A64: Port LGapResolver::Verify().

src/a64/lithium-gap-resolver-a64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
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@@ skipping 135 matching lines @@
     BreakCycle(index);
     return;
   }
 
   // This move is no longer blocked.
   EmitMove(index);
 }
 
 
 void LGapResolver::Verify() {
-  TODO_UNIMPLEMENTED("LGapResolver::Verify");
+#ifdef ENABLE_SLOW_ASSERTS
+  // No operand should be the destination for more than one move.
+  for (int i = 0; i < moves_.length(); ++i) {
+    LOperand* destination = moves_[i].destination();
+    for (int j = i + 1; j < moves_.length(); ++j) {
+      SLOW_ASSERT(!destination->Equals(moves_[j].destination()));
+    }
+  }
+#endif
 }
 
 
 void LGapResolver::BreakCycle(int index) {
   ASSERT(moves_[index].destination()->Equals(moves_[root_index_].source()));
   ASSERT(!in_cycle_);
 
   // We use a register which is not allocatable by crankshaft to break the cycle
   // to be sure it doesn't interfere with the moves we are resolving.
   ASSERT(!kSavedValue.IsAllocatable());
@@ skipping 142 matching lines @@
   LOperand* src = moves_[index].source();
   LOperand* dst = moves_[index].destination();
 
   ASSERT(src->IsStackSlot());
   ASSERT(dst->IsStackSlot());
   __ Ldr(temp, cgen_->ToMemOperand(src));
   __ Str(temp, cgen_->ToMemOperand(dst));
 }
 
 } }  // namespace v8::internal