lcm.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2026 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */


case OP_LCM: {
 Value vb = pop_value(vm);
 Value va = pop_value(vm);
 if (!((va.type == VAL_INT) || (va.type == VAL_FLOAT)) ||
 !((vb.type == VAL_INT) || (vb.type == VAL_FLOAT))) {
 fprintf(stderr, "Runtime type error: LCM expects numbers, got %s and %s\n",
 value_type_name(va.type), value_type_name(vb.type));
 exit(1);
 }
 int64_t a = (va.type == VAL_INT) ? va.i : (int64_t)va.d;
 int64_t b = (vb.type == VAL_INT) ? vb.i : (int64_t)vb.d;
 if (a == INT64_MIN)
 a = (int64_t)INT64_MAX;
 else if (a < 0)
 a = -a;
 if (b == INT64_MIN)
 b = (int64_t)INT64_MAX;
 else if (b < 0)
 b = -b;
 if (a == 0 || b == 0) {
 free_value(va);
 free_value(vb);
 push_value(vm, make_int(0));
 break;
 }
 /* gcd(a,b) */
 int64_t x = a, y = b;
 while (y != 0) {
 int64_t t = x % y;
 x = y;
 y = t;
 }
 int64_t g = x;
 /* lcm = (a/g)*b (attempt to reduce overflow) */
 int64_t l = (a / g) * b;
 Value res = make_int(l);
 free_value(va);
 free_value(vb);
 push_value(vm, res);
 break;
}