MIPS: Fixed faulty branch condition handling for doubles.

This commit also includes BranchF refactoring in macro-assembler.

TEST=mozilla/ecma/TypeConversion/9.2.js

BUG=

Review URL: https://codereview.chromium.org/12505004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13849 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/constants-mips.h

@@ -429,7 +429,9 @@ enum SecondaryField {
 
 // ----- 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,
@@ -450,8 +452,10 @@ enum Condition {
   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,

src/mips/lithium-codegen-mips.cc

@@ -1826,7 +1826,7 @@ void LCodeGen::DoBranch(LBranch* instr) {
     CpuFeatureScope scope(masm(), FPU);
     DoubleRegister reg = ToDoubleRegister(instr->value());
     // Test the double value. Zero and NaN are false.
-    EmitBranchF(true_block, false_block, ne, reg, kDoubleRegZero);
+    EmitBranchF(true_block, false_block, nue, reg, kDoubleRegZero);
   } else {
     ASSERT(r.IsTagged());
     Register reg = ToRegister(instr->value());

src/mips/macro-assembler-mips.cc

@@ -1125,23 +1125,19 @@ void MacroAssembler::BranchF(Label* target,
     // have been handled by the caller.
     // Unsigned conditions are treated as their signed counterpart.
     switch (cc) {
-      case Uless:
-      case less:
+      case lt:
         c(OLT, D, cmp1, cmp2);
         bc1t(target);
         break;
-      case Ugreater:
-      case greater:
+      case gt:
         c(ULE, D, cmp1, cmp2);
         bc1f(target);
         break;
-      case Ugreater_equal:
-      case greater_equal:
+      case ge:
         c(ULT, D, cmp1, cmp2);
         bc1f(target);
         break;
-      case Uless_equal:
-      case less_equal:
+      case le:
         c(OLE, D, cmp1, cmp2);
         bc1t(target);
         break;
@@ -1149,10 +1145,18 @@ void MacroAssembler::BranchF(Label* target,
         c(EQ, D, cmp1, cmp2);
         bc1t(target);
         break;
+      case ueq:
+        c(UEQ, D, cmp1, cmp2);
+        bc1t(target);
+        break;
       case ne:
         c(EQ, D, cmp1, cmp2);
         bc1f(target);
         break;
+      case nue:
+        c(UEQ, D, cmp1, cmp2);
+        bc1f(target);
+        break;
       default:
         CHECK(0);
     };