Remove the different length string types...

src/ia32/codegen-ia32.cc

 // Copyright 2006-2009 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 4759 matching lines @@
   __ sar(index.reg(), kSmiTagSize);
 
   __ bind(&try_again_with_new_string);
   // Fetch the instance type of the receiver into ecx.
   __ mov(ecx, FieldOperand(object.reg(), HeapObject::kMapOffset));
   __ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
   // If the receiver is not a string trigger the slow case.
   __ test(ecx, Immediate(kIsNotStringMask));
   __ j(not_zero, &slow_case);
 
-  // Here we make assumptions about the tag values and the shifts needed.
-  // See the comment in objects.h.
-  ASSERT(kLongStringTag == 0);
-  ASSERT(kMediumStringTag + String::kLongLengthShift ==
-         String::kMediumLengthShift);
-  ASSERT(kShortStringTag + String::kLongLengthShift ==
-         String::kShortLengthShift);
-  __ and_(ecx, kStringSizeMask);
-  __ add(Operand(ecx), Immediate(String::kLongLengthShift));
   // Fetch the length field into the temporary register.
   __ mov(temp.reg(), FieldOperand(object.reg(), String::kLengthOffset));
-  __ shr_cl(temp.reg());
   // Check for index out of range.
   __ cmp(index.reg(), Operand(temp.reg()));
   __ j(greater_equal, &slow_case);
   // Reload the instance type (into the temp register this time)..
   __ mov(temp.reg(), FieldOperand(object.reg(), HeapObject::kMapOffset));
   __ movzx_b(temp.reg(), FieldOperand(temp.reg(), Map::kInstanceTypeOffset));
 
   // We need special handling for non-flat strings.
   ASSERT(kSeqStringTag == 0);
   __ test(temp.reg(), Immediate(kStringRepresentationMask));
@@ skipping 1693 matching lines @@
   __ and_(ebx, 1 << Map::kIsUndetectable);
   __ j(not_zero, &false_result);
 
   // JavaScript object => true.
   __ cmp(ecx, FIRST_JS_OBJECT_TYPE);
   __ j(above_equal, &true_result);
 
   // String value => false iff empty.
   __ cmp(ecx, FIRST_NONSTRING_TYPE);
   __ j(above_equal, &not_string);
-  __ and_(ecx, kStringSizeMask);
-  __ cmp(ecx, kShortStringTag);
-  __ j(not_equal, &true_result);  // Empty string is always short.
   __ mov(edx, FieldOperand(eax, String::kLengthOffset));
-  __ shr(edx, String::kShortLengthShift);
+  __ test(edx, Operand(edx));
   __ j(zero, &false_result);
   __ jmp(&true_result);
 
   __ bind(&not_string);
   // HeapNumber => false iff +0, -0, or NaN.
   __ cmp(edx, Factory::heap_number_map());
   __ j(not_equal, &true_result);
   __ fldz();
   __ fld_d(FieldOperand(eax, HeapNumber::kValueOffset));
   __ FCmp();
@@ skipping 1661 matching lines @@
 
 int CompareStub::MinorKey() {
   // Encode the two parameters in a unique 16 bit value.
   ASSERT(static_cast<unsigned>(cc_) < (1 << 15));
   return (static_cast<unsigned>(cc_) << 1) | (strict_ ? 1 : 0);
 }
 
 #undef __
 
 } }  // namespace v8::internal