x64: Implement regexp literals and string CharCodeAt in lithium backend.

src/ia32/lithium-codegen-ia32.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 2841 matching lines @@
   __ j(not_equal, deferred->entry());
   // Get the first of the two strings and load its instance type.
   __ mov(string, FieldOperand(string, ConsString::kFirstOffset));
   __ mov(result, FieldOperand(string, HeapObject::kMapOffset));
   __ movzx_b(result, FieldOperand(result, Map::kInstanceTypeOffset));
   // If the first cons component is also non-flat, then go to runtime.
   STATIC_ASSERT(kSeqStringTag == 0);
   __ test(result, Immediate(kStringRepresentationMask));
   __ j(not_zero, deferred->entry());
 
-  // Check for 1-byte or 2-byte string.
+  // Check for ASCII or two-byte string.
   __ bind(&flat_string);
   STATIC_ASSERT(kAsciiStringTag != 0);
   __ test(result, Immediate(kStringEncodingMask));
   __ j(not_zero, &ascii_string);
 
-  // 2-byte string.
-  // Load the 2-byte character code into the result register.
+  // Two-byte string.
+  // Load the two-byte character code into the result register.
   STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize == 1);
   if (instr->index()->IsConstantOperand()) {
     __ movzx_w(result,
                FieldOperand(string,
-                            SeqTwoByteString::kHeaderSize + 2 * const_index));
+                            SeqTwoByteString::kHeaderSize + 
+                            (kUC16Size * const_index)));
   } else {
     __ movzx_w(result, FieldOperand(string,
                                     index,
                                     times_2,
                                     SeqTwoByteString::kHeaderSize));
   }
   __ jmp(&done);
 
   // ASCII string.
   // Load the byte into the result register.
@@ skipping 919 matching lines @@
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32