1 /* 2 * Copyright (c) 2018, 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 "precompiled.hpp" 26 #include "c1/c1_Defs.hpp" 27 #include "c1/c1_LIRGenerator.hpp" 28 #include "gc/shared/c1/barrierSetC1.hpp" 29 #include "utilities/macros.hpp" 30 31 #ifndef PATCHED_ADDR 32 #define PATCHED_ADDR (max_jint) 33 #endif 34 35 #ifdef ASSERT 36 #define __ gen->lir(__FILE__, __LINE__)-> 37 #else 38 #define __ gen->lir()-> 39 #endif 40 41 LIR_Opr BarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) { 42 DecoratorSet decorators = access.decorators(); 43 bool is_array = (decorators & IS_ARRAY) != 0; 44 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; 45 46 LIRItem& base = access.base().item(); 47 LIR_Opr offset = access.offset().opr(); 48 LIRGenerator *gen = access.gen(); 49 50 LIR_Opr addr_opr; 51 if (is_array) { 52 addr_opr = LIR_OprFact::address(gen->emit_array_address(base.result(), offset, access.type())); 53 } else if (needs_patching) { 54 // we need to patch the offset in the instruction so don't allow 55 // generate_address to try to be smart about emitting the -1. 56 // Otherwise the patching code won't know how to find the 57 // instruction to patch. 58 addr_opr = LIR_OprFact::address(new LIR_Address(base.result(), PATCHED_ADDR, access.type())); 59 } else { 60 addr_opr = LIR_OprFact::address(gen->generate_address(base.result(), offset, 0, 0, access.type())); 61 } 62 63 if (resolve_in_register) { 64 LIR_Opr resolved_addr = gen->new_pointer_register(); 65 __ leal(addr_opr, resolved_addr); 66 resolved_addr = LIR_OprFact::address(new LIR_Address(resolved_addr, access.type())); 67 return resolved_addr; 68 } else { 69 return addr_opr; 70 } 71 } 72 73 void BarrierSetC1::store_at(LIRAccess& access, LIR_Opr value) { 74 DecoratorSet decorators = access.decorators(); 75 bool in_heap = (decorators & IN_HEAP) != 0; 76 assert(in_heap, "not supported yet"); 77 78 LIR_Opr resolved = resolve_address(access, false); 79 access.set_resolved_addr(resolved); 80 store_at_resolved(access, value); 81 } 82 83 void BarrierSetC1::load_at(LIRAccess& access, LIR_Opr result) { 84 DecoratorSet decorators = access.decorators(); 85 bool in_heap = (decorators & IN_HEAP) != 0; 86 assert(in_heap, "not supported yet"); 87 88 LIR_Opr resolved = resolve_address(access, false); 89 access.set_resolved_addr(resolved); 90 load_at_resolved(access, result); 91 } 92 93 void BarrierSetC1::load(LIRAccess& access, LIR_Opr result) { 94 DecoratorSet decorators = access.decorators(); 95 bool in_heap = (decorators & IN_HEAP) != 0; 96 assert(!in_heap, "consider using load_at"); 97 load_at_resolved(access, result); 98 } 99 100 LIR_Opr BarrierSetC1::atomic_cmpxchg_at(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) { 101 DecoratorSet decorators = access.decorators(); 102 bool in_heap = (decorators & IN_HEAP) != 0; 103 assert(in_heap, "not supported yet"); 104 105 access.load_address(); 106 107 LIR_Opr resolved = resolve_address(access, true); 108 access.set_resolved_addr(resolved); 109 return atomic_cmpxchg_at_resolved(access, cmp_value, new_value); 110 } 111 112 LIR_Opr BarrierSetC1::atomic_xchg_at(LIRAccess& access, LIRItem& value) { 113 DecoratorSet decorators = access.decorators(); 114 bool in_heap = (decorators & IN_HEAP) != 0; 115 assert(in_heap, "not supported yet"); 116 117 access.load_address(); 118 119 LIR_Opr resolved = resolve_address(access, true); 120 access.set_resolved_addr(resolved); 121 return atomic_xchg_at_resolved(access, value); 122 } 123 124 LIR_Opr BarrierSetC1::atomic_add_at(LIRAccess& access, LIRItem& value) { 125 DecoratorSet decorators = access.decorators(); 126 bool in_heap = (decorators & IN_HEAP) != 0; 127 assert(in_heap, "not supported yet"); 128 129 access.load_address(); 130 131 LIR_Opr resolved = resolve_address(access, true); 132 access.set_resolved_addr(resolved); 133 return atomic_add_at_resolved(access, value); 134 } 135 136 void BarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) { 137 DecoratorSet decorators = access.decorators(); 138 bool is_volatile = (((decorators & MO_SEQ_CST) != 0) || AlwaysAtomicAccesses) && os::is_MP(); 139 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; 140 bool mask_boolean = (decorators & C1_MASK_BOOLEAN) != 0; 141 LIRGenerator* gen = access.gen(); 142 143 if (mask_boolean) { 144 value = gen->mask_boolean(access.base().opr(), value, access.access_emit_info()); 145 } 146 147 if (is_volatile && os::is_MP()) { 148 __ membar_release(); 149 } 150 151 LIR_PatchCode patch_code = needs_patching ? lir_patch_normal : lir_patch_none; 152 if (is_volatile && !needs_patching) { 153 gen->volatile_field_store(value, access.resolved_addr()->as_address_ptr(), access.access_emit_info()); 154 } else { 155 __ store(value, access.resolved_addr()->as_address_ptr(), access.access_emit_info(), patch_code); 156 } 157 158 if (is_volatile && !support_IRIW_for_not_multiple_copy_atomic_cpu) { 159 __ membar(); 160 } 161 } 162 163 void BarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) { 164 LIRGenerator *gen = access.gen(); 165 DecoratorSet decorators = access.decorators(); 166 bool is_volatile = (((decorators & MO_SEQ_CST) != 0) || AlwaysAtomicAccesses) && os::is_MP(); 167 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; 168 bool mask_boolean = (decorators & C1_MASK_BOOLEAN) != 0; 169 bool in_native = (decorators & IN_NATIVE) != 0; 170 171 if (support_IRIW_for_not_multiple_copy_atomic_cpu && is_volatile) { 172 __ membar(); 173 } 174 175 LIR_PatchCode patch_code = needs_patching ? lir_patch_normal : lir_patch_none; 176 if (in_native) { 177 __ move_wide(access.resolved_addr()->as_address_ptr(), result); 178 } else if (is_volatile && !needs_patching) { 179 gen->volatile_field_load(access.resolved_addr()->as_address_ptr(), result, access.access_emit_info()); 180 } else { 181 __ load(access.resolved_addr()->as_address_ptr(), result, access.access_emit_info(), patch_code); 182 } 183 184 if (is_volatile && os::is_MP()) { 185 __ membar_acquire(); 186 } 187 188 /* Normalize boolean value returned by unsafe operation, i.e., value != 0 ? value = true : value false. */ 189 if (mask_boolean) { 190 LabelObj* equalZeroLabel = new LabelObj(); 191 __ cmp(lir_cond_equal, result, 0); 192 __ branch(lir_cond_equal, T_BOOLEAN, equalZeroLabel->label()); 193 __ move(LIR_OprFact::intConst(1), result); 194 __ branch_destination(equalZeroLabel->label()); 195 } 196 } 197 198 LIR_Opr BarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) { 199 LIRGenerator *gen = access.gen(); 200 return gen->atomic_cmpxchg(access.type(), access.resolved_addr(), cmp_value, new_value); 201 } 202 203 LIR_Opr BarrierSetC1::atomic_xchg_at_resolved(LIRAccess& access, LIRItem& value) { 204 LIRGenerator *gen = access.gen(); 205 return gen->atomic_xchg(access.type(), access.resolved_addr(), value); 206 } 207 208 LIR_Opr BarrierSetC1::atomic_add_at_resolved(LIRAccess& access, LIRItem& value) { 209 LIRGenerator *gen = access.gen(); 210 return gen->atomic_add(access.type(), access.resolved_addr(), value); 211 } 212 213 void BarrierSetC1::generate_referent_check(LIRAccess& access, LabelObj* cont) { 214 // We might be reading the value of the referent field of a 215 // Reference object in order to attach it back to the live 216 // object graph. If G1 is enabled then we need to record 217 // the value that is being returned in an SATB log buffer. 218 // 219 // We need to generate code similar to the following... 220 // 221 // if (offset == java_lang_ref_Reference::referent_offset) { 222 // if (src != NULL) { 223 // if (klass(src)->reference_type() != REF_NONE) { 224 // pre_barrier(..., value, ...); 225 // } 226 // } 227 // } 228 229 bool gen_pre_barrier = true; // Assume we need to generate pre_barrier. 230 bool gen_offset_check = true; // Assume we need to generate the offset guard. 231 bool gen_source_check = true; // Assume we need to check the src object for null. 232 bool gen_type_check = true; // Assume we need to check the reference_type. 233 234 LIRGenerator *gen = access.gen(); 235 236 LIRItem& base = access.base().item(); 237 LIR_Opr offset = access.offset().opr(); 238 239 if (offset->is_constant()) { 240 LIR_Const* constant = offset->as_constant_ptr(); 241 jlong off_con = (constant->type() == T_INT ? 242 (jlong)constant->as_jint() : 243 constant->as_jlong()); 244 245 246 if (off_con != (jlong) java_lang_ref_Reference::referent_offset) { 247 // The constant offset is something other than referent_offset. 248 // We can skip generating/checking the remaining guards and 249 // skip generation of the code stub. 250 gen_pre_barrier = false; 251 } else { 252 // The constant offset is the same as referent_offset - 253 // we do not need to generate a runtime offset check. 254 gen_offset_check = false; 255 } 256 } 257 258 // We don't need to generate stub if the source object is an array 259 if (gen_pre_barrier && base.type()->is_array()) { 260 gen_pre_barrier = false; 261 } 262 263 if (gen_pre_barrier) { 264 // We still need to continue with the checks. 265 if (base.is_constant()) { 266 ciObject* src_con = base.get_jobject_constant(); 267 guarantee(src_con != NULL, "no source constant"); 268 269 if (src_con->is_null_object()) { 270 // The constant src object is null - We can skip 271 // generating the code stub. 272 gen_pre_barrier = false; 273 } else { 274 // Non-null constant source object. We still have to generate 275 // the slow stub - but we don't need to generate the runtime 276 // null object check. 277 gen_source_check = false; 278 } 279 } 280 } 281 if (gen_pre_barrier && !PatchALot) { 282 // Can the klass of object be statically determined to be 283 // a sub-class of Reference? 284 ciType* type = base.value()->declared_type(); 285 if ((type != NULL) && type->is_loaded()) { 286 if (type->is_subtype_of(gen->compilation()->env()->Reference_klass())) { 287 gen_type_check = false; 288 } else if (type->is_klass() && 289 !gen->compilation()->env()->Object_klass()->is_subtype_of(type->as_klass())) { 290 // Not Reference and not Object klass. 291 gen_pre_barrier = false; 292 } 293 } 294 } 295 296 if (gen_pre_barrier) { 297 // We can have generate one runtime check here. Let's start with 298 // the offset check. 299 if (gen_offset_check) { 300 // if (offset != referent_offset) -> continue 301 // If offset is an int then we can do the comparison with the 302 // referent_offset constant; otherwise we need to move 303 // referent_offset into a temporary register and generate 304 // a reg-reg compare. 305 306 LIR_Opr referent_off; 307 308 if (offset->type() == T_INT) { 309 referent_off = LIR_OprFact::intConst(java_lang_ref_Reference::referent_offset); 310 } else { 311 assert(offset->type() == T_LONG, "what else?"); 312 referent_off = gen->new_register(T_LONG); 313 __ move(LIR_OprFact::longConst(java_lang_ref_Reference::referent_offset), referent_off); 314 } 315 __ cmp(lir_cond_notEqual, offset, referent_off); 316 __ branch(lir_cond_notEqual, offset->type(), cont->label()); 317 } 318 if (gen_source_check) { 319 // offset is a const and equals referent offset 320 // if (source == null) -> continue 321 __ cmp(lir_cond_equal, base.result(), LIR_OprFact::oopConst(NULL)); 322 __ branch(lir_cond_equal, T_OBJECT, cont->label()); 323 } 324 LIR_Opr src_klass = gen->new_register(T_OBJECT); 325 if (gen_type_check) { 326 // We have determined that offset == referent_offset && src != null. 327 // if (src->_klass->_reference_type == REF_NONE) -> continue 328 __ move(new LIR_Address(base.result(), oopDesc::klass_offset_in_bytes(), T_ADDRESS), src_klass); 329 LIR_Address* reference_type_addr = new LIR_Address(src_klass, in_bytes(InstanceKlass::reference_type_offset()), T_BYTE); 330 LIR_Opr reference_type = gen->new_register(T_INT); 331 __ move(reference_type_addr, reference_type); 332 __ cmp(lir_cond_equal, reference_type, LIR_OprFact::intConst(REF_NONE)); 333 __ branch(lir_cond_equal, T_INT, cont->label()); 334 } 335 } 336 }