Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.

  * Copyright 2012, 2013 SAP AG. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "asm/assembler.hpp"

 #include "asm/macroAssembler.inline.hpp"

 #include "interpreter/interpreter.hpp"

 #include "nativeInst_ppc.hpp"

 #include "oops/instanceOop.hpp"

 #include "oops/method.hpp"

 #include "oops/objArrayKlass.hpp"

 #include "oops/oop.inline.hpp"

 #include "prims/methodHandles.hpp"

 #include "runtime/frame.inline.hpp"

 #include "runtime/handles.inline.hpp"

 #include "runtime/sharedRuntime.hpp"

 #include "runtime/stubCodeGenerator.hpp"

 #include "runtime/stubRoutines.hpp"

 #include "utilities/top.hpp"

 #ifdef TARGET_OS_FAMILY_aix

 # include "thread_aix.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_linux

 # include "thread_linux.inline.hpp"

 #endif

 #ifdef COMPILER2

 #include "opto/runtime.hpp"

 #endif

 #define __ _masm->

 #ifdef PRODUCT

 #define BLOCK_COMMENT(str) // nothing

 #else

 #define BLOCK_COMMENT(str) __ block_comment(str)

 #endif

 class StubGenerator: public StubCodeGenerator {

  private:

   // Call stubs are used to call Java from C

   //

   // Arguments:

   //

   //   R3  - call wrapper address     : address

   //   R4  - result                   : intptr_t*

   //   R5  - result type              : BasicType

   //   R6  - method                   : Method

   //   R7  - frame mgr entry point    : address

   //   R8  - parameter block          : intptr_t*

   //   R9  - parameter count in words : int

   //   R10 - thread                   : Thread*

   //

   address generate_call_stub(address& return_address) {

     // Setup a new c frame, copy java arguments, call frame manager or

     // native_entry, and process result.

     StubCodeMark mark(this, "StubRoutines", "call_stub");

     address start = __ function_entry();

     // some sanity checks

     assert((sizeof(frame::abi_minframe) % 16) == 0,           "unaligned");

     assert((sizeof(frame::abi_reg_args) % 16) == 0,           "unaligned");

     assert((sizeof(frame::spill_nonvolatiles) % 16) == 0,     "unaligned");

     assert((sizeof(frame::parent_ijava_frame_abi) % 16) == 0, "unaligned");

     assert((sizeof(frame::entry_frame_locals) % 16) == 0,     "unaligned");

     Register r_arg_call_wrapper_addr        = R3;

     Register r_arg_result_addr              = R4;

     Register r_arg_result_type              = R5;

     Register r_arg_method                   = R6;

     Register r_arg_entry                    = R7;

     Register r_arg_thread                   = R10;

     Register r_temp                         = R24;

     Register r_top_of_arguments_addr        = R25;

     Register r_entryframe_fp                = R26;

     {

       // Stack on entry to call_stub:

       //

       //      F1      [C_FRAME]

       //              ...

       Register r_arg_argument_addr          = R8;

       Register r_arg_argument_count         = R9;

       Register r_frame_alignment_in_bytes   = R27;

       Register r_argument_addr              = R28;

       Register r_argumentcopy_addr          = R29;

       Register r_argument_size_in_bytes     = R30;

       Register r_frame_size                 = R23;

       Label arguments_copied;

       // Save LR/CR to caller's C_FRAME.

       __ save_LR_CR(R0);

       // Zero extend arg_argument_count.

       __ clrldi(r_arg_argument_count, r_arg_argument_count, 32);

       // Save non-volatiles GPRs to ENTRY_FRAME (not yet pushed, but it's safe).

       __ save_nonvolatile_gprs(R1_SP, _spill_nonvolatiles_neg(r14));

       // Keep copy of our frame pointer (caller's SP).

       __ mr(r_entryframe_fp, R1_SP);

       BLOCK_COMMENT("Push ENTRY_FRAME including arguments");

       // Push ENTRY_FRAME including arguments:

       //

       //      F0      [TOP_IJAVA_FRAME_ABI]

       //              alignment (optional)

       //              [outgoing Java arguments]

       //              [ENTRY_FRAME_LOCALS]

       //      F1      [C_FRAME]

       //              ...

       // calculate frame size

       // unaligned size of arguments

       __ sldi(r_argument_size_in_bytes,

                   r_arg_argument_count, Interpreter::logStackElementSize);

       // arguments alignment (max 1 slot)

       // FIXME: use round_to() here

       __ andi_(r_frame_alignment_in_bytes, r_arg_argument_count, 1);

       __ sldi(r_frame_alignment_in_bytes,

               r_frame_alignment_in_bytes, Interpreter::logStackElementSize);

       // size = unaligned size of arguments + top abi's size

       __ addi(r_frame_size, r_argument_size_in_bytes,

               frame::top_ijava_frame_abi_size);

       // size += arguments alignment

       __ add(r_frame_size,

              r_frame_size, r_frame_alignment_in_bytes);

       // size += size of call_stub locals

       __ addi(r_frame_size,

               r_frame_size, frame::entry_frame_locals_size);

       // push ENTRY_FRAME

       __ push_frame(r_frame_size, r_temp);

       // initialize call_stub locals (step 1)

       __ std(r_arg_call_wrapper_addr,

              _entry_frame_locals_neg(call_wrapper_address), r_entryframe_fp);

       __ std(r_arg_result_addr,

              _entry_frame_locals_neg(result_address), r_entryframe_fp);

       __ std(r_arg_result_type,

              _entry_frame_locals_neg(result_type), r_entryframe_fp);

       // we will save arguments_tos_address later

       BLOCK_COMMENT("Copy Java arguments");

       // copy Java arguments

       // Calculate top_of_arguments_addr which will be R17_tos (not prepushed) later.

       // FIXME: why not simply use SP+frame::top_ijava_frame_size?

       __ addi(r_top_of_arguments_addr,

               R1_SP, frame::top_ijava_frame_abi_size);

       __ add(r_top_of_arguments_addr,

              r_top_of_arguments_addr, r_frame_alignment_in_bytes);

       // any arguments to copy?

       __ cmpdi(CCR0, r_arg_argument_count, 0);

       __ beq(CCR0, arguments_copied);

       // prepare loop and copy arguments in reverse order

       {

         // init CTR with arg_argument_count

         __ mtctr(r_arg_argument_count);

         // let r_argumentcopy_addr point to last outgoing Java arguments P

         __ mr(r_argumentcopy_addr, r_top_of_arguments_addr);

         // let r_argument_addr point to last incoming java argument

         __ add(r_argument_addr,

                    r_arg_argument_addr, r_argument_size_in_bytes);

         __ addi(r_argument_addr, r_argument_addr, -BytesPerWord);

         // now loop while CTR > 0 and copy arguments

         {

           Label next_argument;

           __ bind(next_argument);

           __ ld(r_temp, 0, r_argument_addr);

           // argument_addr--;

           __ addi(r_argument_addr, r_argument_addr, -BytesPerWord);

           __ std(r_temp, 0, r_argumentcopy_addr);

           // argumentcopy_addr++;

           __ addi(r_argumentcopy_addr, r_argumentcopy_addr, BytesPerWord);

           __ bdnz(next_argument);

         }

       }

       // Arguments copied, continue.

       __ bind(arguments_copied);

     }

     {

       BLOCK_COMMENT("Call frame manager or native entry.");

       // Call frame manager or native entry.

       Register r_new_arg_entry = R14_state;

       assert_different_registers(r_new_arg_entry, r_top_of_arguments_addr,

                                  r_arg_method, r_arg_thread);

       __ mr(r_new_arg_entry, r_arg_entry);

       // Register state on entry to frame manager / native entry:

       //

       //   tos         -  intptr_t*    sender tos (prepushed) Lesp = (SP) + copied_arguments_offset - 8

       //   R19_method  -  Method

       //   R16_thread  -  JavaThread*

       // Tos must point to last argument - element_size.

       const Register tos = R17_tos;

       __ addi(tos, r_top_of_arguments_addr, -Interpreter::stackElementSize);

       // initialize call_stub locals (step 2)

       // now save tos as arguments_tos_address

       __ std(tos, _entry_frame_locals_neg(arguments_tos_address), r_entryframe_fp);

       // load argument registers for call

       __ mr(R19_method, r_arg_method);

       __ mr(R16_thread, r_arg_thread);

       assert(tos != r_arg_method, "trashed r_arg_method");

       assert(tos != r_arg_thread && R19_method != r_arg_thread, "trashed r_arg_thread");

       // Set R15_prev_state to 0 for simplifying checks in callee.

       __ li(R15_prev_state, 0);

       // Stack on entry to frame manager / native entry:

       //

       //      F0      [TOP_IJAVA_FRAME_ABI]

       //              alignment (optional)

       //              [outgoing Java arguments]

       //              [ENTRY_FRAME_LOCALS]

       //      F1      [C_FRAME]

       //              ...

       //

       // global toc register

       __ load_const(R29, MacroAssembler::global_toc(), R11_scratch1);

       // Load narrow oop base.

       __ reinit_heapbase(R30, R11_scratch1);

       // Remember the senderSP so we interpreter can pop c2i arguments off of the stack

       // when called via a c2i.

       // Pass initial_caller_sp to framemanager.

       __ mr(R21_tmp1, R1_SP);

       // Do a light-weight C-call here, r_new_arg_entry holds the address

       // of the interpreter entry point (frame manager or native entry)

       // and save runtime-value of LR in return_address.

       assert(r_new_arg_entry != tos && r_new_arg_entry != R19_method && r_new_arg_entry != R16_thread,

              "trashed r_new_arg_entry");

       return_address = __ call_stub(r_new_arg_entry);

     }

     {

       BLOCK_COMMENT("Returned from frame manager or native entry.");

       // Returned from frame manager or native entry.

       // Now pop frame, process result, and return to caller.

       // Stack on exit from frame manager / native entry:

       //

       //      F0      [ABI]

       //              ...

       //              [ENTRY_FRAME_LOCALS]

       //      F1      [C_FRAME]

       //              ...

       //

       // Just pop the topmost frame ...

       //

       Label ret_is_object;

       Label ret_is_long;

       Label ret_is_float;

       Label ret_is_double;

       Register r_entryframe_fp = R30;

       Register r_lr            = R7_ARG5;

       Register r_cr            = R8_ARG6;

       // Reload some volatile registers which we've spilled before the call

       // to frame manager / native entry.

       // Access all locals via frame pointer, because we know nothing about

       // the topmost frame's size.

       __ ld(r_entryframe_fp, _abi(callers_sp), R1_SP);

       assert_different_registers(r_entryframe_fp, R3_RET, r_arg_result_addr, r_arg_result_type, r_cr, r_lr);

       __ ld(r_arg_result_addr,

             _entry_frame_locals_neg(result_address), r_entryframe_fp);

       __ ld(r_arg_result_type,

             _entry_frame_locals_neg(result_type), r_entryframe_fp);

       __ ld(r_cr, _abi(cr), r_entryframe_fp);

       __ ld(r_lr, _abi(lr), r_entryframe_fp);

       // pop frame and restore non-volatiles, LR and CR

       __ mr(R1_SP, r_entryframe_fp);

       __ mtcr(r_cr);

       __ mtlr(r_lr);

       // Store result depending on type. Everything that is not

       // T_OBJECT, T_LONG, T_FLOAT, or T_DOUBLE is treated as T_INT.

       __ cmpwi(CCR0, r_arg_result_type, T_OBJECT);

       __ cmpwi(CCR1, r_arg_result_type, T_LONG);

       __ cmpwi(CCR5, r_arg_result_type, T_FLOAT);

       __ cmpwi(CCR6, r_arg_result_type, T_DOUBLE);

       // restore non-volatile registers

       __ restore_nonvolatile_gprs(R1_SP, _spill_nonvolatiles_neg(r14));

       // Stack on exit from call_stub:

       //

       //      0       [C_FRAME]

       //              ...

       //

       //  no call_stub frames left.

       // All non-volatiles have been restored at this point!!

       assert(R3_RET == R3, "R3_RET should be R3");

       __ beq(CCR0, ret_is_object);

       __ beq(CCR1, ret_is_long);

       __ beq(CCR5, ret_is_float);

       __ beq(CCR6, ret_is_double);

       // default:

       __ stw(R3_RET, 0, r_arg_result_addr);

       __ blr(); // return to caller

       // case T_OBJECT:

       __ bind(ret_is_object);

       __ std(R3_RET, 0, r_arg_result_addr);

       __ blr(); // return to caller

       // case T_LONG:

       __ bind(ret_is_long);

       __ std(R3_RET, 0, r_arg_result_addr);

       __ blr(); // return to caller

       // case T_FLOAT:

       __ bind(ret_is_float);

       __ stfs(F1_RET, 0, r_arg_result_addr);

       __ blr(); // return to caller

       // case T_DOUBLE:

       __ bind(ret_is_double);

       __ stfd(F1_RET, 0, r_arg_result_addr);

       __ blr(); // return to caller

     }

     return start;

   }

   // Return point for a Java call if there's an exception thrown in

   // Java code.  The exception is caught and transformed into a

   // pending exception stored in JavaThread that can be tested from

   // within the VM.

   //

   address generate_catch_exception() {

     StubCodeMark mark(this, "StubRoutines", "catch_exception");

     address start = __ pc();

     // Registers alive

     //

     //  R16_thread

     //  R3_ARG1 - address of pending exception

     //  R4_ARG2 - return address in call stub

     const Register exception_file = R21_tmp1;

     const Register exception_line = R22_tmp2;

     __ load_const(exception_file, (void*)__FILE__);

     __ load_const(exception_line, (void*)__LINE__);

     __ std(R3_ARG1, thread_(pending_exception));

     // store into `char *'

     __ std(exception_file, thread_(exception_file));

     // store into `int'

     __ stw(exception_line, thread_(exception_line));

     // complete return to VM

     assert(StubRoutines::_call_stub_return_address != NULL, "must have been generated before");

     __ mtlr(R4_ARG2);

     // continue in call stub

     __ blr();

     return start;

   }

   // Continuation point for runtime calls returning with a pending

   // exception.  The pending exception check happened in the runtime

   // or native call stub.  The pending exception in Thread is

   // converted into a Java-level exception.

   //

   address generate_forward_exception() {

     StubCodeMark mark(this, "StubRoutines", "forward_exception");

     address start = __ pc();

 #if !defined(PRODUCT)

     if (VerifyOops) {

       // Get pending exception oop.

       __ ld(R3_ARG1,

                 in_bytes(Thread::pending_exception_offset()),

                 R16_thread);

       // Make sure that this code is only executed if there is a pending exception.

       {

         Label L;

         __ cmpdi(CCR0, R3_ARG1, 0);

         __ bne(CCR0, L);

         __ stop("StubRoutines::forward exception: no pending exception (1)");

         __ bind(L);

       }

       __ verify_oop(R3_ARG1, "StubRoutines::forward exception: not an oop");

     }

 #endif

     // Save LR/CR and copy exception pc (LR) into R4_ARG2.

     __ save_LR_CR(R4_ARG2);

     __ push_frame_reg_args(0, R0);

     // Find exception handler.

     __ call_VM_leaf(CAST_FROM_FN_PTR(address,

                      SharedRuntime::exception_handler_for_return_address),

                     R16_thread,

                     R4_ARG2);

     // Copy handler's address.

     __ mtctr(R3_RET);

     __ pop_frame();

     __ restore_LR_CR(R0);

     // Set up the arguments for the exception handler:

     //  - R3_ARG1: exception oop

     //  - R4_ARG2: exception pc.

     // Load pending exception oop.

     __ ld(R3_ARG1,

               in_bytes(Thread::pending_exception_offset()),

               R16_thread);

     // The exception pc is the return address in the caller.

     // Must load it into R4_ARG2.

     __ mflr(R4_ARG2);

 #ifdef ASSERT

     // Make sure exception is set.

     {

       Label L;

       __ cmpdi(CCR0, R3_ARG1, 0);

       __ bne(CCR0, L);

       __ stop("StubRoutines::forward exception: no pending exception (2)");

       __ bind(L);

     }

 #endif

     // Clear the pending exception.

     __ li(R0, 0);

     __ std(R0,

                in_bytes(Thread::pending_exception_offset()),

                R16_thread);

     // Jump to exception handler.

     __ bctr();

     return start;

   }

 #undef __

 #define __ masm->

   // Continuation point for throwing of implicit exceptions that are

   // not handled in the current activation. Fabricates an exception

   // oop and initiates normal exception dispatching in this

   // frame. Only callee-saved registers are preserved (through the

   // normal register window / RegisterMap handling).  If the compiler

   // needs all registers to be preserved between the fault point and

   // the exception handler then it must assume responsibility for that

   // in AbstractCompiler::continuation_for_implicit_null_exception or

   // continuation_for_implicit_division_by_zero_exception. All other

   // implicit exceptions (e.g., NullPointerException or

   // AbstractMethodError on entry) are either at call sites or

   // otherwise assume that stack unwinding will be initiated, so

   // caller saved registers were assumed volatile in the compiler.

   //

   // Note that we generate only this stub into a RuntimeStub, because

   // it needs to be properly traversed and ignored during GC, so we

   // change the meaning of the "__" macro within this method.

   //

   // Note: the routine set_pc_not_at_call_for_caller in

   // SharedRuntime.cpp requires that this code be generated into a

   // RuntimeStub.

   address generate_throw_exception(const char* name, address runtime_entry, bool restore_saved_exception_pc,

                                    Register arg1 = noreg, Register arg2 = noreg) {

     CodeBuffer code(name, 1024 DEBUG_ONLY(+ 512), 0);

     MacroAssembler* masm = new MacroAssembler(&code);

     OopMapSet* oop_maps  = new OopMapSet();

     int frame_size_in_bytes = frame::abi_reg_args_size;

     OopMap* map = new OopMap(frame_size_in_bytes / sizeof(jint), 0);

     StubCodeMark mark(this, "StubRoutines", "throw_exception");

     address start = __ pc();

     __ save_LR_CR(R11_scratch1);

     // Push a frame.

     __ push_frame_reg_args(0, R11_scratch1);

     address frame_complete_pc = __ pc();

     if (restore_saved_exception_pc) {

       __ unimplemented("StubGenerator::throw_exception with restore_saved_exception_pc", 74);

     }

     // Note that we always have a runtime stub frame on the top of

     // stack by this point. Remember the offset of the instruction

     // whose address will be moved to R11_scratch1.

     address gc_map_pc = __ get_PC_trash_LR(R11_scratch1);

     __ set_last_Java_frame(/*sp*/R1_SP, /*pc*/R11_scratch1);

     __ mr(R3_ARG1, R16_thread);

     if (arg1 != noreg) {

       __ mr(R4_ARG2, arg1);

     }

     if (arg2 != noreg) {

       __ mr(R5_ARG3, arg2);

     }

 #if defined(ABI_ELFv2)

     __ call_c(runtime_entry, relocInfo::none);

 #else

     __ call_c(CAST_FROM_FN_PTR(FunctionDescriptor*, runtime_entry), relocInfo::none);

 #endif

     // Set an oopmap for the call site.

     oop_maps->add_gc_map((int)(gc_map_pc - start), map);

     __ reset_last_Java_frame();

 #ifdef ASSERT

     // Make sure that this code is only executed if there is a pending

     // exception.

     {

       Label L;

       __ ld(R0,

                 in_bytes(Thread::pending_exception_offset()),

                 R16_thread);

       __ cmpdi(CCR0, R0, 0);

       __ bne(CCR0, L);

       __ stop("StubRoutines::throw_exception: no pending exception");

       __ bind(L);

     }

 #endif

     // Pop frame.

     __ pop_frame();

     __ restore_LR_CR(R11_scratch1);

     __ load_const(R11_scratch1, StubRoutines::forward_exception_entry());

     __ mtctr(R11_scratch1);

     __ bctr();

     // Create runtime stub with OopMap.

     RuntimeStub* stub =

       RuntimeStub::new_runtime_stub(name, &code,

                                     /*frame_complete=*/ (int)(frame_complete_pc - start),

                                     frame_size_in_bytes/wordSize,

                                     oop_maps,

                                     false);

     return stub->entry_point();

   }

 #undef __

 #define __ _masm->

   //  Generate G1 pre-write barrier for array.

   //

   //  Input:

   //     from     - register containing src address (only needed for spilling)

   //     to       - register containing starting address

   //     count    - register containing element count

   //     tmp      - scratch register

   //

   //  Kills:

   //     nothing

   //

   void gen_write_ref_array_pre_barrier(Register from, Register to, Register count, bool dest_uninitialized, Register Rtmp1) {

     BarrierSet* const bs = Universe::heap()->barrier_set();

     switch (bs->kind()) {

       case BarrierSet::G1SATBCT:

       case BarrierSet::G1SATBCTLogging:

         // With G1, don't generate the call if we statically know that the target in uninitialized

         if (!dest_uninitialized) {

           const int spill_slots = 4 * wordSize;

           const int frame_size  = frame::abi_reg_args_size + spill_slots;

           Label filtered;

           // Is marking active?

           if (in_bytes(PtrQueue::byte_width_of_active()) == 4) {

             __ lwz(Rtmp1, in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active()), R16_thread);

           } else {

             guarantee(in_bytes(PtrQueue::byte_width_of_active()) == 1, "Assumption");

             __ lbz(Rtmp1, in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active()), R16_thread);

           }

           __ cmpdi(CCR0, Rtmp1, 0);

           __ beq(CCR0, filtered);

           __ save_LR_CR(R0);

           __ push_frame_reg_args(spill_slots, R0);

           __ std(from,  frame_size - 1 * wordSize, R1_SP);

           __ std(to,    frame_size - 2 * wordSize, R1_SP);

           __ std(count, frame_size - 3 * wordSize, R1_SP);

           __ call_VM_leaf(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_pre), to, count);

           __ ld(from,  frame_size - 1 * wordSize, R1_SP);

           __ ld(to,    frame_size - 2 * wordSize, R1_SP);

           __ ld(count, frame_size - 3 * wordSize, R1_SP);

           __ pop_frame();

           __ restore_LR_CR(R0);

           __ bind(filtered);

         }

         break;

       case BarrierSet::CardTableModRef:

       case BarrierSet::CardTableExtension:

       case BarrierSet::ModRef:

         break;

       default:

         ShouldNotReachHere();

     }

   }

   //  Generate CMS/G1 post-write barrier for array.

   //

   //  Input:

   //     addr     - register containing starting address

   //     count    - register containing element count

   //     tmp      - scratch register

   //

   //  The input registers and R0 are overwritten.

   //

   void gen_write_ref_array_post_barrier(Register addr, Register count, Register tmp, bool branchToEnd) {

     BarrierSet* const bs = Universe::heap()->barrier_set();

     switch (bs->kind()) {

       case BarrierSet::G1SATBCT:

       case BarrierSet::G1SATBCTLogging:

         {

           if (branchToEnd) {

             __ save_LR_CR(R0);

             // We need this frame only to spill LR.

             __ push_frame_reg_args(0, R0);

             __ call_VM_leaf(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_post), addr, count);

             __ pop_frame();

             __ restore_LR_CR(R0);

           } else {

             // Tail call: fake call from stub caller by branching without linking.

             address entry_point = (address)CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_post);

             __ mr_if_needed(R3_ARG1, addr);

             __ mr_if_needed(R4_ARG2, count);

             __ load_const(R11, entry_point, R0);

             __ call_c_and_return_to_caller(R11);

           }

         }

         break;

       case BarrierSet::CardTableModRef:

       case BarrierSet::CardTableExtension:

         {

           Label Lskip_loop, Lstore_loop;

           if (UseConcMarkSweepGC) {

             // TODO PPC port: contribute optimization / requires shared changes

             __ release();

           }

           CardTableModRefBS* const ct = (CardTableModRefBS*)bs;

           assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");

           assert_different_registers(addr, count, tmp);

           __ sldi(count, count, LogBytesPerHeapOop);

           __ addi(count, count, -BytesPerHeapOop);

           __ add(count, addr, count);

           // Use two shifts to clear out those low order two bits! (Cannot opt. into 1.)

           __ srdi(addr, addr, CardTableModRefBS::card_shift);

           __ srdi(count, count, CardTableModRefBS::card_shift);

           __ subf(count, addr, count);

           assert_different_registers(R0, addr, count, tmp);

           __ load_const(tmp, (address)ct->byte_map_base);

           __ addic_(count, count, 1);

           __ beq(CCR0, Lskip_loop);

           __ li(R0, 0);

           __ mtctr(count);

           // Byte store loop

           __ bind(Lstore_loop);

           __ stbx(R0, tmp, addr);

           __ addi(addr, addr, 1);

           __ bdnz(Lstore_loop);

           __ bind(Lskip_loop);

           if (!branchToEnd) __ blr();

         }

       break;

       case BarrierSet::ModRef:

         if (!branchToEnd) __ blr();

         break;

       default:

         ShouldNotReachHere();

     }

   }

   // Support for void zero_words_aligned8(HeapWord* to, size_t count)

   //

   // Arguments:

   //   to:

   //   count:

   //

   // Destroys:

   //

   address generate_zero_words_aligned8() {

     StubCodeMark mark(this, "StubRoutines", "zero_words_aligned8");

     // Implemented as in ClearArray.

     address start = __ function_entry();

     Register base_ptr_reg   = R3_ARG1; // tohw (needs to be 8b aligned)

     Register cnt_dwords_reg = R4_ARG2; // count (in dwords)

     Register tmp1_reg       = R5_ARG3;

     Register tmp2_reg       = R6_ARG4;

     Register zero_reg       = R7_ARG5;

     // Procedure for large arrays (uses data cache block zero instruction).

     Label dwloop, fast, fastloop, restloop, lastdword, done;

     int cl_size=VM_Version::get_cache_line_size(), cl_dwords=cl_size>>3, cl_dwordaddr_bits=exact_log2(cl_dwords);

     int min_dcbz=2; // Needs to be positive, apply dcbz only to at least min_dcbz cache lines.

     // Clear up to 128byte boundary if long enough, dword_cnt=(16-(base>>3))%16.

     __ dcbtst(base_ptr_reg);                    // Indicate write access to first cache line ...

     __ andi(tmp2_reg, cnt_dwords_reg, 1);       // to check if number of dwords is even.

     __ srdi_(tmp1_reg, cnt_dwords_reg, 1);      // number of double dwords

     __ load_const_optimized(zero_reg, 0L);      // Use as zero register.

     __ cmpdi(CCR1, tmp2_reg, 0);                // cnt_dwords even?

     __ beq(CCR0, lastdword);                    // size <= 1

     __ mtctr(tmp1_reg);                         // Speculatively preload counter for rest loop (>0).

     __ cmpdi(CCR0, cnt_dwords_reg, (min_dcbz+1)*cl_dwords-1); // Big enough to ensure >=min_dcbz cache lines are included?

     __ neg(tmp1_reg, base_ptr_reg);             // bit 0..58: bogus, bit 57..60: (16-(base>>3))%16, bit 61..63: 000

     __ blt(CCR0, restloop);                     // Too small. (<31=(2*cl_dwords)-1 is sufficient, but bigger performs better.)

     __ rldicl_(tmp1_reg, tmp1_reg, 64-3, 64-cl_dwordaddr_bits); // Extract number of dwords to 128byte boundary=(16-(base>>3))%16.

     __ beq(CCR0, fast);                         // already 128byte aligned

     __ mtctr(tmp1_reg);                         // Set ctr to hit 128byte boundary (0<ctr<cnt).

     __ subf(cnt_dwords_reg, tmp1_reg, cnt_dwords_reg); // rest (>0 since size>=256-8)

     // Clear in first cache line dword-by-dword if not already 128byte aligned.

     __ bind(dwloop);

       __ std(zero_reg, 0, base_ptr_reg);        // Clear 8byte aligned block.

       __ addi(base_ptr_reg, base_ptr_reg, 8);

     __ bdnz(dwloop);

     // clear 128byte blocks

     __ bind(fast);

     __ srdi(tmp1_reg, cnt_dwords_reg, cl_dwordaddr_bits); // loop count for 128byte loop (>0 since size>=256-8)

     __ andi(tmp2_reg, cnt_dwords_reg, 1);       // to check if rest even

     __ mtctr(tmp1_reg);                         // load counter

     __ cmpdi(CCR1, tmp2_reg, 0);                // rest even?

     __ rldicl_(tmp1_reg, cnt_dwords_reg, 63, 65-cl_dwordaddr_bits); // rest in double dwords

     __ bind(fastloop);

       __ dcbz(base_ptr_reg);                    // Clear 128byte aligned block.

       __ addi(base_ptr_reg, base_ptr_reg, cl_size);

     __ bdnz(fastloop);

     //__ dcbtst(base_ptr_reg);                  // Indicate write access to last cache line.

     __ beq(CCR0, lastdword);                    // rest<=1

     __ mtctr(tmp1_reg);                         // load counter

     // Clear rest.

     __ bind(restloop);

       __ std(zero_reg, 0, base_ptr_reg);        // Clear 8byte aligned block.

       __ std(zero_reg, 8, base_ptr_reg);        // Clear 8byte aligned block.

       __ addi(base_ptr_reg, base_ptr_reg, 16);

     __ bdnz(restloop);

     __ bind(lastdword);

     __ beq(CCR1, done);

     __ std(zero_reg, 0, base_ptr_reg);

     __ bind(done);

     __ blr();                                   // return

     return start;

   }

   // The following routine generates a subroutine to throw an asynchronous

   // UnknownError when an unsafe access gets a fault that could not be

   // reasonably prevented by the programmer.  (Example: SIGBUS/OBJERR.)

   //

   address generate_handler_for_unsafe_access() {

     StubCodeMark mark(this, "StubRoutines", "handler_for_unsafe_access");

     address start = __ function_entry();

     __ unimplemented("StubRoutines::handler_for_unsafe_access", 93);

     return start;

   }

 #if !defined(PRODUCT)

   // Wrapper which calls oopDesc::is_oop_or_null()

   // Only called by MacroAssembler::verify_oop

   static void verify_oop_helper(const char* message, oop o) {

     if (!o->is_oop_or_null()) {

       fatal(message);

     }

     ++ StubRoutines::_verify_oop_count;

   }

 #endif

   // Return address of code to be called from code generated by

   // MacroAssembler::verify_oop.

   //

   // Don't generate, rather use C++ code.

   address generate_verify_oop() {

     StubCodeMark mark(this, "StubRoutines", "verify_oop");

     // this is actually a `FunctionDescriptor*'.

     address start = 0;

 #if !defined(PRODUCT)

     start = CAST_FROM_FN_PTR(address, verify_oop_helper);

 #endif

     return start;

   }

   // Fairer handling of safepoints for native methods.

   //

   // Generate code which reads from the polling page. This special handling is needed as the

   // linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults in 64bit mode

   // (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6), especially when we try

   // to read from the safepoint polling page.

   address generate_load_from_poll() {

     StubCodeMark mark(this, "StubRoutines", "generate_load_from_poll");

     address start = __ function_entry();

     __ unimplemented("StubRoutines::verify_oop", 95);  // TODO PPC port

     return start;

   }

   // -XX:+OptimizeFill : convert fill/copy loops into intrinsic

   //

   // The code is implemented(ported from sparc) as we believe it benefits JVM98, however

   // tracing(-XX:+TraceOptimizeFill) shows the intrinsic replacement doesn't happen at all!

   //

   // Source code in function is_range_check_if() shows that OptimizeFill relaxed the condition

   // for turning on loop predication optimization, and hence the behavior of "array range check"

   // and "loop invariant check" could be influenced, which potentially boosted JVM98.

   //

   // Generate stub for disjoint short fill. If "aligned" is true, the

   // "to" address is assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //   to:    R3_ARG1

   //   value: R4_ARG2

   //   count: R5_ARG3 treated as signed

   //

   address generate_fill(BasicType t, bool aligned, const char* name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

     const Register to    = R3_ARG1;   // source array address

     const Register value = R4_ARG2;   // fill value

     const Register count = R5_ARG3;   // elements count

     const Register temp  = R6_ARG4;   // temp register

     //assert_clean_int(count, O3);    // Make sure 'count' is clean int.

     Label L_exit, L_skip_align1, L_skip_align2, L_fill_byte;

     Label L_fill_2_bytes, L_fill_4_bytes, L_fill_elements, L_fill_32_bytes;

     int shift = -1;

     switch (t) {

        case T_BYTE:

         shift = 2;

         // Clone bytes (zero extend not needed because store instructions below ignore high order bytes).

         __ rldimi(value, value, 8, 48);     // 8 bit -> 16 bit

         __ cmpdi(CCR0, count, 2<<shift);    // Short arrays (< 8 bytes) fill by element.

         __ blt(CCR0, L_fill_elements);

         __ rldimi(value, value, 16, 32);    // 16 bit -> 32 bit

         break;

        case T_SHORT:

         shift = 1;

         // Clone bytes (zero extend not needed because store instructions below ignore high order bytes).

         __ rldimi(value, value, 16, 32);    // 16 bit -> 32 bit

         __ cmpdi(CCR0, count, 2<<shift);    // Short arrays (< 8 bytes) fill by element.

         __ blt(CCR0, L_fill_elements);

         break;

       case T_INT:

         shift = 0;

         __ cmpdi(CCR0, count, 2<<shift);    // Short arrays (< 8 bytes) fill by element.

         __ blt(CCR0, L_fill_4_bytes);

         break;

       default: ShouldNotReachHere();

     }

     if (!aligned && (t == T_BYTE || t == T_SHORT)) {

       // Align source address at 4 bytes address boundary.

       if (t == T_BYTE) {

         // One byte misalignment happens only for byte arrays.

         __ andi_(temp, to, 1);

         __ beq(CCR0, L_skip_align1);

         __ stb(value, 0, to);

         __ addi(to, to, 1);

         __ addi(count, count, -1);

         __ bind(L_skip_align1);

       }

       // Two bytes misalignment happens only for byte and short (char) arrays.

       __ andi_(temp, to, 2);

       __ beq(CCR0, L_skip_align2);

       __ sth(value, 0, to);

       __ addi(to, to, 2);

       __ addi(count, count, -(1 << (shift - 1)));

       __ bind(L_skip_align2);

     }

     if (!aligned) {

       // Align to 8 bytes, we know we are 4 byte aligned to start.

       __ andi_(temp, to, 7);

       __ beq(CCR0, L_fill_32_bytes);

       __ stw(value, 0, to);

       __ addi(to, to, 4);

       __ addi(count, count, -(1 << shift));

       __ bind(L_fill_32_bytes);

     }

     __ li(temp, 8<<shift);                  // Prepare for 32 byte loop.

     // Clone bytes int->long as above.

     __ rldimi(value, value, 32, 0);         // 32 bit -> 64 bit

     Label L_check_fill_8_bytes;

     // Fill 32-byte chunks.

     __ subf_(count, temp, count);

     __ blt(CCR0, L_check_fill_8_bytes);

     Label L_fill_32_bytes_loop;

     __ align(32);

     __ bind(L_fill_32_bytes_loop);

     __ std(value, 0, to);

     __ std(value, 8, to);

     __ subf_(count, temp, count);           // Update count.

     __ std(value, 16, to);

     __ std(value, 24, to);

     __ addi(to, to, 32);

     __ bge(CCR0, L_fill_32_bytes_loop);

     __ bind(L_check_fill_8_bytes);

     __ add_(count, temp, count);

     __ beq(CCR0, L_exit);

     __ addic_(count, count, -(2 << shift));

     __ blt(CCR0, L_fill_4_bytes);

     //

     // Length is too short, just fill 8 bytes at a time.

     //

     Label L_fill_8_bytes_loop;

     __ bind(L_fill_8_bytes_loop);

     __ std(value, 0, to);

     __ addic_(count, count, -(2 << shift));

     __ addi(to, to, 8);

     __ bge(CCR0, L_fill_8_bytes_loop);

     // Fill trailing 4 bytes.

     __ bind(L_fill_4_bytes);

     __ andi_(temp, count, 1<<shift);

     __ beq(CCR0, L_fill_2_bytes);

     __ stw(value, 0, to);

     if (t == T_BYTE || t == T_SHORT) {

       __ addi(to, to, 4);

       // Fill trailing 2 bytes.

       __ bind(L_fill_2_bytes);

       __ andi_(temp, count, 1<<(shift-1));

       __ beq(CCR0, L_fill_byte);

       __ sth(value, 0, to);

       if (t == T_BYTE) {

         __ addi(to, to, 2);

         // Fill trailing byte.

         __ bind(L_fill_byte);

         __ andi_(count, count, 1);

         __ beq(CCR0, L_exit);

         __ stb(value, 0, to);

       } else {

         __ bind(L_fill_byte);

       }

     } else {

       __ bind(L_fill_2_bytes);

     }

     __ bind(L_exit);

     __ blr();

     // Handle copies less than 8 bytes. Int is handled elsewhere.

     if (t == T_BYTE) {

       __ bind(L_fill_elements);

       Label L_fill_2, L_fill_4;

       __ andi_(temp, count, 1);

       __ beq(CCR0, L_fill_2);

       __ stb(value, 0, to);

       __ addi(to, to, 1);

       __ bind(L_fill_2);

       __ andi_(temp, count, 2);

       __ beq(CCR0, L_fill_4);

       __ stb(value, 0, to);

       __ stb(value, 0, to);

       __ addi(to, to, 2);

       __ bind(L_fill_4);

       __ andi_(temp, count, 4);

       __ beq(CCR0, L_exit);

       __ stb(value, 0, to);

       __ stb(value, 1, to);

       __ stb(value, 2, to);

       __ stb(value, 3, to);

       __ blr();

     }

     if (t == T_SHORT) {

       Label L_fill_2;

       __ bind(L_fill_elements);

       __ andi_(temp, count, 1);

       __ beq(CCR0, L_fill_2);

       __ sth(value, 0, to);

       __ addi(to, to, 2);

       __ bind(L_fill_2);

       __ andi_(temp, count, 2);

       __ beq(CCR0, L_exit);

       __ sth(value, 0, to);

       __ sth(value, 2, to);

       __ blr();

     }

     return start;

   }

   // Generate overlap test for array copy stubs.

   //

   // Input:

   //   R3_ARG1    -  from

   //   R4_ARG2    -  to

   //   R5_ARG3    -  element count

   //

   void array_overlap_test(address no_overlap_target, int log2_elem_size) {

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Label l_overlap;

 #ifdef ASSERT

     __ srdi_(tmp2, R5_ARG3, 31);

     __ asm_assert_eq("missing zero extend", 0xAFFE);

 #endif

     __ subf(tmp1, R3_ARG1, R4_ARG2); // distance in bytes

     __ sldi(tmp2, R5_ARG3, log2_elem_size); // size in bytes

     __ cmpld(CCR0, R3_ARG1, R4_ARG2); // Use unsigned comparison!

     __ cmpld(CCR1, tmp1, tmp2);

     __ crand(/*CCR0 lt*/0, /*CCR1 lt*/4+0, /*CCR0 lt*/0);

     __ blt(CCR0, l_overlap); // Src before dst and distance smaller than size.

     // need to copy forwards

     if (__ is_within_range_of_b(no_overlap_target, __ pc())) {

       __ b(no_overlap_target);

     } else {

       __ load_const(tmp1, no_overlap_target, tmp2);

       __ mtctr(tmp1);

       __ bctr();

     }

     __ bind(l_overlap);

     // need to copy backwards

   }

   // The guideline in the implementations of generate_disjoint_xxx_copy

   // (xxx=byte,short,int,long,oop) is to copy as many elements as possible with

   // single instructions, but to avoid alignment interrupts (see subsequent

   // comment). Furthermore, we try to minimize misaligned access, even

   // though they cause no alignment interrupt.

   //

   // In Big-Endian mode, the PowerPC architecture requires implementations to

   // handle automatically misaligned integer halfword and word accesses,

   // word-aligned integer doubleword accesses, and word-aligned floating-point

   // accesses. Other accesses may or may not generate an Alignment interrupt

   // depending on the implementation.

   // Alignment interrupt handling may require on the order of hundreds of cycles,

   // so every effort should be made to avoid misaligned memory values.

   //

   //

   // Generate stub for disjoint byte copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   address generate_disjoint_byte_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

     Register tmp4 = R9_ARG7;

     Label l_1, l_2, l_3, l_4, l_5, l_6, l_7, l_8, l_9;

     // Don't try anything fancy if arrays don't have many elements.

     __ li(tmp3, 0);

     __ cmpwi(CCR0, R5_ARG3, 17);

     __ ble(CCR0, l_6); // copy 4 at a time

     if (!aligned) {

       __ xorr(tmp1, R3_ARG1, R4_ARG2);

       __ andi_(tmp1, tmp1, 3);

       __ bne(CCR0, l_6); // If arrays don't have the same alignment mod 4, do 4 element copy.

       // Copy elements if necessary to align to 4 bytes.

       __ neg(tmp1, R3_ARG1); // Compute distance to alignment boundary.

       __ andi_(tmp1, tmp1, 3);

       __ beq(CCR0, l_2);

       __ subf(R5_ARG3, tmp1, R5_ARG3);

       __ bind(l_9);

       __ lbz(tmp2, 0, R3_ARG1);

       __ addic_(tmp1, tmp1, -1);

       __ stb(tmp2, 0, R4_ARG2);

       __ addi(R3_ARG1, R3_ARG1, 1);

       __ addi(R4_ARG2, R4_ARG2, 1);

       __ bne(CCR0, l_9);

       __ bind(l_2);

     }

     // copy 8 elements at a time

     __ xorr(tmp2, R3_ARG1, R4_ARG2); // skip if src & dest have differing alignment mod 8

     __ andi_(tmp1, tmp2, 7);

     __ bne(CCR0, l_7); // not same alignment -> to or from is aligned -> copy 8

     // copy a 2-element word if necessary to align to 8 bytes

     __ andi_(R0, R3_ARG1, 7);

     __ beq(CCR0, l_7);

     __ lwzx(tmp2, R3_ARG1, tmp3);

     __ addi(R5_ARG3, R5_ARG3, -4);

     __ stwx(tmp2, R4_ARG2, tmp3);

     { // FasterArrayCopy

       __ addi(R3_ARG1, R3_ARG1, 4);

       __ addi(R4_ARG2, R4_ARG2, 4);

     }

     __ bind(l_7);

     { // FasterArrayCopy

       __ cmpwi(CCR0, R5_ARG3, 31);

       __ ble(CCR0, l_6); // copy 2 at a time if less than 32 elements remain

       __ srdi(tmp1, R5_ARG3, 5);

       __ andi_(R5_ARG3, R5_ARG3, 31);

       __ mtctr(tmp1);

       __ bind(l_8);

       // Use unrolled version for mass copying (copy 32 elements a time)

       // Load feeding store gets zero latency on Power6, however not on Power5.

       // Therefore, the following sequence is made for the good of both.

       __ ld(tmp1, 0, R3_ARG1);

       __ ld(tmp2, 8, R3_ARG1);

       __ ld(tmp3, 16, R3_ARG1);

       __ ld(tmp4, 24, R3_ARG1);

       __ std(tmp1, 0, R4_ARG2);

       __ std(tmp2, 8, R4_ARG2);

       __ std(tmp3, 16, R4_ARG2);

       __ std(tmp4, 24, R4_ARG2);

       __ addi(R3_ARG1, R3_ARG1, 32);

       __ addi(R4_ARG2, R4_ARG2, 32);

       __ bdnz(l_8);

     }

     __ bind(l_6);

     // copy 4 elements at a time

     __ cmpwi(CCR0, R5_ARG3, 4);

     __ blt(CCR0, l_1);

     __ srdi(tmp1, R5_ARG3, 2);

     __ mtctr(tmp1); // is > 0

     __ andi_(R5_ARG3, R5_ARG3, 3);

     { // FasterArrayCopy

       __ addi(R3_ARG1, R3_ARG1, -4);

       __ addi(R4_ARG2, R4_ARG2, -4);

       __ bind(l_3);

       __ lwzu(tmp2, 4, R3_ARG1);

       __ stwu(tmp2, 4, R4_ARG2);

       __ bdnz(l_3);

       __ addi(R3_ARG1, R3_ARG1, 4);

       __ addi(R4_ARG2, R4_ARG2, 4);

     }

     // do single element copy

     __ bind(l_1);

     __ cmpwi(CCR0, R5_ARG3, 0);

     __ beq(CCR0, l_4);

     { // FasterArrayCopy

       __ mtctr(R5_ARG3);

       __ addi(R3_ARG1, R3_ARG1, -1);

       __ addi(R4_ARG2, R4_ARG2, -1);

       __ bind(l_5);

       __ lbzu(tmp2, 1, R3_ARG1);

       __ stbu(tmp2, 1, R4_ARG2);

       __ bdnz(l_5);

     }

     __ bind(l_4);

     __ blr();

     return start;

   }

   // Generate stub for conjoint byte copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   address generate_conjoint_byte_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

 #if defined(ABI_ELFv2)

      address nooverlap_target = aligned ?

        StubRoutines::arrayof_jbyte_disjoint_arraycopy() :

        StubRoutines::jbyte_disjoint_arraycopy();

 #else

     address nooverlap_target = aligned ?

       ((FunctionDescriptor*)StubRoutines::arrayof_jbyte_disjoint_arraycopy())->entry() :

       ((FunctionDescriptor*)StubRoutines::jbyte_disjoint_arraycopy())->entry();

 #endif

     array_overlap_test(nooverlap_target, 0);

     // Do reverse copy. We assume the case of actual overlap is rare enough

     // that we don't have to optimize it.

     Label l_1, l_2;

     __ b(l_2);

     __ bind(l_1);

     __ stbx(tmp1, R4_ARG2, R5_ARG3);

     __ bind(l_2);

     __ addic_(R5_ARG3, R5_ARG3, -1);

     __ lbzx(tmp1, R3_ARG1, R5_ARG3);

     __ bge(CCR0, l_1);

     __ blr();

     return start;

   }

   // Generate stub for disjoint short copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //  elm.count: R5_ARG3 treated as signed

   //

   // Strategy for aligned==true:

   //

   //  If length <= 9:

   //     1. copy 2 elements at a time (l_6)

   //     2. copy last element if original element count was odd (l_1)

   //

   //  If length > 9:

   //     1. copy 4 elements at a time until less than 4 elements are left (l_7)

   //     2. copy 2 elements at a time until less than 2 elements are left (l_6)

   //     3. copy last element if one was left in step 2. (l_1)

   //

   //

   // Strategy for aligned==false:

   //

   //  If length <= 9: same as aligned==true case, but NOTE: load/stores

   //                  can be unaligned (see comment below)

   //

   //  If length > 9:

   //     1. continue with step 6. if the alignment of from and to mod 4

   //        is different.

   //     2. align from and to to 4 bytes by copying 1 element if necessary

   //     3. at l_2 from and to are 4 byte aligned; continue with

   //        5. if they cannot be aligned to 8 bytes because they have

   //        got different alignment mod 8.

   //     4. at this point we know that both, from and to, have the same

   //        alignment mod 8, now copy one element if necessary to get

   //        8 byte alignment of from and to.

   //     5. copy 4 elements at a time until less than 4 elements are

   //        left; depending on step 3. all load/stores are aligned or

   //        either all loads or all stores are unaligned.

   //     6. copy 2 elements at a time until less than 2 elements are

   //        left (l_6); arriving here from step 1., there is a chance

   //        that all accesses are unaligned.

   //     7. copy last element if one was left in step 6. (l_1)

   //

   //  There are unaligned data accesses using integer load/store

   //  instructions in this stub. POWER allows such accesses.

   //

   //  According to the manuals (PowerISA_V2.06_PUBLIC, Book II,

   //  Chapter 2: Effect of Operand Placement on Performance) unaligned

   //  integer load/stores have good performance. Only unaligned

   //  floating point load/stores can have poor performance.

   //

   //  TODO:

   //

   //  1. check if aligning the backbranch target of loops is beneficial

   //

   address generate_disjoint_short_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

     Register tmp4 = R9_ARG7;

     address start = __ function_entry();

       Label l_1, l_2, l_3, l_4, l_5, l_6, l_7, l_8;

     // don't try anything fancy if arrays don't have many elements

     __ li(tmp3, 0);

     __ cmpwi(CCR0, R5_ARG3, 9);

     __ ble(CCR0, l_6); // copy 2 at a time

     if (!aligned) {

       __ xorr(tmp1, R3_ARG1, R4_ARG2);

       __ andi_(tmp1, tmp1, 3);

       __ bne(CCR0, l_6); // if arrays don't have the same alignment mod 4, do 2 element copy

       // At this point it is guaranteed that both, from and to have the same alignment mod 4.

       // Copy 1 element if necessary to align to 4 bytes.

       __ andi_(tmp1, R3_ARG1, 3);

       __ beq(CCR0, l_2);

       __ lhz(tmp2, 0, R3_ARG1);

       __ addi(R3_ARG1, R3_ARG1, 2);

       __ sth(tmp2, 0, R4_ARG2);

       __ addi(R4_ARG2, R4_ARG2, 2);

       __ addi(R5_ARG3, R5_ARG3, -1);

       __ bind(l_2);

       // At this point the positions of both, from and to, are at least 4 byte aligned.

       // Copy 4 elements at a time.

       // Align to 8 bytes, but only if both, from and to, have same alignment mod 8.

       __ xorr(tmp2, R3_ARG1, R4_ARG2);

       __ andi_(tmp1, tmp2, 7);

       __ bne(CCR0, l_7); // not same alignment mod 8 -> copy 4, either from or to will be unaligned

       // Copy a 2-element word if necessary to align to 8 bytes.

       __ andi_(R0, R3_ARG1, 7);

       __ beq(CCR0, l_7);

       __ lwzx(tmp2, R3_ARG1, tmp3);

       __ addi(R5_ARG3, R5_ARG3, -2);

       __ stwx(tmp2, R4_ARG2, tmp3);

       { // FasterArrayCopy

         __ addi(R3_ARG1, R3_ARG1, 4);

         __ addi(R4_ARG2, R4_ARG2, 4);

       }

     }

     __ bind(l_7);

     // Copy 4 elements at a time; either the loads or the stores can

     // be unaligned if aligned == false.

     { // FasterArrayCopy

       __ cmpwi(CCR0, R5_ARG3, 15);

       __ ble(CCR0, l_6); // copy 2 at a time if less than 16 elements remain

       __ srdi(tmp1, R5_ARG3, 4);

       __ andi_(R5_ARG3, R5_ARG3, 15);

       __ mtctr(tmp1);

       __ bind(l_8);

       // Use unrolled version for mass copying (copy 16 elements a time).

       // Load feeding store gets zero latency on Power6, however not on Power5.

       // Therefore, the following sequence is made for the good of both.

       __ ld(tmp1, 0, R3_ARG1);

       __ ld(tmp2, 8, R3_ARG1);

       __ ld(tmp3, 16, R3_ARG1);

       __ ld(tmp4, 24, R3_ARG1);

       __ std(tmp1, 0, R4_ARG2);

       __ std(tmp2, 8, R4_ARG2);

       __ std(tmp3, 16, R4_ARG2);

       __ std(tmp4, 24, R4_ARG2);

       __ addi(R3_ARG1, R3_ARG1, 32);

       __ addi(R4_ARG2, R4_ARG2, 32);

       __ bdnz(l_8);

     }

     __ bind(l_6);

     // copy 2 elements at a time

     { // FasterArrayCopy

       __ cmpwi(CCR0, R5_ARG3, 2);

       __ blt(CCR0, l_1);

       __ srdi(tmp1, R5_ARG3, 1);

       __ andi_(R5_ARG3, R5_ARG3, 1);

       __ addi(R3_ARG1, R3_ARG1, -4);

       __ addi(R4_ARG2, R4_ARG2, -4);

       __ mtctr(tmp1);

       __ bind(l_3);

       __ lwzu(tmp2, 4, R3_ARG1);

       __ stwu(tmp2, 4, R4_ARG2);

       __ bdnz(l_3);

       __ addi(R3_ARG1, R3_ARG1, 4);

       __ addi(R4_ARG2, R4_ARG2, 4);

     }

     // do single element copy

     __ bind(l_1);

     __ cmpwi(CCR0, R5_ARG3, 0);

     __ beq(CCR0, l_4);

     { // FasterArrayCopy

       __ mtctr(R5_ARG3);

       __ addi(R3_ARG1, R3_ARG1, -2);

       __ addi(R4_ARG2, R4_ARG2, -2);

       __ bind(l_5);

       __ lhzu(tmp2, 2, R3_ARG1);

       __ sthu(tmp2, 2, R4_ARG2);

       __ bdnz(l_5);

     }

     __ bind(l_4);

     __ blr();

     return start;

   }

   // Generate stub for conjoint short copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   address generate_conjoint_short_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

 #if defined(ABI_ELFv2)

     address nooverlap_target = aligned ?

         StubRoutines::arrayof_jshort_disjoint_arraycopy() :

         StubRoutines::jshort_disjoint_arraycopy();

 #else

     address nooverlap_target = aligned ?

         ((FunctionDescriptor*)StubRoutines::arrayof_jshort_disjoint_arraycopy())->entry() :

         ((FunctionDescriptor*)StubRoutines::jshort_disjoint_arraycopy())->entry();

 #endif

     array_overlap_test(nooverlap_target, 1);

     Label l_1, l_2;

     __ sldi(tmp1, R5_ARG3, 1);

     __ b(l_2);

     __ bind(l_1);

     __ sthx(tmp2, R4_ARG2, tmp1);

     __ bind(l_2);

     __ addic_(tmp1, tmp1, -2);

     __ lhzx(tmp2, R3_ARG1, tmp1);

     __ bge(CCR0, l_1);

     __ blr();

     return start;

   }

   // Generate core code for disjoint int copy (and oop copy on 32-bit).  If "aligned"

   // is true, the "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   void generate_disjoint_int_copy_core(bool aligned) {

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

     Register tmp4 = R0;

     Label l_1, l_2, l_3, l_4, l_5, l_6;

     // for short arrays, just do single element copy

     __ li(tmp3, 0);

     __ cmpwi(CCR0, R5_ARG3, 5);

     __ ble(CCR0, l_2);

     if (!aligned) {

         // check if arrays have same alignment mod 8.

         __ xorr(tmp1, R3_ARG1, R4_ARG2);

         __ andi_(R0, tmp1, 7);

         // Not the same alignment, but ld and std just need to be 4 byte aligned.

         __ bne(CCR0, l_4); // to OR from is 8 byte aligned -> copy 2 at a time

         // copy 1 element to align to and from on an 8 byte boundary

         __ andi_(R0, R3_ARG1, 7);

         __ beq(CCR0, l_4);

         __ lwzx(tmp2, R3_ARG1, tmp3);

         __ addi(R5_ARG3, R5_ARG3, -1);

         __ stwx(tmp2, R4_ARG2, tmp3);

         { // FasterArrayCopy

           __ addi(R3_ARG1, R3_ARG1, 4);

           __ addi(R4_ARG2, R4_ARG2, 4);

         }

         __ bind(l_4);

       }

     { // FasterArrayCopy

       __ cmpwi(CCR0, R5_ARG3, 7);

       __ ble(CCR0, l_2); // copy 1 at a time if less than 8 elements remain

       __ srdi(tmp1, R5_ARG3, 3);

       __ andi_(R5_ARG3, R5_ARG3, 7);

       __ mtctr(tmp1);

       __ bind(l_6);

       // Use unrolled version for mass copying (copy 8 elements a time).

       // Load feeding store gets zero latency on power6, however not on power 5.

       // Therefore, the following sequence is made for the good of both.

       __ ld(tmp1, 0, R3_ARG1);

       __ ld(tmp2, 8, R3_ARG1);

       __ ld(tmp3, 16, R3_ARG1);

       __ ld(tmp4, 24, R3_ARG1);

       __ std(tmp1, 0, R4_ARG2);

       __ std(tmp2, 8, R4_ARG2);

       __ std(tmp3, 16, R4_ARG2);

       __ std(tmp4, 24, R4_ARG2);

       __ addi(R3_ARG1, R3_ARG1, 32);

       __ addi(R4_ARG2, R4_ARG2, 32);

       __ bdnz(l_6);

     }

     // copy 1 element at a time

     __ bind(l_2);

     __ cmpwi(CCR0, R5_ARG3, 0);

     __ beq(CCR0, l_1);

     { // FasterArrayCopy

       __ mtctr(R5_ARG3);

       __ addi(R3_ARG1, R3_ARG1, -4);

       __ addi(R4_ARG2, R4_ARG2, -4);

       __ bind(l_3);

       __ lwzu(tmp2, 4, R3_ARG1);

       __ stwu(tmp2, 4, R4_ARG2);

       __ bdnz(l_3);

     }

     __ bind(l_1);

     return;

   }

   // Generate stub for disjoint int copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   address generate_disjoint_int_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

     generate_disjoint_int_copy_core(aligned);

     __ blr();

     return start;

   }

   // Generate core code for conjoint int copy (and oop copy on

   // 32-bit).  If "aligned" is true, the "from" and "to" addresses

   // are assumed to be heapword aligned.

   //

   // Arguments:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   void generate_conjoint_int_copy_core(bool aligned) {

     // Do reverse copy.  We assume the case of actual overlap is rare enough

     // that we don't have to optimize it.

     Label l_1, l_2, l_3, l_4, l_5, l_6;

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

     Register tmp4 = R0;

     { // FasterArrayCopy

       __ cmpwi(CCR0, R5_ARG3, 0);

       __ beq(CCR0, l_6);

       __ sldi(R5_ARG3, R5_ARG3, 2);

       __ add(R3_ARG1, R3_ARG1, R5_ARG3);

       __ add(R4_ARG2, R4_ARG2, R5_ARG3);

       __ srdi(R5_ARG3, R5_ARG3, 2);

       __ cmpwi(CCR0, R5_ARG3, 7);

       __ ble(CCR0, l_5); // copy 1 at a time if less than 8 elements remain

       __ srdi(tmp1, R5_ARG3, 3);

       __ andi(R5_ARG3, R5_ARG3, 7);

       __ mtctr(tmp1);

       __ bind(l_4);

       // Use unrolled version for mass copying (copy 4 elements a time).

       // Load feeding store gets zero latency on Power6, however not on Power5.

       // Therefore, the following sequence is made for the good of both.

       __ addi(R3_ARG1, R3_ARG1, -32);

       __ addi(R4_ARG2, R4_ARG2, -32);

       __ ld(tmp4, 24, R3_ARG1);

       __ ld(tmp3, 16, R3_ARG1);

       __ ld(tmp2, 8, R3_ARG1);

       __ ld(tmp1, 0, R3_ARG1);

       __ std(tmp4, 24, R4_ARG2);

       __ std(tmp3, 16, R4_ARG2);

       __ std(tmp2, 8, R4_ARG2);

       __ std(tmp1, 0, R4_ARG2);

       __ bdnz(l_4);

       __ cmpwi(CCR0, R5_ARG3, 0);

       __ beq(CCR0, l_6);

       __ bind(l_5);

       __ mtctr(R5_ARG3);

       __ bind(l_3);

       __ lwz(R0, -4, R3_ARG1);

       __ stw(R0, -4, R4_ARG2);

       __ addi(R3_ARG1, R3_ARG1, -4);

       __ addi(R4_ARG2, R4_ARG2, -4);

       __ bdnz(l_3);

       __ bind(l_6);

     }

   }

   // Generate stub for conjoint int copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   address generate_conjoint_int_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

 #if defined(ABI_ELFv2)

     address nooverlap_target = aligned ?

       StubRoutines::arrayof_jint_disjoint_arraycopy() :

       StubRoutines::jint_disjoint_arraycopy();

 #else

     address nooverlap_target = aligned ?

       ((FunctionDescriptor*)StubRoutines::arrayof_jint_disjoint_arraycopy())->entry() :

       ((FunctionDescriptor*)StubRoutines::jint_disjoint_arraycopy())->entry();

 #endif

     array_overlap_test(nooverlap_target, 2);

     generate_conjoint_int_copy_core(aligned);

     __ blr();

     return start;

   }

   // Generate core code for disjoint long copy (and oop copy on

   // 64-bit).  If "aligned" is true, the "from" and "to" addresses

   // are assumed to be heapword aligned.

   //

   // Arguments:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   void generate_disjoint_long_copy_core(bool aligned) {

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

     Register tmp4 = R0;

     Label l_1, l_2, l_3, l_4;

     { // FasterArrayCopy

       __ cmpwi(CCR0, R5_ARG3, 3);

       __ ble(CCR0, l_3); // copy 1 at a time if less than 4 elements remain

       __ srdi(tmp1, R5_ARG3, 2);

       __ andi_(R5_ARG3, R5_ARG3, 3);

       __ mtctr(tmp1);

       __ bind(l_4);

       // Use unrolled version for mass copying (copy 4 elements a time).

       // Load feeding store gets zero latency on Power6, however not on Power5.

       // Therefore, the following sequence is made for the good of both.

       __ ld(tmp1, 0, R3_ARG1);

       __ ld(tmp2, 8, R3_ARG1);

       __ ld(tmp3, 16, R3_ARG1);

       __ ld(tmp4, 24, R3_ARG1);

       __ std(tmp1, 0, R4_ARG2);

       __ std(tmp2, 8, R4_ARG2);

       __ std(tmp3, 16, R4_ARG2);

       __ std(tmp4, 24, R4_ARG2);

       __ addi(R3_ARG1, R3_ARG1, 32);

       __ addi(R4_ARG2, R4_ARG2, 32);

       __ bdnz(l_4);

     }

     // copy 1 element at a time

     __ bind(l_3);

     __ cmpwi(CCR0, R5_ARG3, 0);

     __ beq(CCR0, l_1);

     { // FasterArrayCopy

       __ mtctr(R5_ARG3);

       __ addi(R3_ARG1, R3_ARG1, -8);

       __ addi(R4_ARG2, R4_ARG2, -8);

       __ bind(l_2);

       __ ldu(R0, 8, R3_ARG1);

       __ stdu(R0, 8, R4_ARG2);

       __ bdnz(l_2);

     }

     __ bind(l_1);

   }

   // Generate stub for disjoint long copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   address generate_disjoint_long_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

     generate_disjoint_long_copy_core(aligned);

     __ blr();

     return start;

   }

   // Generate core code for conjoint long copy (and oop copy on

   // 64-bit).  If "aligned" is true, the "from" and "to" addresses

   // are assumed to be heapword aligned.

   //

   // Arguments:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   void generate_conjoint_long_copy_core(bool aligned) {

     Register tmp1 = R6_ARG4;

     Register tmp2 = R7_ARG5;

     Register tmp3 = R8_ARG6;

     Register tmp4 = R0;

     Label l_1, l_2, l_3, l_4, l_5;

     __ cmpwi(CCR0, R5_ARG3, 0);

     __ beq(CCR0, l_1);

     { // FasterArrayCopy

       __ sldi(R5_ARG3, R5_ARG3, 3);

       __ add(R3_ARG1, R3_ARG1, R5_ARG3);

       __ add(R4_ARG2, R4_ARG2, R5_ARG3);

       __ srdi(R5_ARG3, R5_ARG3, 3);

       __ cmpwi(CCR0, R5_ARG3, 3);

       __ ble(CCR0, l_5); // copy 1 at a time if less than 4 elements remain

       __ srdi(tmp1, R5_ARG3, 2);

       __ andi(R5_ARG3, R5_ARG3, 3);

       __ mtctr(tmp1);

       __ bind(l_4);

       // Use unrolled version for mass copying (copy 4 elements a time).

       // Load feeding store gets zero latency on Power6, however not on Power5.

       // Therefore, the following sequence is made for the good of both.

       __ addi(R3_ARG1, R3_ARG1, -32);

       __ addi(R4_ARG2, R4_ARG2, -32);

       __ ld(tmp4, 24, R3_ARG1);

       __ ld(tmp3, 16, R3_ARG1);

       __ ld(tmp2, 8, R3_ARG1);

       __ ld(tmp1, 0, R3_ARG1);

       __ std(tmp4, 24, R4_ARG2);

       __ std(tmp3, 16, R4_ARG2);

       __ std(tmp2, 8, R4_ARG2);

       __ std(tmp1, 0, R4_ARG2);

       __ bdnz(l_4);

       __ cmpwi(CCR0, R5_ARG3, 0);

       __ beq(CCR0, l_1);

       __ bind(l_5);

       __ mtctr(R5_ARG3);

       __ bind(l_3);

       __ ld(R0, -8, R3_ARG1);

       __ std(R0, -8, R4_ARG2);

       __ addi(R3_ARG1, R3_ARG1, -8);

       __ addi(R4_ARG2, R4_ARG2, -8);

       __ bdnz(l_3);

     }

     __ bind(l_1);

   }

   // Generate stub for conjoint long copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //

   address generate_conjoint_long_copy(bool aligned, const char * name) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

 #if defined(ABI_ELFv2)

     address nooverlap_target = aligned ?

       StubRoutines::arrayof_jlong_disjoint_arraycopy() :

       StubRoutines::jlong_disjoint_arraycopy();

 #else

     address nooverlap_target = aligned ?

       ((FunctionDescriptor*)StubRoutines::arrayof_jlong_disjoint_arraycopy())->entry() :

       ((FunctionDescriptor*)StubRoutines::jlong_disjoint_arraycopy())->entry();

 #endif

     array_overlap_test(nooverlap_target, 3);

     generate_conjoint_long_copy_core(aligned);

     __ blr();

     return start;

   }

   // Generate stub for conjoint oop copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //      dest_uninitialized: G1 support

   //

   address generate_conjoint_oop_copy(bool aligned, const char * name, bool dest_uninitialized) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

 #if defined(ABI_ELFv2)

     address nooverlap_target = aligned ?

       StubRoutines::arrayof_oop_disjoint_arraycopy() :

       StubRoutines::oop_disjoint_arraycopy();

 #else

     address nooverlap_target = aligned ?

       ((FunctionDescriptor*)StubRoutines::arrayof_oop_disjoint_arraycopy())->entry() :

       ((FunctionDescriptor*)StubRoutines::oop_disjoint_arraycopy())->entry();

 #endif

     gen_write_ref_array_pre_barrier(R3_ARG1, R4_ARG2, R5_ARG3, dest_uninitialized, R9_ARG7);

     // Save arguments.

     __ mr(R9_ARG7, R4_ARG2);

     __ mr(R10_ARG8, R5_ARG3);

     if (UseCompressedOops) {

       array_overlap_test(nooverlap_target, 2);

       generate_conjoint_int_copy_core(aligned);

     } else {

       array_overlap_test(nooverlap_target, 3);

       generate_conjoint_long_copy_core(aligned);

     }

     gen_write_ref_array_post_barrier(R9_ARG7, R10_ARG8, R11_scratch1, /*branchToEnd*/ false);

     return start;

   }

   // Generate stub for disjoint oop copy.  If "aligned" is true, the

   // "from" and "to" addresses are assumed to be heapword aligned.

   //

   // Arguments for generated stub:

   //      from:  R3_ARG1

   //      to:    R4_ARG2

   //      count: R5_ARG3 treated as signed

   //      dest_uninitialized: G1 support

   //

   address generate_disjoint_oop_copy(bool aligned, const char * name, bool dest_uninitialized) {

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ function_entry();

     gen_write_ref_array_pre_barrier(R3_ARG1, R4_ARG2, R5_ARG3, dest_uninitialized, R9_ARG7);

     // save some arguments, disjoint_long_copy_core destroys them.

     // needed for post barrier

     __ mr(R9_ARG7, R4_ARG2);

     __ mr(R10_ARG8, R5_ARG3);

     if (UseCompressedOops) {

       generate_disjoint_int_copy_core(aligned);

     } else {

       generate_disjoint_long_copy_core(aligned);

     }

     gen_write_ref_array_post_barrier(R9_ARG7, R10_ARG8, R11_scratch1, /*branchToEnd*/ false);

     return start;

   }

   void generate_arraycopy_stubs() {

     // Note: the disjoint stubs must be generated first, some of

     // the conjoint stubs use them.

     // non-aligned disjoint versions

     StubRoutines::_jbyte_disjoint_arraycopy       = generate_disjoint_byte_copy(false, "jbyte_disjoint_arraycopy");

     StubRoutines::_jshort_disjoint_arraycopy      = generate_disjoint_short_copy(false, "jshort_disjoint_arraycopy");

     StubRoutines::_jint_disjoint_arraycopy        = generate_disjoint_int_copy(false, "jint_disjoint_arraycopy");

     StubRoutines::_jlong_disjoint_arraycopy       = generate_disjoint_long_copy(false, "jlong_disjoint_arraycopy");

     StubRoutines::_oop_disjoint_arraycopy         = generate_disjoint_oop_copy(false, "oop_disjoint_arraycopy", false);

     StubRoutines::_oop_disjoint_arraycopy_uninit  = generate_disjoint_oop_copy(false, "oop_disjoint_arraycopy_uninit", true);

     // aligned disjoint versions

     StubRoutines::_arrayof_jbyte_disjoint_arraycopy      = generate_disjoint_byte_copy(true, "arrayof_jbyte_disjoint_arraycopy");

     StubRoutines::_arrayof_jshort_disjoint_arraycopy     = generate_disjoint_short_copy(true, "arrayof_jshort_disjoint_arraycopy");

     StubRoutines::_arrayof_jint_disjoint_arraycopy       = generate_disjoint_int_copy(true, "arrayof_jint_disjoint_arraycopy");

     StubRoutines::_arrayof_jlong_disjoint_arraycopy      = generate_disjoint_long_copy(true, "arrayof_jlong_disjoint_arraycopy");

     StubRoutines::_arrayof_oop_disjoint_arraycopy        = generate_disjoint_oop_copy(true, "arrayof_oop_disjoint_arraycopy", false);

     StubRoutines::_arrayof_oop_disjoint_arraycopy_uninit = generate_disjoint_oop_copy(true, "oop_disjoint_arraycopy_uninit", true);

     // non-aligned conjoint versions

     StubRoutines::_jbyte_arraycopy      = generate_conjoint_byte_copy(false, "jbyte_arraycopy");

     StubRoutines::_jshort_arraycopy     = generate_conjoint_short_copy(false, "jshort_arraycopy");

     StubRoutines::_jint_arraycopy       = generate_conjoint_int_copy(false, "jint_arraycopy");

     StubRoutines::_jlong_arraycopy      = generate_conjoint_long_copy(false, "jlong_arraycopy");

     StubRoutines::_oop_arraycopy        = generate_conjoint_oop_copy(false, "oop_arraycopy", false);

     StubRoutines::_oop_arraycopy_uninit = generate_conjoint_oop_copy(false, "oop_arraycopy_uninit", true);

     // aligned conjoint versions

     StubRoutines::_arrayof_jbyte_arraycopy      = generate_conjoint_byte_copy(true, "arrayof_jbyte_arraycopy");

     StubRoutines::_arrayof_jshort_arraycopy     = generate_conjoint_short_copy(true, "arrayof_jshort_arraycopy");

     StubRoutines::_arrayof_jint_arraycopy       = generate_conjoint_int_copy(true, "arrayof_jint_arraycopy");

     StubRoutines::_arrayof_jlong_arraycopy      = generate_conjoint_long_copy(true, "arrayof_jlong_arraycopy");

     StubRoutines::_arrayof_oop_arraycopy        = generate_conjoint_oop_copy(true, "arrayof_oop_arraycopy", false);

     StubRoutines::_arrayof_oop_arraycopy_uninit = generate_conjoint_oop_copy(true, "arrayof_oop_arraycopy", true);

     // fill routines

     StubRoutines::_jbyte_fill          = generate_fill(T_BYTE,  false, "jbyte_fill");

     StubRoutines::_jshort_fill         = generate_fill(T_SHORT, false, "jshort_fill");

     StubRoutines::_jint_fill           = generate_fill(T_INT,   false, "jint_fill");

     StubRoutines::_arrayof_jbyte_fill  = generate_fill(T_BYTE,  true, "arrayof_jbyte_fill");

     StubRoutines::_arrayof_jshort_fill = generate_fill(T_SHORT, true, "arrayof_jshort_fill");

     StubRoutines::_arrayof_jint_fill   = generate_fill(T_INT,   true, "arrayof_jint_fill");

   }

   // Safefetch stubs.

   void generate_safefetch(const char* name, int size, address* entry, address* fault_pc, address* continuation_pc) {

     // safefetch signatures:

     //   int      SafeFetch32(int*      adr, int      errValue);

     //   intptr_t SafeFetchN (intptr_t* adr, intptr_t errValue);

     //

     // arguments:

     //   R3_ARG1 = adr

     //   R4_ARG2 = errValue

     //

     // result:

     //   R3_RET  = *adr or errValue

     StubCodeMark mark(this, "StubRoutines", name);

     // Entry point, pc or function descriptor.

     *entry = __ function_entry();

     // Load *adr into R4_ARG2, may fault.

     *fault_pc = __ pc();

     switch (size) {

       case 4:

         // int32_t, signed extended

         __ lwa(R4_ARG2, 0, R3_ARG1);

         break;

       case 8:

         // int64_t

         __ ld(R4_ARG2, 0, R3_ARG1);

         break;

       default:

         ShouldNotReachHere();

     }

     // return errValue or *adr

     *continuation_pc = __ pc();

     __ mr(R3_RET, R4_ARG2);

     __ blr();

   }

   // Initialization

   void generate_initial() {

     // Generates all stubs and initializes the entry points

     // Entry points that exist in all platforms.

     // Note: This is code that could be shared among different platforms - however the

     // benefit seems to be smaller than the disadvantage of having a

     // much more complicated generator structure. See also comment in

     // stubRoutines.hpp.

     StubRoutines::_forward_exception_entry          = generate_forward_exception();

     StubRoutines::_call_stub_entry                  = generate_call_stub(StubRoutines::_call_stub_return_address);

     StubRoutines::_catch_exception_entry            = generate_catch_exception();

     // Build this early so it's available for the interpreter.

     StubRoutines::_throw_StackOverflowError_entry   =

       generate_throw_exception("StackOverflowError throw_exception",

                                CAST_FROM_FN_PTR(address, SharedRuntime::throw_StackOverflowError), false);

   }

   void generate_all() {

     // Generates all stubs and initializes the entry points

     // These entry points require SharedInfo::stack0 to be set up in

     // non-core builds

     StubRoutines::_throw_AbstractMethodError_entry         = generate_throw_exception("AbstractMethodError throw_exception",          CAST_FROM_FN_PTR(address, SharedRuntime::throw_AbstractMethodError),  false);

     // Handle IncompatibleClassChangeError in itable stubs.

     StubRoutines::_throw_IncompatibleClassChangeError_entry= generate_throw_exception("IncompatibleClassChangeError throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_IncompatibleClassChangeError),  false);

     StubRoutines::_throw_NullPointerException_at_call_entry= generate_throw_exception("NullPointerException at call throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_NullPointerException_at_call), false);

     StubRoutines::_handler_for_unsafe_access_entry         = generate_handler_for_unsafe_access();

     // support for verify_oop (must happen after universe_init)

     StubRoutines::_verify_oop_subroutine_entry             = generate_verify_oop();

     // arraycopy stubs used by compilers

     generate_arraycopy_stubs();

     if (UseAESIntrinsics) {

       guarantee(!UseAESIntrinsics, "not yet implemented.");

     }

     // PPC uses stubs for safefetch.

     generate_safefetch("SafeFetch32", sizeof(int),     &StubRoutines::_safefetch32_entry,

                                                        &StubRoutines::_safefetch32_fault_pc,

                                                        &StubRoutines::_safefetch32_continuation_pc);

     generate_safefetch("SafeFetchN", sizeof(intptr_t), &StubRoutines::_safefetchN_entry,

                                                        &StubRoutines::_safefetchN_fault_pc,

                                                        &StubRoutines::_safefetchN_continuation_pc);

   }

  public:

   StubGenerator(CodeBuffer* code, bool all) : StubCodeGenerator(code) {

     // replace the standard masm with a special one:

     _masm = new MacroAssembler(code);

     if (all) {

       generate_all();

     } else {

       generate_initial();

     }

   }

 };

 void StubGenerator_generate(CodeBuffer* code, bool all) {

   StubGenerator g(code, all);

 }