Extend RemapInstruction and friends to take an optional new parameter, a ValueMaterializer.

Extend LinkModules to pass a ValueMaterializer to RemapInstruction and friends to lazily create Functions for lazily linked globals. This is a big win when linking small modules with large (mostly unused) library modules.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182776 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 27 insertions, 7 deletions

diff --git a/include/llvm/Transforms/Utils/Cloning.h b/include/llvm/Transforms/Utils/Cloning.h
index 14212f622b..3ec132937c 100644
--- a/include/llvm/Transforms/Utils/Cloning.h
+++ b/include/llvm/Transforms/Utils/Cloning.h
@@ -131,7 +131,8 @@ void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
                        SmallVectorImpl<ReturnInst*> &Returns,
                        const char *NameSuffix = "", 
                        ClonedCodeInfo *CodeInfo = 0,
-                       ValueMapTypeRemapper *TypeMapper = 0);
+                       ValueMapTypeRemapper *TypeMapper = 0,
+                       ValueMaterializer *Materializer = 0);
 
 /// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
 /// except that it does some simple constant prop and DCE on the fly.  The
diff --git a/include/llvm/Transforms/Utils/ValueMapper.h b/include/llvm/Transforms/Utils/ValueMapper.h
index 5390c5e8ed..d56ac07690 100644
--- a/include/llvm/Transforms/Utils/ValueMapper.h
+++ b/include/llvm/Transforms/Utils/ValueMapper.h
@@ -33,6 +33,19 @@ namespace llvm {
     /// remap types while mapping values.
     virtual Type *remapType(Type *SrcTy) = 0;
   };
+
+  /// ValueMaterializer - This is a class that can be implemented by clients
+  /// to materialize Values on demand.
+  class ValueMaterializer {
+    virtual void anchor(); // Out of line method.
+  public:
+    virtual ~ValueMaterializer() {}
+
+    /// materializeValueFor - The client should implement this method if they
+    /// want to generate a mapped Value on demand. For example, if linking
+    /// lazily.
+    virtual Value *materializeValueFor(Value *V) = 0;
+  };
   
   /// RemapFlags - These are flags that the value mapping APIs allow.
   enum RemapFlags {
@@ -55,23 +68,29 @@ namespace llvm {
   
   Value *MapValue(const Value *V, ValueToValueMapTy &VM,
                   RemapFlags Flags = RF_None,
-                  ValueMapTypeRemapper *TypeMapper = 0);
+                  ValueMapTypeRemapper *TypeMapper = 0,
+                  ValueMaterializer *Materializer = 0);
 
   void RemapInstruction(Instruction *I, ValueToValueMapTy &VM,
                         RemapFlags Flags = RF_None,
-                        ValueMapTypeRemapper *TypeMapper = 0);
+                        ValueMapTypeRemapper *TypeMapper = 0,
+                        ValueMaterializer *Materializer = 0);
   
   /// MapValue - provide versions that preserve type safety for MDNode and
   /// Constants.
   inline MDNode *MapValue(const MDNode *V, ValueToValueMapTy &VM,
                           RemapFlags Flags = RF_None,
-                          ValueMapTypeRemapper *TypeMapper = 0) {
-    return cast<MDNode>(MapValue((const Value*)V, VM, Flags, TypeMapper));
+                          ValueMapTypeRemapper *TypeMapper = 0,
+                          ValueMaterializer *Materializer = 0) {
+    return cast<MDNode>(MapValue((const Value*)V, VM, Flags, TypeMapper,
+                                 Materializer));
   }
   inline Constant *MapValue(const Constant *V, ValueToValueMapTy &VM,
                             RemapFlags Flags = RF_None,
-                            ValueMapTypeRemapper *TypeMapper = 0) {
-    return cast<Constant>(MapValue((const Value*)V, VM, Flags, TypeMapper));
+                            ValueMapTypeRemapper *TypeMapper = 0,
+                            ValueMaterializer *Materializer = 0) {
+    return cast<Constant>(MapValue((const Value*)V, VM, Flags, TypeMapper,
+                                   Materializer));
   }