[PATCH] D143742: [VirtRegMap] Further optimize emitting KILL for copy

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/CodeGen/VirtRegMap.cpp:441
+      ((MI.getNumOperands() > 2) &&
+       !isCopyWithReservedImplicitOpnds(MI, *MRI))) {
     MI.setDesc(TII->get(TargetOpcode::KILL));
----------------
qcolombet wrote:
> Instead of not emitting the `KILL` could we just drop the implicit reserved registers?
If COPYs can have arbitrary implicit operands at this point, it seems like we need a much more precise check for an implicit-def of a super-register of the result?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D143742/new/

https://reviews.llvm.org/D143742