[Bug c++/18049] wrong result without -O2 with g++-3.4.2 and completely wrong result with any other g++ version

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-10-18 20:32 -------
Actually, the typedef has nothing to do with it. Here's a modified FEMmain.cc 
file: 
------------------------- 
#include <iostream> 
#include "Elements.h" 
 
int main() 
{ 
  Container2D<R> Vec(6,6,1.0); 
  FiniteElement<Simplex, _2D, P2> SP2(&Vec); 
  Mesh mesh; 
  AssemblyTerm<0, Simplex, _2D, P2> u(mesh, &Vec); 
  AssemblyTerm<0, Simplex, _2D, P2> v(mesh, &Vec); 
 
  // Give Vec its final values 
  for (size_t i = 0; i < 6; i++) 
    for (unsigned int j=0; j<6; ++j) 
      Vec[j][i] += j; 
 
  R x = 1.0; 
  R y = 0.0; 
  R z = 2.0; 
 
  AssemblyTerm<1, Simplex, _2D, P2> vdx(mesh, &Vec); 
  std::cout << "Before:  " << vdx(0,x,y,z) << "\n"; 
  std::cout << "After:   " << vdx(0,x,y,z) << "\n"; 
} 
-------------------------- 
The typedef is gone, and I output only the first element. What I get is this: 
 
g/x> /home/bangerth/bin/gcc-3.4.3-pre/bin/c++ *.cc -o x ; ./x 
Before:  3 
After:   -0.994019 
 
In other words, the output changes if I call the same function vdx(0,x,y,z) 
twice. I will have to see what's going on in the function. 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18049