Extend intrinsic name mangling to support arrays, named structs, and …

…function types.

Currently, we have a type parameter mechanism for intrinsics. Rather than having to specify a separate intrinsic for each combination of argument and return types, we can specify a single intrinsic with one or more type parameters. These type parameters are passed explicitly to Intrinsic::getDeclaration or can be specified implicitly in the naming of the intrinsic function in an LL file.

Today, the types are limited to integer, floating point, and pointer types. With a goal of supporting symbolic targets for patchpoints and statepoints, this change adds support for function types.  The change also includes support for first class aggregate types (named structures and arrays) since these appear in function types we've encountered.  

Reviewed by: atrick, ributzka
Differential Revision: http://reviews.llvm.org/D4608

llvm-svn: 221742

llvm/lib/IR/Function.cpp

@@ -455,6 +455,33 @@ unsigned Function::lookupIntrinsicID() const {
   return 0;
 }
 
+/// Returns a stable mangling for the type specified for use in the name
+/// mangling scheme used by 'any' types in intrinsic signatures.
+static std::string getMangledTypeStr(Type* Ty) {
+  std::string Result;
+  if (PointerType* PTyp = dyn_cast<PointerType>(Ty)) {
+    Result += "p" + llvm::utostr(PTyp->getAddressSpace()) +
+      getMangledTypeStr(PTyp->getElementType());
+  } else if (ArrayType* ATyp = dyn_cast<ArrayType>(Ty)) {
+    Result += "a" + llvm::utostr(ATyp->getNumElements()) +
+      getMangledTypeStr(ATyp->getElementType());
+  } else if (StructType* STyp = dyn_cast<StructType>(Ty)) {
+    if (!STyp->isLiteral())
+      Result += STyp->getName();
+    else
+      llvm_unreachable("TODO: implement literal types");
+  } else if (FunctionType* FT = dyn_cast<FunctionType>(Ty)) {
+    Result += "f_" + getMangledTypeStr(FT->getReturnType());
+    for (size_t i = 0; i < FT->getNumParams(); i++)
+      Result += getMangledTypeStr(FT->getParamType(i));
+    if (FT->isVarArg())
+      Result += "vararg";
+    Result += "f"; //ensure distinguishable
+  } else if (Ty)
+    Result += EVT::getEVT(Ty).getEVTString();
+  return Result;
+}
+
 std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
   assert(id < num_intrinsics && "Invalid intrinsic ID!");
   static const char * const Table[] = {
@@ -467,12 +494,7 @@ std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
     return Table[id];
   std::string Result(Table[id]);
   for (unsigned i = 0; i < Tys.size(); ++i) {
-    if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) {
-      Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) +
-                EVT::getEVT(PTyp->getElementType()).getEVTString();
-    }
-    else if (Tys[i])
-      Result += "." + EVT::getEVT(Tys[i]).getEVTString();
+    Result += "." + getMangledTypeStr(Tys[i]);
   }
   return Result;
 }