1 /* 2 * Copyright (c) 2004, 2009, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 # include "incls/_precompiled.incl" 26 # include "incls/_dump_sparc.cpp.incl" 27 28 29 30 // Generate the self-patching vtable method: 31 // 32 // This method will be called (as any other Klass virtual method) with 33 // the Klass itself as the first argument. Example: 34 // 35 // oop obj; 36 // int size = obj->klass()->klass_part()->oop_size(this); 37 // 38 // for which the virtual method call is Klass::oop_size(); 39 // 40 // The dummy method is called with the Klass object as the first 41 // operand, and an object as the second argument. 42 // 43 44 //===================================================================== 45 46 // All of the dummy methods in the vtable are essentially identical, 47 // differing only by an ordinal constant, and they bear no releationship 48 // to the original method which the caller intended. Also, there needs 49 // to be 'vtbl_list_size' instances of the vtable in order to 50 // differentiate between the 'vtable_list_size' original Klass objects. 51 52 #define __ masm-> 53 54 void CompactingPermGenGen::generate_vtable_methods(void** vtbl_list, 55 void** vtable, 56 char** md_top, 57 char* md_end, 58 char** mc_top, 59 char* mc_end) { 60 61 intptr_t vtable_bytes = (num_virtuals * vtbl_list_size) * sizeof(void*); 62 *(intptr_t *)(*md_top) = vtable_bytes; 63 *md_top += sizeof(intptr_t); 64 void** dummy_vtable = (void**)*md_top; 65 *vtable = dummy_vtable; 66 *md_top += vtable_bytes; 67 68 guarantee(*md_top <= md_end, "Insufficient space for vtables."); 69 70 // Get ready to generate dummy methods. 71 72 CodeBuffer cb((unsigned char*)*mc_top, mc_end - *mc_top); 73 MacroAssembler* masm = new MacroAssembler(&cb); 74 75 Label common_code; 76 for (int i = 0; i < vtbl_list_size; ++i) { 77 for (int j = 0; j < num_virtuals; ++j) { 78 dummy_vtable[num_virtuals * i + j] = (void*)masm->pc(); 79 __ save(SP, -256, SP); 80 __ brx(Assembler::always, false, Assembler::pt, common_code); 81 82 // Load L0 with a value indicating vtable/offset pair. 83 // -- bits[ 7..0] (8 bits) which virtual method in table? 84 // -- bits[12..8] (5 bits) which virtual method table? 85 // -- must fit in 13-bit instruction immediate field. 86 __ delayed()->set((i << 8) + j, L0); 87 } 88 } 89 90 __ bind(common_code); 91 92 // Expecting to be called with the "this" pointer in O0/I0 (where 93 // "this" is a Klass object). In addition, L0 was set (above) to 94 // identify the method and table. 95 96 // Look up the correct vtable pointer. 97 98 __ set((intptr_t)vtbl_list, L2); // L2 = address of new vtable list. 99 __ srl(L0, 8, L3); // Isolate L3 = vtable identifier. 100 __ sll(L3, LogBytesPerWord, L3); 101 __ ld_ptr(L2, L3, L3); // L3 = new (correct) vtable pointer. 102 __ st_ptr(L3, Address(I0, 0)); // Save correct vtable ptr in entry. 103 104 // Restore registers and jump to the correct method; 105 106 __ and3(L0, 255, L4); // Isolate L3 = method offset;. 107 __ sll(L4, LogBytesPerWord, L4); 108 __ ld_ptr(L3, L4, L4); // Get address of correct virtual method 109 __ jmpl(L4, 0, G0); // Jump to correct method. 110 __ delayed()->restore(); // Restore registers. 111 112 __ flush(); 113 *mc_top = (char*)__ pc(); 114 115 guarantee(*mc_top <= mc_end, "Insufficient space for method wrappers."); 116 }