1 /* 2 * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2014, 2021, Red Hat Inc. 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 "c1/c1_MacroAssembler.hpp" 28 #include "c1/c1_Runtime1.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 40 void C1_MacroAssembler::float_cmp(bool is_float, int unordered_result, 41 FloatRegister f0, FloatRegister f1, 42 Register result) 43 { 44 Label done; 45 if (is_float) { 46 fcmps(f0, f1); 47 } else { 48 fcmpd(f0, f1); 49 } 50 if (unordered_result < 0) { 51 // we want -1 for unordered or less than, 0 for equal and 1 for 52 // greater than. 53 cset(result, NE); // Not equal or unordered 54 cneg(result, result, LT); // Less than or unordered 55 } else { 56 // we want -1 for less than, 0 for equal and 1 for unordered or 57 // greater than. 58 cset(result, NE); // Not equal or unordered 59 cneg(result, result, LO); // Less than 60 } 61 } 62 63 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 64 const int aligned_mask = BytesPerWord -1; 65 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 66 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 67 Label done; 68 int null_check_offset = -1; 69 70 verify_oop(obj); 71 72 // save object being locked into the BasicObjectLock 73 str(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 74 75 null_check_offset = offset(); 76 77 if (DiagnoseSyncOnValueBasedClasses != 0) { 78 load_klass(hdr, obj); 79 ldrw(hdr, Address(hdr, Klass::access_flags_offset())); 80 tstw(hdr, JVM_ACC_IS_VALUE_BASED_CLASS); 81 br(Assembler::NE, slow_case); 82 } 83 84 // Load object header 85 ldr(hdr, Address(obj, hdr_offset)); 86 if (UseFastLocking) { 87 fast_lock(obj, hdr, rscratch1, rscratch2, slow_case, false); 88 } else { 89 // and mark it as unlocked 90 orr(hdr, hdr, markWord::unlocked_value); 91 // save unlocked object header into the displaced header location on the stack 92 str(hdr, Address(disp_hdr, 0)); 93 // test if object header is still the same (i.e. unlocked), and if so, store the 94 // displaced header address in the object header - if it is not the same, get the 95 // object header instead 96 lea(rscratch2, Address(obj, hdr_offset)); 97 cmpxchgptr(hdr, disp_hdr, rscratch2, rscratch1, done, /*fallthough*/NULL); 98 // if the object header was the same, we're done 99 // if the object header was not the same, it is now in the hdr register 100 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 101 // 102 // 1) (hdr & aligned_mask) == 0 103 // 2) sp <= hdr 104 // 3) hdr <= sp + page_size 105 // 106 // these 3 tests can be done by evaluating the following expression: 107 // 108 // (hdr - sp) & (aligned_mask - page_size) 109 // 110 // assuming both the stack pointer and page_size have their least 111 // significant 2 bits cleared and page_size is a power of 2 112 mov(rscratch1, sp); 113 sub(hdr, hdr, rscratch1); 114 ands(hdr, hdr, aligned_mask - (int)os::vm_page_size()); 115 // for recursive locking, the result is zero => save it in the displaced header 116 // location (NULL in the displaced hdr location indicates recursive locking) 117 str(hdr, Address(disp_hdr, 0)); 118 // otherwise we don't care about the result and handle locking via runtime call 119 cbnz(hdr, slow_case); 120 } 121 // done 122 bind(done); 123 increment(Address(rthread, JavaThread::held_monitor_count_offset())); 124 return null_check_offset; 125 } 126 127 128 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 129 const int aligned_mask = BytesPerWord -1; 130 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 131 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 132 Label done; 133 134 if (!UseFastLocking) { 135 // load displaced header 136 ldr(hdr, Address(disp_hdr, 0)); 137 // if the loaded hdr is NULL we had recursive locking 138 // if we had recursive locking, we are done 139 cbz(hdr, done); 140 } 141 142 // load object 143 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 144 verify_oop(obj); 145 146 if (UseFastLocking) { 147 ldr(hdr, Address(obj, oopDesc::mark_offset_in_bytes())); 148 fast_unlock(obj, hdr, rscratch1, rscratch2, slow_case); 149 } else { 150 // test if object header is pointing to the displaced header, and if so, restore 151 // the displaced header in the object - if the object header is not pointing to 152 // the displaced header, get the object header instead 153 // if the object header was not pointing to the displaced header, 154 // we do unlocking via runtime call 155 if (hdr_offset) { 156 lea(rscratch1, Address(obj, hdr_offset)); 157 cmpxchgptr(disp_hdr, hdr, rscratch1, rscratch2, done, &slow_case); 158 } else { 159 cmpxchgptr(disp_hdr, hdr, obj, rscratch2, done, &slow_case); 160 } 161 // done 162 bind(done); 163 } 164 decrement(Address(rthread, JavaThread::held_monitor_count_offset())); 165 } 166 167 168 // Defines obj, preserves var_size_in_bytes 169 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) { 170 if (UseTLAB) { 171 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 172 } else { 173 b(slow_case); 174 } 175 } 176 177 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 178 assert_different_registers(obj, klass, len); 179 if (UseCompactObjectHeaders) { 180 ldr(t1, Address(klass, Klass::prototype_header_offset())); 181 str(t1, Address(obj, oopDesc::mark_offset_in_bytes())); 182 } else { 183 // This assumes that all prototype bits fit in an int32_t 184 mov(t1, (int32_t)(intptr_t)markWord::prototype().value()); 185 str(t1, Address(obj, oopDesc::mark_offset_in_bytes())); 186 187 if (UseCompressedClassPointers) { // Take care not to kill klass 188 encode_klass_not_null(t1, klass); 189 strw(t1, Address(obj, oopDesc::klass_offset_in_bytes())); 190 } else { 191 str(klass, Address(obj, oopDesc::klass_offset_in_bytes())); 192 } 193 } 194 195 if (len->is_valid()) { 196 strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 197 } else if (UseCompressedClassPointers && !UseCompactObjectHeaders) { 198 store_klass_gap(obj, zr); 199 } 200 } 201 202 // preserves obj, destroys len_in_bytes 203 // 204 // Scratch registers: t1 = r10, t2 = r11 205 // 206 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1, Register t2) { 207 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 208 assert(t1 == r10 && t2 == r11, "must be"); 209 210 Label done; 211 212 // len_in_bytes is positive and ptr sized 213 subs(len_in_bytes, len_in_bytes, hdr_size_in_bytes); 214 br(Assembler::EQ, done); 215 216 // Zero first 4 bytes, if start offset is not word aligned. 217 if (!is_aligned(hdr_size_in_bytes, BytesPerWord)) { 218 strw(zr, Address(obj, hdr_size_in_bytes)); 219 hdr_size_in_bytes += BytesPerInt; 220 } 221 222 // zero_words() takes ptr in r10 and count in words in r11 223 mov(rscratch1, len_in_bytes); 224 lea(t1, Address(obj, hdr_size_in_bytes)); 225 lsr(t2, rscratch1, LogBytesPerWord); 226 address tpc = zero_words(t1, t2); 227 228 bind(done); 229 if (tpc == nullptr) { 230 Compilation::current()->bailout("no space for trampoline stub"); 231 } 232 } 233 234 235 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 236 assert_different_registers(obj, t1, t2); // XXX really? 237 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 238 239 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 240 241 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 242 } 243 244 // Scratch registers: t1 = r10, t2 = r11 245 void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, bool is_tlab_allocated) { 246 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 247 "con_size_in_bytes is not multiple of alignment"); 248 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 249 250 initialize_header(obj, klass, noreg, t1, t2); 251 252 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 253 // clear rest of allocated space 254 const Register index = t2; 255 if (var_size_in_bytes != noreg) { 256 mov(index, var_size_in_bytes); 257 initialize_body(obj, index, hdr_size_in_bytes, t1, t2); 258 if (Compilation::current()->bailed_out()) { 259 return; 260 } 261 } else if (con_size_in_bytes > hdr_size_in_bytes) { 262 con_size_in_bytes -= hdr_size_in_bytes; 263 lea(t1, Address(obj, hdr_size_in_bytes)); 264 address tpc = zero_words(t1, con_size_in_bytes / BytesPerWord); 265 if (tpc == nullptr) { 266 Compilation::current()->bailout("no space for trampoline stub"); 267 return; 268 } 269 } 270 } 271 272 membar(StoreStore); 273 274 if (CURRENT_ENV->dtrace_alloc_probes()) { 275 assert(obj == r0, "must be"); 276 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 277 } 278 279 verify_oop(obj); 280 } 281 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, int f, Register klass, Label& slow_case) { 282 assert_different_registers(obj, len, t1, t2, klass); 283 284 // determine alignment mask 285 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 286 287 // check for negative or excessive length 288 mov(rscratch1, (int32_t)max_array_allocation_length); 289 cmp(len, rscratch1); 290 br(Assembler::HS, slow_case); 291 292 const Register arr_size = t2; // okay to be the same 293 // align object end 294 mov(arr_size, (int32_t)base_offset_in_bytes + MinObjAlignmentInBytesMask); 295 add(arr_size, arr_size, len, ext::uxtw, f); 296 andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask); 297 298 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 299 300 initialize_header(obj, klass, len, t1, t2); 301 302 // clear rest of allocated space 303 initialize_body(obj, arr_size, base_offset_in_bytes, t1, t2); 304 if (Compilation::current()->bailed_out()) { 305 return; 306 } 307 308 membar(StoreStore); 309 310 if (CURRENT_ENV->dtrace_alloc_probes()) { 311 assert(obj == r0, "must be"); 312 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 313 } 314 315 verify_oop(obj); 316 } 317 318 319 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 320 verify_oop(receiver); 321 // explicit NULL check not needed since load from [klass_offset] causes a trap 322 // check against inline cache 323 if (UseCompactObjectHeaders) { 324 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::mark_offset_in_bytes()), "must add explicit null check"); 325 } else { 326 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check"); 327 } 328 329 cmp_klass(receiver, iCache, rscratch1); 330 } 331 332 333 void C1_MacroAssembler::build_frame(int framesize, int bang_size_in_bytes, int max_monitors) { 334 assert(bang_size_in_bytes >= framesize, "stack bang size incorrect"); 335 // Make sure there is enough stack space for this method's activation. 336 // Note that we do this before creating a frame. 337 generate_stack_overflow_check(bang_size_in_bytes); 338 MacroAssembler::build_frame(framesize); 339 340 if (UseFastLocking && max_monitors > 0) { 341 Label ok; 342 ldr(r9, Address(rthread, JavaThread::lock_stack_current_offset())); 343 ldr(r10, Address(rthread, JavaThread::lock_stack_limit_offset())); 344 add(r9, r9, max_monitors * oopSize); 345 cmp(r9, r10); 346 br(Assembler::LT, ok); 347 assert(StubRoutines::aarch64::check_lock_stack() != NULL, "need runtime call stub"); 348 far_call(StubRoutines::aarch64::check_lock_stack()); 349 bind(ok); 350 } 351 352 // Insert nmethod entry barrier into frame. 353 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 354 bs->nmethod_entry_barrier(this, NULL /* slow_path */, NULL /* continuation */, NULL /* guard */); 355 } 356 357 void C1_MacroAssembler::remove_frame(int framesize) { 358 MacroAssembler::remove_frame(framesize); 359 } 360 361 362 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 363 // If we have to make this method not-entrant we'll overwrite its 364 // first instruction with a jump. For this action to be legal we 365 // must ensure that this first instruction is a B, BL, NOP, BKPT, 366 // SVC, HVC, or SMC. Make it a NOP. 367 nop(); 368 } 369 370 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 371 // rfp, + 0: link 372 // + 1: return address 373 // + 2: argument with offset 0 374 // + 3: argument with offset 1 375 // + 4: ... 376 377 ldr(reg, Address(rfp, (offset_in_words + 2) * BytesPerWord)); 378 } 379 380 #ifndef PRODUCT 381 382 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 383 if (!VerifyOops) return; 384 verify_oop_addr(Address(sp, stack_offset)); 385 } 386 387 void C1_MacroAssembler::verify_not_null_oop(Register r) { 388 if (!VerifyOops) return; 389 Label not_null; 390 cbnz(r, not_null); 391 stop("non-null oop required"); 392 bind(not_null); 393 verify_oop(r); 394 } 395 396 void C1_MacroAssembler::invalidate_registers(bool inv_r0, bool inv_r19, bool inv_r2, bool inv_r3, bool inv_r4, bool inv_r5) { 397 #ifdef ASSERT 398 static int nn; 399 if (inv_r0) mov(r0, 0xDEAD); 400 if (inv_r19) mov(r19, 0xDEAD); 401 if (inv_r2) mov(r2, nn++); 402 if (inv_r3) mov(r3, 0xDEAD); 403 if (inv_r4) mov(r4, 0xDEAD); 404 if (inv_r5) mov(r5, 0xDEAD); 405 #endif 406 } 407 #endif // ifndef PRODUCT