Combine %_SubString and %_StringCharAt.

src/code-stubs.h

 // 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 1042 matching lines @@
   // Generates the fast case code. On the fallthrough path |result|
   // register contains the result.
   void GenerateFast(MacroAssembler* masm);
 
   // Generates the slow case code. Must not be naturally
   // reachable. Expected to be put after a ret instruction (e.g., in
   // deferred code). Always jumps back to the fast case.
   void GenerateSlow(MacroAssembler* masm,
                     const RuntimeCallHelper& call_helper);
 
+  // Skip handling slow case and directly jump to bailout.
+  void SkipSlow(MacroAssembler* masm, Label* bailout) {
+    masm->bind(&index_not_smi_);
+    masm->bind(&call_runtime_);
+    masm->jmp(bailout);
+  }
+
  private:
   Register object_;
   Register index_;
   Register result_;
 
   Label* receiver_not_string_;
   Label* index_not_number_;
   Label* index_out_of_range_;
 
   StringIndexFlags index_flags_;
@@ skipping 20 matching lines @@
   // Generates the fast case code. On the fallthrough path |result|
   // register contains the result.
   void GenerateFast(MacroAssembler* masm);
 
   // Generates the slow case code. Must not be naturally
   // reachable. Expected to be put after a ret instruction (e.g., in
   // deferred code). Always jumps back to the fast case.
   void GenerateSlow(MacroAssembler* masm,
                     const RuntimeCallHelper& call_helper);
 
+  // Skip handling slow case and directly jump to bailout.
+  void SkipSlow(MacroAssembler* masm, Label* bailout) {
+    masm->bind(&slow_case_);
+    masm->jmp(bailout);
+  }
+
  private:
   Register code_;
   Register result_;
 
   Label slow_case_;
   Label exit_;
 
   DISALLOW_COPY_AND_ASSIGN(StringCharFromCodeGenerator);
 };
 
@@ skipping 22 matching lines @@
                                 index,
                                 scratch,
                                 receiver_not_string,
                                 index_not_number,
                                 index_out_of_range,
                                 index_flags),
         char_from_code_generator_(scratch, result) {}
 
   // Generates the fast case code. On the fallthrough path |result|
   // register contains the result.
-  void GenerateFast(MacroAssembler* masm);
+  void GenerateFast(MacroAssembler* masm) {
+    char_code_at_generator_.GenerateFast(masm);
+    char_from_code_generator_.GenerateFast(masm);
+  }
 
   // Generates the slow case code. Must not be naturally
   // reachable. Expected to be put after a ret instruction (e.g., in
   // deferred code). Always jumps back to the fast case.
   void GenerateSlow(MacroAssembler* masm,
-                    const RuntimeCallHelper& call_helper);
+                    const RuntimeCallHelper& call_helper) {
+    char_code_at_generator_.GenerateSlow(masm, call_helper);
+    char_from_code_generator_.GenerateSlow(masm, call_helper);
+  }
+
+  // Skip handling slow case and directly jump to bailout.
+  void SkipSlow(MacroAssembler* masm, Label* bailout) {
+    char_code_at_generator_.SkipSlow(masm, bailout);
+    char_from_code_generator_.SkipSlow(masm, bailout);
+  }
 
  private:
   StringCharCodeAtGenerator char_code_at_generator_;
   StringCharFromCodeGenerator char_from_code_generator_;
 
   DISALLOW_COPY_AND_ASSIGN(StringCharAtGenerator);
 };
 
 
 class AllowStubCallsScope {
@@ skipping 311 matching lines @@
 
   // The current function entry hook.
   static FunctionEntryHook entry_hook_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_