[turbofan] Improve code generation for unordered comparisons.

src/compiler/instruction-selector-impl.h

 // 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.
 
 #ifndef V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 
 #include "src/compiler/instruction.h"
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/linkage.h"
@@ skipping 285 matching lines @@
         return;
       case kUnsignedLessThanOrEqual:
         condition_ = kUnsignedGreaterThanOrEqual;
         return;
       case kUnsignedGreaterThan:
         condition_ = kUnsignedLessThan;
         return;
       case kUnorderedEqual:
       case kUnorderedNotEqual:
         return;
-      case kUnorderedLessThan:
-        condition_ = kUnorderedGreaterThan;
-        return;
-      case kUnorderedGreaterThanOrEqual:
-        condition_ = kUnorderedLessThanOrEqual;
-        return;
-      case kUnorderedLessThanOrEqual:
-        condition_ = kUnorderedGreaterThanOrEqual;
-        return;
-      case kUnorderedGreaterThan:
-        condition_ = kUnorderedLessThan;
-        return;
     }
     UNREACHABLE();
   }
 
   void OverwriteAndNegateIfEqual(FlagsCondition condition) {
     bool negate = condition_ == kEqual;
     condition_ = condition;
     if (negate) Negate();
   }
 
@@ skipping 39 matching lines @@
                : (frame_state_descriptor->GetTotalSize() +
                   1);  // Include deopt id.
   }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_