Add Crankshaft support for smi-only elements

src/x64/lithium-codegen-x64.cc

 // Copyright 2011 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 3140 matching lines @@
   }
   DeoptimizeIf(below_equal, instr->environment());
 }
 
 
 void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
   Register value = ToRegister(instr->value());
   Register elements = ToRegister(instr->object());
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
 
+  // This instruction cannot handle the FAST_SMI_ONLY_ELEMENTS -> FAST_ELEMENTS
+  // conversion, so it deopts in that case.
+  if (instr->hydrogen()->ValueNeedsSmiCheck()) {
+    Condition cc = masm()->CheckSmi(value);
+    DeoptimizeIf(NegateCondition(cc), instr->environment());
+  }
+
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
     LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
     int offset =
         ToInteger32(const_operand) * kPointerSize + FixedArray::kHeaderSize;
     __ movq(FieldOperand(elements, offset), value);
   } else {
     __ movq(FieldOperand(elements,
                          key,
@@ skipping 1013 matching lines @@
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64