[PATCH] D34402: [AArch64] Preserve register flags when promoting a load from store.

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added a comment.

The first part of the patch looks fine to me.

The second part of adding an extra kill flag should be unnecessary and I'd prefer staying with the naive code:

- Kill flags are optional. So not adding them should never be a correctness problem.
- Missing kill flags may mean missed optimizations today, though I believe that I fixed all passes used by AArch64 in that respect so there should be no change. (Admittedly I still have to do some larger scaling testing with a debugging mode that drops all kill flags to verify it is true).
- The long term plan is to get rid of kill flags and hence having simpler code.



================
Comment at: test/CodeGen/AArch64/ldst-opt.mir:153
+  bb.0:
+    liveins: %w1, %x0, %x2, %lr
+
----------------
Is it possible to make %w1 not live-in to make the test slightly more obvious.


https://reviews.llvm.org/D34402