// examples/fib_iter

// BEGIN mycpp output

#include "gc_heap.h"

using gc_heap::Alloc;
using gc_heap::kZeroMask;
using gc_heap::StackRoots;
#include "my_runtime.h"
#include "mylib2.h"

using gc_heap::NewStr;
using gc_heap::NewList;
using gc_heap::NewDict;
GLOBAL_STR(str0, "fib_iter(%d) = %d");
GLOBAL_STR(str1, "fib_iter(%d) = %d");
GLOBAL_STR(str2, "Ran %d iterations of fib_iter");

namespace fib_iter {  // forward declare

}  // forward declare namespace fib_iter

namespace fib_iter {  // declare
int fib_iter(int n);
void run_tests();
void run_benchmarks();
inline Str* fmt0(int a0, int a1) {
  gBuf.reset();
  gBuf.write_const("fib_iter(", 9);
  gBuf.format_d(a0);
  gBuf.write_const(") = ", 4);
  gBuf.format_d(a1);
  return gBuf.getvalue();
}

inline Str* fmt1(int a0, int a1) {
  gBuf.reset();
  gBuf.write_const("fib_iter(", 9);
  gBuf.format_d(a0);
  gBuf.write_const(") = ", 4);
  gBuf.format_d(a1);
  return gBuf.getvalue();
}

inline Str* fmt2(int a0) {
  gBuf.reset();
  gBuf.write_const("Ran ", 4);
  gBuf.format_d(a0);
  gBuf.write_const(" iterations of fib_iter", 23);
  return gBuf.getvalue();
}


}  // declare namespace fib_iter

namespace fib_iter {  // define

int fib_iter(int n) {
  int a;
  int b;
  int i;
  int tmp;
  a = 0;
  b = 1;
  i = 0;
  while (i < n) {
    tmp = (a + b);
    a = b;
    b = tmp;
    i += 1;
  }
  return b;
}

void run_tests() {
  int x;
  int result;
  x = 33;
  result = fib_iter(x);
  println_stderr(fmt0(x, result));
}

void run_benchmarks() {
  int n;
  int x;
  int result;
  int i;
  n = 500000;
  x = 33;
  result = -1;
  i = 0;
  while (i < n) {
    result = fib_iter(x);
    i += 1;
  }
  println_stderr(fmt1(x, result));
  println_stderr(fmt2(n));
}

}  // define namespace fib_iter


int main(int argc, char **argv) {
  // gc_heap::gHeap.Init(512);
  gc_heap::gHeap.Init(128 << 10);  // 128 KiB; doubling in size
  // gc_heap::gHeap.Init(400 << 20);  // 400 MiB to avoid garbage collection

  if (getenv("BENCHMARK")) {
    fprintf(stderr, "Benchmarking...\n");
    fib_iter::run_benchmarks();
  } else {
    fib_iter::run_tests();
  }
}