MIPS: Fixed faulty branch condition handling for doubles.

src/mips/constants-mips.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 411 matching lines @@
   // COP1 Encoding of Function Field When rs=PS.
   // COP1X Encoding of Function Field.
   MADD_D    =   ((4 << 3) + 1),
 
   NULLSF    =   0
 };
 
 
 // ----- Emulated conditions.
 // On MIPS we use this enum to abstract from conditionnal branch instructions.
-// the 'U' prefix is used to specify unsigned comparisons.
+// The 'U' prefix is used to specify unsigned comparisons.
+// Oppposite conditions must be paired as odd/even numbers
+// because 'NegateCondition' function flips LSB to negate condition.
 enum Condition {
   // Any value < 0 is considered no_condition.
   kNoCondition  = -1,
 
   overflow      =  0,
   no_overflow   =  1,
   Uless         =  2,
   Ugreater_equal=  3,
   equal         =  4,
   not_equal     =  5,
   Uless_equal   =  6,
   Ugreater      =  7,
   negative      =  8,
   positive      =  9,
   parity_even   = 10,
   parity_odd    = 11,
   less          = 12,
   greater_equal = 13,
   less_equal    = 14,
   greater       = 15,
+  ueq           = 16,  // Unordered or Equal.
+  nue           = 17,  // Not (Unordered or Equal).
 
-  cc_always     = 16,
+  cc_always     = 18,
 
   // Aliases.
   carry         = Uless,
   not_carry     = Ugreater_equal,
   zero          = equal,
   eq            = equal,
   not_zero      = not_equal,
   ne            = not_equal,
   nz            = not_equal,
   sign          = negative,
@@ skipping 329 matching lines @@
 // JS argument slots size.
 const int kJSArgsSlotsSize = 0 * Instruction::kInstrSize;
 // Assembly builtins argument slots size.
 const int kBArgsSlotsSize = 0 * Instruction::kInstrSize;
 
 const int kBranchReturnOffset = 2 * Instruction::kInstrSize;
 
 } }   // namespace v8::internal
 
 #endif    // #ifndef V8_MIPS_CONSTANTS_H_