Add new HSeqStringGetChar instruction.

src/hydrogen-instructions.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 3973 matching lines @@
       if ((right_val == 0) && (left_val < 0)) {
         return H_CONSTANT_DOUBLE(static_cast<uint32_t>(left_val));
       }
       return H_CONSTANT_INT(static_cast<uint32_t>(left_val) >> right_val);
     }
   }
   return new(zone) HShr(context, left, right);
 }
 
 
+HInstruction* HSeqStringGetChar::New(Zone* zone,
+                                     HValue* context,
+                                     String::Encoding encoding,
+                                     HValue* string,
+                                     HValue* index) {
+  if (FLAG_fold_constants && string->IsConstant() && index->IsConstant()) {
+    HConstant* c_string = HConstant::cast(string);
+    HConstant* c_index = HConstant::cast(index);
+    if (c_string->HasStringValue() && c_index->HasInteger32Value()) {
+      Handle<String> s = c_string->StringValue();
+      int32_t i = c_index->Integer32Value();
+      ASSERT_LE(0, i);
+      ASSERT_LT(i, s->length());
+      return H_CONSTANT_INT(s->Get(i));
+    }
+  }
+  return new(zone) HSeqStringGetChar(encoding, string, index);
+}
+
+
 #undef H_CONSTANT_INT
 #undef H_CONSTANT_DOUBLE
 
 
 void HBitwise::PrintDataTo(StringStream* stream) {
   stream->Add(Token::Name(op_));
   stream->Add(" ");
   HBitwiseBinaryOperation::PrintDataTo(stream);
 }
 
@@ skipping 294 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal