1 /* 2 * Copyright (c) 2008, 2023, 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_MacroAssembler.hpp" 27 #include "c1/c1_Runtime1.hpp" 28 #include "gc/shared/barrierSet.hpp" 29 #include "gc/shared/barrierSetAssembler.hpp" 30 #include "gc/shared/collectedHeap.hpp" 31 #include "gc/shared/tlab_globals.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "oops/arrayOop.hpp" 34 #include "oops/markWord.hpp" 35 #include "runtime/basicLock.hpp" 36 #include "runtime/os.hpp" 37 #include "runtime/sharedRuntime.hpp" 38 #include "runtime/stubRoutines.hpp" 39 #include "utilities/powerOfTwo.hpp" 40 41 // Note: Rtemp usage is this file should not impact C2 and should be 42 // correct as long as it is not implicitly used in lower layers (the 43 // arm [macro]assembler) and used with care in the other C1 specific 44 // files. 45 46 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) { 47 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 48 assert((frame_size_in_bytes % StackAlignmentInBytes) == 0, "frame size should be aligned"); 49 50 51 arm_stack_overflow_check(bang_size_in_bytes, Rtemp); 52 53 // FP can no longer be used to memorize SP. It may be modified 54 // if this method contains a methodHandle call site 55 raw_push(FP, LR); 56 sub_slow(SP, SP, frame_size_in_bytes); 57 58 // Insert nmethod entry barrier into frame. 59 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 60 bs->nmethod_entry_barrier(this); 61 } 62 63 void C1_MacroAssembler::remove_frame(int frame_size_in_bytes) { 64 add_slow(SP, SP, frame_size_in_bytes); 65 raw_pop(FP, LR); 66 } 67 68 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 69 if (breakAtEntry) { 70 breakpoint(); 71 } 72 } 73 74 // Puts address of allocated object into register `obj` and end of allocated object into register `obj_end`. 75 void C1_MacroAssembler::try_allocate(Register obj, Register obj_end, Register tmp1, Register tmp2, 76 RegisterOrConstant size_expression, Label& slow_case) { 77 if (UseTLAB) { 78 tlab_allocate(obj, obj_end, tmp1, size_expression, slow_case); 79 } else { 80 b(slow_case); 81 } 82 } 83 84 85 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register tmp) { 86 assert_different_registers(obj, klass, len, tmp); 87 88 mov(tmp, (intptr_t)markWord::prototype().value()); 89 90 str(tmp, Address(obj, oopDesc::mark_offset_in_bytes())); 91 str(klass, Address(obj, oopDesc::klass_offset_in_bytes())); 92 93 if (len->is_valid()) { 94 str_32(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 95 } 96 } 97 98 99 // Cleans object body [base..obj_end]. Clobbers `base` and `tmp` registers. 100 void C1_MacroAssembler::initialize_body(Register base, Register obj_end, Register tmp) { 101 zero_memory(base, obj_end, tmp); 102 } 103 104 105 void C1_MacroAssembler::initialize_object(Register obj, Register obj_end, Register klass, 106 Register len, Register tmp1, Register tmp2, 107 RegisterOrConstant header_size, int obj_size_in_bytes, 108 bool is_tlab_allocated) 109 { 110 assert_different_registers(obj, obj_end, klass, len, tmp1, tmp2); 111 initialize_header(obj, klass, len, tmp1); 112 113 const Register ptr = tmp2; 114 115 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 116 if (obj_size_in_bytes >= 0 && obj_size_in_bytes <= 8 * BytesPerWord) { 117 mov(tmp1, 0); 118 const int base = instanceOopDesc::header_size() * HeapWordSize; 119 for (int i = base; i < obj_size_in_bytes; i += wordSize) { 120 str(tmp1, Address(obj, i)); 121 } 122 } else { 123 assert(header_size.is_constant() || header_size.as_register() == ptr, "code assumption"); 124 add(ptr, obj, header_size); 125 initialize_body(ptr, obj_end, tmp1); 126 } 127 } 128 129 // StoreStore barrier required after complete initialization 130 // (headers + content zeroing), before the object may escape. 131 membar(MacroAssembler::StoreStore, tmp1); 132 } 133 134 void C1_MacroAssembler::allocate_object(Register obj, Register tmp1, Register tmp2, Register tmp3, 135 int header_size, int object_size, 136 Register klass, Label& slow_case) { 137 assert_different_registers(obj, tmp1, tmp2, tmp3, klass, Rtemp); 138 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 139 const int object_size_in_bytes = object_size * BytesPerWord; 140 141 const Register obj_end = tmp1; 142 const Register len = noreg; 143 144 if (Assembler::is_arith_imm_in_range(object_size_in_bytes)) { 145 try_allocate(obj, obj_end, tmp2, tmp3, object_size_in_bytes, slow_case); 146 } else { 147 // Rtemp should be free at c1 LIR level 148 mov_slow(Rtemp, object_size_in_bytes); 149 try_allocate(obj, obj_end, tmp2, tmp3, Rtemp, slow_case); 150 } 151 initialize_object(obj, obj_end, klass, len, tmp2, tmp3, instanceOopDesc::header_size() * HeapWordSize, object_size_in_bytes, /* is_tlab_allocated */ UseTLAB); 152 } 153 154 void C1_MacroAssembler::allocate_array(Register obj, Register len, 155 Register tmp1, Register tmp2, Register tmp3, 156 int header_size_in_bytes, int element_size, 157 Register klass, Label& slow_case) { 158 assert_different_registers(obj, len, tmp1, tmp2, tmp3, klass, Rtemp); 159 const int scale_shift = exact_log2(element_size); 160 const Register obj_size = Rtemp; // Rtemp should be free at c1 LIR level 161 162 cmp_32(len, max_array_allocation_length); 163 b(slow_case, hs); 164 165 bool align_header = ((header_size_in_bytes | element_size) & MinObjAlignmentInBytesMask) != 0; 166 assert(align_header || ((header_size_in_bytes & MinObjAlignmentInBytesMask) == 0), "must be"); 167 assert(align_header || ((element_size & MinObjAlignmentInBytesMask) == 0), "must be"); 168 169 mov(obj_size, header_size_in_bytes + (align_header ? (MinObjAlignmentInBytes - 1) : 0)); 170 add_ptr_scaled_int32(obj_size, obj_size, len, scale_shift); 171 172 if (align_header) { 173 align_reg(obj_size, obj_size, MinObjAlignmentInBytes); 174 } 175 176 try_allocate(obj, tmp1, tmp2, tmp3, obj_size, slow_case); 177 initialize_object(obj, tmp1, klass, len, tmp2, tmp3, header_size_in_bytes, -1, /* is_tlab_allocated */ UseTLAB); 178 } 179 180 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 181 Label done, fast_lock, fast_lock_done; 182 int null_check_offset = 0; 183 184 const Register tmp2 = Rtemp; // Rtemp should be free at c1 LIR level 185 assert_different_registers(hdr, obj, disp_hdr, tmp2); 186 187 assert(BasicObjectLock::lock_offset() == 0, "adjust this code"); 188 const ByteSize obj_offset = BasicObjectLock::obj_offset(); 189 const int mark_offset = BasicLock::displaced_header_offset_in_bytes(); 190 191 // save object being locked into the BasicObjectLock 192 str(obj, Address(disp_hdr, obj_offset)); 193 194 null_check_offset = offset(); 195 196 if (DiagnoseSyncOnValueBasedClasses != 0) { 197 load_klass(tmp2, obj); 198 ldr_u32(tmp2, Address(tmp2, Klass::access_flags_offset())); 199 tst(tmp2, JVM_ACC_IS_VALUE_BASED_CLASS); 200 b(slow_case, ne); 201 } 202 203 assert(oopDesc::mark_offset_in_bytes() == 0, "Required by atomic instructions"); 204 205 if (LockingMode == LM_LIGHTWEIGHT) { 206 207 Register t1 = disp_hdr; // Needs saving, probably 208 Register t2 = hdr; // blow 209 Register t3 = Rtemp; // blow 210 211 lightweight_lock(obj /* obj */, t1, t2, t3, 1 /* savemask - save t1 */, slow_case); 212 // Success: fall through 213 214 } else if (LockingMode == LM_LEGACY) { 215 216 // On MP platforms the next load could return a 'stale' value if the memory location has been modified by another thread. 217 // That would be acceptable as ether CAS or slow case path is taken in that case. 218 219 // Must be the first instruction here, because implicit null check relies on it 220 ldr(hdr, Address(obj, oopDesc::mark_offset_in_bytes())); 221 222 tst(hdr, markWord::unlocked_value); 223 b(fast_lock, ne); 224 225 // Check for recursive locking 226 // See comments in InterpreterMacroAssembler::lock_object for 227 // explanations on the fast recursive locking check. 228 // -1- test low 2 bits 229 movs(tmp2, AsmOperand(hdr, lsl, 30)); 230 // -2- test (hdr - SP) if the low two bits are 0 231 sub(tmp2, hdr, SP, eq); 232 movs(tmp2, AsmOperand(tmp2, lsr, exact_log2(os::vm_page_size())), eq); 233 // If still 'eq' then recursive locking OK 234 // set to zero if recursive lock, set to non zero otherwise (see discussion in JDK-8267042) 235 str(tmp2, Address(disp_hdr, mark_offset)); 236 b(fast_lock_done, eq); 237 // else need slow case 238 b(slow_case); 239 240 241 bind(fast_lock); 242 // Save previous object header in BasicLock structure and update the header 243 str(hdr, Address(disp_hdr, mark_offset)); 244 245 cas_for_lock_acquire(hdr, disp_hdr, obj, tmp2, slow_case); 246 247 bind(fast_lock_done); 248 } 249 bind(done); 250 251 return null_check_offset; 252 } 253 254 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 255 assert_different_registers(hdr, obj, disp_hdr, Rtemp); 256 Register tmp2 = Rtemp; 257 258 assert(BasicObjectLock::lock_offset() == 0, "adjust this code"); 259 const ByteSize obj_offset = BasicObjectLock::obj_offset(); 260 const int mark_offset = BasicLock::displaced_header_offset_in_bytes(); 261 262 Label done; 263 264 assert(oopDesc::mark_offset_in_bytes() == 0, "Required by atomic instructions"); 265 266 if (LockingMode == LM_LIGHTWEIGHT) { 267 268 ldr(obj, Address(disp_hdr, obj_offset)); 269 270 Register t1 = disp_hdr; // Needs saving, probably 271 Register t2 = hdr; // blow 272 Register t3 = Rtemp; // blow 273 274 lightweight_unlock(obj /* object */, t1, t2, t3, 1 /* savemask (save t1) */, 275 slow_case); 276 // Success: Fall through 277 278 } else if (LockingMode == LM_LEGACY) { 279 280 // Load displaced header and object from the lock 281 ldr(hdr, Address(disp_hdr, mark_offset)); 282 // If hdr is null, we've got recursive locking and there's nothing more to do 283 cbz(hdr, done); 284 285 // load object 286 ldr(obj, Address(disp_hdr, obj_offset)); 287 288 // Restore the object header 289 cas_for_lock_release(disp_hdr, hdr, obj, tmp2, slow_case); 290 } 291 bind(done); 292 } 293 294 #ifndef PRODUCT 295 296 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 297 if (!VerifyOops) return; 298 verify_oop_addr(Address(SP, stack_offset)); 299 } 300 301 void C1_MacroAssembler::verify_not_null_oop(Register r) { 302 Label not_null; 303 cbnz(r, not_null); 304 stop("non-null oop required"); 305 bind(not_null); 306 if (!VerifyOops) return; 307 verify_oop(r); 308 } 309 310 #endif // !PRODUCT