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

Michael Kuperstein via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Thu Dec 15 11:55:07 PST 2016

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".



More information about the llvm-commits mailing list