diff --git a/include/swift/SIL/SILFunction.h b/include/swift/SIL/SILFunction.h
index 9050d987a4f..0b9541b5b31 100644
--- a/include/swift/SIL/SILFunction.h
+++ b/include/swift/SIL/SILFunction.h
@@ -63,6 +63,9 @@ private:
   /// The lowered type of the function.
   CanSILFunctionType LoweredType;
   
+  /// The context archetypes of the function.
+  GenericParamList *ContextGenericParams;
+
   /// The collection of all BasicBlocks in the SILFunction. Empty for external
   /// function references.
   BlockListType BlockList;
@@ -168,6 +171,32 @@ public:
   /// Get this function's transparent attribute.
   IsTransparent_t isTransparent() const { return IsTransparent_t(Transparent); }
   void setTransparent(IsTransparent_t isT) { Transparent = isT; }
+    
+  /// Retrieve the generic parameter list containing the contextual archetypes
+  /// of the function.
+  ///
+  /// FIXME: We should remove this in favor of lazy archetype instantiation
+  /// using the 'getArchetype' and 'mapTypeIntoContext' interfaces.
+  GenericParamList *getContextGenericParams() const {
+    return ContextGenericParams;
+  }
+  void setContextGenericParams(GenericParamList *params) {
+    ContextGenericParams = params;
+  }
+    
+  /// Map the given type, which is based on an interface SILFunctionType and may
+  /// therefore be dependent, to a type based on the context archetypes of this
+  /// SILFunction.
+  Type mapTypeIntoContext(Type type) const;
+    
+  /// Map the given type, which is based on an interface SILFunctionType and may
+  /// therefore be dependent, to a type based on the context archetypes of this
+  /// SILFunction.
+  SILType mapTypeIntoContext(SILType type) const {
+    return SILType::getPrimitiveType(
+             mapTypeIntoContext(type.getSwiftRValueType())->getCanonicalType(),
+             type.getCategory());
+  }
 
   //===--------------------------------------------------------------------===//
   // Block List Access
diff --git a/lib/SIL/SILFunction.cpp b/lib/SIL/SILFunction.cpp
index 48f64cfe1e5..e593c029471 100644
--- a/lib/SIL/SILFunction.cpp
+++ b/lib/SIL/SILFunction.cpp
@@ -12,6 +12,8 @@
 
 #include "swift/SIL/SILFunction.h"
 #include "swift/SIL/SILModule.h"
+// FIXME: For mapTypeInContext
+#include "swift/AST/ArchetypeBuilder.h"
 
 using namespace swift;
 
@@ -26,6 +28,8 @@ SILFunction::SILFunction(SILModule &Module, SILLinkage Linkage,
   : ModuleAndLinkage(&Module, Linkage),
     Name(Name),
     LoweredType(LoweredType),
+    // FIXME: Context params should be independent of the function type.
+    ContextGenericParams(LoweredType->getGenericParams()),
     Location(Loc),
     DeclCtx(DC),
     DebugScope(DebugScope),
@@ -65,3 +69,11 @@ void SILFunction::setDeclContext(Expr *E) {
 ASTContext &SILFunction::getASTContext() const {
   return getModule().getASTContext();
 }
+
+Type SILFunction::mapTypeIntoContext(Type type) const {
+  if (!type->isDependentType())
+    return type;
+  
+  return ArchetypeBuilder::mapTypeIntoContext(getContextGenericParams(),
+                                              type);
+}