1 /*

     2  * Copyright 2003-2006 Sun Microsystems, Inc.  All Rights Reserved.

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

     4  *

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

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

     7  * published by the Free Software Foundation.

     8  *

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

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

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

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 #include "incls/_precompiled.incl"

    26 #include "incls/_vtableStubs_x86_64.cpp.incl"

    27 

    28 // machine-dependent part of VtableStubs: create VtableStub of correct size and

    29 // initialize its code

    30 

    31 #define __ masm->

    32 

    33 #ifndef PRODUCT

    34 extern "C" void bad_compiled_vtable_index(JavaThread* thread,

    35                                           oop receiver,

    36                                           int index);

    37 #endif

    38 

    39 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {

    40   const int amd64_code_length = VtableStub::pd_code_size_limit(true);

    41   VtableStub* s = new(amd64_code_length) VtableStub(true, vtable_index);

    42   ResourceMark rm;

    43   CodeBuffer cb(s->entry_point(), amd64_code_length);

    44   MacroAssembler* masm = new MacroAssembler(&cb);

    45 

    46 #ifndef PRODUCT

    47   if (CountCompiledCalls) {

    48     __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));

    49   }

    50 #endif

    51 

    52   // get receiver (need to skip return address on top of stack)

    53   assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");

    54 

    55   // Free registers (non-args) are rax, rbx

    56 

    57   // get receiver klass

    58   address npe_addr = __ pc();

    59   __ movq(rax, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));

    60 

    61   // compute entry offset (in words)

    62   int entry_offset =

    63     instanceKlass::vtable_start_offset() + vtable_index * vtableEntry::size();

    64 

    65 #ifndef PRODUCT

    66   if (DebugVtables) {

    67     Label L;

    68     // check offset vs vtable length

    69     __ cmpl(Address(rax, instanceKlass::vtable_length_offset() * wordSize),

    70             vtable_index * vtableEntry::size());

    71     __ jcc(Assembler::greater, L);

    72     __ movl(rbx, vtable_index);

    73     __ call_VM(noreg,

    74                CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, rbx);

    75     __ bind(L);

    76   }

    77 #endif // PRODUCT

    78 

    79   // load methodOop and target address

    80   const Register method = rbx;

    81 

    82   __ movq(method, Address(rax,

    83                           entry_offset * wordSize +

    84                           vtableEntry::method_offset_in_bytes()));

    85   if (DebugVtables) {

    86     Label L;

    87     __ cmpq(method, (int)NULL);

    88     __ jcc(Assembler::equal, L);

    89     __ cmpq(Address(method, methodOopDesc::from_compiled_offset()), (int)NULL_WORD);

    90     __ jcc(Assembler::notZero, L);

    91     __ stop("Vtable entry is NULL");

    92     __ bind(L);

    93   }

    94   // rax: receiver klass

    95   // rbx: methodOop

    96   // rcx: receiver

    97   address ame_addr = __ pc();

    98   __ jmp( Address(rbx, methodOopDesc::from_compiled_offset()));

    99 

   100   __ flush();

   101   s->set_exception_points(npe_addr, ame_addr);

   102   return s;

   103 }

   104 

   105 

   106 VtableStub* VtableStubs::create_itable_stub(int vtable_index) {

   107   // Note well: pd_code_size_limit is the absolute minimum we can get

   108   // away with.  If you add code here, bump the code stub size

   109   // returned by pd_code_size_limit!

   110   const int amd64_code_length = VtableStub::pd_code_size_limit(false);

   111   VtableStub* s = new(amd64_code_length) VtableStub(false, vtable_index);

   112   ResourceMark rm;

   113   CodeBuffer cb(s->entry_point(), amd64_code_length);

   114   MacroAssembler* masm = new MacroAssembler(&cb);

   115 

   116 #ifndef PRODUCT

   117   if (CountCompiledCalls) {

   118     __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));

   119   }

   120 #endif

   121 

   122   // Entry arguments:

   123   //  rax: Interface

   124   //  j_rarg0: Receiver

   125 

   126   // Free registers (non-args) are rax (interface), rbx

   127 

   128   // get receiver (need to skip return address on top of stack)

   129 

   130   assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");

   131   // get receiver klass (also an implicit null-check)

   132   address npe_addr = __ pc();

   133 

   134   __ movq(rbx, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));

   135 

   136   // If we take a trap while this arg is on the stack we will not

   137   // be able to walk the stack properly. This is not an issue except

   138   // when there are mistakes in this assembly code that could generate

   139   // a spurious fault. Ask me how I know...

   140 

   141   __ pushq(j_rarg1);     // Most registers are in use, so save one

   142 

   143   // compute itable entry offset (in words)

   144   const int base = instanceKlass::vtable_start_offset() * wordSize;

   145   assert(vtableEntry::size() * wordSize == 8,

   146          "adjust the scaling in the code below");

   147   // Get length of vtable

   148   __ movl(j_rarg1,

   149           Address(rbx, instanceKlass::vtable_length_offset() * wordSize));

   150   __ leaq(rbx, Address(rbx, j_rarg1, Address::times_8, base));

   151 

   152   if (HeapWordsPerLong > 1) {

   153     // Round up to align_object_offset boundary

   154     __ round_to_q(rbx, BytesPerLong);

   155   }

   156   Label hit, next, entry;

   157 

   158   __ jmpb(entry);

   159 

   160   __ bind(next);

   161   __ addq(rbx, itableOffsetEntry::size() * wordSize);

   162 

   163   __ bind(entry);

   164 

   165 #ifdef ASSERT

   166     // Check that the entry is non-null

   167   if (DebugVtables) {

   168     Label L;

   169     __ pushq(rbx);

   170     __ movq(rbx, Address(rbx, itableOffsetEntry::interface_offset_in_bytes()));

   171     __ testq(rbx, rbx);

   172     __ jcc(Assembler::notZero, L);

   173     __ stop("null entry point found in itable's offset table");

   174     __ bind(L);

   175     __ popq(rbx);

   176   }

   177 #endif

   178 

   179   __ cmpq(rax, Address(rbx, itableOffsetEntry::interface_offset_in_bytes()));

   180   __ jcc(Assembler::notEqual, next);

   181 

   182   // We found a hit, move offset into j_rarg1

   183   __ movl(j_rarg1, Address(rbx, itableOffsetEntry::offset_offset_in_bytes()));

   184 

   185   // Compute itableMethodEntry

   186   const int method_offset =

   187     (itableMethodEntry::size() * wordSize * vtable_index) +

   188     itableMethodEntry::method_offset_in_bytes();

   189 

   190   // Get methodOop and entrypoint for compiler

   191 

   192   // Get klass pointer again

   193   __ movq(rax, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));

   194 

   195   const Register method = rbx;

   196   __ movq(method, Address(rax, j_rarg1, Address::times_1, method_offset));

   197 

   198   // Restore saved register, before possible trap.

   199   __ popq(j_rarg1);

   200 

   201   // method (rbx): methodOop

   202   // j_rarg0: receiver

   203 

   204 

   205 #ifdef ASSERT

   206     if (DebugVtables) {

   207       Label L2;

   208       __ cmpq(method, (int)NULL);

   209       __ jcc(Assembler::equal, L2);

   210       __ cmpq(Address(method, methodOopDesc::from_compiled_offset()), (int)NULL_WORD);

   211       __ jcc(Assembler::notZero, L2);

   212       __ stop("compiler entrypoint is null");

   213       __ bind(L2);

   214     }

   215 #endif // ASSERT

   216 

   217     // rbx: methodOop

   218     // j_rarg0: receiver

   219     address ame_addr = __ pc();

   220     __ jmp(Address(method, methodOopDesc::from_compiled_offset()));

   221 

   222   __ flush();

   223   s->set_exception_points(npe_addr, ame_addr);

   224   return s;

   225 }

   226 

   227 int VtableStub::pd_code_size_limit(bool is_vtable_stub) {

   228   if (is_vtable_stub) {

   229     // Vtable stub size

   230     return (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0);

   231   } else {

   232     // Itable stub size

   233     return (DebugVtables ? 636 : 64) + (CountCompiledCalls ? 13 : 0);

   234   }

   235 }

   236 

   237 int VtableStub::pd_code_alignment() {

   238   return wordSize;

   239 }