[turbofan] Improve code generation for unordered comparisons.

test/cctest/compiler/test-branch-combine.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "test/cctest/cctest.h"
 #include "test/cctest/compiler/codegen-tester.h"
 #include "test/cctest/compiler/value-helper.h"
 
@@ skipping 426 matching lines @@
 
       MLabel blocka, blockb;
       Node* cond = cmp.MakeNode(&m, a, b);
       if (invert) cond = m.Word32Equal(cond, m.Int32Constant(0));
       m.Branch(cond, &blocka, &blockb);
       m.Bind(&blocka);
       m.Return(m.Int32Constant(eq_constant));
       m.Bind(&blockb);
       m.Return(m.Int32Constant(ne_constant));
 
-      for (size_t i = 0; i < arraysize(inputs); i++) {
-        for (size_t j = 0; j < arraysize(inputs); j += 2) {
+      for (size_t i = 0; i < arraysize(inputs); ++i) {
+        for (size_t j = 0; j < arraysize(inputs); ++j) {
           input_a = inputs[i];
-          input_b = inputs[i];
+          input_b = inputs[j];
           int32_t expected =
               invert ? (cmp.Float64Compare(input_a, input_b) ? ne_constant
                                                              : eq_constant)
                      : (cmp.Float64Compare(input_a, input_b) ? eq_constant
                                                              : ne_constant);
           CHECK_EQ(expected, m.Call());
         }
       }
     }
   }
 }
 #endif  // V8_TURBOFAN_TARGET