struct tiny_align_8 {
  long long m0;
};
long long tiny_align_8_get_m0(struct tiny_align_8 m) { return m.m0; }
void tiny_align_8_mutate(volatile struct tiny_align_8 m) {
  m.m0++;
}
struct tiny_align_8 tiny_align_8_return(long long val) {
  struct tiny_align_8 result;
  result.m0 = val;
  return result;
}
struct tiny_align_8 tiny_align_8_identity(struct tiny_align_8 m) {
  return m;
}

/* A small structure with 8-byte alignment.
    SysV x86-64 and AAPCS64 will pass this by register.
*/
struct small_align_8 {
  long long m0, m1;
};
long long small_align_8_get_m0(struct small_align_8 m) { return m.m0; }
long long small_align_8_get_m1(struct small_align_8 m) { return m.m1; }
void small_align_8_mutate(volatile struct small_align_8 m) {
  m.m0++;
  m.m1++;
}
struct small_align_8 small_align_8_return(long long v0, long long v1) {
  struct small_align_8 result;
  result.m0 = v0;
  result.m1 = v1;
  return result;
}
struct small_align_8 small_align_8_identity(struct small_align_8 m) {
  return m;
}

/* A large structure with 8-byte alignment.
    This should be too big for any architecture to pass by registers.
*/
struct large_align_8 {
  long long m0, m4, m8, m12;
  long long m1, m5, m9, m13;
  long long m2, m6, m10, m14;
  long long m3, m7, m11, m15;
};
#define large_align_8_get(member)                                \
  long long large_align_8_get_##member(struct large_align_8 m) { \
    return m.member;                                              \
  }
large_align_8_get(m0);
large_align_8_get(m1);
large_align_8_get(m2);
large_align_8_get(m3);
large_align_8_get(m4);
large_align_8_get(m5);
large_align_8_get(m6);
large_align_8_get(m7);
large_align_8_get(m8);
large_align_8_get(m9);
large_align_8_get(m10);
large_align_8_get(m11);
large_align_8_get(m12);
large_align_8_get(m13);
large_align_8_get(m14);
large_align_8_get(m15);

/* Mutates the input struct. Volatile to avoid compiler optimizing away the mutation.*/
void large_align_8_mutate(volatile struct large_align_8 m) {
  m.m0++;
  m.m1++;
  m.m2++;
  m.m3++;
  m.m4++;
  m.m5++;
  m.m6++;
  m.m7++;
  m.m8++;
  m.m9++;
  m.m10++;
  m.m11++;
  m.m12++;
  m.m13++;
  m.m14++;
  m.m15++;
}
struct large_align_8 large_align_8_return(long long v0, long long v1) {
  struct large_align_8 result = {0};
  result.m0 = v0;
  result.m1 = v1;
  return result;
}
struct large_align_8 large_align_8_identity(struct large_align_8 m) {
  return m;
}

/** Structs with floating point members for SSE register testing */
struct two_doubles {
  double d0, d1;
};
struct two_doubles two_doubles_return(double d0, double d1) {
  struct two_doubles result;
  result.d0 = d0;
  result.d1 = d1;
  return result;
}
double two_doubles_sum(struct two_doubles m) {
  return m.d0 + m.d1;
}
struct two_doubles two_doubles_identity(struct two_doubles m) {
  return m;
}

struct two_floats {
  float f0, f1;
};
struct two_floats two_floats_return(float f0, float f1) {
  struct two_floats result;
  result.f0 = f0;
  result.f1 = f1;
  return result;
}
float two_floats_sum(struct two_floats m) {
  return m.f0 + m.f1;
}
struct two_floats two_floats_identity(struct two_floats m) {
  return m;
}

/** Mixed int and float struct - tests split register handling on x86-64 */
struct int_double {
  long long i;
  double d;
};
struct int_double int_double_return(long long i, double d) {
  struct int_double result;
  result.i = i;
  result.d = d;
  return result;
}
long long int_double_get_int(struct int_double m) { return m.i; }
double int_double_get_double(struct int_double m) { return m.d; }
struct int_double int_double_identity(struct int_double m) {
  return m;
}

/** Medium struct (24 bytes) - too large for ARM64 registers, tests boundary */
struct medium_align_8 {
  long long m0, m1, m2;
};
struct medium_align_8 medium_align_8_return(long long v0, long long v1, long long v2) {
  struct medium_align_8 result;
  result.m0 = v0;
  result.m1 = v1;
  result.m2 = v2;
  return result;
}
long long medium_align_8_get_m0(struct medium_align_8 m) { return m.m0; }
long long medium_align_8_get_m1(struct medium_align_8 m) { return m.m1; }
long long medium_align_8_get_m2(struct medium_align_8 m) { return m.m2; }
struct medium_align_8 medium_align_8_identity(struct medium_align_8 m) {
  return m;
}

/** Four floats struct - tests HFA (Homogeneous Floating-point Aggregate) on ARM64 */
struct four_floats {
  float f0, f1, f2, f3;
};
struct four_floats four_floats_return(float f0, float f1, float f2, float f3) {
  struct four_floats result;
  result.f0 = f0;
  result.f1 = f1;
  result.f2 = f2;
  result.f3 = f3;
  return result;
}
float four_floats_sum(struct four_floats m) {
  return m.f0 + m.f1 + m.f2 + m.f3;
}
struct four_floats four_floats_identity(struct four_floats m) {
  return m;
}

/** Three doubles struct - tests HFA boundary (3 doubles = 24 bytes) */
struct three_doubles {
  double d0, d1, d2;
};
struct three_doubles three_doubles_return(double d0, double d1, double d2) {
  struct three_doubles result;
  result.d0 = d0;
  result.d1 = d1;
  result.d2 = d2;
  return result;
}
double three_doubles_sum(struct three_doubles m) {
  return m.d0 + m.d1 + m.d2;
}
struct three_doubles three_doubles_identity(struct three_doubles m) {
  return m;
}

/** HFA with array of 4 floats - tests array-based HFA detection on ARM64 */
struct float_array_4 {
  float arr[4];
};
struct float_array_4 float_array_4_return(float f0, float f1, float f2, float f3) {
  struct float_array_4 result;
  result.arr[0] = f0;
  result.arr[1] = f1;
  result.arr[2] = f2;
  result.arr[3] = f3;
  return result;
}
float float_array_4_sum(struct float_array_4 m) {
  return m.arr[0] + m.arr[1] + m.arr[2] + m.arr[3];
}
float float_array_4_get(struct float_array_4 m, int index) {
  return m.arr[index];
}
struct float_array_4 float_array_4_identity(struct float_array_4 m) {
  return m;
}

/** HFA with array of 2 doubles - tests array-based HFA with doubles */
struct double_array_2 {
  double arr[2];
};
struct double_array_2 double_array_2_return(double d0, double d1) {
  struct double_array_2 result;
  result.arr[0] = d0;
  result.arr[1] = d1;
  return result;
}
double double_array_2_sum(struct double_array_2 m) {
  return m.arr[0] + m.arr[1];
}
double double_array_2_get(struct double_array_2 m, int index) {
  return m.arr[index];
}
struct double_array_2 double_array_2_identity(struct double_array_2 m) {
  return m;
}

/** HFA with array of 3 floats - tests odd-sized array HFA */
struct float_array_3 {
  float arr[3];
};
struct float_array_3 float_array_3_return(float f0, float f1, float f2) {
  struct float_array_3 result;
  result.arr[0] = f0;
  result.arr[1] = f1;
  result.arr[2] = f2;
  return result;
}
float float_array_3_sum(struct float_array_3 m) {
  return m.arr[0] + m.arr[1] + m.arr[2];
}
struct float_array_3 float_array_3_identity(struct float_array_3 m) {
  return m;
}

/** Callback tests for struct-by-value parameters */

/* Callback type taking a small struct (16 bytes, passed in registers) */
typedef long long (*small_struct_callback)(struct small_align_8 s);

/* Callback type taking a large struct (32+ bytes, passed on stack) */
typedef long long (*large_struct_callback)(struct large_align_8 s);

/* Callback type taking two small structs (like CXCursor pattern) */
typedef long long (*two_structs_callback)(struct small_align_8 s1, struct small_align_8 s2);

/* Callback type taking a struct with floats */
typedef double (*float_struct_callback)(struct two_doubles s);

/* Function that calls a callback with a small struct */
long long call_with_small_struct(small_struct_callback cb, long long v0, long long v1) {
  struct small_align_8 s;
  s.m0 = v0;
  s.m1 = v1;
  return cb(s);
}

/* Function that calls a callback with a large struct */
long long call_with_large_struct(large_struct_callback cb,
                                  long long v0, long long v1, long long v2, long long v3) {
  struct large_align_8 s = {0};
  s.m0 = v0;
  s.m1 = v1;
  s.m2 = v2;
  s.m3 = v3;
  return cb(s);
}

/* Function that calls a callback with two small structs */
long long call_with_two_structs(two_structs_callback cb,
                                 long long a0, long long a1,
                                 long long b0, long long b1) {
  struct small_align_8 s1, s2;
  s1.m0 = a0;
  s1.m1 = a1;
  s2.m0 = b0;
  s2.m1 = b1;
  return cb(s1, s2);
}

/* Function that calls a callback with a float struct */
double call_with_float_struct(float_struct_callback cb, double d0, double d1) {
  struct two_doubles s;
  s.d0 = d0;
  s.d1 = d1;
  return cb(s);
}

/* Callback type returning a small struct (16 bytes, in registers) */
typedef struct small_align_8 (*small_struct_return_callback)(long long v0, long long v1);

/* Callback type returning a struct with doubles (SSE registers) */
typedef struct two_doubles (*double_struct_return_callback)(double d0, double d1);

/* Callback type returning a large struct (>16 bytes, via hidden pointer) */
typedef struct medium_align_8 (*medium_struct_return_callback)(long long v0, long long v1, long long v2);

/* Function that calls a callback returning a small struct */
struct small_align_8 call_returning_small_struct(small_struct_return_callback cb,
                                                  long long v0, long long v1) {
  return cb(v0, v1);
}

/* Function that calls a callback returning a struct with doubles */
struct two_doubles call_returning_double_struct(double_struct_return_callback cb,
                                                 double d0, double d1) {
  return cb(d0, d1);
}

/* Function that calls a callback returning a large struct (hidden pointer) */
struct medium_align_8 call_returning_medium_struct(medium_struct_return_callback cb,
                                                    long long v0, long long v1, long long v2) {
  return cb(v0, v1, v2);
}

/** Union tests - unions are a special case of records where all members share memory */

/* Small union (8 bytes) - fits in one register */
union small_union {
  long long as_int;
  double as_double;
};
union small_union small_union_from_int(long long val) {
  union small_union u;
  u.as_int = val;
  return u;
}
union small_union small_union_from_double(double val) {
  union small_union u;
  u.as_double = val;
  return u;
}
long long small_union_get_int(union small_union u) { return u.as_int; }
double small_union_get_double(union small_union u) { return u.as_double; }
union small_union small_union_identity(union small_union u) { return u; }

/* Medium union (16 bytes) - fits in two registers */
union medium_union {
  struct { long long lo, hi; } as_pair;
  struct { double d0, d1; } as_doubles;
};
union medium_union medium_union_from_pair(long long lo, long long hi) {
  union medium_union u;
  u.as_pair.lo = lo;
  u.as_pair.hi = hi;
  return u;
}
union medium_union medium_union_from_doubles(double d0, double d1) {
  union medium_union u;
  u.as_doubles.d0 = d0;
  u.as_doubles.d1 = d1;
  return u;
}
long long medium_union_get_lo(union medium_union u) { return u.as_pair.lo; }
long long medium_union_get_hi(union medium_union u) { return u.as_pair.hi; }
double medium_union_get_d0(union medium_union u) { return u.as_doubles.d0; }
double medium_union_get_d1(union medium_union u) { return u.as_doubles.d1; }
union medium_union medium_union_identity(union medium_union u) { return u; }

/* Large union (>16 bytes) - uses hidden pointer for return */
union large_union {
  long long arr_int[4];
  double arr_double[4];
};
union large_union large_union_from_ints(long long v0, long long v1, long long v2, long long v3) {
  union large_union u;
  u.arr_int[0] = v0;
  u.arr_int[1] = v1;
  u.arr_int[2] = v2;
  u.arr_int[3] = v3;
  return u;
}
long long large_union_get_int(union large_union u, int index) { return u.arr_int[index]; }
double large_union_get_double(union large_union u, int index) { return u.arr_double[index]; }
union large_union large_union_identity(union large_union u) { return u; }

/* Callback tests for unions */
typedef long long (*small_union_callback)(union small_union u);
typedef union small_union (*small_union_return_callback)(long long val);

long long call_with_small_union(small_union_callback cb, long long val) {
  union small_union u;
  u.as_int = val;
  return cb(u);
}

union small_union call_returning_small_union(small_union_return_callback cb, long long val) {
  return cb(val);
}