[PATCH] D135541: [TargetLowering][RISCV][X86] Support even divisors in expandDIVREMByConstant.

[Craig Topper via Phabricator via llvm-commits]

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If the divisor is even, we can first shift the dividend and divisor
right by the number of trailing zeros. Now the divisor is odd and we
can do the original algorithm to calculate a remainder. Then we shift
that remainder left by the number of trailing zeros and add the bits
that were shifted out of the dividend.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D135541

Files:
  llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
  llvm/test/CodeGen/RISCV/split-udiv-by-constant.ll
  llvm/test/CodeGen/RISCV/split-urem-by-constant.ll
  llvm/test/CodeGen/X86/divide-by-constant.ll
  llvm/test/CodeGen/X86/divmod128.ll

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