ARM64: Introduce TempDoubleRegister as a lithium operand constraint.

src/lithium.h

 // Copyright 2012 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_LITHIUM_H_
 #define V8_LITHIUM_H_
 
 #include <set>
 
 #include "allocation.h"
@@ skipping 63 matching lines @@
     FIXED_SLOT,
     EXTENDED_POLICY
   };
 
   enum ExtendedPolicy {
     NONE,
     ANY,
     FIXED_REGISTER,
     FIXED_DOUBLE_REGISTER,
     MUST_HAVE_REGISTER,
+    MUST_HAVE_DOUBLE_REGISTER,
     WRITABLE_REGISTER,
     SAME_AS_FIRST_INPUT
   };
 
   // Lifetime of operand inside the instruction.
   enum Lifetime {
     // USED_AT_START operand is guaranteed to be live only at
     // instruction start. Register allocator is free to assign the same register
     // to some other operand used inside instruction (i.e. temporary or
     // output).
@@ skipping 89 matching lines @@
   bool HasFixedPolicy() const {
     return basic_policy() == FIXED_SLOT ||
         extended_policy() == FIXED_REGISTER ||
         extended_policy() == FIXED_DOUBLE_REGISTER;
   }
   bool HasRegisterPolicy() const {
     return basic_policy() == EXTENDED_POLICY && (
         extended_policy() == WRITABLE_REGISTER ||
         extended_policy() == MUST_HAVE_REGISTER);
   }
+  bool HasDoubleRegisterPolicy() const {
+    return basic_policy() == EXTENDED_POLICY &&
+        extended_policy() == MUST_HAVE_DOUBLE_REGISTER;
+  }
   bool HasSameAsInputPolicy() const {
     return basic_policy() == EXTENDED_POLICY &&
         extended_policy() == SAME_AS_FIRST_INPUT;
   }
   bool HasFixedSlotPolicy() const {
     return basic_policy() == FIXED_SLOT;
   }
   bool HasFixedRegisterPolicy() const {
     return basic_policy() == EXTENDED_POLICY &&
         extended_policy() == FIXED_REGISTER;
@@ skipping 527 matching lines @@
  private:
   LChunk* chunk_;
 
   DISALLOW_COPY_AND_ASSIGN(LPhase);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LITHIUM_H_