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

[Ben Shi via Phabricator via llvm-commits]

benshi001 updated this revision to Diff 275545.
benshi001 added a comment.

Thanks for all of your suggestions. I have uploaded a new patch edition.

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.

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

Shall we seperate this inverse transform in another patch? At least this patch works
for "clang a.c -O2 -Wall --target=x86/riscv/aarch64" if a.c contains code pattern like
"(a + 999) * 888". At least this patch can prevent the regression in such circumstance.


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

https://reviews.llvm.org/D83153

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/AArch64/urem-seteq-nonzero.ll
  llvm/test/CodeGen/X86/urem-seteq-nonzero.ll

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