[arm64] Optimize fcmp when lhs operand is #0.0

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 273 matching lines @@
     return false_block_;
   }
 
   void Negate() {
     DCHECK(!IsNone());
     condition_ = NegateFlagsCondition(condition_);
   }
 
   void Commute() {
     DCHECK(!IsNone());
-    switch (condition_) {
-      case kEqual:
-      case kNotEqual:
-      case kOverflow:
-      case kNotOverflow:
-        return;
-      case kSignedLessThan:
-        condition_ = kSignedGreaterThan;
-        return;
-      case kSignedGreaterThanOrEqual:
-        condition_ = kSignedLessThanOrEqual;
-        return;
-      case kSignedLessThanOrEqual:
-        condition_ = kSignedGreaterThanOrEqual;
-        return;
-      case kSignedGreaterThan:
-        condition_ = kSignedLessThan;
-        return;
-      case kUnsignedLessThan:
-        condition_ = kUnsignedGreaterThan;
-        return;
-      case kUnsignedGreaterThanOrEqual:
-        condition_ = kUnsignedLessThanOrEqual;
-        return;
-      case kUnsignedLessThanOrEqual:
-        condition_ = kUnsignedGreaterThanOrEqual;
-        return;
-      case kUnsignedGreaterThan:
-        condition_ = kUnsignedLessThan;
-        return;
-      case kUnorderedEqual:
-      case kUnorderedNotEqual:
-        return;
-    }
-    UNREACHABLE();
+    condition_ = CommuteFlagsCondition(condition_);
   }
 
   void OverwriteAndNegateIfEqual(FlagsCondition condition) {
     bool negate = condition_ == kEqual;
     condition_ = condition;
     if (negate) Negate();
   }
 
   // Encodes this flags continuation into the given opcode.
   InstructionCode Encode(InstructionCode opcode) {
@@ skipping 37 matching lines @@
                : (frame_state_descriptor->GetTotalSize() +
                   1);  // Include deopt id.
   }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_