[Bug tree-optimization/56321] [4.8 Regression] ICE:segfault in midend for -funsafe-math-optimizations -O3

[wschmidt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56321



--- Comment #6 from William J. Schmidt <wschmidt at gcc dot gnu.org> 2013-02-14 
20:11:32 UTC ---

Odd.  Reassociation makes a correct and profitable transformation into



foo (int n)

{

  double _2;

  double _5;

  double _6;

  double _7;

  double _8;

  float _9;



  <bb 2>:

  _2 = (double) n_1(D);

  _6 = _2 * 6.6666666666666662965923251249478198587894439697265625e-1;

  _7 = _6 + 2.0e+0;

  _5 = _7 * _2;

  _8 = _5;

  _9 = (float) _8;

  return _9;



}



but somehow verify_ssa() thinks the last statement (return _9;) contains a use

of the undefined SSA name _4.



Will continue to investigate later.