Eliminate redundant bitwise operations when using a llvm/ADT/PointerUnion.

[oota-llvm.git] / include / llvm / ADT / PointerIntPair.h

diff --git a/include/llvm/ADT/PointerIntPair.h b/include/llvm/ADT/PointerIntPair.h
index 19b71d43c92ff13b9aba5896dfe7085492f28fe4..cce2efb6ac996261471140c000459936c3b05325 100644 (file)
--- a/include/llvm/ADT/PointerIntPair.h
+++ b/include/llvm/ADT/PointerIntPair.h
@@ -42,28 +42,33 @@ class PointerIntPair {
   intptr_t Value;
   enum {
     /// PointerBitMask - The bits that come from the pointer.
-    PointerBitMask = ~(((intptr_t)1 << PtrTraits::NumLowBitsAvailable)-1),
+    PointerBitMask =
+      ~(uintptr_t)(((intptr_t)1 << PtrTraits::NumLowBitsAvailable)-1),
+
     /// IntShift - The number of low bits that we reserve for other uses, and
     /// keep zero.
-    IntShift = PtrTraits::NumLowBitsAvailable-IntBits,
+    IntShift = (uintptr_t)PtrTraits::NumLowBitsAvailable-IntBits,
     
     /// IntMask - This is the unshifted mask for valid bits of the int type.
-    IntMask = ((intptr_t)1 << IntBits)-1,
+    IntMask = (uintptr_t)(((intptr_t)1 << IntBits)-1),
     
     // ShiftedIntMask - This is the bits for the integer shifted in place.
-    ShiftedIntMask = IntMask << IntShift
+    ShiftedIntMask = (uintptr_t)(IntMask << IntShift)
   };
 public:
   PointerIntPair() : Value(0) {}
-  PointerIntPair(PointerTy Ptr, IntType Int) : Value(0) {
+  PointerIntPair(PointerTy Ptr, IntType Int) {
     assert(IntBits <= PtrTraits::NumLowBitsAvailable &&
            "PointerIntPair formed with integer size too large for pointer");
-    setPointer(Ptr);
-    setInt(Int);
+    setPointerAndInt(Ptr, Int);
+  }
+  explicit PointerIntPair(PointerTy Ptr) {
+    initWithPointer(Ptr);
   }
 
   PointerTy getPointer() const {
-    return reinterpret_cast<PointerTy>(Value & PointerBitMask);
+    return PtrTraits::getFromVoidPointer(
+                         reinterpret_cast<void*>(Value & PointerBitMask));
   }
 
   IntType getInt() const {
@@ -71,7 +76,8 @@ public:
   }
 
   void setPointer(PointerTy Ptr) {
-    intptr_t PtrVal = reinterpret_cast<intptr_t>(Ptr);
+    intptr_t PtrVal
+      = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(Ptr));
     assert((PtrVal & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 &&
            "Pointer is not sufficiently aligned");
     // Preserve all low bits, just update the pointer.
@@ -87,13 +93,50 @@ public:
     Value |= IntVal << IntShift;  // Set new integer.
   }
 
+  void initWithPointer(PointerTy Ptr) {
+    intptr_t PtrVal
+      = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(Ptr));
+    assert((PtrVal & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 &&
+           "Pointer is not sufficiently aligned");
+    Value = PtrVal;
+  }
+
+  void setPointerAndInt(PointerTy Ptr, IntType Int) {
+    intptr_t PtrVal
+      = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(Ptr));
+    assert((PtrVal & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 &&
+           "Pointer is not sufficiently aligned");
+    intptr_t IntVal = Int;
+    assert(IntVal < (1 << IntBits) && "Integer too large for field");
+
+    Value = PtrVal | (IntVal << IntShift);
+  }
+
+  PointerTy const *getAddrOfPointer() const {
+    return const_cast<PointerIntPair *>(this)->getAddrOfPointer();
+  }
+
+  PointerTy *getAddrOfPointer() {
+    assert(Value == reinterpret_cast<intptr_t>(getPointer()) &&
+           "Can only return the address if IntBits is cleared and "
+           "PtrTraits doesn't change the pointer");
+    return reinterpret_cast<PointerTy *>(&Value);
+  }
+
   void *getOpaqueValue() const { return reinterpret_cast<void*>(Value); }
   void setFromOpaqueValue(void *Val) { Value = reinterpret_cast<intptr_t>(Val);}
 
   static PointerIntPair getFromOpaqueValue(void *V) {
     PointerIntPair P; P.setFromOpaqueValue(V); return P; 
   }
-  
+
+  // Allow PointerIntPairs to be created from const void * if and only if the
+  // pointer type could be created from a const void *.
+  static PointerIntPair getFromOpaqueValue(const void *V) {
+    (void)PtrTraits::getFromVoidPointer(V);
+    return getFromOpaqueValue(const_cast<void *>(V));
+  }
+
   bool operator==(const PointerIntPair &RHS) const {return Value == RHS.Value;}
   bool operator!=(const PointerIntPair &RHS) const {return Value != RHS.Value;}
   bool operator<(const PointerIntPair &RHS) const {return Value < RHS.Value;}
@@ -102,17 +145,23 @@ public:
   bool operator>=(const PointerIntPair &RHS) const {return Value >= RHS.Value;}
 };
 
+template <typename T> struct isPodLike;
+template<typename PointerTy, unsigned IntBits, typename IntType>
+struct isPodLike<PointerIntPair<PointerTy, IntBits, IntType> > {
+   static const bool value = true;
+};
+  
 // Provide specialization of DenseMapInfo for PointerIntPair.
 template<typename PointerTy, unsigned IntBits, typename IntType>
 struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType> > {
   typedef PointerIntPair<PointerTy, IntBits, IntType> Ty;
   static Ty getEmptyKey() {
-    intptr_t Val = -1;
+    uintptr_t Val = static_cast<uintptr_t>(-1);
     Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
     return Ty(reinterpret_cast<PointerTy>(Val), IntType((1 << IntBits)-1));
   }
   static Ty getTombstoneKey() {
-    intptr_t Val = -2;
+    uintptr_t Val = static_cast<uintptr_t>(-2);
     Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
     return Ty(reinterpret_cast<PointerTy>(Val), IntType(0));
   }
@@ -121,12 +170,13 @@ struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType> > {
     return unsigned(IV) ^ unsigned(IV >> 9);
   }
   static bool isEqual(const Ty &LHS, const Ty &RHS) { return LHS == RHS; }
-  static bool isPod() { return true; }
 };
 
 // Teach SmallPtrSet that PointerIntPair is "basically a pointer".
-template<typename PointerTy, unsigned IntBits, typename IntType>
-class PointerLikeTypeTraits<PointerIntPair<PointerTy, IntBits, IntType> > {
+template<typename PointerTy, unsigned IntBits, typename IntType,
+         typename PtrTraits>
+class PointerLikeTypeTraits<PointerIntPair<PointerTy, IntBits, IntType,
+                                           PtrTraits> > {
 public:
   static inline void *
   getAsVoidPointer(const PointerIntPair<PointerTy, IntBits, IntType> &P) {
@@ -136,9 +186,12 @@ public:
   getFromVoidPointer(void *P) {
     return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P);
   }
+  static inline PointerIntPair<PointerTy, IntBits, IntType>
+  getFromVoidPointer(const void *P) {
+    return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P);
+  }
   enum {
-    NumLowBitsAvailable = 
-           PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable - IntBits
+    NumLowBitsAvailable = PtrTraits::NumLowBitsAvailable - IntBits
   };
 };