1 /* 2 * Copyright (c) 2018, 2019, 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 if (needs_patching) { 66 __ leal(addr_opr, resolved_addr, lir_patch_normal, access.patch_emit_info()); 67 access.clear_decorators(C1_NEEDS_PATCHING); 68 } else { 69 __ leal(addr_opr, resolved_addr); 70 } 71 return LIR_OprFact::address(new LIR_Address(resolved_addr, access.type())); 72 } else { 73 return addr_opr; 74 } 75 } 76 77 void BarrierSetC1::store_at(LIRAccess& access, LIR_Opr value) { 78 DecoratorSet decorators = access.decorators(); 79 bool in_heap = (decorators & IN_HEAP) != 0; 80 assert(in_heap, "not supported yet"); 81 82 LIR_Opr resolved = resolve_address(access, false); 83 access.set_resolved_addr(resolved); 84 store_at_resolved(access, value); 85 } 86 87 void BarrierSetC1::load_at(LIRAccess& access, LIR_Opr result) { 88 DecoratorSet decorators = access.decorators(); 89 bool in_heap = (decorators & IN_HEAP) != 0; 90 assert(in_heap, "not supported yet"); 91 92 LIR_Opr resolved = resolve_address(access, false); 93 access.set_resolved_addr(resolved); 94 load_at_resolved(access, result); 95 } 96 97 void BarrierSetC1::load(LIRAccess& access, LIR_Opr result) { 98 DecoratorSet decorators = access.decorators(); 99 bool in_heap = (decorators & IN_HEAP) != 0; 100 assert(!in_heap, "consider using load_at"); 101 load_at_resolved(access, result); 102 } 103 104 LIR_Opr BarrierSetC1::atomic_cmpxchg_at(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) { 105 DecoratorSet decorators = access.decorators(); 106 bool in_heap = (decorators & IN_HEAP) != 0; 107 assert(in_heap, "not supported yet"); 108 109 access.load_address(); 110 111 LIR_Opr resolved = resolve_address(access, true); 112 access.set_resolved_addr(resolved); 113 return atomic_cmpxchg_at_resolved(access, cmp_value, new_value); 114 } 115 116 LIR_Opr BarrierSetC1::atomic_xchg_at(LIRAccess& access, LIRItem& value) { 117 DecoratorSet decorators = access.decorators(); 118 bool in_heap = (decorators & IN_HEAP) != 0; 119 assert(in_heap, "not supported yet"); 120 121 access.load_address(); 122 123 LIR_Opr resolved = resolve_address(access, true); 124 access.set_resolved_addr(resolved); 125 return atomic_xchg_at_resolved(access, value); 126 } 127 128 LIR_Opr BarrierSetC1::atomic_add_at(LIRAccess& access, LIRItem& value) { 129 DecoratorSet decorators = access.decorators(); 130 bool in_heap = (decorators & IN_HEAP) != 0; 131 assert(in_heap, "not supported yet"); 132 133 access.load_address(); 134 135 LIR_Opr resolved = resolve_address(access, true); 136 access.set_resolved_addr(resolved); 137 return atomic_add_at_resolved(access, value); 138 } 139 140 void BarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) { 141 DecoratorSet decorators = access.decorators(); 142 bool is_volatile = (((decorators & MO_SEQ_CST) != 0) || AlwaysAtomicAccesses); 143 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; 144 bool mask_boolean = (decorators & C1_MASK_BOOLEAN) != 0; 145 LIRGenerator* gen = access.gen(); 146 147 if (mask_boolean) { 148 value = gen->mask_boolean(access.base().opr(), value, access.access_emit_info()); 149 } 150 151 if (is_volatile) { 152 __ membar_release(); 153 } 154 155 LIR_PatchCode patch_code = needs_patching ? lir_patch_normal : lir_patch_none; 156 if (is_volatile && !needs_patching) { 157 gen->volatile_field_store(value, access.resolved_addr()->as_address_ptr(), access.access_emit_info()); 158 } else { 159 __ store(value, access.resolved_addr()->as_address_ptr(), access.access_emit_info(), patch_code); 160 } 161 162 if (is_volatile && !support_IRIW_for_not_multiple_copy_atomic_cpu) { 163 __ membar(); 164 } 165 } 166 167 void BarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) { 168 LIRGenerator *gen = access.gen(); 169 DecoratorSet decorators = access.decorators(); 170 bool is_volatile = (((decorators & MO_SEQ_CST) != 0) || AlwaysAtomicAccesses); 171 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0; 172 bool mask_boolean = (decorators & C1_MASK_BOOLEAN) != 0; 173 bool in_native = (decorators & IN_NATIVE) != 0; 174 175 if (support_IRIW_for_not_multiple_copy_atomic_cpu && is_volatile) { 176 __ membar(); 177 } 178 179 LIR_PatchCode patch_code = needs_patching ? lir_patch_normal : lir_patch_none; 180 if (in_native) { 181 __ move_wide(access.resolved_addr()->as_address_ptr(), result); 182 } else if (is_volatile && !needs_patching) { 183 gen->volatile_field_load(access.resolved_addr()->as_address_ptr(), result, access.access_emit_info()); 184 } else { 185 __ load(access.resolved_addr()->as_address_ptr(), result, access.access_emit_info(), patch_code); 186 } 187 188 if (is_volatile) { 189 __ membar_acquire(); 190 } 191 192 /* Normalize boolean value returned by unsafe operation, i.e., value != 0 ? value = true : value false. */ 193 if (mask_boolean) { 194 LabelObj* equalZeroLabel = new LabelObj(); 195 __ cmp(lir_cond_equal, result, 0); 196 __ branch(lir_cond_equal, T_BOOLEAN, equalZeroLabel->label()); 197 __ move(LIR_OprFact::intConst(1), result); 198 __ branch_destination(equalZeroLabel->label()); 199 } 200 } 201 202 LIR_Opr BarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) { 203 LIRGenerator *gen = access.gen(); 204 return gen->atomic_cmpxchg(access.type(), access.resolved_addr(), cmp_value, new_value); 205 } 206 207 LIR_Opr BarrierSetC1::atomic_xchg_at_resolved(LIRAccess& access, LIRItem& value) { 208 LIRGenerator *gen = access.gen(); 209 return gen->atomic_xchg(access.type(), access.resolved_addr(), value); 210 } 211 212 LIR_Opr BarrierSetC1::atomic_add_at_resolved(LIRAccess& access, LIRItem& value) { 213 LIRGenerator *gen = access.gen(); 214 return gen->atomic_add(access.type(), access.resolved_addr(), value); 215 } 216 217 void BarrierSetC1::generate_referent_check(LIRAccess& access, LabelObj* cont) { 218 // We might be reading the value of the referent field of a 219 // Reference object in order to attach it back to the live 220 // object graph. If G1 is enabled then we need to record 221 // the value that is being returned in an SATB log buffer. 222 // 223 // We need to generate code similar to the following... 224 // 225 // if (offset == java_lang_ref_Reference::referent_offset) { 226 // if (src != NULL) { 227 // if (klass(src)->reference_type() != REF_NONE) { 228 // pre_barrier(..., value, ...); 229 // } 230 // } 231 // } 232 233 bool gen_pre_barrier = true; // Assume we need to generate pre_barrier. 234 bool gen_offset_check = true; // Assume we need to generate the offset guard. 235 bool gen_source_check = true; // Assume we need to check the src object for null. 236 bool gen_type_check = true; // Assume we need to check the reference_type. 237 238 LIRGenerator *gen = access.gen(); 239 240 LIRItem& base = access.base().item(); 241 LIR_Opr offset = access.offset().opr(); 242 243 if (offset->is_constant()) { 244 LIR_Const* constant = offset->as_constant_ptr(); 245 jlong off_con = (constant->type() == T_INT ? 246 (jlong)constant->as_jint() : 247 constant->as_jlong()); 248 249 250 if (off_con != (jlong) java_lang_ref_Reference::referent_offset) { 251 // The constant offset is something other than referent_offset. 252 // We can skip generating/checking the remaining guards and 253 // skip generation of the code stub. 254 gen_pre_barrier = false; 255 } else { 256 // The constant offset is the same as referent_offset - 257 // we do not need to generate a runtime offset check. 258 gen_offset_check = false; 259 } 260 } 261 262 // We don't need to generate stub if the source object is an array 263 if (gen_pre_barrier && base.type()->is_array()) { 264 gen_pre_barrier = false; 265 } 266 267 if (gen_pre_barrier) { 268 // We still need to continue with the checks. 269 if (base.is_constant()) { 270 ciObject* src_con = base.get_jobject_constant(); 271 guarantee(src_con != NULL, "no source constant"); 272 273 if (src_con->is_null_object()) { 274 // The constant src object is null - We can skip 275 // generating the code stub. 276 gen_pre_barrier = false; 277 } else { 278 // Non-null constant source object. We still have to generate 279 // the slow stub - but we don't need to generate the runtime 280 // null object check. 281 gen_source_check = false; 282 } 283 } 284 } 285 if (gen_pre_barrier && !PatchALot) { 286 // Can the klass of object be statically determined to be 287 // a sub-class of Reference? 288 ciType* type = base.value()->declared_type(); 289 if ((type != NULL) && type->is_loaded()) { 290 if (type->is_subtype_of(gen->compilation()->env()->Reference_klass())) { 291 gen_type_check = false; 292 } else if (type->is_klass() && 293 !gen->compilation()->env()->Object_klass()->is_subtype_of(type->as_klass())) { 294 // Not Reference and not Object klass. 295 gen_pre_barrier = false; 296 } 297 } 298 } 299 300 if (gen_pre_barrier) { 301 // We can have generate one runtime check here. Let's start with 302 // the offset check. 303 // Allocate temp register to base and load it here, otherwise 304 // control flow below may confuse register allocator. 305 LIR_Opr base_reg = gen->new_register(T_OBJECT); 306 __ move(base.result(), base_reg); 307 if (gen_offset_check) { 308 // if (offset != referent_offset) -> continue 309 // If offset is an int then we can do the comparison with the 310 // referent_offset constant; otherwise we need to move 311 // referent_offset into a temporary register and generate 312 // a reg-reg compare. 313 314 LIR_Opr referent_off; 315 316 if (offset->type() == T_INT) { 317 referent_off = LIR_OprFact::intConst(java_lang_ref_Reference::referent_offset); 318 } else { 319 assert(offset->type() == T_LONG, "what else?"); 320 referent_off = gen->new_register(T_LONG); 321 __ move(LIR_OprFact::longConst(java_lang_ref_Reference::referent_offset), referent_off); 322 } 323 __ cmp(lir_cond_notEqual, offset, referent_off); 324 __ branch(lir_cond_notEqual, offset->type(), cont->label()); 325 } 326 if (gen_source_check) { 327 // offset is a const and equals referent offset 328 // if (source == null) -> continue 329 __ cmp(lir_cond_equal, base_reg, LIR_OprFact::oopConst(NULL)); 330 __ branch(lir_cond_equal, T_OBJECT, cont->label()); 331 } 332 LIR_Opr src_klass = gen->new_register(T_METADATA); 333 if (gen_type_check) { 334 // We have determined that offset == referent_offset && src != null. 335 // if (src->_klass->_reference_type == REF_NONE) -> continue 336 __ move(new LIR_Address(base_reg, oopDesc::klass_offset_in_bytes(), T_ADDRESS), src_klass); 337 LIR_Address* reference_type_addr = new LIR_Address(src_klass, in_bytes(InstanceKlass::reference_type_offset()), T_BYTE); 338 LIR_Opr reference_type = gen->new_register(T_INT); 339 __ move(reference_type_addr, reference_type); 340 __ cmp(lir_cond_equal, reference_type, LIR_OprFact::intConst(REF_NONE)); 341 __ branch(lir_cond_equal, T_INT, cont->label()); 342 } 343 } 344 } 345 346 LIR_Opr BarrierSetC1::resolve(LIRGenerator* gen, DecoratorSet decorators, LIR_Opr obj) { 347 return obj; 348 }