jdk8-mips64-public/hotspot: src/cpu/ppc/vm/stubGenerator

src/cpu/ppc/vm/stubGenerator_ppc.cpp@04ff2f6cd0eb (annotated)

src/cpu/ppc/vm/stubGenerator_ppc.cpp

Tue, 17 Oct 2017 12:58:25 +0800

author: aoqi
date: Tue, 17 Oct 2017 12:58:25 +0800
changeset 7994: 04ff2f6cd0eb
parent 7535: 7ae4e26cb1e0
child 8856: ac27a9c85bea
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2012, 2014 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/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"
 #include "runtime/thread.inline.hpp"
 #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;
       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.
 #ifdef CC_INTERP
       const Register tos = R17_tos;
 #else
       const Register tos = R15_esp;
 #endif
       __ 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.
 #ifdef CC_INTERP
       __ li(R15_prev_state, 0);
 #else
       __ load_const_optimized(R25_templateTableBase, (address)Interpreter::dispatch_table((TosState)0), R11_scratch1);
 #endif
       // 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.");
     }
     // Safefetch stubs.
     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);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/cpu/ppc/vm/stubGenerator_ppc.cpp@04ff2f6cd0eb (annotated)

src/cpu/ppc/vm/stubGenerator_ppc.cpp