A64: Improve constraints on StoreKeyed instructions

src/a64/lithium-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
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2151 matching lines @@
   } else {
     return new(zone()) LStoreGlobalCell(value, TempRegister(), NULL);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
   LOperand* temp = NULL;
   LOperand* elements = NULL;
   LOperand* val = NULL;
-  LOperand* key = NULL;
+  LOperand* key = UseRegisterOrConstantAtStart(instr->key());
 
   if (!instr->is_typed_elements() &&
       instr->value()->representation().IsTagged() &&
       instr->NeedsWriteBarrier()) {
     // RecordWrite() will clobber all registers.
     elements = UseRegisterAndClobber(instr->elements());
     val = UseRegisterAndClobber(instr->value());
-    key = UseRegisterAndClobber(instr->key());
+    temp = TempRegister();
   } else {
     elements = UseRegister(instr->elements());
     val = UseRegister(instr->value());
-    key = UseRegisterOrConstantAtStart(instr->key());
+    temp = instr->key()->IsConstant() ? NULL : TempRegister();
   }
 
   if (instr->is_typed_elements()) {
     ASSERT((instr->value()->representation().IsInteger32() &&
             !IsDoubleOrFloatElementsKind(instr->elements_kind())) ||
            (instr->value()->representation().IsDouble() &&
             IsDoubleOrFloatElementsKind(instr->elements_kind())));
     ASSERT((instr->is_fixed_typed_array() &&
             instr->elements()->representation().IsTagged()) ||
            (instr->is_external() &&
             instr->elements()->representation().IsExternal()));
-    temp = instr->key()->IsConstant() ? NULL : TempRegister();
     return new(zone()) LStoreKeyedExternal(elements, key, val, temp);
 
   } else if (instr->value()->representation().IsDouble()) {
     ASSERT(instr->elements()->representation().IsTagged());
-
-    // The constraint used here is UseRegister, even though the StoreKeyed
-    // instruction may canonicalize the value in the register if it is a NaN.
-    temp = TempRegister();
     return new(zone()) LStoreKeyedFixedDouble(elements, key, val, temp);
 
   } else {
     ASSERT(instr->elements()->representation().IsTagged());
     ASSERT(instr->value()->representation().IsSmiOrTagged() ||
            instr->value()->representation().IsInteger32());
-
-    temp = TempRegister();
     return new(zone()) LStoreKeyedFixed(elements, key, val, temp);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoStoreKeyedGeneric(HStoreKeyedGeneric* instr) {
   LOperand* context = UseFixed(instr->context(), cp);
   LOperand* object = UseFixed(instr->object(), x2);
   LOperand* key = UseFixed(instr->key(), x1);
   LOperand* value = UseFixed(instr->value(), x0);
@@ skipping 329 matching lines @@
 
 LInstruction* LChunkBuilder::DoWrapReceiver(HWrapReceiver* instr) {
   LOperand* receiver = UseRegister(instr->receiver());
   LOperand* function = UseRegister(instr->function());
   LWrapReceiver* result = new(zone()) LWrapReceiver(receiver, function);
   return AssignEnvironment(DefineAsRegister(result));
 }
 
 
 } }  // namespace v8::internal