Teach LSR about loop-variant expressions, such as loops like this:

  for (i = 0; i < N; ++i)
    A[i][foo()] = 0;

here we still want to strength reduce the A[i] part, even though foo() is
l-v.

This also simplifies some of the 'CanReduce' logic.

This implements Transforms/LoopStrengthReduce/ops_after_indvar.ll

llvm-svn: 22652
1 file changed
tree: 14209f8e9348e21adbc17b1710c1422432dbc832
  1. llvm/