Optimize array-length and fast element loads....

src/arm/lithium-codegen-arm.cc

 // Copyright 2010 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 880 matching lines @@
   Abort("DoConstantD unimplemented.");
 }
 
 
 void LCodeGen::DoConstantT(LConstantT* instr) {
   ASSERT(instr->result()->IsRegister());
   __ mov(ToRegister(instr->result()), Operand(instr->value()));
 }
 
 
-void LCodeGen::DoArrayLength(LArrayLength* instr) {
+void LCodeGen::DoJSArrayLength(LJSArrayLength* instr) {
   Register result = ToRegister(instr->result());
-
-  if (instr->hydrogen()->value()->IsLoadElements()) {
-    // We load the length directly from the elements array.
-    Register elements = ToRegister(instr->input());
-    __ ldr(result, FieldMemOperand(elements, FixedArray::kLengthOffset));
-  } else {
-    // Check that the receiver really is an array.
-    Register array = ToRegister(instr->input());
-    Register temporary = ToRegister(instr->temporary());
-    __ CompareObjectType(array, temporary, temporary, JS_ARRAY_TYPE);
-    DeoptimizeIf(ne, instr->environment());
-
-    // Load length directly from the array.
-    __ ldr(result, FieldMemOperand(array, JSArray::kLengthOffset));
-  }
-  Abort("DoArrayLength untested.");
+  Register array = ToRegister(instr->input());
+  __ ldr(result, FieldMemOperand(array, JSArray::kLengthOffset));
+  Abort("DoJSArrayLength untested.");
 }
 
 
+void LCodeGen::DoFixedArrayLength(LFixedArrayLength* instr) {
+  Register result = ToRegister(instr->result());
+  Register array = ToRegister(instr->input());
+  __ ldr(result, FieldMemOperand(array, FixedArray::kLengthOffset));
+  Abort("DoFixedArrayLength untested.");
+}
+
+
 void LCodeGen::DoValueOf(LValueOf* instr) {
   Abort("DoValueOf unimplemented.");
 }
 
 
 void LCodeGen::DoBitNotI(LBitNotI* instr) {
   LOperand* input = instr->input();
   ASSERT(input->Equals(instr->result()));
   __ mvn(ToRegister(input), Operand(ToRegister(input)));
   Abort("DoBitNotI untested.");
@@ skipping 1277 matching lines @@
 
 
 void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
   Abort("DoOsrEntry unimplemented.");
 }
 
 
 #undef __
 
 } }  // namespace v8::internal