[Bug tree-optimization/49651] [C++0x] nested lambdas and -O3 produced incorrect integer variable increments

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49651

--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-07-12 
15:19:48 UTC ---
Shorter testcase that also terminates when successful:

#include <vector>
#include <algorithm>

extern "C" void abort (void);

typedef unsigned int u32;
using namespace std;
vector<u32> g;
void f(u32 a, u32 b)
{
  g.push_back(b);
  for(int i=1; i<g.size() && ! g.empty(); ++i)
    if ( g[i-1]+1 != g[i])
      abort ();
}

int main(int argc, char *argv[])
{
  int cnt = 256;
  u32 a = 0;
  vector<int> vi;
  vi.push_back(0);
  vi.push_back(1);
  vi.push_back(2);
  vi.push_back(3);
  vi.push_back(4);
  vector<int> vo;
  vo.push_back(5);
  vo.push_back(5);
  vector<int> ve;
  ve.push_back(5);
  vector<int> v3;
  vector<int> v4;
  vector<int> v5;
  vector<int> v6;
  vector<int> v7;

  f(32, a++);
  f(32, a++);

  auto run = [&](int& i) {
      // inside this lambda &a is not the same as the &a in the first line
      v3.push_back(i);
      v4.push_back(i);
      v5.push_back(i);
      v6.push_back(i);
      v7.push_back(i);
      f(32, a++);

      v3.push_back(i);
      v4.push_back(i);
      v5.push_back(i);
      v6.push_back(i);
      v7.push_back(i);
      f(32, a++);

      for_each(ve.begin(), ve.end(), [&](int& xi) {
               v7.push_back(xi);
               f(32, a++);
               });

      f(32, a++);
  };

  f(32, a++);

  while(--cnt) {
      for_each(vi.begin(), vi.end(), [&](int& xi) {
               f(32, a++);
               for_each(vo.begin(), vo.end(), run);
               f(32, a++);
               for_each(ve.begin(), ve.end(), run);
               f(32, a++);
               });
  }
}