[PATCH] D112268: [LegalizeTypes][RISCV][PowerPC] Expand CTLZ/CTTZ/CTPOP instead of promoting if they'll be expanded later.

[Craig Topper via Phabricator via llvm-commits]

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Expanding these requires multiple constants. If we promote during type
legalization when they'll end up getting expanded in LegalizeDAG, we'll
end with larger constants. These constants may be harder to materialize.
For example, 64-bit constants on 64-bit RISCV are very expensive.

This is similar to what has already been done to BSWAP and BITREVERSE.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D112268

Files:
  llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
  llvm/test/CodeGen/PowerPC/popcnt-zext.ll
  llvm/test/CodeGen/RISCV/bswap-ctlz-cttz-ctpop.ll
  llvm/test/CodeGen/RISCV/rv64zbb.ll

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