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 /*

  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

  * Copyright 2013, 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"

 #ifndef CC_INTERP

 #include "asm/macroAssembler.inline.hpp"

 #include "interpreter/bytecodeHistogram.hpp"

 #include "interpreter/interpreter.hpp"

 #include "interpreter/interpreterGenerator.hpp"

 #include "interpreter/interpreterRuntime.hpp"

 #include "interpreter/templateTable.hpp"

 #include "oops/arrayOop.hpp"

 #include "oops/methodData.hpp"

 #include "oops/method.hpp"

 #include "oops/oop.inline.hpp"

 #include "prims/jvmtiExport.hpp"

 #include "prims/jvmtiThreadState.hpp"

 #include "runtime/arguments.hpp"

 #include "runtime/deoptimization.hpp"

 #include "runtime/frame.inline.hpp"

 #include "runtime/sharedRuntime.hpp"

 #include "runtime/stubRoutines.hpp"

 #include "runtime/synchronizer.hpp"

 #include "runtime/timer.hpp"

 #include "runtime/vframeArray.hpp"

 #include "utilities/debug.hpp"

 #include "utilities/macros.hpp"

 #undef __

 #define __ _masm->

 #ifdef PRODUCT

 #define BLOCK_COMMENT(str) /* nothing */

 #else

 #define BLOCK_COMMENT(str) __ block_comment(str)

 #endif

 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")

 //-----------------------------------------------------------------------------

 // Actually we should never reach here since we do stack overflow checks before pushing any frame.

 address TemplateInterpreterGenerator::generate_StackOverflowError_handler() {

   address entry = __ pc();

   __ unimplemented("generate_StackOverflowError_handler");

   return entry;

 }

 address TemplateInterpreterGenerator::generate_ArrayIndexOutOfBounds_handler(const char* name) {

   address entry = __ pc();

   __ empty_expression_stack();

   __ load_const_optimized(R4_ARG2, (address) name);

   // Index is in R17_tos.

   __ mr(R5_ARG3, R17_tos);

   __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_ArrayIndexOutOfBoundsException));

   return entry;

 }

 #if 0

 // Call special ClassCastException constructor taking object to cast

 // and target class as arguments.

 address TemplateInterpreterGenerator::generate_ClassCastException_verbose_handler() {

   address entry = __ pc();

   // Expression stack must be empty before entering the VM if an

   // exception happened.

   __ empty_expression_stack();

   // Thread will be loaded to R3_ARG1.

   // Target class oop is in register R5_ARG3 by convention!

   __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_ClassCastException_verbose), R17_tos, R5_ARG3);

   // Above call must not return here since exception pending.

   DEBUG_ONLY(__ should_not_reach_here();)

   return entry;

 }

 #endif

 address TemplateInterpreterGenerator::generate_ClassCastException_handler() {

   address entry = __ pc();

   // Expression stack must be empty before entering the VM if an

   // exception happened.

   __ empty_expression_stack();

   // Load exception object.

   // Thread will be loaded to R3_ARG1.

   __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_ClassCastException), R17_tos);

 #ifdef ASSERT

   // Above call must not return here since exception pending.

   __ should_not_reach_here();

 #endif

   return entry;

 }

 address TemplateInterpreterGenerator::generate_exception_handler_common(const char* name, const char* message, bool pass_oop) {

   address entry = __ pc();

   //__ untested("generate_exception_handler_common");

   Register Rexception = R17_tos;

   // Expression stack must be empty before entering the VM if an exception happened.

   __ empty_expression_stack();

   __ load_const_optimized(R4_ARG2, (address) name, R11_scratch1);

   if (pass_oop) {

     __ mr(R5_ARG3, Rexception);

     __ call_VM(Rexception, CAST_FROM_FN_PTR(address, InterpreterRuntime::create_klass_exception), false);

   } else {

     __ load_const_optimized(R5_ARG3, (address) message, R11_scratch1);

     __ call_VM(Rexception, CAST_FROM_FN_PTR(address, InterpreterRuntime::create_exception), false);

   }

   // Throw exception.

   __ mr(R3_ARG1, Rexception);

   __ load_const_optimized(R11_scratch1, Interpreter::throw_exception_entry(), R12_scratch2);

   __ mtctr(R11_scratch1);

   __ bctr();

   return entry;

 }

 address TemplateInterpreterGenerator::generate_continuation_for(TosState state) {

   address entry = __ pc();

   __ unimplemented("generate_continuation_for");

   return entry;

 }

 // This entry is returned to when a call returns to the interpreter.

 // When we arrive here, we expect that the callee stack frame is already popped.

 address TemplateInterpreterGenerator::generate_return_entry_for(TosState state, int step, size_t index_size) {

   address entry = __ pc();

   // Move the value out of the return register back to the TOS cache of current frame.

   switch (state) {

     case ltos:

     case btos:

     case ctos:

     case stos:

     case atos:

     case itos: __ mr(R17_tos, R3_RET); break;   // RET -> TOS cache

     case ftos:

     case dtos: __ fmr(F15_ftos, F1_RET); break; // TOS cache -> GR_FRET

     case vtos: break;                           // Nothing to do, this was a void return.

     default  : ShouldNotReachHere();

   }

   __ restore_interpreter_state(R11_scratch1); // Sets R11_scratch1 = fp.

   __ ld(R12_scratch2, _ijava_state_neg(top_frame_sp), R11_scratch1);

   __ resize_frame_absolute(R12_scratch2, R11_scratch1, R0);

   // Compiled code destroys templateTableBase, reload.

   __ load_const_optimized(R25_templateTableBase, (address)Interpreter::dispatch_table((TosState)0), R12_scratch2);

   if (state == atos) {

     __ profile_return_type(R3_RET, R11_scratch1, R12_scratch2);

   }

   const Register cache = R11_scratch1;

   const Register size  = R12_scratch2;

   __ get_cache_and_index_at_bcp(cache, 1, index_size);

   // Get least significant byte of 64 bit value:

 #if defined(VM_LITTLE_ENDIAN)

   __ lbz(size, in_bytes(ConstantPoolCache::base_offset() + ConstantPoolCacheEntry::flags_offset()), cache);

 #else

   __ lbz(size, in_bytes(ConstantPoolCache::base_offset() + ConstantPoolCacheEntry::flags_offset()) + 7, cache);

 #endif

   __ sldi(size, size, Interpreter::logStackElementSize);

   __ add(R15_esp, R15_esp, size);

   __ dispatch_next(state, step);

   return entry;

 }

 address TemplateInterpreterGenerator::generate_deopt_entry_for(TosState state, int step) {

   address entry = __ pc();

   // If state != vtos, we're returning from a native method, which put it's result

   // into the result register. So move the value out of the return register back

   // to the TOS cache of current frame.

   switch (state) {

     case ltos:

     case btos:

     case ctos:

     case stos:

     case atos:

     case itos: __ mr(R17_tos, R3_RET); break;   // GR_RET -> TOS cache

     case ftos:

     case dtos: __ fmr(F15_ftos, F1_RET); break; // TOS cache -> GR_FRET

     case vtos: break;                           // Nothing to do, this was a void return.

     default  : ShouldNotReachHere();

   }

   // Load LcpoolCache @@@ should be already set!

   __ get_constant_pool_cache(R27_constPoolCache);

   // Handle a pending exception, fall through if none.

   __ check_and_forward_exception(R11_scratch1, R12_scratch2);

   // Start executing bytecodes.

   __ dispatch_next(state, step);

   return entry;

 }

 // A result handler converts the native result into java format.

 // Use the shared code between c++ and template interpreter.

 address TemplateInterpreterGenerator::generate_result_handler_for(BasicType type) {

   return AbstractInterpreterGenerator::generate_result_handler_for(type);

 }

 address TemplateInterpreterGenerator::generate_safept_entry_for(TosState state, address runtime_entry) {

   address entry = __ pc();

   __ push(state);

   __ call_VM(noreg, runtime_entry);

   __ dispatch_via(vtos, Interpreter::_normal_table.table_for(vtos));

   return entry;

 }

 // Helpers for commoning out cases in the various type of method entries.

 // Increment invocation count & check for overflow.

 //

 // Note: checking for negative value instead of overflow

 //       so we have a 'sticky' overflow test.

 //

 void TemplateInterpreterGenerator::generate_counter_incr(Label* overflow, Label* profile_method, Label* profile_method_continue) {

   // Note: In tiered we increment either counters in method or in MDO depending if we're profiling or not.

   Register Rscratch1   = R11_scratch1;

   Register Rscratch2   = R12_scratch2;

   Register R3_counters = R3_ARG1;

   Label done;

   if (TieredCompilation) {

     const int increment = InvocationCounter::count_increment;

     const int mask = ((1 << Tier0InvokeNotifyFreqLog) - 1) << InvocationCounter::count_shift;

     Label no_mdo;

     if (ProfileInterpreter) {

       const Register Rmdo = Rscratch1;

       // If no method data exists, go to profile_continue.

       __ ld(Rmdo, in_bytes(Method::method_data_offset()), R19_method);

       __ cmpdi(CCR0, Rmdo, 0);

       __ beq(CCR0, no_mdo);

       // Increment backedge counter in the MDO.

       const int mdo_bc_offs = in_bytes(MethodData::backedge_counter_offset()) + in_bytes(InvocationCounter::counter_offset());

       __ lwz(Rscratch2, mdo_bc_offs, Rmdo);

       __ addi(Rscratch2, Rscratch2, increment);

       __ stw(Rscratch2, mdo_bc_offs, Rmdo);

       __ load_const_optimized(Rscratch1, mask, R0);

       __ and_(Rscratch1, Rscratch2, Rscratch1);

       __ bne(CCR0, done);

       __ b(*overflow);

     }

     // Increment counter in MethodCounters*.

     const int mo_bc_offs = in_bytes(MethodCounters::backedge_counter_offset()) + in_bytes(InvocationCounter::counter_offset());

     __ bind(no_mdo);

     __ get_method_counters(R19_method, R3_counters, done);

     __ lwz(Rscratch2, mo_bc_offs, R3_counters);

     __ addi(Rscratch2, Rscratch2, increment);

     __ stw(Rscratch2, mo_bc_offs, R3_counters);

     __ load_const_optimized(Rscratch1, mask, R0);

     __ and_(Rscratch1, Rscratch2, Rscratch1);

     __ beq(CCR0, *overflow);

     __ bind(done);

   } else {

     // Update standard invocation counters.

     Register Rsum_ivc_bec = R4_ARG2;

     __ get_method_counters(R19_method, R3_counters, done);

     __ increment_invocation_counter(R3_counters, Rsum_ivc_bec, R12_scratch2);

     // Increment interpreter invocation counter.

     if (ProfileInterpreter) {  // %%% Merge this into methodDataOop.

       __ lwz(R12_scratch2, in_bytes(MethodCounters::interpreter_invocation_counter_offset()), R3_counters);

       __ addi(R12_scratch2, R12_scratch2, 1);

       __ stw(R12_scratch2, in_bytes(MethodCounters::interpreter_invocation_counter_offset()), R3_counters);

     }

     // Check if we must create a method data obj.

     if (ProfileInterpreter && profile_method != NULL) {

       const Register profile_limit = Rscratch1;

       int pl_offs = __ load_const_optimized(profile_limit, &InvocationCounter::InterpreterProfileLimit, R0, true);

       __ lwz(profile_limit, pl_offs, profile_limit);

       // Test to see if we should create a method data oop.

       __ cmpw(CCR0, Rsum_ivc_bec, profile_limit);

       __ blt(CCR0, *profile_method_continue);

       // If no method data exists, go to profile_method.

       __ test_method_data_pointer(*profile_method);

     }

     // Finally check for counter overflow.

     if (overflow) {

       const Register invocation_limit = Rscratch1;

       int il_offs = __ load_const_optimized(invocation_limit, &InvocationCounter::InterpreterInvocationLimit, R0, true);

       __ lwz(invocation_limit, il_offs, invocation_limit);

       assert(4 == sizeof(InvocationCounter::InterpreterInvocationLimit), "unexpected field size");

       __ cmpw(CCR0, Rsum_ivc_bec, invocation_limit);

       __ bge(CCR0, *overflow);

     }

     __ bind(done);

   }

 }

 // Generate code to initiate compilation on invocation counter overflow.

 void TemplateInterpreterGenerator::generate_counter_overflow(Label& continue_entry) {

   // Generate code to initiate compilation on the counter overflow.

   // InterpreterRuntime::frequency_counter_overflow takes one arguments,

   // which indicates if the counter overflow occurs at a backwards branch (NULL bcp)

   // We pass zero in.

   // The call returns the address of the verified entry point for the method or NULL

   // if the compilation did not complete (either went background or bailed out).

   //

   // Unlike the C++ interpreter above: Check exceptions!

   // Assumption: Caller must set the flag "do_not_unlock_if_sychronized" if the monitor of a sync'ed

   // method has not yet been created. Thus, no unlocking of a non-existing monitor can occur.

   __ li(R4_ARG2, 0);

   __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::frequency_counter_overflow), R4_ARG2, true);

   // Returns verified_entry_point or NULL.

   // We ignore it in any case.

   __ b(continue_entry);

 }

 void TemplateInterpreterGenerator::generate_stack_overflow_check(Register Rmem_frame_size, Register Rscratch1) {

   assert_different_registers(Rmem_frame_size, Rscratch1);

   __ generate_stack_overflow_check_with_compare_and_throw(Rmem_frame_size, Rscratch1);

 }

 void TemplateInterpreterGenerator::unlock_method(bool check_exceptions) {

   __ unlock_object(R26_monitor, check_exceptions);

 }

 // Lock the current method, interpreter register window must be set up!

 void TemplateInterpreterGenerator::lock_method(Register Rflags, Register Rscratch1, Register Rscratch2, bool flags_preloaded) {

   const Register Robj_to_lock = Rscratch2;

   {

     if (!flags_preloaded) {

       __ lwz(Rflags, method_(access_flags));

     }

 #ifdef ASSERT

     // Check if methods needs synchronization.

     {

       Label Lok;

       __ testbitdi(CCR0, R0, Rflags, JVM_ACC_SYNCHRONIZED_BIT);

       __ btrue(CCR0,Lok);

       __ stop("method doesn't need synchronization");

       __ bind(Lok);

     }

 #endif // ASSERT

   }

   // Get synchronization object to Rscratch2.

   {

     const int mirror_offset = in_bytes(Klass::java_mirror_offset());

     Label Lstatic;

     Label Ldone;

     __ testbitdi(CCR0, R0, Rflags, JVM_ACC_STATIC_BIT);

     __ btrue(CCR0, Lstatic);

     // Non-static case: load receiver obj from stack and we're done.

     __ ld(Robj_to_lock, R18_locals);

     __ b(Ldone);

     __ bind(Lstatic); // Static case: Lock the java mirror

     __ ld(Robj_to_lock, in_bytes(Method::const_offset()), R19_method);

     __ ld(Robj_to_lock, in_bytes(ConstMethod::constants_offset()), Robj_to_lock);

     __ ld(Robj_to_lock, ConstantPool::pool_holder_offset_in_bytes(), Robj_to_lock);

     __ ld(Robj_to_lock, mirror_offset, Robj_to_lock);

     __ bind(Ldone);

     __ verify_oop(Robj_to_lock);

   }

   // Got the oop to lock => execute!

   __ add_monitor_to_stack(true, Rscratch1, R0);

   __ std(Robj_to_lock, BasicObjectLock::obj_offset_in_bytes(), R26_monitor);

   __ lock_object(R26_monitor, Robj_to_lock);

 }

 // Generate a fixed interpreter frame for pure interpreter

 // and I2N native transition frames.

 //

 // Before (stack grows downwards):

 //

 //         |  ...         |

 //         |------------- |

 //         |  java arg0   |

 //         |  ...         |

 //         |  java argn   |

 //         |              |   <-   R15_esp

 //         |              |

 //         |--------------|

 //         | abi_112      |

 //         |              |   <-   R1_SP

 //         |==============|

 //

 //

 // After:

 //

 //         |  ...         |

 //         |  java arg0   |<-   R18_locals

 //         |  ...         |

 //         |  java argn   |

 //         |--------------|

 //         |              |

 //         |  java locals |

 //         |              |

 //         |--------------|

 //         |  abi_48      |

 //         |==============|

 //         |              |

 //         |   istate     |

 //         |              |

 //         |--------------|

 //         |   monitor    |<-   R26_monitor

 //         |--------------|

 //         |              |<-   R15_esp

 //         | expression   |

 //         | stack        |

 //         |              |

 //         |--------------|

 //         |              |

 //         | abi_112      |<-   R1_SP

 //         |==============|

 //

 // The top most frame needs an abi space of 112 bytes. This space is needed,

 // since we call to c. The c function may spill their arguments to the caller

 // frame. When we call to java, we don't need these spill slots. In order to save

 // space on the stack, we resize the caller. However, java local reside in

 // the caller frame and the frame has to be increased. The frame_size for the

 // current frame was calculated based on max_stack as size for the expression

 // stack. At the call, just a part of the expression stack might be used.

 // We don't want to waste this space and cut the frame back accordingly.

 // The resulting amount for resizing is calculated as follows:

 // resize =   (number_of_locals - number_of_arguments) * slot_size

 //          + (R1_SP - R15_esp) + 48

 //

 // The size for the callee frame is calculated:

 // framesize = 112 + max_stack + monitor + state_size

 //

 // maxstack:   Max number of slots on the expression stack, loaded from the method.

 // monitor:    We statically reserve room for one monitor object.

 // state_size: We save the current state of the interpreter to this area.

 //

 void TemplateInterpreterGenerator::generate_fixed_frame(bool native_call, Register Rsize_of_parameters, Register Rsize_of_locals) {

   Register parent_frame_resize = R6_ARG4, // Frame will grow by this number of bytes.

            top_frame_size      = R7_ARG5,

            Rconst_method       = R8_ARG6;

   assert_different_registers(Rsize_of_parameters, Rsize_of_locals, parent_frame_resize, top_frame_size);

   __ ld(Rconst_method, method_(const));

   __ lhz(Rsize_of_parameters /* number of params */,

          in_bytes(ConstMethod::size_of_parameters_offset()), Rconst_method);

   if (native_call) {

     // If we're calling a native method, we reserve space for the worst-case signature

     // handler varargs vector, which is max(Argument::n_register_parameters, parameter_count+2).

     // We add two slots to the parameter_count, one for the jni

     // environment and one for a possible native mirror.

     Label skip_native_calculate_max_stack;

     __ addi(top_frame_size, Rsize_of_parameters, 2);

     __ cmpwi(CCR0, top_frame_size, Argument::n_register_parameters);

     __ bge(CCR0, skip_native_calculate_max_stack);

     __ li(top_frame_size, Argument::n_register_parameters);

     __ bind(skip_native_calculate_max_stack);

     __ sldi(Rsize_of_parameters, Rsize_of_parameters, Interpreter::logStackElementSize);

     __ sldi(top_frame_size, top_frame_size, Interpreter::logStackElementSize);

     __ sub(parent_frame_resize, R1_SP, R15_esp); // <0, off by Interpreter::stackElementSize!

     assert(Rsize_of_locals == noreg, "Rsize_of_locals not initialized"); // Only relevant value is Rsize_of_parameters.

   } else {

     __ lhz(Rsize_of_locals /* number of params */, in_bytes(ConstMethod::size_of_locals_offset()), Rconst_method);

     __ sldi(Rsize_of_parameters, Rsize_of_parameters, Interpreter::logStackElementSize);

     __ sldi(Rsize_of_locals, Rsize_of_locals, Interpreter::logStackElementSize);

     __ lhz(top_frame_size, in_bytes(ConstMethod::max_stack_offset()), Rconst_method);

     __ sub(R11_scratch1, Rsize_of_locals, Rsize_of_parameters); // >=0

     __ sub(parent_frame_resize, R1_SP, R15_esp); // <0, off by Interpreter::stackElementSize!

     __ sldi(top_frame_size, top_frame_size, Interpreter::logStackElementSize);

     __ add(parent_frame_resize, parent_frame_resize, R11_scratch1);

   }

   // Compute top frame size.

   __ addi(top_frame_size, top_frame_size, frame::abi_reg_args_size + frame::ijava_state_size);

   // Cut back area between esp and max_stack.

   __ addi(parent_frame_resize, parent_frame_resize, frame::abi_minframe_size - Interpreter::stackElementSize);

   __ round_to(top_frame_size, frame::alignment_in_bytes);

   __ round_to(parent_frame_resize, frame::alignment_in_bytes);

   // parent_frame_resize = (locals-parameters) - (ESP-SP-ABI48) Rounded to frame alignment size.

   // Enlarge by locals-parameters (not in case of native_call), shrink by ESP-SP-ABI48.

   {

     // --------------------------------------------------------------------------

     // Stack overflow check

     Label cont;

     __ add(R11_scratch1, parent_frame_resize, top_frame_size);

     generate_stack_overflow_check(R11_scratch1, R12_scratch2);

   }

   // Set up interpreter state registers.

   __ add(R18_locals, R15_esp, Rsize_of_parameters);

   __ ld(R27_constPoolCache, in_bytes(ConstMethod::constants_offset()), Rconst_method);

   __ ld(R27_constPoolCache, ConstantPool::cache_offset_in_bytes(), R27_constPoolCache);

   // Set method data pointer.

   if (ProfileInterpreter) {

     Label zero_continue;

     __ ld(R28_mdx, method_(method_data));

     __ cmpdi(CCR0, R28_mdx, 0);

     __ beq(CCR0, zero_continue);

     __ addi(R28_mdx, R28_mdx, in_bytes(MethodData::data_offset()));

     __ bind(zero_continue);

   }

   if (native_call) {

     __ li(R14_bcp, 0); // Must initialize.

   } else {

     __ add(R14_bcp, in_bytes(ConstMethod::codes_offset()), Rconst_method);

   }

   // Resize parent frame.

   __ mflr(R12_scratch2);

   __ neg(parent_frame_resize, parent_frame_resize);

   __ resize_frame(parent_frame_resize, R11_scratch1);

   __ std(R12_scratch2, _abi(lr), R1_SP);

   __ addi(R26_monitor, R1_SP, - frame::ijava_state_size);

   __ addi(R15_esp, R26_monitor, - Interpreter::stackElementSize);

   // Store values.

   // R15_esp, R14_bcp, R26_monitor, R28_mdx are saved at java calls

   // in InterpreterMacroAssembler::call_from_interpreter.

   __ std(R19_method, _ijava_state_neg(method), R1_SP);

   __ std(R21_sender_SP, _ijava_state_neg(sender_sp), R1_SP);

   __ std(R27_constPoolCache, _ijava_state_neg(cpoolCache), R1_SP);

   __ std(R18_locals, _ijava_state_neg(locals), R1_SP);

   // Note: esp, bcp, monitor, mdx live in registers. Hence, the correct version can only

   // be found in the frame after save_interpreter_state is done. This is always true

   // for non-top frames. But when a signal occurs, dumping the top frame can go wrong,

   // because e.g. frame::interpreter_frame_bcp() will not access the correct value

   // (Enhanced Stack Trace).

   // The signal handler does not save the interpreter state into the frame.

   __ li(R0, 0);

 #ifdef ASSERT

   // Fill remaining slots with constants.

   __ load_const_optimized(R11_scratch1, 0x5afe);

   __ load_const_optimized(R12_scratch2, 0xdead);

 #endif

   // We have to initialize some frame slots for native calls (accessed by GC).

   if (native_call) {

     __ std(R26_monitor, _ijava_state_neg(monitors), R1_SP);

     __ std(R14_bcp, _ijava_state_neg(bcp), R1_SP);

     if (ProfileInterpreter) { __ std(R28_mdx, _ijava_state_neg(mdx), R1_SP); }

   }

 #ifdef ASSERT

   else {

     __ std(R12_scratch2, _ijava_state_neg(monitors), R1_SP);

     __ std(R12_scratch2, _ijava_state_neg(bcp), R1_SP);

     __ std(R12_scratch2, _ijava_state_neg(mdx), R1_SP);

   }

   __ std(R11_scratch1, _ijava_state_neg(ijava_reserved), R1_SP);

   __ std(R12_scratch2, _ijava_state_neg(esp), R1_SP);

   __ std(R12_scratch2, _ijava_state_neg(lresult), R1_SP);

   __ std(R12_scratch2, _ijava_state_neg(fresult), R1_SP);

 #endif

   __ subf(R12_scratch2, top_frame_size, R1_SP);

   __ std(R0, _ijava_state_neg(oop_tmp), R1_SP);

   __ std(R12_scratch2, _ijava_state_neg(top_frame_sp), R1_SP);

   // Push top frame.

   __ push_frame(top_frame_size, R11_scratch1);

 }

 // End of helpers

 // ============================================================================

 // Various method entries

 //

 // Empty method, generate a very fast return. We must skip this entry if

 // someone's debugging, indicated by the flag

 // "interp_mode" in the Thread obj.

 // Note: empty methods are generated mostly methods that do assertions, which are

 // disabled in the "java opt build".

 address TemplateInterpreterGenerator::generate_empty_entry(void) {

   if (!UseFastEmptyMethods) {

     NOT_PRODUCT(__ should_not_reach_here();)

     return Interpreter::entry_for_kind(Interpreter::zerolocals);

   }

   Label Lslow_path;

   const Register Rjvmti_mode = R11_scratch1;

   address entry = __ pc();

   __ lwz(Rjvmti_mode, thread_(interp_only_mode));

   __ cmpwi(CCR0, Rjvmti_mode, 0);

   __ bne(CCR0, Lslow_path); // jvmti_mode!=0

   // Noone's debuggin: Simply return.

   // Pop c2i arguments (if any) off when we return.

 #ifdef ASSERT

     __ ld(R9_ARG7, 0, R1_SP);

     __ ld(R10_ARG8, 0, R21_sender_SP);

     __ cmpd(CCR0, R9_ARG7, R10_ARG8);

     __ asm_assert_eq("backlink", 0x545);

 #endif // ASSERT

   __ mr(R1_SP, R21_sender_SP); // Cut the stack back to where the caller started.

   // And we're done.

   __ blr();

   __ bind(Lslow_path);

   __ branch_to_entry(Interpreter::entry_for_kind(Interpreter::zerolocals), R11_scratch1);

   __ flush();

   return entry;

 }

 // Support abs and sqrt like in compiler.

 // For others we can use a normal (native) entry.

 inline bool math_entry_available(AbstractInterpreter::MethodKind kind) {

   // Provide math entry with debugging on demand.

   // Note: Debugging changes which code will get executed:

   // Debugging or disabled InlineIntrinsics: java method will get interpreted and performs a native call.

   // Not debugging and enabled InlineIntrinics: processor instruction will get used.

   // Result might differ slightly due to rounding etc.

   if (!InlineIntrinsics && (!FLAG_IS_ERGO(InlineIntrinsics))) return false; // Generate a vanilla entry.

   return ((kind==Interpreter::java_lang_math_sqrt && VM_Version::has_fsqrt()) ||

           (kind==Interpreter::java_lang_math_abs));

 }

 address TemplateInterpreterGenerator::generate_math_entry(AbstractInterpreter::MethodKind kind) {

   if (!math_entry_available(kind)) {

     NOT_PRODUCT(__ should_not_reach_here();)

     return Interpreter::entry_for_kind(Interpreter::zerolocals);

   }

   Label Lslow_path;

   const Register Rjvmti_mode = R11_scratch1;

   address entry = __ pc();

   // Provide math entry with debugging on demand.

   __ lwz(Rjvmti_mode, thread_(interp_only_mode));

   __ cmpwi(CCR0, Rjvmti_mode, 0);

   __ bne(CCR0, Lslow_path); // jvmti_mode!=0

   __ lfd(F1_RET, Interpreter::stackElementSize, R15_esp);

   // Pop c2i arguments (if any) off when we return.

 #ifdef ASSERT

   __ ld(R9_ARG7, 0, R1_SP);

   __ ld(R10_ARG8, 0, R21_sender_SP);

   __ cmpd(CCR0, R9_ARG7, R10_ARG8);

   __ asm_assert_eq("backlink", 0x545);

 #endif // ASSERT

   __ mr(R1_SP, R21_sender_SP); // Cut the stack back to where the caller started.

   if (kind == Interpreter::java_lang_math_sqrt) {

     __ fsqrt(F1_RET, F1_RET);

   } else if (kind == Interpreter::java_lang_math_abs) {

     __ fabs(F1_RET, F1_RET);

   } else {

     ShouldNotReachHere();

   }

   // And we're done.

   __ blr();

   // Provide slow path for JVMTI case.

   __ bind(Lslow_path);

   __ branch_to_entry(Interpreter::entry_for_kind(Interpreter::zerolocals), R12_scratch2);

   __ flush();

   return entry;

 }

 // Interpreter stub for calling a native method. (asm interpreter)

 // This sets up a somewhat different looking stack for calling the

 // native method than the typical interpreter frame setup.

 //

 // On entry:

 //   R19_method    - method

 //   R16_thread    - JavaThread*

 //   R15_esp       - intptr_t* sender tos

 //

 //   abstract stack (grows up)

 //     [  IJava (caller of JNI callee)  ]  <-- ASP

 //        ...

 address TemplateInterpreterGenerator::generate_native_entry(bool synchronized) {

   address entry = __ pc();

   const bool inc_counter = UseCompiler || CountCompiledCalls;

   // -----------------------------------------------------------------------------

   // Allocate a new frame that represents the native callee (i2n frame).

   // This is not a full-blown interpreter frame, but in particular, the

   // following registers are valid after this:

   // - R19_method

   // - R18_local (points to start of argumuments to native function)

   //

   //   abstract stack (grows up)

   //     [  IJava (caller of JNI callee)  ]  <-- ASP

   //        ...

   const Register signature_handler_fd = R11_scratch1;

   const Register pending_exception    = R0;

   const Register result_handler_addr  = R31;

   const Register native_method_fd     = R11_scratch1;

   const Register access_flags         = R22_tmp2;

   const Register active_handles       = R11_scratch1; // R26_monitor saved to state.

   const Register sync_state           = R12_scratch2;

   const Register sync_state_addr      = sync_state;   // Address is dead after use.

   const Register suspend_flags        = R11_scratch1;

   //=============================================================================

   // Allocate new frame and initialize interpreter state.

   Label exception_return;

   Label exception_return_sync_check;

   Label stack_overflow_return;

   // Generate new interpreter state and jump to stack_overflow_return in case of

   // a stack overflow.

   //generate_compute_interpreter_state(stack_overflow_return);

   Register size_of_parameters = R22_tmp2;

   generate_fixed_frame(true, size_of_parameters, noreg /* unused */);

   //=============================================================================

   // Increment invocation counter. On overflow, entry to JNI method

   // will be compiled.

   Label invocation_counter_overflow, continue_after_compile;

   if (inc_counter) {

     if (synchronized) {

       // Since at this point in the method invocation the exception handler

       // would try to exit the monitor of synchronized methods which hasn't

       // been entered yet, we set the thread local variable

       // _do_not_unlock_if_synchronized to true. If any exception was thrown by

       // runtime, exception handling i.e. unlock_if_synchronized_method will

       // check this thread local flag.

       // This flag has two effects, one is to force an unwind in the topmost

       // interpreter frame and not perform an unlock while doing so.

       __ li(R0, 1);

       __ stb(R0, in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()), R16_thread);

     }

     generate_counter_incr(&invocation_counter_overflow, NULL, NULL);

     __ BIND(continue_after_compile);

     // Reset the _do_not_unlock_if_synchronized flag.

     if (synchronized) {

       __ li(R0, 0);

       __ stb(R0, in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()), R16_thread);

     }

   }

   // access_flags = method->access_flags();

   // Load access flags.

   assert(access_flags->is_nonvolatile(),

          "access_flags must be in a non-volatile register");

   // Type check.

   assert(4 == sizeof(AccessFlags), "unexpected field size");

   __ lwz(access_flags, method_(access_flags));

   // We don't want to reload R19_method and access_flags after calls

   // to some helper functions.

   assert(R19_method->is_nonvolatile(),

          "R19_method must be a non-volatile register");

   // Check for synchronized methods. Must happen AFTER invocation counter

   // check, so method is not locked if counter overflows.

   if (synchronized) {

     lock_method(access_flags, R11_scratch1, R12_scratch2, true);

     // Update monitor in state.

     __ ld(R11_scratch1, 0, R1_SP);

     __ std(R26_monitor, _ijava_state_neg(monitors), R11_scratch1);

   }

   // jvmti/jvmpi support

   __ notify_method_entry();

   //=============================================================================

   // Get and call the signature handler.

   __ ld(signature_handler_fd, method_(signature_handler));

   Label call_signature_handler;

   __ cmpdi(CCR0, signature_handler_fd, 0);

   __ bne(CCR0, call_signature_handler);

   // Method has never been called. Either generate a specialized

   // handler or point to the slow one.

   //

   // Pass parameter 'false' to avoid exception check in call_VM.

   __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::prepare_native_call), R19_method, false);

   // Check for an exception while looking up the target method. If we

   // incurred one, bail.

   __ ld(pending_exception, thread_(pending_exception));

   __ cmpdi(CCR0, pending_exception, 0);

   __ bne(CCR0, exception_return_sync_check); // Has pending exception.

   // Reload signature handler, it may have been created/assigned in the meanwhile.

   __ ld(signature_handler_fd, method_(signature_handler));

   __ twi_0(signature_handler_fd); // Order wrt. load of klass mirror and entry point (isync is below).

   __ BIND(call_signature_handler);

   // Before we call the signature handler we push a new frame to

   // protect the interpreter frame volatile registers when we return

   // from jni but before we can get back to Java.

   // First set the frame anchor while the SP/FP registers are

   // convenient and the slow signature handler can use this same frame

   // anchor.

   // We have a TOP_IJAVA_FRAME here, which belongs to us.

   __ set_top_ijava_frame_at_SP_as_last_Java_frame(R1_SP, R12_scratch2/*tmp*/);

   // Now the interpreter frame (and its call chain) have been

   // invalidated and flushed. We are now protected against eager

   // being enabled in native code. Even if it goes eager the

   // registers will be reloaded as clean and we will invalidate after

   // the call so no spurious flush should be possible.

   // Call signature handler and pass locals address.

   //

   // Our signature handlers copy required arguments to the C stack

   // (outgoing C args), R3_ARG1 to R10_ARG8, and FARG1 to FARG13.

   __ mr(R3_ARG1, R18_locals);

 #if !defined(ABI_ELFv2)

   __ ld(signature_handler_fd, 0, signature_handler_fd);

 #endif

   __ call_stub(signature_handler_fd);

   // Remove the register parameter varargs slots we allocated in

   // compute_interpreter_state. SP+16 ends up pointing to the ABI

   // outgoing argument area.

   //

   // Not needed on PPC64.

   //__ add(SP, SP, Argument::n_register_parameters*BytesPerWord);

   assert(result_handler_addr->is_nonvolatile(), "result_handler_addr must be in a non-volatile register");

   // Save across call to native method.

   __ mr(result_handler_addr, R3_RET);

   __ isync(); // Acquire signature handler before trying to fetch the native entry point and klass mirror.

   // Set up fixed parameters and call the native method.

   // If the method is static, get mirror into R4_ARG2.

   {

     Label method_is_not_static;

     // Access_flags is non-volatile and still, no need to restore it.

     // Restore access flags.

     __ testbitdi(CCR0, R0, access_flags, JVM_ACC_STATIC_BIT);

     __ bfalse(CCR0, method_is_not_static);

     // constants = method->constants();

     __ ld(R11_scratch1, in_bytes(Method::const_offset()), R19_method);

     __ ld(R11_scratch1, in_bytes(ConstMethod::constants_offset()), R11_scratch1);

     // pool_holder = method->constants()->pool_holder();

     __ ld(R11_scratch1/*pool_holder*/, ConstantPool::pool_holder_offset_in_bytes(),

           R11_scratch1/*constants*/);

     const int mirror_offset = in_bytes(Klass::java_mirror_offset());

     // mirror = pool_holder->klass_part()->java_mirror();

     __ ld(R0/*mirror*/, mirror_offset, R11_scratch1/*pool_holder*/);

     // state->_native_mirror = mirror;

     __ ld(R11_scratch1, 0, R1_SP);

     __ std(R0/*mirror*/, _ijava_state_neg(oop_tmp), R11_scratch1);

     // R4_ARG2 = &state->_oop_temp;

     __ addi(R4_ARG2, R11_scratch1, _ijava_state_neg(oop_tmp));

     __ BIND(method_is_not_static);

   }

   // At this point, arguments have been copied off the stack into

   // their JNI positions. Oops are boxed in-place on the stack, with

   // handles copied to arguments. The result handler address is in a

   // register.

   // Pass JNIEnv address as first parameter.

   __ addir(R3_ARG1, thread_(jni_environment));

   // Load the native_method entry before we change the thread state.

   __ ld(native_method_fd, method_(native_function));

   //=============================================================================

   // Transition from _thread_in_Java to _thread_in_native. As soon as

   // we make this change the safepoint code needs to be certain that

   // the last Java frame we established is good. The pc in that frame

   // just needs to be near here not an actual return address.

   // We use release_store_fence to update values like the thread state, where

   // we don't want the current thread to continue until all our prior memory

   // accesses (including the new thread state) are visible to other threads.

   __ li(R0, _thread_in_native);

   __ release();

   // TODO PPC port assert(4 == JavaThread::sz_thread_state(), "unexpected field size");

   __ stw(R0, thread_(thread_state));

   if (UseMembar) {

     __ fence();

   }

   //=============================================================================

   // Call the native method. Argument registers must not have been

   // overwritten since "__ call_stub(signature_handler);" (except for

   // ARG1 and ARG2 for static methods).

   __ call_c(native_method_fd);

   __ li(R0, 0);

   __ ld(R11_scratch1, 0, R1_SP);

   __ std(R3_RET, _ijava_state_neg(lresult), R11_scratch1);

   __ stfd(F1_RET, _ijava_state_neg(fresult), R11_scratch1);

   __ std(R0/*mirror*/, _ijava_state_neg(oop_tmp), R11_scratch1); // reset

   // Note: C++ interpreter needs the following here:

   // The frame_manager_lr field, which we use for setting the last

   // java frame, gets overwritten by the signature handler. Restore

   // it now.

   //__ get_PC_trash_LR(R11_scratch1);

   //__ std(R11_scratch1, _top_ijava_frame_abi(frame_manager_lr), R1_SP);

   // Because of GC R19_method may no longer be valid.

   // Block, if necessary, before resuming in _thread_in_Java state.

   // In order for GC to work, don't clear the last_Java_sp until after

   // blocking.

   //=============================================================================

   // Switch thread to "native transition" state before reading the

   // synchronization state. This additional state is necessary

   // because reading and testing the synchronization state is not

   // atomic w.r.t. GC, as this scenario demonstrates: Java thread A,

   // in _thread_in_native state, loads _not_synchronized and is

   // preempted. VM thread changes sync state to synchronizing and

   // suspends threads for GC. Thread A is resumed to finish this

   // native method, but doesn't block here since it didn't see any

   // synchronization in progress, and escapes.

   // We use release_store_fence to update values like the thread state, where

   // we don't want the current thread to continue until all our prior memory

   // accesses (including the new thread state) are visible to other threads.

   __ li(R0/*thread_state*/, _thread_in_native_trans);

   __ release();

   __ stw(R0/*thread_state*/, thread_(thread_state));

   if (UseMembar) {

     __ fence();

   }

   // Write serialization page so that the VM thread can do a pseudo remote

   // membar. We use the current thread pointer to calculate a thread

   // specific offset to write to within the page. This minimizes bus

   // traffic due to cache line collision.

   else {

     __ serialize_memory(R16_thread, R11_scratch1, R12_scratch2);

   }

   // Now before we return to java we must look for a current safepoint

   // (a new safepoint can not start since we entered native_trans).

   // We must check here because a current safepoint could be modifying

   // the callers registers right this moment.

   // Acquire isn't strictly necessary here because of the fence, but

   // sync_state is declared to be volatile, so we do it anyway

   // (cmp-br-isync on one path, release (same as acquire on PPC64) on the other path).

   int sync_state_offs = __ load_const_optimized(sync_state_addr, SafepointSynchronize::address_of_state(), /*temp*/R0, true);

   // TODO PPC port assert(4 == SafepointSynchronize::sz_state(), "unexpected field size");

   __ lwz(sync_state, sync_state_offs, sync_state_addr);

   // TODO PPC port assert(4 == Thread::sz_suspend_flags(), "unexpected field size");

   __ lwz(suspend_flags, thread_(suspend_flags));

   Label sync_check_done;

   Label do_safepoint;

   // No synchronization in progress nor yet synchronized.

   __ cmpwi(CCR0, sync_state, SafepointSynchronize::_not_synchronized);

   // Not suspended.

   __ cmpwi(CCR1, suspend_flags, 0);

   __ bne(CCR0, do_safepoint);

   __ beq(CCR1, sync_check_done);

   __ bind(do_safepoint);

   __ isync();

   // Block. We do the call directly and leave the current

   // last_Java_frame setup undisturbed. We must save any possible

   // native result across the call. No oop is present.

   __ mr(R3_ARG1, R16_thread);

 #if defined(ABI_ELFv2)

   __ call_c(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans),

             relocInfo::none);

 #else

   __ call_c(CAST_FROM_FN_PTR(FunctionDescriptor*, JavaThread::check_special_condition_for_native_trans),

             relocInfo::none);

 #endif

   __ bind(sync_check_done);

   //=============================================================================

   // <<<<<< Back in Interpreter Frame >>>>>

   // We are in thread_in_native_trans here and back in the normal

   // interpreter frame. We don't have to do anything special about

   // safepoints and we can switch to Java mode anytime we are ready.

   // Note: frame::interpreter_frame_result has a dependency on how the

   // method result is saved across the call to post_method_exit. For

   // native methods it assumes that the non-FPU/non-void result is

   // saved in _native_lresult and a FPU result in _native_fresult. If

   // this changes then the interpreter_frame_result implementation

   // will need to be updated too.

   // On PPC64, we have stored the result directly after the native call.

   //=============================================================================

   // Back in Java

   // We use release_store_fence to update values like the thread state, where

   // we don't want the current thread to continue until all our prior memory

   // accesses (including the new thread state) are visible to other threads.

   __ li(R0/*thread_state*/, _thread_in_Java);

   __ release();

   __ stw(R0/*thread_state*/, thread_(thread_state));

   if (UseMembar) {

     __ fence();

   }

   __ reset_last_Java_frame();

   // Jvmdi/jvmpi support. Whether we've got an exception pending or

   // not, and whether unlocking throws an exception or not, we notify

   // on native method exit. If we do have an exception, we'll end up

   // in the caller's context to handle it, so if we don't do the

   // notify here, we'll drop it on the floor.

   __ notify_method_exit(true/*native method*/,

                         ilgl /*illegal state (not used for native methods)*/,

                         InterpreterMacroAssembler::NotifyJVMTI,

                         false /*check_exceptions*/);

   //=============================================================================

   // Handle exceptions

   if (synchronized) {

     // Don't check for exceptions since we're still in the i2n frame. Do that

     // manually afterwards.

     unlock_method(false);

   }

   // Reset active handles after returning from native.

   // thread->active_handles()->clear();

   __ ld(active_handles, thread_(active_handles));

   // TODO PPC port assert(4 == JNIHandleBlock::top_size_in_bytes(), "unexpected field size");

   __ li(R0, 0);

   __ stw(R0, JNIHandleBlock::top_offset_in_bytes(), active_handles);

   Label exception_return_sync_check_already_unlocked;

   __ ld(R0/*pending_exception*/, thread_(pending_exception));

   __ cmpdi(CCR0, R0/*pending_exception*/, 0);

   __ bne(CCR0, exception_return_sync_check_already_unlocked);

   //-----------------------------------------------------------------------------

   // No exception pending.

   // Move native method result back into proper registers and return.

   // Invoke result handler (may unbox/promote).

   __ ld(R11_scratch1, 0, R1_SP);

   __ ld(R3_RET, _ijava_state_neg(lresult), R11_scratch1);

   __ lfd(F1_RET, _ijava_state_neg(fresult), R11_scratch1);

   __ call_stub(result_handler_addr);

   __ merge_frames(/*top_frame_sp*/ R21_sender_SP, /*return_pc*/ R0, R11_scratch1, R12_scratch2);

   // Must use the return pc which was loaded from the caller's frame

   // as the VM uses return-pc-patching for deoptimization.

   __ mtlr(R0);

   __ blr();

   //-----------------------------------------------------------------------------

   // An exception is pending. We call into the runtime only if the

   // caller was not interpreted. If it was interpreted the

   // interpreter will do the correct thing. If it isn't interpreted

   // (call stub/compiled code) we will change our return and continue.

   __ BIND(exception_return_sync_check);

   if (synchronized) {

     // Don't check for exceptions since we're still in the i2n frame. Do that

     // manually afterwards.

     unlock_method(false);

   }

   __ BIND(exception_return_sync_check_already_unlocked);

   const Register return_pc = R31;

   __ ld(return_pc, 0, R1_SP);

   __ ld(return_pc, _abi(lr), return_pc);

   // Get the address of the exception handler.

   __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::exception_handler_for_return_address),

                   R16_thread,

                   return_pc /* return pc */);

   __ merge_frames(/*top_frame_sp*/ R21_sender_SP, noreg, R11_scratch1, R12_scratch2);

   // Load the PC of the the exception handler into LR.

   __ mtlr(R3_RET);

   // Load exception into R3_ARG1 and clear pending exception in thread.

   __ ld(R3_ARG1/*exception*/, thread_(pending_exception));

   __ li(R4_ARG2, 0);

   __ std(R4_ARG2, thread_(pending_exception));

   // Load the original return pc into R4_ARG2.

   __ mr(R4_ARG2/*issuing_pc*/, return_pc);

   // Return to exception handler.

   __ blr();

   //=============================================================================

   // Counter overflow.

   if (inc_counter) {

     // Handle invocation counter overflow.

     __ bind(invocation_counter_overflow);

     generate_counter_overflow(continue_after_compile);

   }

   return entry;

 }

 // Generic interpreted method entry to (asm) interpreter.

 //

 address TemplateInterpreterGenerator::generate_normal_entry(bool synchronized) {

   bool inc_counter = UseCompiler || CountCompiledCalls;

   address entry = __ pc();

   // Generate the code to allocate the interpreter stack frame.

   Register Rsize_of_parameters = R4_ARG2, // Written by generate_fixed_frame.

            Rsize_of_locals     = R5_ARG3; // Written by generate_fixed_frame.

   generate_fixed_frame(false, Rsize_of_parameters, Rsize_of_locals);

 #ifdef FAST_DISPATCH

   __ unimplemented("Fast dispatch in generate_normal_entry");

 #if 0

   __ set((intptr_t)Interpreter::dispatch_table(), IdispatchTables);

   // Set bytecode dispatch table base.

 #endif

 #endif

   // --------------------------------------------------------------------------

   // Zero out non-parameter locals.

   // Note: *Always* zero out non-parameter locals as Sparc does. It's not

   // worth to ask the flag, just do it.

   Register Rslot_addr = R6_ARG4,

            Rnum       = R7_ARG5;

   Label Lno_locals, Lzero_loop;

   // Set up the zeroing loop.

   __ subf(Rnum, Rsize_of_parameters, Rsize_of_locals);

   __ subf(Rslot_addr, Rsize_of_parameters, R18_locals);

   __ srdi_(Rnum, Rnum, Interpreter::logStackElementSize);

   __ beq(CCR0, Lno_locals);

   __ li(R0, 0);

   __ mtctr(Rnum);

   // The zero locals loop.

   __ bind(Lzero_loop);

   __ std(R0, 0, Rslot_addr);

   __ addi(Rslot_addr, Rslot_addr, -Interpreter::stackElementSize);

   __ bdnz(Lzero_loop);

   __ bind(Lno_locals);

   // --------------------------------------------------------------------------

   // Counter increment and overflow check.

   Label invocation_counter_overflow,

         profile_method,

         profile_method_continue;

   if (inc_counter || ProfileInterpreter) {

     Register Rdo_not_unlock_if_synchronized_addr = R11_scratch1;

     if (synchronized) {

       // Since at this point in the method invocation the exception handler

       // would try to exit the monitor of synchronized methods which hasn't

       // been entered yet, we set the thread local variable

       // _do_not_unlock_if_synchronized to true. If any exception was thrown by

       // runtime, exception handling i.e. unlock_if_synchronized_method will

       // check this thread local flag.

       // This flag has two effects, one is to force an unwind in the topmost

       // interpreter frame and not perform an unlock while doing so.

       __ li(R0, 1);

       __ stb(R0, in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()), R16_thread);

     }

     // Argument and return type profiling.

     __ profile_parameters_type(R3_ARG1, R4_ARG2, R5_ARG3, R6_ARG4);

     // Increment invocation counter and check for overflow.

     if (inc_counter) {

       generate_counter_incr(&invocation_counter_overflow, &profile_method, &profile_method_continue);

     }

     __ bind(profile_method_continue);

     // Reset the _do_not_unlock_if_synchronized flag.

     if (synchronized) {

       __ li(R0, 0);

       __ stb(R0, in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()), R16_thread);

     }

   }

   // --------------------------------------------------------------------------

   // Locking of synchronized methods. Must happen AFTER invocation_counter

   // check and stack overflow check, so method is not locked if overflows.

   if (synchronized) {

     lock_method(R3_ARG1, R4_ARG2, R5_ARG3);

   }

 #ifdef ASSERT

   else {

     Label Lok;

     __ lwz(R0, in_bytes(Method::access_flags_offset()), R19_method);

     __ andi_(R0, R0, JVM_ACC_SYNCHRONIZED);

     __ asm_assert_eq("method needs synchronization", 0x8521);

     __ bind(Lok);

   }

 #endif // ASSERT

   __ verify_thread();

   // --------------------------------------------------------------------------

   // JVMTI support

   __ notify_method_entry();

   // --------------------------------------------------------------------------

   // Start executing instructions.

   __ dispatch_next(vtos);

   // --------------------------------------------------------------------------

   // Out of line counter overflow and MDO creation code.

   if (ProfileInterpreter) {

     // We have decided to profile this method in the interpreter.

     __ bind(profile_method);

     __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::profile_method));

     __ set_method_data_pointer_for_bcp();

     __ b(profile_method_continue);

   }

   if (inc_counter) {

     // Handle invocation counter overflow.

     __ bind(invocation_counter_overflow);

     generate_counter_overflow(profile_method_continue);

   }

   return entry;

 }

 // =============================================================================

 // Entry points

 address AbstractInterpreterGenerator::generate_method_entry(

                                         AbstractInterpreter::MethodKind kind) {

   // Determine code generation flags.

   bool synchronized = false;

   address entry_point = NULL;

   switch (kind) {

   case Interpreter::zerolocals             :                                                                             break;

   case Interpreter::zerolocals_synchronized: synchronized = true;                                                        break;

   case Interpreter::native                 : entry_point = ((InterpreterGenerator*) this)->generate_native_entry(false); break;

   case Interpreter::native_synchronized    : entry_point = ((InterpreterGenerator*) this)->generate_native_entry(true);  break;

   case Interpreter::empty                  : entry_point = ((InterpreterGenerator*) this)->generate_empty_entry();       break;

   case Interpreter::accessor               : entry_point = ((InterpreterGenerator*) this)->generate_accessor_entry();    break;

   case Interpreter::abstract               : entry_point = ((InterpreterGenerator*) this)->generate_abstract_entry();    break;

   case Interpreter::java_lang_math_sin     : // fall thru

   case Interpreter::java_lang_math_cos     : // fall thru

   case Interpreter::java_lang_math_tan     : // fall thru

   case Interpreter::java_lang_math_abs     : // fall thru

   case Interpreter::java_lang_math_log     : // fall thru

   case Interpreter::java_lang_math_log10   : // fall thru

   case Interpreter::java_lang_math_sqrt    : // fall thru

   case Interpreter::java_lang_math_pow     : // fall thru

   case Interpreter::java_lang_math_exp     : entry_point = ((InterpreterGenerator*) this)->generate_math_entry(kind);    break;

   case Interpreter::java_lang_ref_reference_get

                                            : entry_point = ((InterpreterGenerator*)this)->generate_Reference_get_entry(); break;

   default                                  : ShouldNotReachHere();                                                       break;

   }

   if (entry_point) {

     return entry_point;

   }

   return ((InterpreterGenerator*) this)->generate_normal_entry(synchronized);

 }

 // These should never be compiled since the interpreter will prefer

 // the compiled version to the intrinsic version.

 bool AbstractInterpreter::can_be_compiled(methodHandle m) {

   return !math_entry_available(method_kind(m));

 }

 // How much stack a method activation needs in stack slots.

 // We must calc this exactly like in generate_fixed_frame.

 // Note: This returns the conservative size assuming maximum alignment.

 int AbstractInterpreter::size_top_interpreter_activation(Method* method) {

   const int max_alignment_size = 2;

   const int abi_scratch = frame::abi_reg_args_size;

   return method->max_locals() + method->max_stack() +

          frame::interpreter_frame_monitor_size() + max_alignment_size + abi_scratch;

 }

 // Returns number of stackElementWords needed for the interpreter frame with the

 // given sections.

 // This overestimates the stack by one slot in case of alignments.

 int AbstractInterpreter::size_activation(int max_stack,

                                          int temps,

                                          int extra_args,

                                          int monitors,

                                          int callee_params,

                                          int callee_locals,

                                          bool is_top_frame) {

   // Note: This calculation must exactly parallel the frame setup

   // in AbstractInterpreterGenerator::generate_method_entry.

   assert(Interpreter::stackElementWords == 1, "sanity");

   const int max_alignment_space = StackAlignmentInBytes / Interpreter::stackElementSize;

   const int abi_scratch = is_top_frame ? (frame::abi_reg_args_size / Interpreter::stackElementSize) :

                                          (frame::abi_minframe_size / Interpreter::stackElementSize);

   const int size =

     max_stack                                                +

     (callee_locals - callee_params)                          +

     monitors * frame::interpreter_frame_monitor_size()       +

     max_alignment_space                                      +

     abi_scratch                                              +

     frame::ijava_state_size / Interpreter::stackElementSize;

   // Fixed size of an interpreter frame, align to 16-byte.

   return (size & -2);

 }

 // Fills a sceletal interpreter frame generated during deoptimizations.

 //

 // Parameters:

 //

 // interpreter_frame != NULL:

 //   set up the method, locals, and monitors.

 //   The frame interpreter_frame, if not NULL, is guaranteed to be the

 //   right size, as determined by a previous call to this method.

 //   It is also guaranteed to be walkable even though it is in a skeletal state

 //

 // is_top_frame == true:

 //   We're processing the *oldest* interpreter frame!

 //

 // pop_frame_extra_args:

 //   If this is != 0 we are returning to a deoptimized frame by popping

 //   off the callee frame. We want to re-execute the call that called the

 //   callee interpreted, but since the return to the interpreter would pop

 //   the arguments off advance the esp by dummy popframe_extra_args slots.

 //   Popping off those will establish the stack layout as it was before the call.

 //

 void AbstractInterpreter::layout_activation(Method* method,

                                             int tempcount,

                                             int popframe_extra_args,

                                             int moncount,

                                             int caller_actual_parameters,

                                             int callee_param_count,

                                             int callee_locals_count,

                                             frame* caller,

                                             frame* interpreter_frame,

                                             bool is_top_frame,

                                             bool is_bottom_frame) {

   const int abi_scratch = is_top_frame ? (frame::abi_reg_args_size / Interpreter::stackElementSize) :

                                          (frame::abi_minframe_size / Interpreter::stackElementSize);

   intptr_t* locals_base  = (caller->is_interpreted_frame()) ?

     caller->interpreter_frame_esp() + caller_actual_parameters :

     caller->sp() + method->max_locals() - 1 + (frame::abi_minframe_size / Interpreter::stackElementSize) ;

   intptr_t* monitor_base = caller->sp() - frame::ijava_state_size / Interpreter::stackElementSize ;

   intptr_t* monitor      = monitor_base - (moncount * frame::interpreter_frame_monitor_size());

   intptr_t* esp_base     = monitor - 1;

   intptr_t* esp          = esp_base - tempcount - popframe_extra_args;

   intptr_t* sp           = (intptr_t *) (((intptr_t) (esp_base - callee_locals_count + callee_param_count - method->max_stack()- abi_scratch)) & -StackAlignmentInBytes);

   intptr_t* sender_sp    = caller->sp() + (frame::abi_minframe_size - frame::abi_reg_args_size) / Interpreter::stackElementSize;

   intptr_t* top_frame_sp = is_top_frame ? sp : sp + (frame::abi_minframe_size - frame::abi_reg_args_size) / Interpreter::stackElementSize;

   interpreter_frame->interpreter_frame_set_method(method);

   interpreter_frame->interpreter_frame_set_locals(locals_base);

   interpreter_frame->interpreter_frame_set_cpcache(method->constants()->cache());

   interpreter_frame->interpreter_frame_set_esp(esp);

   interpreter_frame->interpreter_frame_set_monitor_end((BasicObjectLock *)monitor);

   interpreter_frame->interpreter_frame_set_top_frame_sp(top_frame_sp);

   if (!is_bottom_frame) {

     interpreter_frame->interpreter_frame_set_sender_sp(sender_sp);

   }

 }

 // =============================================================================

 // Exceptions

 void TemplateInterpreterGenerator::generate_throw_exception() {

   Register Rexception    = R17_tos,

            Rcontinuation = R3_RET;

   // --------------------------------------------------------------------------

   // Entry point if an method returns with a pending exception (rethrow).

   Interpreter::_rethrow_exception_entry = __ pc();

   {

     __ restore_interpreter_state(R11_scratch1); // Sets R11_scratch1 = fp.

     __ ld(R12_scratch2, _ijava_state_neg(top_frame_sp), R11_scratch1);

     __ resize_frame_absolute(R12_scratch2, R11_scratch1, R0);

     // Compiled code destroys templateTableBase, reload.

     __ load_const_optimized(R25_templateTableBase, (address)Interpreter::dispatch_table((TosState)0), R11_scratch1);

   }

   // Entry point if a interpreted method throws an exception (throw).

   Interpreter::_throw_exception_entry = __ pc();

   {

     __ mr(Rexception, R3_RET);

     __ verify_thread();

     __ verify_oop(Rexception);

     // Expression stack must be empty before entering the VM in case of an exception.

     __ empty_expression_stack();

     // Find exception handler address and preserve exception oop.

     // Call C routine to find handler and jump to it.

     __ call_VM(Rexception, CAST_FROM_FN_PTR(address, InterpreterRuntime::exception_handler_for_exception), Rexception);

     __ mtctr(Rcontinuation);

     // Push exception for exception handler bytecodes.

     __ push_ptr(Rexception);

     // Jump to exception handler (may be remove activation entry!).

     __ bctr();

   }

   // If the exception is not handled in the current frame the frame is

   // removed and the exception is rethrown (i.e. exception

   // continuation is _rethrow_exception).

   //

   // Note: At this point the bci is still the bxi for the instruction

   // which caused the exception and the expression stack is

   // empty. Thus, for any VM calls at this point, GC will find a legal

   // oop map (with empty expression stack).

   // In current activation

   // tos: exception

   // bcp: exception bcp

   // --------------------------------------------------------------------------

   // JVMTI PopFrame support

   Interpreter::_remove_activation_preserving_args_entry = __ pc();

   {

     // Set the popframe_processing bit in popframe_condition indicating that we are

     // currently handling popframe, so that call_VMs that may happen later do not

     // trigger new popframe handling cycles.

     __ lwz(R11_scratch1, in_bytes(JavaThread::popframe_condition_offset()), R16_thread);

     __ ori(R11_scratch1, R11_scratch1, JavaThread::popframe_processing_bit);

     __ stw(R11_scratch1, in_bytes(JavaThread::popframe_condition_offset()), R16_thread);

     // Empty the expression stack, as in normal exception handling.

     __ empty_expression_stack();

     __ unlock_if_synchronized_method(vtos, /* throw_monitor_exception */ false, /* install_monitor_exception */ false);

     // Check to see whether we are returning to a deoptimized frame.

     // (The PopFrame call ensures that the caller of the popped frame is

     // either interpreted or compiled and deoptimizes it if compiled.)

     // Note that we don't compare the return PC against the

     // deoptimization blob's unpack entry because of the presence of

     // adapter frames in C2.

     Label Lcaller_not_deoptimized;

     Register return_pc = R3_ARG1;

     __ ld(return_pc, 0, R1_SP);

     __ ld(return_pc, _abi(lr), return_pc);

     __ call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::interpreter_contains), return_pc);

     __ cmpdi(CCR0, R3_RET, 0);

     __ bne(CCR0, Lcaller_not_deoptimized);

     // The deoptimized case.

     // In this case, we can't call dispatch_next() after the frame is

     // popped, but instead must save the incoming arguments and restore

     // them after deoptimization has occurred.

     __ ld(R4_ARG2, in_bytes(Method::const_offset()), R19_method);

     __ lhz(R4_ARG2 /* number of params */, in_bytes(ConstMethod::size_of_parameters_offset()), R4_ARG2);

     __ slwi(R4_ARG2, R4_ARG2, Interpreter::logStackElementSize);

     __ addi(R5_ARG3, R18_locals, Interpreter::stackElementSize);

     __ subf(R5_ARG3, R4_ARG2, R5_ARG3);

     // Save these arguments.

     __ call_VM_leaf(CAST_FROM_FN_PTR(address, Deoptimization::popframe_preserve_args), R16_thread, R4_ARG2, R5_ARG3);

     // Inform deoptimization that it is responsible for restoring these arguments.

     __ load_const_optimized(R11_scratch1, JavaThread::popframe_force_deopt_reexecution_bit);

     __ stw(R11_scratch1, in_bytes(JavaThread::popframe_condition_offset()), R16_thread);

     // Return from the current method into the deoptimization blob. Will eventually

     // end up in the deopt interpeter entry, deoptimization prepared everything that

     // we will reexecute the call that called us.

     __ merge_frames(/*top_frame_sp*/ R21_sender_SP, /*reload return_pc*/ return_pc, R11_scratch1, R12_scratch2);

     __ mtlr(return_pc);

     __ blr();

     // The non-deoptimized case.

     __ bind(Lcaller_not_deoptimized);

     // Clear the popframe condition flag.

     __ li(R0, 0);

     __ stw(R0, in_bytes(JavaThread::popframe_condition_offset()), R16_thread);

     // Get out of the current method and re-execute the call that called us.

     __ merge_frames(/*top_frame_sp*/ R21_sender_SP, /*return_pc*/ noreg, R11_scratch1, R12_scratch2);

     __ restore_interpreter_state(R11_scratch1);

     __ ld(R12_scratch2, _ijava_state_neg(top_frame_sp), R11_scratch1);

     __ resize_frame_absolute(R12_scratch2, R11_scratch1, R0);

     if (ProfileInterpreter) {

       __ set_method_data_pointer_for_bcp();

       __ ld(R11_scratch1, 0, R1_SP);

       __ std(R28_mdx, _ijava_state_neg(mdx), R11_scratch1);

     }

 #if INCLUDE_JVMTI

     Label L_done;

     __ lbz(R11_scratch1, 0, R14_bcp);

     __ cmpwi(CCR0, R11_scratch1, Bytecodes::_invokestatic);

     __ bne(CCR0, L_done);

     // The member name argument must be restored if _invokestatic is re-executed after a PopFrame call.

     // Detect such a case in the InterpreterRuntime function and return the member name argument, or NULL.

     __ ld(R4_ARG2, 0, R18_locals);

     __ MacroAssembler::call_VM(R4_ARG2, CAST_FROM_FN_PTR(address, InterpreterRuntime::member_name_arg_or_null), R4_ARG2, R19_method, R14_bcp, false);

     __ restore_interpreter_state(R11_scratch1, /*bcp_and_mdx_only*/ true);

     __ cmpdi(CCR0, R4_ARG2, 0);

     __ beq(CCR0, L_done);

     __ std(R4_ARG2, wordSize, R15_esp);

     __ bind(L_done);

 #endif // INCLUDE_JVMTI

     __ dispatch_next(vtos);

   }

   // end of JVMTI PopFrame support

   // --------------------------------------------------------------------------

   // Remove activation exception entry.

   // This is jumped to if an interpreted method can't handle an exception itself

   // (we come from the throw/rethrow exception entry above). We're going to call

   // into the VM to find the exception handler in the caller, pop the current

   // frame and return the handler we calculated.

   Interpreter::_remove_activation_entry = __ pc();

   {

     __ pop_ptr(Rexception);

     __ verify_thread();

     __ verify_oop(Rexception);

     __ std(Rexception, in_bytes(JavaThread::vm_result_offset()), R16_thread);

     __ unlock_if_synchronized_method(vtos, /* throw_monitor_exception */ false, true);

     __ notify_method_exit(false, vtos, InterpreterMacroAssembler::SkipNotifyJVMTI, false);

     __ get_vm_result(Rexception);

     // We are done with this activation frame; find out where to go next.

     // The continuation point will be an exception handler, which expects

     // the following registers set up:

     //

     // RET:  exception oop

     // ARG2: Issuing PC (see generate_exception_blob()), only used if the caller is compiled.

     Register return_pc = R31; // Needs to survive the runtime call.

     __ ld(return_pc, 0, R1_SP);

     __ ld(return_pc, _abi(lr), return_pc);

     __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::exception_handler_for_return_address), R16_thread, return_pc);

     // Remove the current activation.

     __ merge_frames(/*top_frame_sp*/ R21_sender_SP, /*return_pc*/ noreg, R11_scratch1, R12_scratch2);

     __ mr(R4_ARG2, return_pc);

     __ mtlr(R3_RET);

     __ mr(R3_RET, Rexception);

     __ blr();

   }

 }

 // JVMTI ForceEarlyReturn support.

 // Returns "in the middle" of a method with a "fake" return value.

 address TemplateInterpreterGenerator::generate_earlyret_entry_for(TosState state) {

   Register Rscratch1 = R11_scratch1,

            Rscratch2 = R12_scratch2;

   address entry = __ pc();

   __ empty_expression_stack();

   __ load_earlyret_value(state, Rscratch1);

   __ ld(Rscratch1, in_bytes(JavaThread::jvmti_thread_state_offset()), R16_thread);

   // Clear the earlyret state.

   __ li(R0, 0);

   __ stw(R0, in_bytes(JvmtiThreadState::earlyret_state_offset()), Rscratch1);

   __ remove_activation(state, false, false);

   // Copied from TemplateTable::_return.

   // Restoration of lr done by remove_activation.

   switch (state) {

     case ltos:

     case btos:

     case ctos:

     case stos:

     case atos:

     case itos: __ mr(R3_RET, R17_tos); break;

     case ftos:

     case dtos: __ fmr(F1_RET, F15_ftos); break;

     case vtos: // This might be a constructor. Final fields (and volatile fields on PPC64) need

                // to get visible before the reference to the object gets stored anywhere.

                __ membar(Assembler::StoreStore); break;

     default  : ShouldNotReachHere();

   }

   __ blr();

   return entry;

 } // end of ForceEarlyReturn support

 //-----------------------------------------------------------------------------

 // Helper for vtos entry point generation

 void TemplateInterpreterGenerator::set_vtos_entry_points(Template* t,

                                                          address& bep,

                                                          address& cep,

                                                          address& sep,

                                                          address& aep,

                                                          address& iep,

                                                          address& lep,

                                                          address& fep,

                                                          address& dep,

                                                          address& vep) {

   assert(t->is_valid() && t->tos_in() == vtos, "illegal template");

   Label L;

   aep = __ pc();  __ push_ptr();  __ b(L);

   fep = __ pc();  __ push_f();    __ b(L);

   dep = __ pc();  __ push_d();    __ b(L);

   lep = __ pc();  __ push_l();    __ b(L);

   __ align(32, 12, 24); // align L

   bep = cep = sep =

   iep = __ pc();  __ push_i();

   vep = __ pc();

   __ bind(L);

   generate_and_dispatch(t);

 }

 //-----------------------------------------------------------------------------

 // Generation of individual instructions

 // helpers for generate_and_dispatch

 InterpreterGenerator::InterpreterGenerator(StubQueue* code)

   : TemplateInterpreterGenerator(code) {

   generate_all(); // Down here so it can be "virtual".

 }

 //-----------------------------------------------------------------------------

 // Non-product code

 #ifndef PRODUCT

 address TemplateInterpreterGenerator::generate_trace_code(TosState state) {

   //__ flush_bundle();

   address entry = __ pc();

   const char *bname = NULL;

   uint tsize = 0;

   switch(state) {

   case ftos:

     bname = "trace_code_ftos {";

     tsize = 2;

     break;

   case btos:

     bname = "trace_code_btos {";

     tsize = 2;

     break;

   case ctos:

     bname = "trace_code_ctos {";

     tsize = 2;

     break;

   case stos:

     bname = "trace_code_stos {";

     tsize = 2;

     break;

   case itos:

     bname = "trace_code_itos {";

     tsize = 2;

     break;

   case ltos:

     bname = "trace_code_ltos {";

     tsize = 3;

     break;

   case atos:

     bname = "trace_code_atos {";

     tsize = 2;

     break;

   case vtos:

     // Note: In case of vtos, the topmost of stack value could be a int or doubl

     // In case of a double (2 slots) we won't see the 2nd stack value.

     // Maybe we simply should print the topmost 3 stack slots to cope with the problem.

     bname = "trace_code_vtos {";

     tsize = 2;

     break;

   case dtos:

     bname = "trace_code_dtos {";

     tsize = 3;

     break;

   default:

     ShouldNotReachHere();

   }

   BLOCK_COMMENT(bname);

   // Support short-cut for TraceBytecodesAt.

   // Don't call into the VM if we don't want to trace to speed up things.

   Label Lskip_vm_call;

   if (TraceBytecodesAt > 0 && TraceBytecodesAt < max_intx) {

     int offs1 = __ load_const_optimized(R11_scratch1, (address) &TraceBytecodesAt, R0, true);

     int offs2 = __ load_const_optimized(R12_scratch2, (address) &BytecodeCounter::_counter_value, R0, true);

     __ ld(R11_scratch1, offs1, R11_scratch1);

     __ lwa(R12_scratch2, offs2, R12_scratch2);

     __ cmpd(CCR0, R12_scratch2, R11_scratch1);

     __ blt(CCR0, Lskip_vm_call);

   }

   __ push(state);

   // Load 2 topmost expression stack values.

   __ ld(R6_ARG4, tsize*Interpreter::stackElementSize, R15_esp);

   __ ld(R5_ARG3, Interpreter::stackElementSize, R15_esp);

   __ mflr(R31);

   __ call_VM(noreg, CAST_FROM_FN_PTR(address, SharedRuntime::trace_bytecode), /* unused */ R4_ARG2, R5_ARG3, R6_ARG4, false);

   __ mtlr(R31);

   __ pop(state);

   if (TraceBytecodesAt > 0 && TraceBytecodesAt < max_intx) {

     __ bind(Lskip_vm_call);

   }

   __ blr();

   BLOCK_COMMENT("} trace_code");

   return entry;

 }

 void TemplateInterpreterGenerator::count_bytecode() {

   int offs = __ load_const_optimized(R11_scratch1, (address) &BytecodeCounter::_counter_value, R12_scratch2, true);

   __ lwz(R12_scratch2, offs, R11_scratch1);

   __ addi(R12_scratch2, R12_scratch2, 1);

   __ stw(R12_scratch2, offs, R11_scratch1);

 }

 void TemplateInterpreterGenerator::histogram_bytecode(Template* t) {

   int offs = __ load_const_optimized(R11_scratch1, (address) &BytecodeHistogram::_counters[t->bytecode()], R12_scratch2, true);

   __ lwz(R12_scratch2, offs, R11_scratch1);

   __ addi(R12_scratch2, R12_scratch2, 1);

   __ stw(R12_scratch2, offs, R11_scratch1);

 }

 void TemplateInterpreterGenerator::histogram_bytecode_pair(Template* t) {

   const Register addr = R11_scratch1,

                  tmp  = R12_scratch2;

   // Get index, shift out old bytecode, bring in new bytecode, and store it.

   // _index = (_index >> log2_number_of_codes) |

   //          (bytecode << log2_number_of_codes);

   int offs1 = __ load_const_optimized(addr, (address)&BytecodePairHistogram::_index, tmp, true);

   __ lwz(tmp, offs1, addr);

   __ srwi(tmp, tmp, BytecodePairHistogram::log2_number_of_codes);

   __ ori(tmp, tmp, ((int) t->bytecode()) << BytecodePairHistogram::log2_number_of_codes);

   __ stw(tmp, offs1, addr);

   // Bump bucket contents.

   // _counters[_index] ++;

   int offs2 = __ load_const_optimized(addr, (address)&BytecodePairHistogram::_counters, R0, true);

   __ sldi(tmp, tmp, LogBytesPerInt);

   __ add(addr, tmp, addr);

   __ lwz(tmp, offs2, addr);

   __ addi(tmp, tmp, 1);

   __ stw(tmp, offs2, addr);

 }

 void TemplateInterpreterGenerator::trace_bytecode(Template* t) {

   // Call a little run-time stub to avoid blow-up for each bytecode.

   // The run-time runtime saves the right registers, depending on

   // the tosca in-state for the given template.

   assert(Interpreter::trace_code(t->tos_in()) != NULL,

          "entry must have been generated");

   // Note: we destroy LR here.

   __ bl(Interpreter::trace_code(t->tos_in()));

 }

 void TemplateInterpreterGenerator::stop_interpreter_at() {

   Label L;

   int offs1 = __ load_const_optimized(R11_scratch1, (address) &StopInterpreterAt, R0, true);

   int offs2 = __ load_const_optimized(R12_scratch2, (address) &BytecodeCounter::_counter_value, R0, true);

   __ ld(R11_scratch1, offs1, R11_scratch1);

   __ lwa(R12_scratch2, offs2, R12_scratch2);

   __ cmpd(CCR0, R12_scratch2, R11_scratch1);

   __ bne(CCR0, L);

   __ illtrap();

   __ bind(L);

 }

 #endif // !PRODUCT

 #endif // !CC_INTERP