[PATCH] D66380: [SDAG] Fold umul_lohi with 0 or 1 multiplicand

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added reviewers: spatel, RKSimon, lebedev.ri.
Herald added subscribers: llvm-commits, hiraditya.
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These can turn up during multiplication legalization. In principle these should also apply to smul_lohi, but I wasn't able to figure out how to produce those.


Repository:
  rL LLVM

https://reviews.llvm.org/D66380

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/X86/i128-mul.ll
  llvm/test/CodeGen/X86/imul.ll
  llvm/test/CodeGen/X86/mul-i1024.ll
  llvm/test/CodeGen/X86/mul-i256.ll
  llvm/test/CodeGen/X86/mul-i512.ll
  llvm/test/CodeGen/X86/mul128.ll
  llvm/test/CodeGen/X86/overflow.ll
  llvm/test/CodeGen/X86/umul_lohi.ll
  llvm/test/CodeGen/X86/umulo-128-legalisation-lowering.ll