[all-commits] [llvm/llvm-project] f67158: [CFIInstrInserter] Use number of supported registe...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f67158422c3bf37ce3884f4579a93f65e083e7fa
      https://github.com/llvm/llvm-project/commit/f67158422c3bf37ce3884f4579a93f65e083e7fa
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-11-09 (Thu, 09 Nov 2023)

  Changed paths:
    M llvm/lib/CodeGen/CFIInstrInserter.cpp

  Log Message:
  -----------
  [CFIInstrInserter] Use number of supported registers (NFC) (#71797)

This makes use of the more accurate register number introduced in PR
#70222 to avoid CFI calculations for unsupported registers.

This has basically no impact right now, but results in a 0.2% compile-time
improvement at O0 when applied on top of #70958.

The reason is that the extra registers that PR adds push the `BitVector`
out of the `SmallVector` space, which results in an outsized impact.
(This does make me wonder whether `BitVector` should accept an `N`
template parameter to allow using a larger `SmallVector`...)