Revert of [regexp] Remove remainder of native RegExpExecStub

src/regexp/arm64/regexp-macro-assembler-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/regexp/arm64/regexp-macro-assembler-arm64.h"
 
 #include "src/arm64/macro-assembler-arm64-inl.h"
 #include "src/code-stubs.h"
@@ skipping 38 matching lines @@
  *
  * The remaining registers are free for computations.
  * Each call to a public method should retain this convention.
  *
  * The stack will have the following structure:
  *
  *  Location    Name               Description
  *              (as referred to in
  *              the code)
  *
- *  - fp[96]   isolate            Address of the current isolate.
+ *  - fp[104]   isolate            Address of the current isolate.
+ *  - fp[96]    return_address     Secondary link/return address
+ *                                 used by an exit frame if this is a
+ *                                 native call.
  *  ^^^ csp when called ^^^
  *  - fp[88]    lr                 Return from the RegExp code.
  *  - fp[80]    r29                Old frame pointer (CalleeSaved).
  *  - fp[0..72] r19-r28            Backup of CalleeSaved registers.
  *  - fp[-8]    direct_call        1 => Direct call from JavaScript code.
  *                                 0 => Call through the runtime system.
  *  - fp[-16]   stack_base         High end of the memory area to use as
  *                                 the backtracking stack.
  *  - fp[-24]   output_size        Output may fit multiple sets of matches.
  *  - fp[-32]   input              Handle containing the input string.
  *  - fp[-40]   success_counter
  *  ^^^^^^^^^^^^^ From here and downwards we store 32 bit values ^^^^^^^^^^^^^
  *  - fp[-44]   register N         Capture registers initialized with
  *  - fp[-48]   register N + 1     non_position_value.
  *              ...                The first kNumCachedRegisters (N) registers
  *              ...                are cached in x0 to x7.
  *              ...                Only positions must be stored in the first
  *  -           ...                num_saved_registers_ registers.
  *  -           ...
  *  -           register N + num_registers - 1
  *  ^^^^^^^^^ csp ^^^^^^^^^
  *
  * The first num_saved_registers_ registers are initialized to point to
  * "character -1" in the string (i.e., char_size() bytes before the first
  * character of the string). The remaining registers start out as garbage.
  *
  * The data up to the return address must be placed there by the calling
  * code and the remaining arguments are passed in registers, e.g. by calling the
  * code entry as cast to a function with the signature:
- * int (*match)(String* input_string,
- *              int start_index,
- *              Address start,
- *              Address end,
- *              int* capture_output_array,
- *              int num_capture_registers,
- *              byte* stack_area_base,
+ * int (*match)(String* input,
+ *              int start_offset,
+ *              Address input_start,
+ *              Address input_end,
+ *              int* output,
+ *              int output_size,
+ *              Address stack_base,
  *              bool direct_call = false,
- *              Isolate* isolate);
+ *              Address secondary_return_address,  // Only used by native call.
+ *              Isolate* isolate)
  * The call is performed by NativeRegExpMacroAssembler::Execute()
  * (in regexp-macro-assembler.cc) via the CALL_GENERATED_REGEXP_CODE macro
  * in arm64/simulator-arm64.h.
+ * When calling as a non-direct call (i.e., from C++ code), the return address
+ * area is overwritten with the LR register by the RegExp code. When doing a
+ * direct call from generated code, the return address is placed there by
+ * the calling code, as in a normal exit frame.
  */
 
 #define __ ACCESS_MASM(masm_)
 
 RegExpMacroAssemblerARM64::RegExpMacroAssemblerARM64(Isolate* isolate,
                                                      Zone* zone, Mode mode,
                                                      int registers_to_save)
     : NativeRegExpMacroAssembler(isolate, zone),
       masm_(new MacroAssembler(isolate, NULL, kRegExpCodeSize,
                                CodeObjectRequired::kYes)),
@@ skipping 1538 matching lines @@
     }
   }
 }
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64