[PATCH] D22601: [SCCP] Mark constant xor %blah, %blah even if the lattice value is overdefined

[Eli Friedman via llvm-commits]

eli.friedman added a comment.

There, SCCP actually does add power to the transformation; consider a construct like the following:

  int f();
  int g() { 
      int x = 0;
      for (int i = 0; i < 1000000; ++i) {
          x &= f();
      }
      return x;
  }

SCCP can prove that this function returns zero.


https://reviews.llvm.org/D22601