clamp.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2025 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */
 
/**
 * @file clamp.c
 * @brief Implements the OP_CLAMP opcode for value clamping in the VM.
 *
 * This file handles the OP_CLAMP instruction, which clamps a value between
 * a minimum and maximum.
 *
 * Behavior:
 * - Pops x, lo, hi from stack
 * - Pushes x clamped to [lo,hi]
 *
 * Error Handling:
 * - Exits if arguments wrong types
 * - Handles hi < lo case
 */
 
case OP_CLAMP: {
  Value hi = pop_value(vm);
  Value lo = pop_value(vm);
  Value x = pop_value(vm);
  if (x.type != VAL_INT || lo.type != VAL_INT || hi.type != VAL_INT) {
    fprintf(stderr, "CLAMP expects ints\n");
    exit(1);
  }
  int64_t v = x.i;
  if (v < lo.i) v = lo.i;
  if (v > hi.i) v = hi.i;
  push_value(vm, make_int(v));
  free_value(x);
  free_value(lo);
  free_value(hi);
  break;
}