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 /*

  * Copyright (c) 2002, 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.

  *

  */

 #ifndef CPU_PPC_VM_MACROASSEMBLER_PPC_HPP

 #define CPU_PPC_VM_MACROASSEMBLER_PPC_HPP

 #include "asm/assembler.hpp"

 // MacroAssembler extends Assembler by a few frequently used macros.

 class ciTypeArray;

 class MacroAssembler: public Assembler {

  public:

   MacroAssembler(CodeBuffer* code) : Assembler(code) {}

   //

   // Optimized instruction emitters

   //

   inline static int largeoffset_si16_si16_hi(int si31) { return (si31 + (1<<15)) >> 16; }

   inline static int largeoffset_si16_si16_lo(int si31) { return si31 - (((si31 + (1<<15)) >> 16) << 16); }

   // load d = *[a+si31]

   // Emits several instructions if the offset is not encodable in one instruction.

   void ld_largeoffset_unchecked(Register d, int si31, Register a, int emit_filler_nop);

   void ld_largeoffset          (Register d, int si31, Register a, int emit_filler_nop);

   inline static bool is_ld_largeoffset(address a);

   inline static int get_ld_largeoffset_offset(address a);

   inline void round_to(Register r, int modulus);

   // Load/store with type given by parameter.

   void load_sized_value( Register dst, RegisterOrConstant offs, Register base, size_t size_in_bytes, bool is_signed);

   void store_sized_value(Register dst, RegisterOrConstant offs, Register base, size_t size_in_bytes);

   // Move register if destination register and target register are different

   inline void mr_if_needed(Register rd, Register rs);

   inline void fmr_if_needed(FloatRegister rd, FloatRegister rs);

   // This is dedicated for emitting scheduled mach nodes. For better

   // readability of the ad file I put it here.

   // Endgroups are not needed if

   //  - the scheduler is off

   //  - the scheduler found that there is a natural group end, in that

   //    case it reduced the size of the instruction used in the test

   //    yielding 'needed'.

   inline void endgroup_if_needed(bool needed);

   // Memory barriers.

   inline void membar(int bits);

   inline void release();

   inline void acquire();

   inline void fence();

   // nop padding

   void align(int modulus, int max = 252, int rem = 0);

   //

   // Constants, loading constants, TOC support

   //

   // Address of the global TOC.

   inline static address global_toc();

   // Offset of given address to the global TOC.

   inline static int offset_to_global_toc(const address addr);

   // Address of TOC of the current method.

   inline address method_toc();

   // Offset of given address to TOC of the current method.

   inline int offset_to_method_toc(const address addr);

   // Global TOC.

   void calculate_address_from_global_toc(Register dst, address addr,

                                          bool hi16 = true, bool lo16 = true,

                                          bool add_relocation = true, bool emit_dummy_addr = false);

   inline void calculate_address_from_global_toc_hi16only(Register dst, address addr) {

     calculate_address_from_global_toc(dst, addr, true, false);

   };

   inline void calculate_address_from_global_toc_lo16only(Register dst, address addr) {

     calculate_address_from_global_toc(dst, addr, false, true);

   };

   inline static bool is_calculate_address_from_global_toc_at(address a, address bound);

   static int patch_calculate_address_from_global_toc_at(address a, address addr, address bound);

   static address get_address_of_calculate_address_from_global_toc_at(address a, address addr);

 #ifdef _LP64

   // Patch narrow oop constant.

   inline static bool is_set_narrow_oop(address a, address bound);

   static int patch_set_narrow_oop(address a, address bound, narrowOop data);

   static narrowOop get_narrow_oop(address a, address bound);

 #endif

   inline static bool is_load_const_at(address a);

   // Emits an oop const to the constant pool, loads the constant, and

   // sets a relocation info with address current_pc.

   void load_const_from_method_toc(Register dst, AddressLiteral& a, Register toc);

   void load_toc_from_toc(Register dst, AddressLiteral& a, Register toc) {

     assert(dst == R2_TOC, "base register must be TOC");

     load_const_from_method_toc(dst, a, toc);

   }

   static bool is_load_const_from_method_toc_at(address a);

   static int get_offset_of_load_const_from_method_toc_at(address a);

   // Get the 64 bit constant from a `load_const' sequence.

   static long get_const(address load_const);

   // Patch the 64 bit constant of a `load_const' sequence. This is a

   // low level procedure. It neither flushes the instruction cache nor

   // is it atomic.

   static void patch_const(address load_const, long x);

   // Metadata in code that we have to keep track of.

   AddressLiteral allocate_metadata_address(Metadata* obj); // allocate_index

   AddressLiteral constant_metadata_address(Metadata* obj); // find_index

   // Oops used directly in compiled code are stored in the constant pool,

   // and loaded from there.

   // Allocate new entry for oop in constant pool. Generate relocation.

   AddressLiteral allocate_oop_address(jobject obj);

   // Find oop obj in constant pool. Return relocation with it's index.

   AddressLiteral constant_oop_address(jobject obj);

   // Find oop in constant pool and emit instructions to load it.

   // Uses constant_oop_address.

   inline void set_oop_constant(jobject obj, Register d);

   // Same as load_address.

   inline void set_oop         (AddressLiteral obj_addr, Register d);

   // Read runtime constant:  Issue load if constant not yet established,

   // else use real constant.

   virtual RegisterOrConstant delayed_value_impl(intptr_t* delayed_value_addr,

                                                 Register tmp,

                                                 int offset);

   //

   // branch, jump

   //

   inline void pd_patch_instruction(address branch, address target);

   NOT_PRODUCT(static void pd_print_patched_instruction(address branch);)

   // Conditional far branch for destinations encodable in 24+2 bits.

   // Same interface as bc, e.g. no inverse boint-field.

   enum {

     bc_far_optimize_not         = 0,

     bc_far_optimize_on_relocate = 1

   };

   // optimize: flag for telling the conditional far branch to optimize

   //           itself when relocated.

   void bc_far(int boint, int biint, Label& dest, int optimize);

   // Relocation of conditional far branches.

   static bool    is_bc_far_at(address instruction_addr);

   static address get_dest_of_bc_far_at(address instruction_addr);

   static void    set_dest_of_bc_far_at(address instruction_addr, address dest);

  private:

   static bool inline is_bc_far_variant1_at(address instruction_addr);

   static bool inline is_bc_far_variant2_at(address instruction_addr);

   static bool inline is_bc_far_variant3_at(address instruction_addr);

  public:

   // Convenience bc_far versions.

   inline void blt_far(ConditionRegister crx, Label& L, int optimize);

   inline void bgt_far(ConditionRegister crx, Label& L, int optimize);

   inline void beq_far(ConditionRegister crx, Label& L, int optimize);

   inline void bso_far(ConditionRegister crx, Label& L, int optimize);

   inline void bge_far(ConditionRegister crx, Label& L, int optimize);

   inline void ble_far(ConditionRegister crx, Label& L, int optimize);

   inline void bne_far(ConditionRegister crx, Label& L, int optimize);

   inline void bns_far(ConditionRegister crx, Label& L, int optimize);

   // Emit, identify and patch a NOT mt-safe patchable 64 bit absolute call/jump.

  private:

   enum {

     bxx64_patchable_instruction_count = (2/*load_codecache_const*/ + 3/*5load_const*/ + 1/*mtctr*/ + 1/*bctrl*/),

     bxx64_patchable_size              = bxx64_patchable_instruction_count * BytesPerInstWord,

     bxx64_patchable_ret_addr_offset   = bxx64_patchable_size

   };

   void bxx64_patchable(address target, relocInfo::relocType rt, bool link);

   static bool is_bxx64_patchable_at(            address instruction_addr, bool link);

   // Does the instruction use a pc-relative encoding of the destination?

   static bool is_bxx64_patchable_pcrelative_at( address instruction_addr, bool link);

   static bool is_bxx64_patchable_variant1_at(   address instruction_addr, bool link);

   // Load destination relative to global toc.

   static bool is_bxx64_patchable_variant1b_at(  address instruction_addr, bool link);

   static bool is_bxx64_patchable_variant2_at(   address instruction_addr, bool link);

   static void set_dest_of_bxx64_patchable_at(   address instruction_addr, address target, bool link);

   static address get_dest_of_bxx64_patchable_at(address instruction_addr, bool link);

  public:

   // call

   enum {

     bl64_patchable_instruction_count = bxx64_patchable_instruction_count,

     bl64_patchable_size              = bxx64_patchable_size,

     bl64_patchable_ret_addr_offset   = bxx64_patchable_ret_addr_offset

   };

   inline void bl64_patchable(address target, relocInfo::relocType rt) {

     bxx64_patchable(target, rt, /*link=*/true);

   }

   inline static bool is_bl64_patchable_at(address instruction_addr) {

     return is_bxx64_patchable_at(instruction_addr, /*link=*/true);

   }

   inline static bool is_bl64_patchable_pcrelative_at(address instruction_addr) {

     return is_bxx64_patchable_pcrelative_at(instruction_addr, /*link=*/true);

   }

   inline static void set_dest_of_bl64_patchable_at(address instruction_addr, address target) {

     set_dest_of_bxx64_patchable_at(instruction_addr, target, /*link=*/true);

   }

   inline static address get_dest_of_bl64_patchable_at(address instruction_addr) {

     return get_dest_of_bxx64_patchable_at(instruction_addr, /*link=*/true);

   }

   // jump

   enum {

     b64_patchable_instruction_count = bxx64_patchable_instruction_count,

     b64_patchable_size              = bxx64_patchable_size,

   };

   inline void b64_patchable(address target, relocInfo::relocType rt) {

     bxx64_patchable(target, rt, /*link=*/false);

   }

   inline static bool is_b64_patchable_at(address instruction_addr) {

     return is_bxx64_patchable_at(instruction_addr, /*link=*/false);

   }

   inline static bool is_b64_patchable_pcrelative_at(address instruction_addr) {

     return is_bxx64_patchable_pcrelative_at(instruction_addr, /*link=*/false);

   }

   inline static void set_dest_of_b64_patchable_at(address instruction_addr, address target) {

     set_dest_of_bxx64_patchable_at(instruction_addr, target, /*link=*/false);

   }

   inline static address get_dest_of_b64_patchable_at(address instruction_addr) {

     return get_dest_of_bxx64_patchable_at(instruction_addr, /*link=*/false);

   }

   //

   // Support for frame handling

   //

   // some ABI-related functions

   void save_nonvolatile_gprs(   Register dst_base, int offset);

   void restore_nonvolatile_gprs(Register src_base, int offset);

   void save_volatile_gprs(   Register dst_base, int offset);

   void restore_volatile_gprs(Register src_base, int offset);

   void save_LR_CR(   Register tmp);     // tmp contains LR on return.

   void restore_LR_CR(Register tmp);

   // Get current PC using bl-next-instruction trick.

   address get_PC_trash_LR(Register result);

   // Resize current frame either relatively wrt to current SP or absolute.

   void resize_frame(Register offset, Register tmp);

   void resize_frame(int      offset, Register tmp);

   void resize_frame_absolute(Register addr, Register tmp1, Register tmp2);

   // Push a frame of size bytes.

   void push_frame(Register bytes, Register tmp);

   // Push a frame of size `bytes'. No abi space provided.

   void push_frame(unsigned int bytes, Register tmp);

   // Push a frame of size `bytes' plus abi_reg_args on top.

   void push_frame_reg_args(unsigned int bytes, Register tmp);

   // Setup up a new C frame with a spill area for non-volatile GPRs and additional

   // space for local variables

   void push_frame_reg_args_nonvolatiles(unsigned int bytes, Register tmp);

   // pop current C frame

   void pop_frame();

   //

   // Calls

   //

  private:

   address _last_calls_return_pc;

 #if defined(ABI_ELFv2)

   // Generic version of a call to C function.

   // Updates and returns _last_calls_return_pc.

   address branch_to(Register function_entry, bool and_link);

 #else

   // Generic version of a call to C function via a function descriptor

   // with variable support for C calling conventions (TOC, ENV, etc.).

   // updates and returns _last_calls_return_pc.

   address branch_to(Register function_descriptor, bool and_link, bool save_toc_before_call,

                     bool restore_toc_after_call, bool load_toc_of_callee, bool load_env_of_callee);

 #endif

  public:

   // Get the pc where the last call will return to. returns _last_calls_return_pc.

   inline address last_calls_return_pc();

 #if defined(ABI_ELFv2)

   // Call a C function via a function descriptor and use full C

   // calling conventions. Updates and returns _last_calls_return_pc.

   address call_c(Register function_entry);

   // For tail calls: only branch, don't link, so callee returns to caller of this function.

   address call_c_and_return_to_caller(Register function_entry);

   address call_c(address function_entry, relocInfo::relocType rt);

 #else

   // Call a C function via a function descriptor and use full C

   // calling conventions. Updates and returns _last_calls_return_pc.

   address call_c(Register function_descriptor);

   // For tail calls: only branch, don't link, so callee returns to caller of this function.

   address call_c_and_return_to_caller(Register function_descriptor);

   address call_c(const FunctionDescriptor* function_descriptor, relocInfo::relocType rt);

   address call_c_using_toc(const FunctionDescriptor* function_descriptor, relocInfo::relocType rt,

                            Register toc);

 #endif

  protected:

   // It is imperative that all calls into the VM are handled via the

   // call_VM macros. They make sure that the stack linkage is setup

   // correctly. call_VM's correspond to ENTRY/ENTRY_X entry points

   // while call_VM_leaf's correspond to LEAF entry points.

   //

   // This is the base routine called by the different versions of

   // call_VM. The interpreter may customize this version by overriding

   // it for its purposes (e.g., to save/restore additional registers

   // when doing a VM call).

   //

   // If no last_java_sp is specified (noreg) then SP will be used instead.

   virtual void call_VM_base(

      // where an oop-result ends up if any; use noreg otherwise

     Register        oop_result,

     // to set up last_Java_frame in stubs; use noreg otherwise

     Register        last_java_sp,

     // the entry point

     address         entry_point,

     // flag which indicates if exception should be checked

     bool            check_exception = true

   );

   // Support for VM calls. This is the base routine called by the

   // different versions of call_VM_leaf. The interpreter may customize

   // this version by overriding it for its purposes (e.g., to

   // save/restore additional registers when doing a VM call).

   void call_VM_leaf_base(address entry_point);

  public:

   // Call into the VM.

   // Passes the thread pointer (in R3_ARG1) as a prepended argument.

   // Makes sure oop return values are visible to the GC.

   void call_VM(Register oop_result, address entry_point, bool check_exceptions = true);

   void call_VM(Register oop_result, address entry_point, Register arg_1, bool check_exceptions = true);

   void call_VM(Register oop_result, address entry_point, Register arg_1, Register arg_2, bool check_exceptions = true);

   void call_VM(Register oop_result, address entry_point, Register arg_1, Register arg_2, Register arg3, bool check_exceptions = true);

   void call_VM_leaf(address entry_point);

   void call_VM_leaf(address entry_point, Register arg_1);

   void call_VM_leaf(address entry_point, Register arg_1, Register arg_2);

   void call_VM_leaf(address entry_point, Register arg_1, Register arg_2, Register arg_3);

   // Call a stub function via a function descriptor, but don't save

   // TOC before call, don't setup TOC and ENV for call, and don't

   // restore TOC after call. Updates and returns _last_calls_return_pc.

   inline address call_stub(Register function_entry);

   inline void call_stub_and_return_to(Register function_entry, Register return_pc);

   //

   // Java utilities

   //

   // Read from the polling page, its address is already in a register.

   inline void load_from_polling_page(Register polling_page_address, int offset = 0);

   // Check whether instruction is a read access to the polling page

   // which was emitted by load_from_polling_page(..).

   static bool is_load_from_polling_page(int instruction, void* ucontext/*may be NULL*/,

                                         address* polling_address_ptr = NULL);

   // Check whether instruction is a write access to the memory

   // serialization page realized by one of the instructions stw, stwu,

   // stwx, or stwux.

   static bool is_memory_serialization(int instruction, JavaThread* thread, void* ucontext);

   // Support for NULL-checks

   //

   // Generates code that causes a NULL OS exception if the content of reg is NULL.

   // If the accessed location is M[reg + offset] and the offset is known, provide the

   // offset. No explicit code generation is needed if the offset is within a certain

   // range (0 <= offset <= page_size).

   // Stack overflow checking

   void bang_stack_with_offset(int offset);

   // If instruction is a stack bang of the form ld, stdu, or

   // stdux, return the banged address. Otherwise, return 0.

   static address get_stack_bang_address(int instruction, void* ucontext);

   // Atomics

   // CmpxchgX sets condition register to cmpX(current, compare).

   // (flag == ne) => (dest_current_value != compare_value), (!swapped)

   // (flag == eq) => (dest_current_value == compare_value), ( swapped)

   static inline bool cmpxchgx_hint_acquire_lock()  { return true; }

   // The stxcx will probably not be succeeded by a releasing store.

   static inline bool cmpxchgx_hint_release_lock()  { return false; }

   static inline bool cmpxchgx_hint_atomic_update() { return false; }

   // Cmpxchg semantics

   enum {

     MemBarNone = 0,

     MemBarRel  = 1,

     MemBarAcq  = 2,

     MemBarFenceAfter = 4 // use powers of 2

   };

   void cmpxchgw(ConditionRegister flag,

                 Register dest_current_value, Register compare_value, Register exchange_value, Register addr_base,

                 int semantics, bool cmpxchgx_hint = false,

                 Register int_flag_success = noreg, bool contention_hint = false);

   void cmpxchgd(ConditionRegister flag,

                 Register dest_current_value, Register compare_value, Register exchange_value, Register addr_base,

                 int semantics, bool cmpxchgx_hint = false,

                 Register int_flag_success = noreg, Label* failed = NULL, bool contention_hint = false);

   // interface method calling

   void lookup_interface_method(Register recv_klass,

                                Register intf_klass,

                                RegisterOrConstant itable_index,

                                Register method_result,

                                Register temp_reg, Register temp2_reg,

                                Label& no_such_interface);

   // virtual method calling

   void lookup_virtual_method(Register recv_klass,

                              RegisterOrConstant vtable_index,

                              Register method_result);

   // Test sub_klass against super_klass, with fast and slow paths.

   // The fast path produces a tri-state answer: yes / no / maybe-slow.

   // One of the three labels can be NULL, meaning take the fall-through.

   // If super_check_offset is -1, the value is loaded up from super_klass.

   // No registers are killed, except temp_reg and temp2_reg.

   // If super_check_offset is not -1, temp2_reg is not used and can be noreg.

   void check_klass_subtype_fast_path(Register sub_klass,

                                      Register super_klass,

                                      Register temp1_reg,

                                      Register temp2_reg,

                                      Label& L_success,

                                      Label& L_failure);

   // The rest of the type check; must be wired to a corresponding fast path.

   // It does not repeat the fast path logic, so don't use it standalone.

   // The temp_reg can be noreg, if no temps are available.

   // It can also be sub_klass or super_klass, meaning it's OK to kill that one.

   // Updates the sub's secondary super cache as necessary.

   void check_klass_subtype_slow_path(Register sub_klass,

                                      Register super_klass,

                                      Register temp1_reg,

                                      Register temp2_reg,

                                      Label* L_success = NULL,

                                      Register result_reg = noreg);

   // Simplified, combined version, good for typical uses.

   // Falls through on failure.

   void check_klass_subtype(Register sub_klass,

                            Register super_klass,

                            Register temp1_reg,

                            Register temp2_reg,

                            Label& L_success);

   // Method handle support (JSR 292).

   void check_method_handle_type(Register mtype_reg, Register mh_reg, Register temp_reg, Label& wrong_method_type);

   RegisterOrConstant argument_offset(RegisterOrConstant arg_slot, Register temp_reg, int extra_slot_offset = 0);

   // Biased locking support

   // Upon entry,obj_reg must contain the target object, and mark_reg

   // must contain the target object's header.

   // Destroys mark_reg if an attempt is made to bias an anonymously

   // biased lock. In this case a failure will go either to the slow

   // case or fall through with the notEqual condition code set with

   // the expectation that the slow case in the runtime will be called.

   // In the fall-through case where the CAS-based lock is done,

   // mark_reg is not destroyed.

   void biased_locking_enter(ConditionRegister cr_reg, Register obj_reg, Register mark_reg, Register temp_reg,

                             Register temp2_reg, Label& done, Label* slow_case = NULL);

   // Upon entry, the base register of mark_addr must contain the oop.

   // Destroys temp_reg.

   // If allow_delay_slot_filling is set to true, the next instruction

   // emitted after this one will go in an annulled delay slot if the

   // biased locking exit case failed.

   void biased_locking_exit(ConditionRegister cr_reg, Register mark_addr, Register temp_reg, Label& done);

   void compiler_fast_lock_object(  ConditionRegister flag, Register oop, Register box, Register tmp1, Register tmp2, Register tmp3);

   void compiler_fast_unlock_object(ConditionRegister flag, Register oop, Register box, Register tmp1, Register tmp2, Register tmp3);

   // Support for serializing memory accesses between threads

   void serialize_memory(Register thread, Register tmp1, Register tmp2);

   // GC barrier support.

   void card_write_barrier_post(Register Rstore_addr, Register Rnew_val, Register Rtmp);

   void card_table_write(jbyte* byte_map_base, Register Rtmp, Register Robj);

 #if INCLUDE_ALL_GCS

   // General G1 pre-barrier generator.

   void g1_write_barrier_pre(Register Robj, RegisterOrConstant offset, Register Rpre_val,

                             Register Rtmp1, Register Rtmp2, bool needs_frame = false);

   // General G1 post-barrier generator

   void g1_write_barrier_post(Register Rstore_addr, Register Rnew_val, Register Rtmp1,

                              Register Rtmp2, Register Rtmp3, Label *filtered_ext = NULL);

 #endif

   // Support for managing the JavaThread pointer (i.e.; the reference to

   // thread-local information).

   // Support for last Java frame (but use call_VM instead where possible):

   // access R16_thread->last_Java_sp.

   void set_last_Java_frame(Register last_java_sp, Register last_Java_pc);

   void reset_last_Java_frame(void);

   void set_top_ijava_frame_at_SP_as_last_Java_frame(Register sp, Register tmp1);

   // Read vm result from thread: oop_result = R16_thread->result;

   void get_vm_result  (Register oop_result);

   void get_vm_result_2(Register metadata_result);

   static bool needs_explicit_null_check(intptr_t offset);

   // Trap-instruction-based checks.

   // Range checks can be distinguished from zero checks as they check 32 bit,

   // zero checks all 64 bits (tw, td).

   inline void trap_null_check(Register a, trap_to_bits cmp = traptoEqual);

   static bool is_trap_null_check(int x) {

     return is_tdi(x, traptoEqual,               -1/*any reg*/, 0) ||

            is_tdi(x, traptoGreaterThanUnsigned, -1/*any reg*/, 0);

   }

   inline void trap_zombie_not_entrant();

   static bool is_trap_zombie_not_entrant(int x) { return is_tdi(x, traptoUnconditional, 0/*reg 0*/, 1); }

   inline void trap_should_not_reach_here();

   static bool is_trap_should_not_reach_here(int x) { return is_tdi(x, traptoUnconditional, 0/*reg 0*/, 2); }

   inline void trap_ic_miss_check(Register a, Register b);

   static bool is_trap_ic_miss_check(int x) {

     return is_td(x, traptoGreaterThanUnsigned | traptoLessThanUnsigned, -1/*any reg*/, -1/*any reg*/);

   }

   // Implicit or explicit null check, jumps to static address exception_entry.

   inline void null_check_throw(Register a, int offset, Register temp_reg, address exception_entry);

   // Check accessed object for null. Use SIGTRAP-based null checks on AIX.

   inline void load_with_trap_null_check(Register d, int si16, Register s1);

   // Load heap oop and decompress. Loaded oop may not be null.

   inline void load_heap_oop_not_null(Register d, RegisterOrConstant offs, Register s1 = noreg);

   inline void store_heap_oop_not_null(Register d, RegisterOrConstant offs, Register s1,

                                       /*specify if d must stay uncompressed*/ Register tmp = noreg);

   // Null allowed.

   inline void load_heap_oop(Register d, RegisterOrConstant offs, Register s1 = noreg);

   // Encode/decode heap oop. Oop may not be null, else en/decoding goes wrong.

   inline Register encode_heap_oop_not_null(Register d, Register src = noreg);

   inline void decode_heap_oop_not_null(Register d);

   // Null allowed.

   inline void decode_heap_oop(Register d);

   // Load/Store klass oop from klass field. Compress.

   void load_klass(Register dst, Register src);

   void load_klass_with_trap_null_check(Register dst, Register src);

   void store_klass(Register dst_oop, Register klass, Register tmp = R0);

   void store_klass_gap(Register dst_oop, Register val = noreg); // Will store 0 if val not specified.

   static int instr_size_for_decode_klass_not_null();

   void decode_klass_not_null(Register dst, Register src = noreg);

   void encode_klass_not_null(Register dst, Register src = noreg);

   // Load common heap base into register.

   void reinit_heapbase(Register d, Register tmp = noreg);

   // SIGTRAP-based range checks for arrays.

   inline void trap_range_check_l(Register a, Register b);

   inline void trap_range_check_l(Register a, int si16);

   static bool is_trap_range_check_l(int x) {

     return (is_tw (x, traptoLessThanUnsigned, -1/*any reg*/, -1/*any reg*/) ||

             is_twi(x, traptoLessThanUnsigned, -1/*any reg*/)                  );

   }

   inline void trap_range_check_le(Register a, int si16);

   static bool is_trap_range_check_le(int x) {

     return is_twi(x, traptoEqual | traptoLessThanUnsigned, -1/*any reg*/);

   }

   inline void trap_range_check_g(Register a, int si16);

   static bool is_trap_range_check_g(int x) {

     return is_twi(x, traptoGreaterThanUnsigned, -1/*any reg*/);

   }

   inline void trap_range_check_ge(Register a, Register b);

   inline void trap_range_check_ge(Register a, int si16);

   static bool is_trap_range_check_ge(int x) {

     return (is_tw (x, traptoEqual | traptoGreaterThanUnsigned, -1/*any reg*/, -1/*any reg*/) ||

             is_twi(x, traptoEqual | traptoGreaterThanUnsigned, -1/*any reg*/)                  );

   }

   static bool is_trap_range_check(int x) {

     return is_trap_range_check_l(x) || is_trap_range_check_le(x) ||

            is_trap_range_check_g(x) || is_trap_range_check_ge(x);

   }

   void clear_memory_doubleword(Register base_ptr, Register cnt_dwords, Register tmp = R0);

   // Needle of length 1.

   void string_indexof_1(Register result, Register haystack, Register haycnt,

                         Register needle, jchar needleChar,

                         Register tmp1, Register tmp2);

   // General indexof, eventually with constant needle length.

   void string_indexof(Register result, Register haystack, Register haycnt,

                       Register needle, ciTypeArray* needle_values, Register needlecnt, int needlecntval,

                       Register tmp1, Register tmp2, Register tmp3, Register tmp4);

   void string_compare(Register str1_reg, Register str2_reg, Register cnt1_reg, Register cnt2_reg,

                       Register result_reg, Register tmp_reg);

   void char_arrays_equals(Register str1_reg, Register str2_reg, Register cnt_reg, Register result_reg,

                           Register tmp1_reg, Register tmp2_reg, Register tmp3_reg, Register tmp4_reg,

                           Register tmp5_reg);

   void char_arrays_equalsImm(Register str1_reg, Register str2_reg, int cntval, Register result_reg,

                              Register tmp1_reg, Register tmp2_reg);

   //

   // Debugging

   //

   // assert on cr0

   void asm_assert(bool check_equal, const char* msg, int id);

   void asm_assert_eq(const char* msg, int id) { asm_assert(true, msg, id); }

   void asm_assert_ne(const char* msg, int id) { asm_assert(false, msg, id); }

  private:

   void asm_assert_mems_zero(bool check_equal, int size, int mem_offset, Register mem_base,

                             const char* msg, int id);

  public:

   void asm_assert_mem8_is_zero(int mem_offset, Register mem_base, const char* msg, int id) {

     asm_assert_mems_zero(true,  8, mem_offset, mem_base, msg, id);

   }

   void asm_assert_mem8_isnot_zero(int mem_offset, Register mem_base, const char* msg, int id) {

     asm_assert_mems_zero(false, 8, mem_offset, mem_base, msg, id);

   }

   // Verify R16_thread contents.

   void verify_thread();

   // Emit code to verify that reg contains a valid oop if +VerifyOops is set.

   void verify_oop(Register reg, const char* s = "broken oop");

   // TODO: verify method and klass metadata (compare against vptr?)

   void _verify_method_ptr(Register reg, const char * msg, const char * file, int line) {}

   void _verify_klass_ptr(Register reg, const char * msg, const char * file, int line) {}

   // Convenience method returning function entry. For the ELFv1 case

   // creates function descriptor at the current address and returs

   // the pointer to it. For the ELFv2 case returns the current address.

   inline address function_entry();

 #define verify_method_ptr(reg) _verify_method_ptr(reg, "broken method " #reg, __FILE__, __LINE__)

 #define verify_klass_ptr(reg) _verify_klass_ptr(reg, "broken klass " #reg, __FILE__, __LINE__)

  private:

   enum {

     stop_stop                = 0,

     stop_untested            = 1,

     stop_unimplemented       = 2,

     stop_shouldnotreachhere  = 3,

     stop_end                 = 4

   };

   void stop(int type, const char* msg, int id);

  public:

   // Prints msg, dumps registers and stops execution.

   void stop         (const char* msg = "", int id = 0) { stop(stop_stop,               msg, id); }

   void untested     (const char* msg = "", int id = 0) { stop(stop_untested,           msg, id); }

   void unimplemented(const char* msg = "", int id = 0) { stop(stop_unimplemented,      msg, id); }

   void should_not_reach_here()                         { stop(stop_shouldnotreachhere,  "", -1); }

   void zap_from_to(Register low, int before, Register high, int after, Register val, Register addr) PRODUCT_RETURN;

 };

 // class SkipIfEqualZero:

 //

 // Instantiating this class will result in assembly code being output that will

 // jump around any code emitted between the creation of the instance and it's

 // automatic destruction at the end of a scope block, depending on the value of

 // the flag passed to the constructor, which will be checked at run-time.

 class SkipIfEqualZero : public StackObj {

  private:

   MacroAssembler* _masm;

   Label _label;

  public:

    // 'Temp' is a temp register that this object can use (and trash).

    explicit SkipIfEqualZero(MacroAssembler*, Register temp, const bool* flag_addr);

    ~SkipIfEqualZero();

 };

 #endif // CPU_PPC_VM_MACROASSEMBLER_PPC_HPP