Add a new step to legalization to legalize vector math operations. This

will allow simplifying LegalizeDAG to eliminate type legalization.  (I 
have a patch to do that, but it's not quite finished; I'll commit it 
once it's finished and I've fixed any review comments for this patch.)  
See the comment at the beginning of 
lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp for more details on the
motivation for this patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72325 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 5fbda87765..ec2d1d7d07 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -220,6 +220,19 @@ public:
   /// the graph.
   void Legalize(bool TypesNeedLegalizing, CodeGenOpt::Level OptLevel);
 
+  /// LegalizeVectors - This transforms the SelectionDAG into a SelectionDAG
+  /// that only uses vector math operations supported by the target.  This is
+  /// necessary as a separate step from Legalize because unrolling a vector
+  /// operation can introduce illegal types, which requires running
+  /// LegalizeTypes again.
+  ///
+  /// This returns true if it made any changes; in that case, LegalizeTypes
+  /// is called again before Legalize.
+  ///
+  /// Note that this is an involved process that may invalidate pointers into
+  /// the graph.
+  bool LegalizeVectors();
+
   /// RemoveDeadNodes - This method deletes all unreachable nodes in the
   /// SelectionDAG.
   void RemoveDeadNodes();