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

Quentin Colombet via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Fri Feb 17 03:00:03 PST 2023


qcolombet added inline comments.


================
Comment at: llvm/lib/CodeGen/VirtRegMap.cpp:441
+      ((MI.getNumOperands() > 2) &&
+       !isCopyWithReservedImplicitOpnds(MI, *MRI))) {
     MI.setDesc(TII->get(TargetOpcode::KILL));
----------------
foad wrote:
> 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?
Good point.


Repository:
  rG LLVM Github Monorepo

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

https://reviews.llvm.org/D143742



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