[AVX] Make Inits Foldable

Manage Inits in a FoldingSet.  This provides several benefits:

- Memory for Inits is properly managed

- Duplicate Inits are folded into Flyweights, saving memory

- It enforces const-correctness, protecting against certain classes
  of bugs

The above benefits allow Inits to be used in more contexts, which in
turn provides more dynamism to TableGen.  This enhanced capability
will be used by the AVX code generator to a fold common patterns
together.

llvm-svn: 134907

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/utils/TableGen/SetTheory.h b/llvm/utils/TableGen/SetTheory.h
index e37a76ee68c..e2309b2af6f 100644
--- a/llvm/utils/TableGen/SetTheory.h
+++ b/llvm/utils/TableGen/SetTheory.h
@@ -70,7 +70,7 @@ public:
 
     /// apply - Apply this operator to Expr's arguments and insert the result
     /// in Elts.
-    virtual void apply(SetTheory&, DagInit *Expr, RecSet &Elts) =0;
+    virtual void apply(SetTheory&, const DagInit *Expr, RecSet &Elts) =0;
   };
 
   /// Expander - A callback function that can transform a Record representing a
@@ -115,7 +115,7 @@ public:
   void addOperator(StringRef Name, Operator*);
 
   /// evaluate - Evaluate Expr and append the resulting set to Elts.
-  void evaluate(Init *Expr, RecSet &Elts);
+  void evaluate(const Init *Expr, RecSet &Elts);
 
   /// evaluate - Evaluate a sequence of Inits and append to Elts.
   template<typename Iter>