[PATCH] D41578: [SCEV] Do not cache S -> V if S is not equivalent of V

[Evgeny Astigeevich via Phabricator via llvm-commits]

eastig added a comment.

A reproducer:
F5765948: test.ll <https://reviews.llvm.org/F5765948>

  $ opt.patch.off -loop-reduce -S -o test.patch.off.ll test.ll
  $ opt -loop-reduce -S -o test.patch.on.ll test.ll
  $ diff test.patch.off.ll test.patch.on.ll
  26c26,27
  <   %0 = sub i32 %xtraiter289.i, %mul86.i
  ---
  >   %0 = mul i32 %p281, %p280
  >   %1 = sub i32 %xtraiter289.i, %0
  37c38
  <   %lsr.iv = phi i32 [ %0, %for.body106.us.i.preheader ], [ %lsr.iv.next, %for.body106.us.i ]
  ---
  >   %lsr.iv = phi i32 [ %1, %for.body106.us.i.preheader ], [ %lsr.iv.next, %for.body106.us.i ]


Repository:
  rL LLVM

https://reviews.llvm.org/D41578