(*(Int_t *)i);
+    if (colorize) text = Text$concat(Text("\x1b[35m"), text, Text("\x1b[m"));
+    return text;
+}
+
+static bool Int$is_none(const void *i, const TypeInfo_t *info) {
+    (void)info;
+    return ((Int_t *)i)->small == 0L;
+}
+
+public
+PUREFUNC int32_t Int$compare_value(const Int_t x, const Int_t y) {
+    if (likely(x.small & y.small & 1L)) return (x.small > y.small) - (x.small < y.small);
+    else if (x.small & 1) return -mpz_cmp_si(*y.big, x.small);
+    else if (y.small & 1) return mpz_cmp_si(*x.big, y.small);
+    else return x.big == y.big ? 0 : mpz_cmp(*x.big, *y.big);
+}
+
+public
+PUREFUNC int32_t Int$compare(const void *x, const void *y, const TypeInfo_t *info) {
+    (void)info;
+    return Int$compare_value(*(Int_t *)x, *(Int_t *)y);
+}
+
+public
+PUREFUNC bool Int$equal_value(const Int_t x, const Int_t y) {
+    if (likely((x.small | y.small) & 1L)) return x.small == y.small;
+    else return x.big == y.big ? 0 : (mpz_cmp(*x.big, *y.big) == 0);
+}
+
+public
+PUREFUNC bool Int$equal(const void *x, const void *y, const TypeInfo_t *info) {
+    (void)info;
+    return Int$equal_value(*(Int_t *)x, *(Int_t *)y);
+}
+
+public
+CONSTFUNC Int_t Int$clamped(Int_t x, Int_t low, Int_t high) {
+    return (Int$compare(&x, &low, &Int$info) <= 0) ? low : (Int$compare(&x, &high, &Int$info) >= 0 ? high : x);
+}
+
+public
+CONSTFUNC bool Int$is_between(const Int_t x, const Int_t low, const Int_t high) {
+    return Int$compare_value(low, x) <= 0 && Int$compare_value(x, high) <= 0;
+}
+
+public
+PUREFUNC uint64_t Int$hash(const void *vx, const TypeInfo_t *info) {
+    (void)info;
+    Int_t *x = (Int_t *)vx;
+    if (likely(x->small & 1L)) {
+        return siphash24((void *)x, sizeof(Int_t));
+    } else {
+        char *str = mpz_get_str(NULL, 16, *x->big);
+        return siphash24((void *)str, strlen(str));
+    }
+}
+
+public
+Text_t Int$hex(Int_t i, Int_t digits_int, bool uppercase, bool prefix) {
+    if (Int$is_negative(i)) return Text$concat(Text("-"), Int$hex(Int$negative(i), digits_int, uppercase, prefix));
+
+    if (likely(i.small & 1L)) {
+        uint64_t u64 = (uint64_t)(i.small >> 2);
+        return Text$from_str(String(
+            hex(u64, .no_prefix = !prefix, .digits = Int32$from_int(digits_int, false), .uppercase = uppercase)));
+    } else {
+        char *str = mpz_get_str(NULL, 16, *i.big);
+        if (uppercase) {
+            for (char *c = str; *c; c++)
+                *c = (char)toupper(*c);
+        }
+        int64_t digits = Int64$from_int(digits_int, false);
+        int64_t needed_zeroes = digits - (int64_t)strlen(str);
+        if (needed_zeroes <= 0) return prefix ? Text$concat(Text("0x"), Text$from_str(str)) : Text$from_str(str);
+
+        char *zeroes = GC_MALLOC_ATOMIC((size_t)(needed_zeroes));
+        memset(zeroes, '0', (size_t)(needed_zeroes));
+        if (prefix) return Text$concat(Text("0x"), Text$from_str(zeroes), Text$from_str(str));
+        else return Text$concat(Text$from_str(zeroes), Text$from_str(str));
+    }
+}
+
+public
+Text_t Int$octal(Int_t i, Int_t digits_int, bool prefix) {
+    if (Int$is_negative(i)) return Text$concat(Text("-"), Int$octal(Int$negative(i), digits_int, prefix));
+
+    if (likely(i.small & 1L)) {
+        uint64_t u64 = (uint64_t)(i.small >> 2);
+        return Text$from_str(String(oct(u64, .no_prefix = !prefix, .digits = Int32$from_int(digits_int, false))));
+    } else {
+        int64_t digits = Int64$from_int(digits_int, false);
+        char *str = mpz_get_str(NULL, 8, *i.big);
+        int64_t needed_zeroes = digits - (int64_t)strlen(str);
+        if (needed_zeroes <= 0) return prefix ? Text$concat(Text("0o"), Text$from_str(str)) : Text$from_str(str);
+
+        char *zeroes = GC_MALLOC_ATOMIC((size_t)(needed_zeroes));
+        memset(zeroes, '0', (size_t)(needed_zeroes));
+        if (prefix) return Text$concat(Text("0o"), Text$from_str(zeroes), Text$from_str(str));
+        else return Text$concat(Text$from_str(zeroes), Text$from_str(str));
+    }
+}
+
+public
+Int_t Int$slow_plus(Int_t x, Int_t y) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    if (y.small & 1L) {
+        if (y.small < 0L) mpz_sub_ui(result, result, (uint64_t)(-(y.small >> 2L)));
+        else mpz_add_ui(result, result, (uint64_t)(y.small >> 2L));
+    } else {
+        mpz_add(result, result, *y.big);
+    }
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_minus(Int_t x, Int_t y) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    if (y.small & 1L) {
+        if (y.small < 0L) mpz_add_ui(result, result, (uint64_t)(-(y.small >> 2L)));
+        else mpz_sub_ui(result, result, (uint64_t)(y.small >> 2L));
+    } else {
+        mpz_sub(result, result, *y.big);
+    }
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_times(Int_t x, Int_t y) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    if (y.small & 1L) mpz_mul_si(result, result, y.small >> 2L);
+    else mpz_mul(result, result, *y.big);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_divided_by(Int_t dividend, Int_t divisor) {
+    // Euclidean division, see:
+    // https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/divmodnote-letter.pdf
+    mpz_t quotient, remainder;
+    mpz_init_set_int(quotient, dividend);
+    mpz_init_set_int(remainder, divisor);
+    mpz_tdiv_qr(quotient, remainder, quotient, remainder);
+    if (mpz_sgn(remainder) < 0) {
+        bool d_positive = likely(divisor.small & 1L) ? divisor.small > 0x1L : mpz_sgn(*divisor.big) > 0;
+        if (d_positive) mpz_sub_ui(quotient, quotient, 1);
+        else mpz_add_ui(quotient, quotient, 1);
+    }
+    return Int$from_mpz(quotient);
+}
+
+public
+Int_t Int$slow_modulo(Int_t x, Int_t modulus) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_t divisor;
+    mpz_init_set_int(divisor, modulus);
+    mpz_mod(result, result, divisor);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_modulo1(Int_t x, Int_t modulus) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_sub_ui(result, result, 1);
+    mpz_t divisor;
+    mpz_init_set_int(divisor, modulus);
+    mpz_mod(result, result, divisor);
+    mpz_add_ui(result, result, 1);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_left_shifted(Int_t x, Int_t y) {
+    mp_bitcnt_t bits = (mp_bitcnt_t)Int64$from_int(y, false);
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_mul_2exp(result, result, bits);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_right_shifted(Int_t x, Int_t y) {
+    mp_bitcnt_t bits = (mp_bitcnt_t)Int64$from_int(y, false);
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_tdiv_q_2exp(result, result, bits);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_bit_and(Int_t x, Int_t y) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_t y_mpz;
+    mpz_init_set_int(y_mpz, y);
+    mpz_and(result, result, y_mpz);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_bit_or(Int_t x, Int_t y) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_t y_mpz;
+    mpz_init_set_int(y_mpz, y);
+    mpz_ior(result, result, y_mpz);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_bit_xor(Int_t x, Int_t y) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_t y_mpz;
+    mpz_init_set_int(y_mpz, y);
+    mpz_xor(result, result, y_mpz);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_negated(Int_t x) {
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_neg(result, result);
+    mpz_sub_ui(result, result, 1);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$slow_negative(Int_t x) {
+    if (likely(x.small & 1L)) return (Int_t){.small = 4L * -((x.small) >> 2L) + 1L};
+
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_neg(result, result);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$abs(Int_t x) {
+    if (likely(x.small & 1L)) return (Int_t){.small = 4L * labs((x.small) >> 2L) + 1L};
+
+    mpz_t result;
+    mpz_init_set_int(result, x);
+    mpz_abs(result, result);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$power(Int_t base, Int_t exponent) {
+    int64_t exp = Int64$from_int(exponent, false);
+    if (unlikely(exp < 0)) fail("Cannot take a negative power of an integer!");
+    mpz_t result;
+    mpz_init_set_int(result, base);
+    mpz_pow_ui(result, result, (uint64_t)exp);
+    return Int$from_mpz(result);
+}
+
+public
+Int_t Int$gcd(Int_t x, Int_t y) {
+    if (likely(x.small & y.small & 0x1L)) return I_small(Int32$gcd(x.small >> 2L, y.small >> 2L));
+
+    mpz_t result;
+    mpz_init(result);
+    if (x.small & 0x1L) mpz_gcd_ui(result, *y.big, (uint64_t)labs(x.small >> 2L));
+    else if (y.small & 0x1L) mpz_gcd_ui(result, *x.big, (uint64_t)labs(y.small >> 2L));
+    else mpz_gcd(result, *x.big, *y.big);
+    return Int$from_mpz(result);
+}
+
+public
+OptionalInt_t Int$sqrt(Int_t i) {
+    if (Int$compare_value(i, I(0)) < 0) return NONE_INT;
+    mpz_t result;
+    mpz_init_set_int(result, i);
+    mpz_sqrt(result, result);
+    return Int$from_mpz(result);
+}
+
+public
+bool Int$get_bit(Int_t x, Int_t bit_index) {
+    mpz_t i;
+    mpz_init_set_int(i, x);
+    if (Int$compare_value(bit_index, I(1)) < 0) fail("Invalid bit index (expected 1 or higher): ", bit_index);
+    if (Int$compare_value(bit_index, Int$from_int64(INT64_MAX)) > 0) fail("Bit index is too large! ", bit_index);
+
+    int is_bit_set = mpz_tstbit(i, (mp_bitcnt_t)(Int64$from_int(bit_index, true) - 1));
+    return (bool)is_bit_set;
+}
+
+typedef struct {
+    OptionalInt_t current, last;
+    Int_t step;
+} IntRange_t;
+
+static OptionalInt_t _next_int(IntRange_t *info) {
+    OptionalInt_t i = info->current;
+    if (!Int$is_none(&i, &Int$info)) {
+        Int_t next = Int$plus(i, info->step);
+        if (!Int$is_none(&info->last, &Int$info)
+            && Int$compare_value(next, info->last) == Int$compare_value(info->step, I(0)))
+            next = NONE_INT;
+        info->current = next;
+    }
+    return i;
+}
+
+public
+PUREFUNC Closure_t Int$to(Int_t first, Int_t last, OptionalInt_t step) {
+    IntRange_t *range = GC_MALLOC(sizeof(IntRange_t));
+    range->current = first;
+    range->last = last;
+    range->step = Int$is_none(&step, &Int$info) ? Int$compare_value(last, first) >= 0
+                                                      ? (Int_t){.small = (1L << 2L) | 1L}
+                                                      : (Int_t){.small = (-1L >> 2L) | 1L}
+                                                : step;
+    return (Closure_t){.fn = _next_int, .userdata = range};
+}
+
+public
+PUREFUNC Closure_t Int$onward(Int_t first, Int_t step) {
+    IntRange_t *range = GC_MALLOC(sizeof(IntRange_t));
+    range->current = first;
+    range->last = NONE_INT;
+    range->step = step;
+    return (Closure_t){.fn = _next_int, .userdata = range};
+}
+
+public
+Int_t Int$from_str(const char *str) {
+    mpz_t i;
+    int result;
+    if (strncmp(str, "0x", 2) == 0) {
+        result = mpz_init_set_str(i, str + 2, 16);
+    } else if (strncmp(str, "0o", 2) == 0) {
+        result = mpz_init_set_str(i, str + 2, 8);
+    } else if (strncmp(str, "0b", 2) == 0) {
+        result = mpz_init_set_str(i, str + 2, 2);
+    } else {
+        result = mpz_init_set_str(i, str, 10);
+    }
+    if (result != 0) return NONE_INT;
+    return Int$from_mpz(i);
+}
+
+public
+OptionalInt_t Int$parse(Text_t text, Text_t *remainder) {
+    const char *str = Text$as_c_string(text);
+    mpz_t i;
+    int result;
+    if (strncmp(str, "0x", 2) == 0) {
+        const char *end = str + 2 + strspn(str + 2, "0123456789abcdefABCDEF");
+        if (remainder) *remainder = Text$from_str(end);
+        else if (*end != '\0') return NONE_INT;
+        result = mpz_init_set_str(i, str + 2, 16);
+    } else if (strncmp(str, "0o", 2) == 0) {
+        const char *end = str + 2 + strspn(str + 2, "01234567");
+        if (remainder) *remainder = Text$from_str(end);
+        else if (*end != '\0') return NONE_INT;
+        result = mpz_init_set_str(i, str + 2, 8);
+    } else if (strncmp(str, "0b", 2) == 0) {
+        const char *end = str + 2 + strspn(str + 2, "01");
+        if (remainder) *remainder = Text$from_str(end);
+        else if (*end != '\0') return NONE_INT;
+        result = mpz_init_set_str(i, str + 2, 2);
+    } else {
+        const char *end = str + strspn(str, "0123456789");
+        if (remainder) *remainder = Text$from_str(end);
+        else if (*end != '\0') return NONE_INT;
+        result = mpz_init_set_str(i, str, 10);
+    }
+    if (result != 0) {
+        if (remainder) *remainder = text;
+        return NONE_INT;
+    }
+    return Int$from_mpz(i);
+}
+
+public
+bool Int$is_prime(Int_t x, Int_t reps) {
+    mpz_t p;
+    mpz_init_set_int(p, x);
+    if (unlikely(Int$compare_value(reps, I(9999)) > 0))
+        fail("Number of prime-test repetitions should not be above 9999");
+    int reps_int = Int32$from_int(reps, false);
+    return (mpz_probab_prime_p(p, reps_int) != 0);
+}
+
+public
+Int_t Int$next_prime(Int_t x) {
+    mpz_t p;
+    mpz_init_set_int(p, x);
+    mpz_nextprime(p, p);
+    return Int$from_mpz(p);
+}
+
+#if __GNU_MP_VERSION >= 6
+#if __GNU_MP_VERSION_MINOR >= 3
+public
+OptionalInt_t Int$prev_prime(Int_t x) {
+    mpz_t p;
+    mpz_init_set_int(p, x);
+    if (unlikely(mpz_prevprime(p, p) == 0)) return NONE_INT;
+    return Int$from_mpz(p);
+}
+#endif
+#endif
+
+public
+Int_t Int$choose(Int_t n, Int_t k) {
+    if unlikely (Int$compare_value(n, I_small(0)) < 0) fail("Negative inputs are not supported for choose()");
+
+    mpz_t ret;
+    mpz_init(ret);
+
+    int64_t k_i64 = Int64$from_int(k, false);
+    if unlikely (k_i64 < 0) fail("Negative inputs are not supported for choose()");
+
+    if likely (n.small & 1L) {
+        mpz_bin_uiui(ret, (unsigned long)(n.small >> 2L), (unsigned long)k_i64);
+    } else {
+        mpz_t n_mpz;
+        mpz_init_set_int(n_mpz, n);
+        mpz_bin_ui(ret, n_mpz, (unsigned long)k_i64);
+    }
+    return Int$from_mpz(ret);
+}
+
+public
+Int_t Int$factorial(Int_t n) {
+    mpz_t ret;
+    mpz_init(ret);
+    int64_t n_i64 = Int64$from_int(n, false);
+    if unlikely (n_i64 < 0) fail("Factorials are not defined for negative numbers");
+    mpz_fac_ui(ret, (unsigned long)n_i64);
+    return Int$from_mpz(ret);
+}
+
+static void Int$serialize(const void *obj, FILE *out, Table_t *pointers, const TypeInfo_t *info) {
+    (void)info;
+    Int_t i = *(Int_t *)obj;
+    if (likely(i.small & 1L)) {
+        fputc(0, out);
+        int64_t i64 = i.small >> 2L;
+        Int64$serialize(&i64, out, pointers, &Int64$info);
+    } else {
+        fputc(1, out);
+        mpz_t n;
+        mpz_init_set_int(n, *(Int_t *)obj);
+        mpz_out_raw(out, n);
+    }
+}
+
+static void Int$deserialize(FILE *in, void *obj, List_t *pointers, const TypeInfo_t *info) {
+    (void)info;
+    if (fgetc(in) == 0) {
+        int64_t i = 0;
+        Int64$deserialize(in, &i, pointers, &Int64$info);
+        *(Int_t *)obj = (Int_t){.small = (i << 2L) | 1L};
+    } else {
+        mpz_t n;
+        mpz_init(n);
+        mpz_inp_raw(n, in);
+        *(Int_t *)obj = Int$from_mpz(n);
+    }
+}
+
+public
+const TypeInfo_t Int$info = {
+    .size = sizeof(Int_t),
+    .align = __alignof__(Int_t),
+    .metamethods =
+        {
+            .compare = Int$compare,
+            .equal = Int$equal,
+            .hash = Int$hash,
+            .as_text = Int$as_text,
+            .is_none = Int$is_none,
+            .serialize = Int$serialize,
+            .deserialize = Int$deserialize,
+        },
+};