When loading from a constant, fold inttoptr if the integer type and the resulting pointer type both have the same size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124987 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/ConstantFolding.cpp

@@ -340,6 +340,17 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
     return true;
   }
   
+  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+    if (CE->getOpcode() == Instruction::IntToPtr) {
+      uint64_t PtrSize = TD.getTypeAllocSize(C->getType());
+      uint64_t IntSize = TD.getTypeAllocSize(C->getOperand(0)->getType());
+
+      if (PtrSize == IntSize)
+        return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr, 
+                                  BytesLeft, TD);
+    }
+  }
+
   // Otherwise, unknown initializer type.
   return false;
 }