1 files changed, 48 insertions, 0 deletions
diff --git a/lib/VMCore/LLVMContextImpl.cpp b/lib/VMCore/LLVMContextImpl.cpp
new file mode 100644
index 0000000000..a92c19fe04
--- /dev/null
+++ b/lib/VMCore/LLVMContextImpl.cpp
@@ -0,0 +1,48 @@
+//===--------------- LLVMContextImpl.cpp - Implementation ------*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements LLVMContextImpl, the opaque implementation 
+//  of LLVMContext.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LLVMContextImpl.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/LLVMContext.h"
+using namespace llvm;
+
+// Get a ConstantInt from an APInt. Note that the value stored in the DenseMap 
+// as the key, is a DenseMapAPIntKeyInfo::KeyTy which has provided the
+// 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 *LLVMContextImpl::getConstantInt(const APInt& V) {
+  // Get the corresponding integer type for the bit width of the value.
+  const IntegerType *ITy = Context.getIntegerType(V.getBitWidth());
+  // get an existing value or the insertion position
+  DenseMapAPIntKeyInfo::KeyTy Key(V, ITy);
+  
+  ConstantsLock.reader_acquire();
+  ConstantInt *&Slot = IntConstants[Key]; 
+  ConstantsLock.reader_release();
+    
+  if (!Slot) {
+    sys::SmartScopedWriter<true> Writer(ConstantsLock);
+    ConstantInt *&NewSlot = IntConstants[Key]; 
+    if (!Slot) {
+      NewSlot = new ConstantInt(ITy, V);
+    }
+    
+    return NewSlot;
+  } else {
+    return Slot;
+  }
+}
+