1 #ifdef USE_PRAGMA_IDENT_SRC 2 #pragma ident "@(#)dump_x86_64.cpp 1.13 07/09/17 09:25:59 JVM" 3 #endif 4 /* 5 * Copyright 2004-2007 Sun Microsystems, Inc. All Rights Reserved. 6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 7 * 8 * This code is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License version 2 only, as 10 * published by the Free Software Foundation. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 23 * CA 95054 USA or visit www.sun.com if you need additional information or 24 * have any questions. 25 * 26 */ 27 28 # include "incls/_precompiled.incl" 29 # include "incls/_dump_x86_64.cpp.incl" 30 31 32 33 // Generate the self-patching vtable method: 34 // 35 // This method will be called (as any other Klass virtual method) with 36 // the Klass itself as the first argument. Example: 37 // 38 // oop obj; 39 // int size = obj->klass()->klass_part()->oop_size(this); 40 // 41 // for which the virtual method call is Klass::oop_size(); 42 // 43 // The dummy method is called with the Klass object as the first 44 // operand, and an object as the second argument. 45 // 46 47 //===================================================================== 48 49 // All of the dummy methods in the vtable are essentially identical, 50 // differing only by an ordinal constant, and they bear no releationship 51 // to the original method which the caller intended. Also, there needs 52 // to be 'vtbl_list_size' instances of the vtable in order to 53 // differentiate between the 'vtable_list_size' original Klass objects. 54 55 #define __ masm-> 56 57 void CompactingPermGenGen::generate_vtable_methods(void** vtbl_list, 58 void** vtable, 59 char** md_top, 60 char* md_end, 61 char** mc_top, 62 char* mc_end) { 63 64 intptr_t vtable_bytes = (num_virtuals * vtbl_list_size) * sizeof(void*); 65 *(intptr_t *)(*md_top) = vtable_bytes; 66 *md_top += sizeof(intptr_t); 67 void** dummy_vtable = (void**)*md_top; 68 *vtable = dummy_vtable; 69 *md_top += vtable_bytes; 70 71 // Get ready to generate dummy methods. 72 73 CodeBuffer cb((unsigned char*)*mc_top, mc_end - *mc_top); 74 MacroAssembler* masm = new MacroAssembler(&cb); 75 76 Label common_code; 77 for (int i = 0; i < vtbl_list_size; ++i) { 78 for (int j = 0; j < num_virtuals; ++j) { 79 dummy_vtable[num_virtuals * i + j] = (void*)masm->pc(); 80 81 // Load eax with a value indicating vtable/offset pair. 82 // -- bits[ 7..0] (8 bits) which virtual method in table? 83 // -- bits[12..8] (5 bits) which virtual method table? 84 // -- must fit in 13-bit instruction immediate field. 85 __ movl(rax, (i << 8) + j); 86 __ jmp(common_code); 87 } 88 } 89 90 __ bind(common_code); 91 92 // Expecting to be called with "thiscall" convections -- the arguments 93 // are on the stack and the "this" pointer is in c_rarg0. In addition, rax 94 // was set (above) to the offset of the method in the table. 95 96 __ pushq(c_rarg1); // save & free register 97 __ pushq(c_rarg0); // save "this" 98 __ movq(c_rarg0, rax); 99 __ shrq(c_rarg0, 8); // isolate vtable identifier. 100 __ shlq(c_rarg0, LogBytesPerWord); 101 __ lea(c_rarg1, ExternalAddress((address)vtbl_list)); // ptr to correct vtable list. 102 __ addq(c_rarg1, c_rarg0); // ptr to list entry. 103 __ movq(c_rarg1, Address(c_rarg1, 0)); // get correct vtable address. 104 __ popq(c_rarg0); // restore "this" 105 __ movq(Address(c_rarg0, 0), c_rarg1); // update vtable pointer. 106 107 __ andq(rax, 0x00ff); // isolate vtable method index 108 __ shlq(rax, LogBytesPerWord); 109 __ addq(rax, c_rarg1); // address of real method pointer. 110 __ popq(c_rarg1); // restore register. 111 __ movq(rax, Address(rax, 0)); // get real method pointer. 112 __ jmp(rax); // jump to the real method. 113 114 __ flush(); 115 116 *mc_top = (char*)__ pc(); 117 } 118