[PATCH] D27787: Don't combine a shuffle of two BUILD_VECTORs in general.

[Michael Kuperstein via Phabricator via llvm-commits]

mkuper accepted this revision.
mkuper added a comment.
This revision is now accepted and ready to land.

This LGTM with a comment nit.
I'm sure there still are cases it'll pessimize, but I think it's an improvement over what we had. Thanks, Eli!



================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:14132
+
+    // Don't duplicate a BUILD_VECTOR operand; semantically, this is fine,
+    // but it's likely to generate bad code.
----------------
"a non-constant BUILD_VECTOR operand".


Repository:
  rL LLVM

https://reviews.llvm.org/D27787