[all-commits] [llvm/llvm-project] 93139a: [LegalizeTypes] Only expand CTLZ/CTTZ/CTPOP during...

[Craig Topper via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 93139a3c32660bc29ac91dea616aa2501f37c8cc
      https://github.com/llvm/llvm-project/commit/93139a3c32660bc29ac91dea616aa2501f37c8cc
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2021-10-22 (Fri, 22 Oct 2021)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp

  Log Message:
  -----------
  [LegalizeTypes] Only expand CTLZ/CTTZ/CTPOP during type promotion if the new type is legal.

We might be promoting a large non-power of 2 type and the new type
may need to be split. Once we split it we may have a ctlz/cttz/ctpop
instruction for the split type.

I'm also concerned that we may create large shifts with shift amounts
that are too small.