[PATCH] D99203: [RISCV] Add TTI support for cpop with Zbb

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: frasercrmck, asb, luismarques.
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This will tell loop idiom recognize that it can convert popcount loops
to intrinsics. I didn't bother checking for illegal types. Type legalization
knows how to split a ctpop into multiple ctops added together. Assuming we only
receive reasonable integer bit widths, a few cpop instructions added together
is probably better than the loop.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D99203

Files:
  llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
  llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h
  llvm/test/Transforms/LoopIdiom/RISCV/lit.local.cfg
  llvm/test/Transforms/LoopIdiom/RISCV/popcnt.ll

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