[all-commits] [llvm/llvm-project] 55a29c: VirtRegMap: Support partially allocated virtual re...

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 55a29c6b71c9b80353ccb17c0dd15dde5c9940b3
      https://github.com/llvm/llvm-project/commit/55a29c6b71c9b80353ccb17c0dd15dde5c9940b3
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2021-04-29 (Thu, 29 Apr 2021)

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

  Log Message:
  -----------
  VirtRegMap: Support partially allocated virtual registers

Don't assert if there are unassigned virtual registers.  Maintain
LiveIntervals by removing the RegUnits for allocated registers, since
they should not longer be necessary.

One part I find somewhat questionable is the special handling
necessary for handleIdentityCopy. The LiveIntervals for the relevant
regunits needs to be removed.