[PATCH] D83153: [DAGCombiner] Prevent regression in isMulAddWithConstProfitable

[Ben Shi via Phabricator via llvm-commits]

benshi001 added a comment.

Chnage list according to all your comments.

1. Seperate the test cases to show improvement in another patch.

Done. https://reviews.llvm.org/D83159

2. Make sure c1 and c2 do not exceed int64, to avoid assert failure.

Done. One more if-statment is added to check that.
(the condition should be >, not >=, otherwise riscv64 can not be optimized)

3. Check if c1*c2 is overflow.

Done One more if-statment for that is added.

4. Make a inverse transform if "opt -instcombine" has been performed.

Shall we seperate this inverse transform in another patch? At least this patch improves
the test case urem-seteq-nonzero.ll, and the case in https://reviews.llvm.org/D83159


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83153/new/

https://reviews.llvm.org/D83153