Add a helper class (APSInt) which can represent an APInt along with sign

information.  This is useful when a value does have a sign associated with
it.  This shouldn't be used generally in LLVM for mid-level optimizer stuff.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35681 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/APSInt.h

@@ -0,0 +1,101 @@
+//===-- llvm/Support/APSInt.h - Arbitrary Precision Signed Int -*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the APSInt class, which is a simple class that
+// represents an arbitrary sized integer that knows its signedness.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_APSINT_H
+#define LLVM_APSINT_H
+
+#include "llvm/ADT/APInt.h"
+
+namespace llvm {
+  
+  
+class APSInt : public APInt {
+  bool IsUnsigned;
+public:
+  /// APSInt ctor - Create an APSInt with the specified width, default to
+  /// unsigned.
+  explicit APSInt(unsigned BitWidth) : APInt(BitWidth, 0), IsUnsigned(true) {}
+  APSInt(const APInt &I) : APInt(I), IsUnsigned(true) {}
+
+  APSInt &operator=(const APSInt &RHS) {
+    APInt::operator=(RHS); 
+    IsUnsigned = RHS.IsUnsigned;
+    return *this;
+  }
+
+  APSInt &operator=(const APInt &RHS) {
+    // Retain our current sign.
+    APInt::operator=(RHS); 
+    return *this;
+  }
+
+  APSInt &operator=(uint64_t RHS) {
+    // Retain our current sign.
+    APInt::operator=(RHS); 
+    return *this;
+  }
+
+  // Query sign information.
+  bool isSigned() const { return !IsUnsigned; }
+  bool isUnsigned() const { return IsUnsigned; }
+  void setIsUnsigned(bool Val) { IsUnsigned = Val; }
+  
+  
+  const APSInt &operator%=(const APSInt &RHS) {
+    assert(IsUnsigned == RHS.IsUnsigned && "Signedness mismatch!");
+    if (IsUnsigned)
+      *this = urem(RHS);
+    else
+      *this = srem(RHS);
+    return *this;
+  }
+  const APSInt &operator/=(const APSInt &RHS) {
+    assert(IsUnsigned == RHS.IsUnsigned && "Signedness mismatch!");
+    if (IsUnsigned)
+      *this = udiv(RHS);
+    else
+      *this = sdiv(RHS);
+    return *this;
+  }
+  
+  const APSInt &operator>>=(unsigned Amt) {
+    *this = *this >> Amt;
+    return *this;
+  }
+  
+  APSInt operator>>(unsigned Amt) {
+    return IsUnsigned ? lshr(Amt) : ashr(Amt);
+  }
+  
+  inline bool operator<(const APSInt& RHS) const {
+    assert(IsUnsigned == RHS.IsUnsigned && "Signedness mismatch!");
+    return IsUnsigned ? ult(RHS) : slt(RHS);
+  }
+  inline bool operator>(const APSInt& RHS) const {
+    assert(IsUnsigned == RHS.IsUnsigned && "Signedness mismatch!");
+    return IsUnsigned ? ugt(RHS) : sgt(RHS);
+  }
+  inline bool operator<=(const APSInt& RHS) const {
+    assert(IsUnsigned == RHS.IsUnsigned && "Signedness mismatch!");
+    return IsUnsigned ? ule(RHS) : sle(RHS);
+  }
+  inline bool operator>=(const APSInt& RHS) const {
+    assert(IsUnsigned == RHS.IsUnsigned && "Signedness mismatch!");
+    return IsUnsigned ? uge(RHS) : sge(RHS);
+  }
+};
+  
+} // end namespace llvm
+
+#endif