struct Token;
struct BigInt
{
  unsigned digit_count;
  bool is_negative;
  union {
    uint64_t digit;
    uint64_t *digits;
  };
};

#include <inttypes.h>
enum CmpRes
{
  CMP_LT,
  CMP_GT,
  CMP_EQ,
};

#define count_bigint_alloc() (bigint_allocator != thread_ctx.scratch ? bigint_allocation_count++ : 0)
#define malloc_arena(x) (count_bigint_alloc(), arena_push_size(bigint_allocator, x, AF_ZeroMemory))
#define ALLOC_DIGITS(_digits) (uint64_t *)((_digits) ? malloc_arena(sizeof(uint64_t) * (_digits)) : NULL)
#define FATAL_ERROR(x) compiler_error(0, x)

function void compiler_error(Token *token, const char *str, ...);
const char *bigint_to_error_string(Arena *allocator, const BigInt *bigint, uint64_t base);
void bigint_init_unsigned(BigInt *big_int, uint64_t value);
void bigint_init_signed(BigInt *big_int, int64_t value);
void bigint_init_bigint(BigInt *dest, const BigInt *src);
void bigint_init_data(BigInt *dest, const uint64_t *digits, unsigned int digit_count, bool is_negative);
void bigint_negate(BigInt *dest, const BigInt *source);
size_t bigint_clz(const BigInt *big_int, size_t bit_count);
size_t bigint_ctz(const BigInt *big_int, size_t bit_count);
bool bigint_fits_in_bits(const BigInt *big_int, size_t bit_count, bool is_signed);
void bigint_write_twos_complement(const BigInt *big_int, uint8_t *buf, size_t bit_count, bool is_big_endian);
void bigint_read_twos_complement(BigInt *dest, const uint8_t *buf, size_t bit_count, bool is_big_endian, bool is_signed);
void bigint_add(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_add_wrap(BigInt *dest, const BigInt *op1, const BigInt *op2, size_t bit_count, bool is_signed);
void bigint_sub(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_sub_wrap(BigInt *dest, const BigInt *op1, const BigInt *op2, size_t bit_count, bool is_signed);
void bigint_mul(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_mul_wrap(BigInt *dest, const BigInt *op1, const BigInt *op2, size_t bit_count, bool is_signed);
void bigint_rem(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_mod(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_shl(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_shl_int(BigInt *dest, const BigInt *op1, uint64_t shift);
void bigint_shl_trunc(BigInt *dest, const BigInt *op1, const BigInt *op2, size_t bit_count, bool is_signed);
void bigint_shr(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_div_floor(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_or(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_and(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_xor(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_negate_wrap(BigInt *dest, const BigInt *op, size_t bit_count);
void bigint_not(BigInt *dest, const BigInt *op, size_t bit_count, bool is_signed);
bool bigint_eql(BigInt a, BigInt b);
CmpRes bigint_cmp(const BigInt *op1, const BigInt *op2);
CmpRes bigint_cmp_zero(const BigInt *op);
uint32_t bigint_hash(BigInt x);
void bigint_print(BigInt *bigint, uint64_t base);
void bigint_fprint(FILE *file, BigInt *bigint, uint64_t base);
uint64_t bigint_as_unsigned(const BigInt *bigint);
int64_t bigint_as_signed(const BigInt *bigint);
double bigint_as_float(const BigInt *bigint);
void bigint_truncate(BigInt *dst, const BigInt *op, size_t bit_count, bool is_signed);
void bigint_incr(BigInt *x);
size_t bigint_popcount_signed(const BigInt *bi, size_t bit_count);
size_t bigint_popcount_unsigned(const BigInt *big_int);