[all-commits] [llvm/llvm-project] 93977f: Check if register class was changed in constrainOp...

[Daniel Sanders via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 93977f37e67eae26d9bc88e5c3970c11d8861dfc
      https://github.com/llvm/llvm-project/commit/93977f37e67eae26d9bc88e5c3970c11d8861dfc
  Author: Daniel Sanders <daniel_l_sanders at apple.com>
  Date:   2022-04-05 (Tue, 05 Apr 2022)

  Changed paths:
    M llvm/lib/CodeGen/GlobalISel/Utils.cpp

  Log Message:
  -----------
  Check if register class was changed in constrainOperandRegClass()

NFC
When no actual change happens there's no need to notify the
observers about the fact the register class is being constrained.
So we should avoid notifying observers when no change has
happened, because this can dramatically affect compile
time for particular test cases.

Reviewed By: dsanders, arsenm

Differential Revision: https://reviews.llvm.org/D122615