[PATCH] D139679: [X86] Don't zero out %eax if both %al and %ah are used

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/Target/X86/X86FrameLowering.cpp:530-531
+  //
+  // FIXME: It would be nice if the sub_and_super iterators would iterator over
+  // sibling registers as well.
+  for (const MachineBasicBlock &MBB : MF)
----------------
I think you would be better off operating in terms of regunits and then going backwards to registers.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139679/new/

https://reviews.llvm.org/D139679