[Intrinsics] Add a 'NoAlias' intrinsic property; annotate llvm.memcpy

[jdoerfert]

We need a test though.

[xbolva00]

Yes, I will add it soon.

[xbolva00]

Updated

[xbolva00]

Clang test is here: https://reviews.llvm.org/D66173

[xbolva00]

In D66158#1627724, @jdoerfert wrote:

We need a test though.

Done.

[jdoerfert]

Proposed wording for the comment, otherwise LGTM. (with the test case)

include/llvm/IR/Intrinsics.td

66

is not aliasing other "noalias" pointer arguments of the intrinsic wrt. the intrinsic scope.

[xbolva00]

Updated comment

[xbolva00]

Update basicaa test

[lebedev.ri]

These reviews omitted llvm-commits during review; sad that phab is *still* not doing the right thing re subscribing lists

include/llvm/IR/Intrinsics.td

 // Throws - This intrinsic can throw.
 def Throws : IntrinsicProperty;
 
 // NoCapture - The specified argument pointer is not captured by the intrinsic.
 class NoCapture<int argNo> : IntrinsicProperty {
   int ArgNo = argNo;
 }
 
+// NoAlias - The specified argument pointer is not aliasing by the intrinsic.
+class NoAlias<int argNo> : IntrinsicProperty {
+  int ArgNo = argNo;
+}
+
 // Returned - The specified argument is always the return value of the
 // intrinsic.
 class Returned<int argNo> : IntrinsicProperty {
   int ArgNo = argNo;
 }
 
 // ImmArg - The specified argument must be an immediate.
 class ImmArg<int argNo> : IntrinsicProperty {

 
 //===------------------- Standard C Library Intrinsics --------------------===//
 //
 
 def int_memcpy  : Intrinsic<[],
                              [llvm_anyptr_ty, llvm_anyptr_ty, llvm_anyint_ty,
                               llvm_i1_ty],
                             [IntrArgMemOnly, IntrWillReturn, NoCapture<0>, NoCapture<1>,
-                             WriteOnly<0>, ReadOnly<1>, ImmArg<3>]>;
+                             NoAlias<0>, NoAlias<1>, WriteOnly<0>, ReadOnly<1>, ImmArg<3>]>;
 def int_memmove : Intrinsic<[],
                             [llvm_anyptr_ty, llvm_anyptr_ty, llvm_anyint_ty,
                              llvm_i1_ty],
                             [IntrArgMemOnly, IntrWillReturn, NoCapture<0>, NoCapture<1>,
                              ReadOnly<1>, ImmArg<3>]>;
 def int_memset  : Intrinsic<[],
                             [llvm_anyptr_ty, llvm_i8_ty, llvm_anyint_ty,
                              llvm_i1_ty],

utils/TableGen/CodeGenIntrinsics.h

struct CodeGenIntrinsic {
   /// of the other flags.
   bool hasSideEffects;
 
   // True if the intrinsic is marked as speculatable.
   bool isSpeculatable;
 
   enum ArgAttribute {
     NoCapture,
+    NoAlias,
     Returned,
     ReadOnly,
     WriteOnly,
     ReadNone,
     ImmArg
   };
 
   std::vector<std::pair<unsigned, ArgAttribute>> ArgumentAttributes;

utils/TableGen/CodeGenTarget.cpp

else if (Property->getName() == "IntrCold")
       isCold = true;
     else if (Property->getName() == "IntrSpeculatable")
       isSpeculatable = true;
     else if (Property->getName() == "IntrHasSideEffects")
       hasSideEffects = true;
     else if (Property->isSubClassOf("NoCapture")) {
       unsigned ArgNo = Property->getValueAsInt("ArgNo");
       ArgumentAttributes.push_back(std::make_pair(ArgNo, NoCapture));
+    } else if (Property->isSubClassOf("NoAlias")) {
+      unsigned ArgNo = Property->getValueAsInt("ArgNo");
+      ArgumentAttributes.push_back(std::make_pair(ArgNo, NoAlias));
     } else if (Property->isSubClassOf("Returned")) {
       unsigned ArgNo = Property->getValueAsInt("ArgNo");
       ArgumentAttributes.push_back(std::make_pair(ArgNo, Returned));
     } else if (Property->isSubClassOf("ReadOnly")) {
       unsigned ArgNo = Property->getValueAsInt("ArgNo");
       ArgumentAttributes.push_back(std::make_pair(ArgNo, ReadOnly));
     } else if (Property->isSubClassOf("WriteOnly")) {
       unsigned ArgNo = Property->getValueAsInt("ArgNo");

utils/TableGen/IntrinsicEmitter.cpp

if (ae) {
         do {
           switch (intrinsic.ArgumentAttributes[ai].second) {
           case CodeGenIntrinsic::NoCapture:
             if (addComma)
               OS << ",";
             OS << "Attribute::NoCapture";
             addComma = true;
             break;
+          if (addComma)
+              OS << ",";
+            OS << "Attribute::NoAlias";
+            addComma = true;
+            break;
           case CodeGenIntrinsic::Returned:
             if (addComma)
               OS << ",";
             OS << "Attribute::Returned";
             addComma = true;
             break;
           case CodeGenIntrinsic::ReadOnly:
             if (addComma)