Extended Description

I find there is a potential bitmask error with long long type.
In the INTEGER_ASSIGN macro, the program uses (1ull << BitWidth) -1 to get the
bitmask. If BitWidth = 64, the value is 0. The correct way is to use
~(uint64_t)(0ull) >> (BitWidth-1).

Please review the following patch.
Index: lib/ExecutionEngine/Interpreter/Execution.cpp

RCS file: /var/cvs/llvm/llvm/lib/ExecutionEngine/Interpreter/Execution.cpp,v
retrieving revision 1.167
diff -t -d -u -p -5 -r1.167 Execution.cpp
--- lib/ExecutionEngine/Interpreter/Execution.cpp 2 Feb 2007 02:16:22 -0000 1.167
+++ lib/ExecutionEngine/Interpreter/Execution.cpp 7 Feb 2007 23:58:56 -0000
@@ -1305,11 +1305,11 @@ void Interpreter::visitAShr(BinaryOperat
SetValue(&I, Dest, SF);
}

#define INTEGER_ASSIGN(DEST, BITWIDTH, VAL)
{ \

• uint64_t Mask = (1ull << BITWIDTH) - 1; \

• uint64_t Mask = ~(uint64_t)(0ull) >> (64-BITWIDTH);
  if (BITWIDTH == 1) {
  Dest.Int1Val = (bool) (VAL & Mask);
  } else if (BITWIDTH <= 8) {
  Dest.Int8Val = (uint8_t) (VAL & Mask);
  } else if (BITWIDTH <= 16) {
  Index: lib/ExecutionEngine/Interpreter/Interpreter.h
  ===================================================================
  RCS file: /var/cvs/llvm/llvm/lib/ExecutionEngine/Interpreter/Interpreter.h,v
  retrieving revision 1.82
  diff -t -d -u -p -5 -r1.82 Interpreter.h
  --- lib/ExecutionEngine/Interpreter/Interpreter.h 2 Feb 2007 02:16:22 -0000 1.82
  +++ lib/ExecutionEngine/Interpreter/Interpreter.h 7 Feb 2007 23:58:56 -0000
  @@ -234,11 +234,11 @@ private: // Helper functions
  void popStackAndReturnValueToCaller(const Type *RetTy, GenericValue Result);

};

inline void maskToBitWidth(GenericValue& GV, unsigned BitWidth) {

• uint64_t BitMask = (1ull << BitWidth) - 1;

• uint64_t BitMask = ~(uint64_t)(0ull) >> (64-BitWidth);
  if (BitWidth <= 8)
  GV.Int8Val &= BitMask;
  else if (BitWidth <= 16)
  GV.Int16Val &= BitMask;
  else if (BitWidth <= 32)