[PATCH] D36415: Insert IMPLICIT_DEFS for undef uses in tail merging

[Krzysztof Parzyszek via Phabricator via llvm-commits]

kparzysz created this revision.

Tail merging can convert an undef use into a normal one when creating a common tail. Doing so can make the register live out from a block which previously contained the undef use. To keep the liveness up-to-date, insert IMPLICIT_DEFs in such blocks when necessary.


Repository:
  rL LLVM

https://reviews.llvm.org/D36415

Files:
  lib/CodeGen/BranchFolding.cpp
  test/CodeGen/Hexagon/branchfolder-insert-impdef.mir
  test/CodeGen/Hexagon/livephysregs-lane-masks2.mir

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D36415.110026.patch
Type: text/x-patch
Size: 4044 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170807/30fa7599/attachment.bin>