Push safepoint registers in deferred number-to-i/u only on-demand.

src/arm/lithium-arm.cc

 // Copyright 2012 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 1825 matching lines @@
       LOperand* value = UseRegister(instr->value());
       LDoubleToI* res = new(zone()) LDoubleToI(value);
       return AssignEnvironment(DefineAsRegister(res));
     }
   } else if (from.IsInteger32()) {
     info()->MarkAsDeferredCalling();
     if (to.IsTagged()) {
       HValue* val = instr->value();
       LOperand* value = UseRegisterAtStart(val);
       if (val->CheckFlag(HInstruction::kUint32)) {
-        LNumberTagU* result = new(zone()) LNumberTagU(value);
+        LOperand* temp1 = TempRegister();
+        LOperand* temp2 = TempRegister();
+        LNumberTagU* result = new(zone()) LNumberTagU(value, temp1, temp2);
         return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
       } else if (val->HasRange() && val->range()->IsInSmiRange()) {
         return DefineAsRegister(new(zone()) LSmiTag(value));
       } else {
-        LNumberTagI* result = new(zone()) LNumberTagI(value);
+        LOperand* temp1 = TempRegister();
+        LOperand* temp2 = TempRegister();
+        LNumberTagI* result = new(zone()) LNumberTagI(value, temp1, temp2);
         return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
       }
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
       LInstruction* result = val->CheckFlag(HInstruction::kUint32)
           ? DefineAsRegister(new(zone()) LUint32ToSmi(value))
           : DefineAsRegister(new(zone()) LInteger32ToSmi(value));
       if (val->HasRange() && val->range()->IsInSmiRange()) {
         return result;
@@ skipping 614 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseRegister(instr->index());
   return DefineAsRegister(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 } }  // namespace v8::internal