From 25703e8fa3b3f27371d737969e0c27961f0e49dc Mon Sep 17 00:00:00 2001
From: Philip Reames <listmail@philipreames.com>
Date: Wed, 12 Nov 2014 00:21:51 +0000
Subject: [PATCH] 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



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221742 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/IR/Function.cpp | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/lib/IR/Function.cpp b/lib/IR/Function.cpp
index 8a69e39ee32..32b2ec5845c 100644
--- a/lib/IR/Function.cpp
+++ b/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;
 }