Flag -> Glue, the ongoing saga

[oota-llvm.git] / lib / VMCore / Use.cpp

diff --git a/lib/VMCore/Use.cpp b/lib/VMCore/Use.cpp
index d96a0e57fd4dc1004c3555954b2b9c6c8b0e01a1..fec710b39459b2d1cccfe9d80afcec71ab724fae 100644 (file)
--- a/lib/VMCore/Use.cpp
+++ b/lib/VMCore/Use.cpp
@@ -52,7 +52,7 @@ const Use *Use::getImpliedUser() const {
   const Use *Current = this;
 
   while (true) {
-    unsigned Tag = extractTag<PrevPtrTag, fullStopTag>((Current++)->Prev);
+    unsigned Tag = (Current++)->Prev.getInt();
     switch (Tag) {
       case zeroDigitTag:
       case oneDigitTag:
@@ -62,7 +62,7 @@ const Use *Use::getImpliedUser() const {
         ++Current;
         ptrdiff_t Offset = 1;
         while (true) {
-          unsigned Tag = extractTag<PrevPtrTag, fullStopTag>(Current->Prev);
+          unsigned Tag = Current->Prev.getInt();
           switch (Tag) {
             case zeroDigitTag:
             case oneDigitTag:
@@ -86,16 +86,31 @@ const Use *Use::getImpliedUser() const {
 //===----------------------------------------------------------------------===//
 
 Use *Use::initTags(Use * const Start, Use *Stop, ptrdiff_t Done) {
+  while (Done < 20) {
+    if (Start == Stop--)
+      return Start;
+    static const PrevPtrTag tags[20] = { fullStopTag, oneDigitTag, stopTag,
+                                         oneDigitTag, oneDigitTag, stopTag,
+                                         zeroDigitTag, oneDigitTag, oneDigitTag,
+                                         stopTag, zeroDigitTag, oneDigitTag,
+                                         zeroDigitTag, oneDigitTag, stopTag,
+                                         oneDigitTag, oneDigitTag, oneDigitTag,
+                                         oneDigitTag, stopTag
+                                       };
+    Stop->Prev.setFromOpaqueValue(reinterpret_cast<Use**>(tags[Done++]));
+    Stop->Val = 0;
+  }
+
   ptrdiff_t Count = Done;
   while (Start != Stop) {
     --Stop;
     Stop->Val = 0;
     if (!Count) {
-      Stop->Prev = reinterpret_cast<Use**>(Done == 0 ? fullStopTag : stopTag);
+      Stop->Prev.setFromOpaqueValue(reinterpret_cast<Use**>(stopTag));
       ++Done;
       Count = Done;
     } else {
-      Stop->Prev = reinterpret_cast<Use**>(Count & 1);
+      Stop->Prev.setFromOpaqueValue(reinterpret_cast<Use**>(Count & 1));
       Count >>= 1;
       ++Done;
     }
@@ -126,8 +141,8 @@ void Use::zap(Use *Start, const Use *Stop, bool del) {
 //                         AugmentedUse layout struct
 //===----------------------------------------------------------------------===//
 
-struct AugmentedUse : Use {
-  User *ref;
+struct AugmentedUse : public Use {
+  PointerIntPair<User*, 1, Tag> ref;
   AugmentedUse(); // not implemented
 };
 
@@ -138,12 +153,12 @@ struct AugmentedUse : Use {
 
 User *Use::getUser() const {
   const Use *End = getImpliedUser();
-  User *She = static_cast<const AugmentedUse*>(End - 1)->ref;
-  She = extractTag<Tag, tagOne>(She)
-      ? llvm::stripTag<tagOne>(She)
-      : reinterpret_cast<User*>(const_cast<Use*>(End));
-
-  return She;
+  const PointerIntPair<User*, 1, Tag>& ref(
+                                static_cast<const AugmentedUse*>(End - 1)->ref);
+  User *She = ref.getPointer();
+  return ref.getInt()
+    ? She
+    : (User*)End;
 }
 
 //===----------------------------------------------------------------------===//
@@ -155,8 +170,77 @@ Use *User::allocHungoffUses(unsigned N) const {
                                                 + sizeof(AugmentedUse)
                                                 - sizeof(Use)));
   Use *End = Begin + N;
-  static_cast<AugmentedUse&>(End[-1]).ref = addTag(this, tagOne);
+  PointerIntPair<User*, 1, Tag>& ref(static_cast<AugmentedUse&>(End[-1]).ref);
+  ref.setPointer(const_cast<User*>(this));
+  ref.setInt(tagOne);
   return Use::initTags(Begin, End);
 }
 
+//===----------------------------------------------------------------------===//
+//                         User operator new Implementations
+//===----------------------------------------------------------------------===//
+
+void *User::operator new(size_t s, unsigned Us) {
+  void *Storage = ::operator new(s + sizeof(Use) * Us);
+  Use *Start = static_cast<Use*>(Storage);
+  Use *End = Start + Us;
+  User *Obj = reinterpret_cast<User*>(End);
+  Obj->OperandList = Start;
+  Obj->NumOperands = Us;
+  Use::initTags(Start, End);
+  return Obj;
+}
+
+/// Prefixed allocation - just before the first Use, allocate a NULL pointer.
+/// The destructor can detect its presence and readjust the OperandList
+/// for deletition.
+///
+void *User::operator new(size_t s, unsigned Us, bool Prefix) {
+  // currently prefixed allocation only admissible for
+  // unconditional branch instructions
+  if (!Prefix)
+    return operator new(s, Us);
+
+  assert(Us == 1 && "Other than one Use allocated?");
+  typedef PointerIntPair<void*, 2, Use::PrevPtrTag> TaggedPrefix;
+  void *Raw = ::operator new(s + sizeof(TaggedPrefix) + sizeof(Use) * Us);
+  TaggedPrefix *Pre = static_cast<TaggedPrefix*>(Raw);
+  Pre->setFromOpaqueValue(0);
+  void *Storage = Pre + 1; // skip over prefix
+  Use *Start = static_cast<Use*>(Storage);
+  Use *End = Start + Us;
+  User *Obj = reinterpret_cast<User*>(End);
+  Obj->OperandList = Start;
+  Obj->NumOperands = Us;
+  Use::initTags(Start, End);
+  return Obj;
+}
+
+//===----------------------------------------------------------------------===//
+//                         User operator delete Implementation
+//===----------------------------------------------------------------------===//
+
+void User::operator delete(void *Usr) {
+  User *Start = static_cast<User*>(Usr);
+  Use *Storage = static_cast<Use*>(Usr) - Start->NumOperands;
+  //
+  // look for a variadic User
+  if (Storage == Start->OperandList) {
+    ::operator delete(Storage);
+    return;
+  }
+  //
+  // check for the flag whether the destructor has detected a prefixed
+  // allocation, in which case we remove the flag and delete starting
+  // at OperandList
+  if (reinterpret_cast<intptr_t>(Start->OperandList) & 1) {
+    ::operator delete(reinterpret_cast<char*>(Start->OperandList) - 1);
+    return;
+  }
+  //
+  // in all other cases just delete the nullary User (covers hung-off
+  // uses also
+  ::operator delete(Usr);
+}
+
 } // End llvm namespace