For PR1205:

Implement the first step towards arbitrary precision integer support in
LLVM. The APInt class provides arbitrary precision arithmetic and value
representation. This patch changes ConstantInt to use APInt as its value
representation without supporting bit widths > 64 yet. That change will
come after ConstantFolding handles bit widths > 64 bits.

llvm-svn: 34647

1 files changed, 49 insertions, 16 deletions

diff --git a/llvm/lib/VMCore/Constants.cpp b/llvm/lib/VMCore/Constants.cpp
index fa35a8953c7..dc017b355af 100644
--- a/llvm/lib/VMCore/Constants.cpp
+++ b/llvm/lib/VMCore/Constants.cpp
@@ -138,8 +138,9 @@ ConstantVector *ConstantVector::getAllOnesValue(const VectorType *Ty) {
 //                                ConstantInt
 //===----------------------------------------------------------------------===//
 
-ConstantInt::ConstantInt(const IntegerType *Ty, uint64_t V)
+ConstantInt::ConstantInt(const IntegerType *Ty, const APInt& V)
   : Constant(Ty, ConstantIntVal, 0, 0), Val(V) {
+  assert(V.getBitWidth() == Ty->getBitWidth() && "Invalid constant for type");
 }
 
 ConstantInt *ConstantInt::TheTrueVal = 0;
@@ -166,32 +167,55 @@ ConstantInt *ConstantInt::CreateTrueFalseVals(bool WhichOne) {
 
 
 namespace {
-  struct DenseMapInt64KeyInfo {
-    typedef std::pair<uint64_t, const Type*> KeyTy;
-    static inline KeyTy getEmptyKey() { return KeyTy(0, 0); }
-    static inline KeyTy getTombstoneKey() { return KeyTy(1, 0); }
+  struct DenseMapAPIntKeyInfo {
+    struct KeyTy {
+      APInt val;
+      const Type* type;
+      KeyTy(const APInt& V, const Type* Ty) : val(V), type(Ty) {}
+      KeyTy(const KeyTy& that) : val(that.val), type(that.type) {}
+      bool operator==(const KeyTy& that) const {
+        return type == that.type && this->val == that.val;
+      }
+      bool operator!=(const KeyTy& that) const {
+        return !this->operator==(that);
+      }
+    };
+    static inline KeyTy getEmptyKey() { return KeyTy(APInt(1,0), 0); }
+    static inline KeyTy getTombstoneKey() { return KeyTy(APInt(1,1), 0); }
     static unsigned getHashValue(const KeyTy &Key) {
-      return DenseMapKeyInfo<void*>::getHashValue(Key.second) ^ Key.first;
+      return DenseMapKeyInfo<void*>::getHashValue(Key.type) ^ 
+        Key.val.getHashValue();
     }
     static bool isPod() { return true; }
   };
 }
 
 
-typedef DenseMap<DenseMapInt64KeyInfo::KeyTy, ConstantInt*, 
-                 DenseMapInt64KeyInfo> IntMapTy;
+typedef DenseMap<DenseMapAPIntKeyInfo::KeyTy, ConstantInt*, 
+                 DenseMapAPIntKeyInfo> IntMapTy;
 static ManagedStatic<IntMapTy> IntConstants;
 
-// Get a ConstantInt from an int64_t. Note here that we canoncialize the value
-// to a uint64_t value that has been zero extended down to the size of the
-// integer type of the ConstantInt. This allows the getZExtValue method to 
-// just return the stored value while getSExtValue has to convert back to sign
-// extended. getZExtValue is more common in LLVM than getSExtValue().
 ConstantInt *ConstantInt::get(const Type *Ty, int64_t V) {
   const IntegerType *ITy = cast<IntegerType>(Ty);
-  V &= ITy->getBitMask();
-  ConstantInt *&Slot = (*IntConstants)[std::make_pair(uint64_t(V), Ty)];
-  if (Slot) return Slot;
+  APInt Tmp(ITy->getBitWidth(), V);
+  return get(Ty, Tmp);
+}
+
+// Get a ConstantInt from a Type and APInt. Note that the value stored in 
+// the DenseMap as the key is a DensMapAPIntKeyInfo::KeyTy which has provided
+// operator== and operator!= to ensure that the DenseMap doesn't attempt to
+// compare APInt's of different widths, which would violate an APInt class
+// invariant which generates an assertion.
+ConstantInt *ConstantInt::get(const Type *Ty, const APInt& V) {
+  const IntegerType *ITy = cast<IntegerType>(Ty);
+  assert(ITy->getBitWidth() == V.getBitWidth() && "Invalid type for constant");
+  // get an existing value or the insertion position
+  DenseMapAPIntKeyInfo::KeyTy Key(V, Ty);
+  ConstantInt *&Slot = (*IntConstants)[Key]; 
+  // if it exists, return it.
+  if (Slot)
+    return Slot;
+  // otherwise create a new one, insert it, and return it.
   return Slot = new ConstantInt(ITy, V);
 }
 
@@ -215,6 +239,15 @@ bool ConstantFP::isExactlyValue(double V) const {
 
 
 namespace {
+  struct DenseMapInt64KeyInfo {
+    typedef std::pair<uint64_t, const Type*> KeyTy;
+    static inline KeyTy getEmptyKey() { return KeyTy(0, 0); }
+    static inline KeyTy getTombstoneKey() { return KeyTy(1, 0); }
+    static unsigned getHashValue(const KeyTy &Key) {
+      return DenseMapKeyInfo<void*>::getHashValue(Key.second) ^ Key.first;
+    }
+    static bool isPod() { return true; }
+  };
   struct DenseMapInt32KeyInfo {
     typedef std::pair<uint32_t, const Type*> KeyTy;
     static inline KeyTy getEmptyKey() { return KeyTy(0, 0); }