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/barrierSet.hpp" 32 #include "gc/shared/barrierSetAssembler.hpp" 33 #include "gc/shared/tlab_globals.hpp" 34 #include "interpreter/interpreter.hpp" 35 #include "oops/arrayOop.hpp" 36 #include "oops/markWord.hpp" 37 #include "runtime/basicLock.hpp" 38 #include "runtime/os.hpp" 39 #include "runtime/sharedRuntime.hpp" 40 #include "runtime/stubRoutines.hpp" 41 42 void C1_MacroAssembler::float_cmp(bool is_float, int unordered_result, 43 FloatRegister f0, FloatRegister f1, 44 Register result) 45 { 46 Label done; 47 if (is_float) { 48 fcmps(f0, f1); 49 } else { 50 fcmpd(f0, f1); 51 } 52 if (unordered_result < 0) { 53 // we want -1 for unordered or less than, 0 for equal and 1 for 54 // greater than. 55 cset(result, NE); // Not equal or unordered 56 cneg(result, result, LT); // Less than or unordered 57 } else { 58 // we want -1 for less than, 0 for equal and 1 for unordered or 59 // greater than. 60 cset(result, NE); // Not equal or unordered 61 cneg(result, result, LO); // Less than 62 } 63 } 64 65 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 66 const int aligned_mask = BytesPerWord -1; 67 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 68 assert_different_registers(hdr, obj, disp_hdr); 69 int null_check_offset = -1; 70 71 verify_oop(obj); 72 73 // save object being locked into the BasicObjectLock 74 str(obj, Address(disp_hdr, BasicObjectLock::obj_offset())); 75 76 null_check_offset = offset(); 77 78 if (DiagnoseSyncOnValueBasedClasses != 0) { 79 load_klass(hdr, obj); 80 ldrw(hdr, Address(hdr, Klass::access_flags_offset())); 81 tstw(hdr, JVM_ACC_IS_VALUE_BASED_CLASS); 82 br(Assembler::NE, slow_case); 83 } 84 85 // Load object header 86 ldr(hdr, Address(obj, hdr_offset)); 87 if (LockingMode == LM_LIGHTWEIGHT) { 88 fast_lock(obj, hdr, rscratch1, rscratch2, slow_case); 89 } else if (LockingMode == LM_LEGACY) { 90 Label done; 91 // and mark it as unlocked 92 orr(hdr, hdr, markWord::unlocked_value); 93 94 if (EnableValhalla) { 95 // Mask always_locked bit such that we go to the slow path if object is an inline type 96 andr(hdr, hdr, ~markWord::inline_type_bit_in_place); 97 } 98 99 // save unlocked object header into the displaced header location on the stack 100 str(hdr, Address(disp_hdr, 0)); 101 // test if object header is still the same (i.e. unlocked), and if so, store the 102 // displaced header address in the object header - if it is not the same, get the 103 // object header instead 104 lea(rscratch2, Address(obj, hdr_offset)); 105 cmpxchgptr(hdr, disp_hdr, rscratch2, rscratch1, done, /*fallthough*/nullptr); 106 // if the object header was the same, we're done 107 // if the object header was not the same, it is now in the hdr register 108 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 109 // 110 // 1) (hdr & aligned_mask) == 0 111 // 2) sp <= hdr 112 // 3) hdr <= sp + page_size 113 // 114 // these 3 tests can be done by evaluating the following expression: 115 // 116 // (hdr - sp) & (aligned_mask - page_size) 117 // 118 // assuming both the stack pointer and page_size have their least 119 // significant 2 bits cleared and page_size is a power of 2 120 mov(rscratch1, sp); 121 sub(hdr, hdr, rscratch1); 122 ands(hdr, hdr, aligned_mask - (int)os::vm_page_size()); 123 // for recursive locking, the result is zero => save it in the displaced header 124 // location (null in the displaced hdr location indicates recursive locking) 125 str(hdr, Address(disp_hdr, 0)); 126 // otherwise we don't care about the result and handle locking via runtime call 127 cbnz(hdr, slow_case); 128 // done 129 bind(done); 130 } 131 increment(Address(rthread, JavaThread::held_monitor_count_offset())); 132 return null_check_offset; 133 } 134 135 136 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 137 const int aligned_mask = BytesPerWord -1; 138 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 139 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 140 Label done; 141 142 if (LockingMode != LM_LIGHTWEIGHT) { 143 // load displaced header 144 ldr(hdr, Address(disp_hdr, 0)); 145 // if the loaded hdr is null we had recursive locking 146 // if we had recursive locking, we are done 147 cbz(hdr, done); 148 } 149 150 // load object 151 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset())); 152 verify_oop(obj); 153 154 if (LockingMode == LM_LIGHTWEIGHT) { 155 ldr(hdr, Address(obj, oopDesc::mark_offset_in_bytes())); 156 // We cannot use tbnz here, the target might be too far away and cannot 157 // be encoded. 158 tst(hdr, markWord::monitor_value); 159 br(Assembler::NE, slow_case); 160 fast_unlock(obj, hdr, rscratch1, rscratch2, slow_case); 161 } else if (LockingMode == LM_LEGACY) { 162 // test if object header is pointing to the displaced header, and if so, restore 163 // the displaced header in the object - if the object header is not pointing to 164 // the displaced header, get the object header instead 165 // if the object header was not pointing to the displaced header, 166 // we do unlocking via runtime call 167 if (hdr_offset) { 168 lea(rscratch1, Address(obj, hdr_offset)); 169 cmpxchgptr(disp_hdr, hdr, rscratch1, rscratch2, done, &slow_case); 170 } else { 171 cmpxchgptr(disp_hdr, hdr, obj, rscratch2, done, &slow_case); 172 } 173 // done 174 bind(done); 175 } 176 decrement(Address(rthread, JavaThread::held_monitor_count_offset())); 177 } 178 179 180 // Defines obj, preserves var_size_in_bytes 181 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) { 182 if (UseTLAB) { 183 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 184 } else { 185 b(slow_case); 186 } 187 } 188 189 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 190 assert_different_registers(obj, klass, len); 191 if (EnableValhalla) { 192 // Need to copy markWord::prototype header for klass 193 assert_different_registers(obj, klass, len, t1, t2); 194 ldr(t1, Address(klass, Klass::prototype_header_offset())); 195 } else { 196 // This assumes that all prototype bits fit in an int32_t 197 mov(t1, (int32_t)(intptr_t)markWord::prototype().value()); 198 } 199 str(t1, Address(obj, oopDesc::mark_offset_in_bytes())); 200 201 if (UseCompressedClassPointers) { // Take care not to kill klass 202 encode_klass_not_null(t1, klass); 203 strw(t1, Address(obj, oopDesc::klass_offset_in_bytes())); 204 } else { 205 str(klass, Address(obj, oopDesc::klass_offset_in_bytes())); 206 } 207 208 if (len->is_valid()) { 209 strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 210 } else if (UseCompressedClassPointers) { 211 store_klass_gap(obj, zr); 212 } 213 } 214 215 // preserves obj, destroys len_in_bytes 216 // 217 // Scratch registers: t1 = r10, t2 = r11 218 // 219 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1, Register t2) { 220 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 221 assert(t1 == r10 && t2 == r11, "must be"); 222 223 Label done; 224 225 // len_in_bytes is positive and ptr sized 226 subs(len_in_bytes, len_in_bytes, hdr_size_in_bytes); 227 br(Assembler::EQ, done); 228 229 // zero_words() takes ptr in r10 and count in words in r11 230 mov(rscratch1, len_in_bytes); 231 lea(t1, Address(obj, hdr_size_in_bytes)); 232 lsr(t2, rscratch1, LogBytesPerWord); 233 address tpc = zero_words(t1, t2); 234 235 bind(done); 236 if (tpc == nullptr) { 237 Compilation::current()->bailout("no space for trampoline stub"); 238 } 239 } 240 241 242 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 243 assert_different_registers(obj, t1, t2); // XXX really? 244 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 245 246 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 247 248 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 249 } 250 251 // Scratch registers: t1 = r10, t2 = r11 252 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) { 253 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 254 "con_size_in_bytes is not multiple of alignment"); 255 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 256 257 initialize_header(obj, klass, noreg, t1, t2); 258 259 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 260 // clear rest of allocated space 261 const Register index = t2; 262 if (var_size_in_bytes != noreg) { 263 mov(index, var_size_in_bytes); 264 initialize_body(obj, index, hdr_size_in_bytes, t1, t2); 265 if (Compilation::current()->bailed_out()) { 266 return; 267 } 268 } else if (con_size_in_bytes > hdr_size_in_bytes) { 269 con_size_in_bytes -= hdr_size_in_bytes; 270 lea(t1, Address(obj, hdr_size_in_bytes)); 271 address tpc = zero_words(t1, con_size_in_bytes / BytesPerWord); 272 if (tpc == nullptr) { 273 Compilation::current()->bailout("no space for trampoline stub"); 274 return; 275 } 276 } 277 } 278 279 membar(StoreStore); 280 281 if (CURRENT_ENV->dtrace_alloc_probes()) { 282 assert(obj == r0, "must be"); 283 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 284 } 285 286 verify_oop(obj); 287 } 288 289 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, int f, Register klass, Label& slow_case) { 290 assert_different_registers(obj, len, t1, t2, klass); 291 292 // determine alignment mask 293 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 294 295 // check for negative or excessive length 296 mov(rscratch1, (int32_t)max_array_allocation_length); 297 cmp(len, rscratch1); 298 br(Assembler::HS, slow_case); 299 300 const Register arr_size = t2; // okay to be the same 301 // align object end 302 mov(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask); 303 add(arr_size, arr_size, len, ext::uxtw, f); 304 andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask); 305 306 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 307 308 initialize_header(obj, klass, len, t1, t2); 309 310 // clear rest of allocated space 311 initialize_body(obj, arr_size, header_size * BytesPerWord, t1, t2); 312 if (Compilation::current()->bailed_out()) { 313 return; 314 } 315 316 membar(StoreStore); 317 318 if (CURRENT_ENV->dtrace_alloc_probes()) { 319 assert(obj == r0, "must be"); 320 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 321 } 322 323 verify_oop(obj); 324 } 325 326 327 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 328 verify_oop(receiver); 329 // explicit null check not needed since load from [klass_offset] causes a trap 330 // check against inline cache 331 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check"); 332 333 cmp_klass(receiver, iCache, rscratch1); 334 } 335 336 void C1_MacroAssembler::build_frame_helper(int frame_size_in_bytes, int sp_offset_for_orig_pc, int sp_inc, bool reset_orig_pc, bool needs_stack_repair) { 337 MacroAssembler::build_frame(frame_size_in_bytes); 338 339 if (needs_stack_repair) { 340 save_stack_increment(sp_inc, frame_size_in_bytes); 341 } 342 if (reset_orig_pc) { 343 // Zero orig_pc to detect deoptimization during buffering in the entry points 344 str(zr, Address(sp, sp_offset_for_orig_pc)); 345 } 346 } 347 348 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes, int sp_offset_for_orig_pc, bool needs_stack_repair, bool has_scalarized_args, Label* verified_inline_entry_label) { 349 // Make sure there is enough stack space for this method's activation. 350 // Note that we do this before creating a frame. 351 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 352 generate_stack_overflow_check(bang_size_in_bytes); 353 354 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, has_scalarized_args, needs_stack_repair); 355 356 // Insert nmethod entry barrier into frame. 357 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 358 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */, nullptr /* guard */); 359 360 if (verified_inline_entry_label != nullptr) { 361 // Jump here from the scalarized entry points that already created the frame. 362 bind(*verified_inline_entry_label); 363 } 364 } 365 366 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 367 // If we have to make this method not-entrant we'll overwrite its 368 // first instruction with a jump. For this action to be legal we 369 // must ensure that this first instruction is a B, BL, NOP, BKPT, 370 // SVC, HVC, or SMC. Make it a NOP. 371 nop(); 372 if (C1Breakpoint) brk(1); 373 } 374 375 int C1_MacroAssembler::scalarized_entry(const CompiledEntrySignature* ces, int frame_size_in_bytes, int bang_size_in_bytes, int sp_offset_for_orig_pc, Label& verified_inline_entry_label, bool is_inline_ro_entry) { 376 assert(InlineTypePassFieldsAsArgs, "sanity"); 377 // Make sure there is enough stack space for this method's activation. 378 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 379 generate_stack_overflow_check(bang_size_in_bytes); 380 381 GrowableArray<SigEntry>* sig = ces->sig(); 382 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? ces->sig_cc_ro() : ces->sig_cc(); 383 VMRegPair* regs = ces->regs(); 384 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc(); 385 int args_on_stack = ces->args_on_stack(); 386 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc(); 387 388 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!"); 389 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length()); 390 int args_passed = sig->length(); 391 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt); 392 393 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC. 394 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, true, ces->c1_needs_stack_repair()); 395 396 // The runtime call might safepoint, make sure nmethod entry barrier is executed 397 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 398 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub 399 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */, nullptr /* guard */); 400 401 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args. 402 mov(r19, (intptr_t) ces->method()); 403 if (is_inline_ro_entry) { 404 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id))); 405 } else { 406 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id))); 407 } 408 int rt_call_offset = offset(); 409 410 // The runtime call returns the new array in r20 instead of the usual r0 411 // because r0 is also j_rarg7 which may be holding a live argument here. 412 Register val_array = r20; 413 414 // Remove the temp frame 415 MacroAssembler::remove_frame(frame_size_in_bytes); 416 417 // Check if we need to extend the stack for packing 418 int sp_inc = 0; 419 if (args_on_stack > args_on_stack_cc) { 420 sp_inc = extend_stack_for_inline_args(args_on_stack); 421 } 422 423 shuffle_inline_args(true, is_inline_ro_entry, sig_cc, 424 args_passed_cc, args_on_stack_cc, regs_cc, // from 425 args_passed, args_on_stack, regs, // to 426 sp_inc, val_array); 427 428 // Create the real frame. Below jump will then skip over the stack banging and frame 429 // setup code in the verified_inline_entry (which has a different real_frame_size). 430 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, sp_inc, false, ces->c1_needs_stack_repair()); 431 432 b(verified_inline_entry_label); 433 return rt_call_offset; 434 } 435 436 437 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 438 // rfp, + 0: link 439 // + 1: return address 440 // + 2: argument with offset 0 441 // + 3: argument with offset 1 442 // + 4: ... 443 444 ldr(reg, Address(rfp, (offset_in_words + 2) * BytesPerWord)); 445 } 446 447 #ifndef PRODUCT 448 449 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 450 if (!VerifyOops) return; 451 verify_oop_addr(Address(sp, stack_offset)); 452 } 453 454 void C1_MacroAssembler::verify_not_null_oop(Register r) { 455 if (!VerifyOops) return; 456 Label not_null; 457 cbnz(r, not_null); 458 stop("non-null oop required"); 459 bind(not_null); 460 verify_oop(r); 461 } 462 463 void C1_MacroAssembler::invalidate_registers(bool inv_r0, bool inv_r19, bool inv_r2, bool inv_r3, bool inv_r4, bool inv_r5) { 464 #ifdef ASSERT 465 static int nn; 466 if (inv_r0) mov(r0, 0xDEAD); 467 if (inv_r19) mov(r19, 0xDEAD); 468 if (inv_r2) mov(r2, nn++); 469 if (inv_r3) mov(r3, 0xDEAD); 470 if (inv_r4) mov(r4, 0xDEAD); 471 if (inv_r5) mov(r5, 0xDEAD); 472 #endif 473 } 474 #endif // ifndef PRODUCT