1 /*
2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3  * Copyright (c) 2018, SAP SE. 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.inline.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/cardTable.hpp"
30 #include "gc/shared/cardTableBarrierSet.hpp"
31 #include "gc/shared/cardTableBarrierSetAssembler.hpp"
32 #include "interpreter/interp_masm.hpp"
33 
34 #define __ masm->
35 
36 #ifdef PRODUCT
37 #define BLOCK_COMMENT(str) /* nothing */
38 #else
39 #define BLOCK_COMMENT(str) __ block_comment(str)
40 #endif
41 
42 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
43 
44 #define TIMES_OOP (UseCompressedOops ? Address::times_4 : Address::times_8)
45 
gen_write_ref_array_post_barrier(MacroAssembler * masm,DecoratorSet decorators,Register addr,Register count,bool do_return)46 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr, Register count,
47                                                                     bool do_return) {
48   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
49   CardTable* ct = ctbs->card_table();
50   assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
51 
52   NearLabel doXC, done;
53   assert_different_registers(Z_R0, Z_R1, addr, count);
54 
55   // Nothing to do if count <= 0.
56   if (!do_return) {
57     __ compare64_and_branch(count, (intptr_t) 0, Assembler::bcondNotHigh, done);
58   } else {
59     __ z_ltgr(count, count);
60     __ z_bcr(Assembler::bcondNotPositive, Z_R14);
61   }
62 
63   // Note: We can't combine the shifts. We could lose a carry
64   // from calculating the array end address.
65   // count = (count-1)*BytesPerHeapOop + addr
66   // Count holds addr of last oop in array then.
67   __ z_sllg(count, count, LogBytesPerHeapOop);
68   __ add2reg_with_index(count, -BytesPerHeapOop, count, addr);
69 
70   // Get base address of card table.
71   __ load_const_optimized(Z_R1, (address)ct->byte_map_base());
72 
73   // count = (count>>shift) - (addr>>shift)
74   __ z_srlg(addr,  addr,  CardTable::card_shift);
75   __ z_srlg(count, count, CardTable::card_shift);
76 
77   // Prefetch first elements of card table for update.
78   if (VM_Version::has_Prefetch()) {
79     __ z_pfd(0x02, 0, addr, Z_R1);
80   }
81 
82   // Special case: clear just one byte.
83   __ clear_reg(Z_R0, true, false);  // Used for doOneByte.
84   __ z_sgr(count, addr);            // Count = n-1 now, CC used for brc below.
85   __ z_stc(Z_R0, 0, addr, Z_R1);    // Must preserve CC from z_sgr.
86   if (!do_return) {
87     __ z_brz(done);
88   } else {
89     __ z_bcr(Assembler::bcondZero, Z_R14);
90   }
91 
92   __ z_cghi(count, 255);
93   __ z_brnh(doXC);
94 
95   // MVCLE: clear a long area.
96   // Start addr of card table range = base + addr.
97   // # bytes in    card table range = (count + 1)
98   __ add2reg_with_index(Z_R0, 0, Z_R1, addr);
99   __ add2reg(Z_R1, 1, count);
100 
101   // dirty hack:
102   // There are just two callers. Both pass
103   // count in Z_ARG3 = Z_R4
104   // addr  in Z_ARG2 = Z_R3
105   // ==> use Z_ARG2 as src len reg = 0
106   //         Z_ARG1 as src addr (ignored)
107   assert(count == Z_ARG3, "count: unexpected register number");
108   assert(addr  == Z_ARG2, "addr:  unexpected register number");
109   __ clear_reg(Z_ARG2, true, false);
110 
111   __ MacroAssembler::move_long_ext(Z_R0, Z_ARG1, 0);
112 
113   if (!do_return) {
114     __ z_bru(done);
115   } else {
116     __ z_bcr(Assembler::bcondAlways, Z_R14);
117   }
118 
119   // XC: clear a short area.
120   Label XC_template; // Instr template, never exec directly!
121   __ bind(XC_template);
122   __ z_xc(0, 0, addr, 0, addr);
123 
124   __ bind(doXC);
125   // start addr of card table range = base + addr
126   // end   addr of card table range = base + addr + count
127   __ add2reg_with_index(addr, 0, Z_R1, addr);
128 
129   if (VM_Version::has_ExecuteExtensions()) {
130     __ z_exrl(count, XC_template);   // Execute XC with var. len.
131   } else {
132     __ z_larl(Z_R1, XC_template);
133     __ z_ex(count, 0, Z_R0, Z_R1);   // Execute XC with var. len.
134   }
135   if (do_return) {
136     __ z_br(Z_R14);
137   }
138 
139   __ bind(done);
140 }
141 
store_check(MacroAssembler * masm,Register store_addr,Register tmp)142 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register store_addr, Register tmp) {
143   // Does a store check for the oop in register obj. The content of
144   // register obj is destroyed afterwards.
145   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
146   CardTable* ct = ctbs->card_table();
147   assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
148 
149   assert_different_registers(store_addr, tmp);
150 
151   __ z_srlg(store_addr, store_addr, CardTable::card_shift);
152   __ load_absolute_address(tmp, (address)ct->byte_map_base());
153   __ z_agr(store_addr, tmp);
154   __ z_mvi(0, store_addr, CardTable::dirty_card_val());
155 }
156 
oop_store_at(MacroAssembler * masm,DecoratorSet decorators,BasicType type,const Address & dst,Register val,Register tmp1,Register tmp2,Register tmp3)157 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
158                                                 const Address& dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
159   bool is_array = (decorators & IS_ARRAY) != 0;
160   bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
161   bool precise = is_array || on_anonymous;
162 
163   BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
164 
165   // No need for post barrier if storing NULL
166   if (val != noreg) {
167     const Register base = dst.base(),
168                    idx  = dst.index();
169     const intptr_t disp = dst.disp();
170     if (precise && (disp != 0 || idx != noreg)) {
171       __ add2reg_with_index(base, disp, idx, base);
172     }
173     store_check(masm, base, tmp1);
174   }
175 }
176