+ for (DenseSet<MachineConstantPoolValue*>::iterator I =
+ MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
+ I != E; ++I)
+ delete *I;
+}
+
+/// CanShareConstantPoolEntry - Test whether the given two constants
+/// can be allocated the same constant pool entry.
+static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
+ const TargetData *TD) {
+ // Handle the trivial case quickly.
+ if (A == B) return true;
+
+ // If they have the same type but weren't the same constant, quickly
+ // reject them.
+ if (A->getType() == B->getType()) return false;
+
+ // For now, only support constants with the same size.
+ if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
+ return false;
+
+ // If a floating-point value and an integer value have the same encoding,
+ // they can share a constant-pool entry.
+ if (const ConstantFP *AFP = dyn_cast<ConstantFP>(A))
+ if (const ConstantInt *BI = dyn_cast<ConstantInt>(B))
+ return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
+ if (const ConstantFP *BFP = dyn_cast<ConstantFP>(B))
+ if (const ConstantInt *AI = dyn_cast<ConstantInt>(A))
+ return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
+
+ // Two vectors can share an entry if each pair of corresponding
+ // elements could.
+ if (const ConstantVector *AV = dyn_cast<ConstantVector>(A))
+ if (const ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
+ if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
+ return false;
+ for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
+ if (!CanShareConstantPoolEntry(AV->getOperand(i),
+ BV->getOperand(i), TD))
+ return false;
+ return true;
+ }
+
+ // TODO: Handle other cases.
+
+ return false;