[DAG] Refactor the shuffle combining logic in DAGCombiner. NFC.
authorAndrea Di Biagio <Andrea_DiBiagio@sn.scee.net>
Fri, 21 Nov 2014 11:33:07 +0000 (11:33 +0000)
committerAndrea Di Biagio <Andrea_DiBiagio@sn.scee.net>
Fri, 21 Nov 2014 11:33:07 +0000 (11:33 +0000)
commit04fab61b356ce7bc64374c4838fc770b824717d8
tree9922322ae6a307eda7beb2003d749d31f0c51660
parentd0d042436876cee0ef37b1faf8cb50c878549407
[DAG] Refactor the shuffle combining logic in DAGCombiner. NFC.

This patch simplifies the logic that combines a pair of shuffle nodes into
a single shuffle if there is a legal mask. Also added comments to better
describe the algorithm. No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222522 91177308-0d34-0410-b5e6-96231b3b80d8
lib/CodeGen/SelectionDAG/DAGCombiner.cpp