diff -r 4adb1148ef73 src/arch/mips/registers.hh
--- a/src/arch/mips/registers.hh	Tue Jun 28 18:27:38 2011 -0500
+++ b/src/arch/mips/registers.hh	Thu Jun 30 17:06:45 2011 +0800
@@ -55,7 +55,7 @@
 const int NumFloatRegs = NumFloatArchRegs + NumFloatSpecialRegs;//
 
 const uint32_t MIPS32_QNAN = 0x7fbfffff;
-const uint64_t MIPS64_QNAN = ULL(0x7fbfffffffffffff);
+const uint64_t MIPS64_QNAN = ULL(0x7ff7ffffffffffff);
 
 enum FPControlRegNums {
    FLOATREG_FIR = NumFloatArchRegs,