1 /*

     2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.

     3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.

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

     5  *

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

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

     8  * published by the Free Software Foundation.

     9  *

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

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

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

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

    14  * accompanied this code).

    15  *

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

    17  * 2 along with this work; if not, write to the Free Software Foundation,

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

    19  *

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

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

    22  * questions.

    23  *

    24  */

    25 

    26 #include "precompiled.hpp"

    27 #include "asm/macroAssembler.hpp"

    28 #include "asm/macroAssembler.inline.hpp"

    29 #include "code/icBuffer.hpp"

    30 #include "gc/shared/collectedHeap.inline.hpp"

    31 #include "interpreter/bytecodes.hpp"

    32 #include "memory/resourceArea.hpp"

    33 #include "nativeInst_aarch64.hpp"

    34 #include "oops/oop.inline.hpp"

    35 

    36 int InlineCacheBuffer::ic_stub_code_size() {

    37   return (MacroAssembler::far_branches() ? 6 : 4) * NativeInstruction::instruction_size;

    38 }

    39 

    40 #define __ masm->

    41 

    42 void InlineCacheBuffer::assemble_ic_buffer_code(address code_begin, void* cached_value, address entry_point) {

    43   ResourceMark rm;

    44   CodeBuffer      code(code_begin, ic_stub_code_size());

    45   MacroAssembler* masm            = new MacroAssembler(&code);

    46   // note: even though the code contains an embedded value, we do not need reloc info

    47   // because

    48   // (1) the value is old (i.e., doesn't matter for scavenges)

    49   // (2) these ICStubs are removed *before* a GC happens, so the roots disappear

    50   // assert(cached_value == NULL || cached_oop->is_perm(), "must be perm oop");

    51 

    52   address start = __ pc();

    53   Label l;

    54   __ ldr(rscratch2, l);

    55   __ far_jump(ExternalAddress(entry_point));

    56   __ align(wordSize);

    57   __ bind(l);

    58   __ emit_int64((int64_t)cached_value);

    59   // Only need to invalidate the 1st two instructions - not the whole ic stub

    60   ICache::invalidate_range(code_begin, InlineCacheBuffer::ic_stub_code_size());

    61   assert(__ pc() - start == ic_stub_code_size(), "must be");

    62 }

    63 

    64 address InlineCacheBuffer::ic_buffer_entry_point(address code_begin) {

    65   NativeMovConstReg* move = nativeMovConstReg_at(code_begin);   // creation also verifies the object

    66   NativeJump* jump = nativeJump_at(code_begin + 4);

    67   return jump->jump_destination();

    68 }

    69 

    70 

    71 void* InlineCacheBuffer::ic_buffer_cached_value(address code_begin) {

    72   // The word containing the cached value is at the end of this IC buffer

    73   uintptr_t *p = (uintptr_t *)(code_begin + ic_stub_code_size() - wordSize);

    74   void* o = (void*)*p;

    75   return o;

    76 }