1 /* 2 * Copyright (c) 1999, 2024, 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 "code/compiledIC.hpp" 29 #include "compiler/compilerDefinitions.inline.hpp" 30 #include "gc/shared/barrierSet.hpp" 31 #include "gc/shared/barrierSetAssembler.hpp" 32 #include "gc/shared/collectedHeap.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/frame.inline.hpp" 39 #include "runtime/globals.hpp" 40 #include "runtime/os.hpp" 41 #include "runtime/sharedRuntime.hpp" 42 #include "runtime/stubRoutines.hpp" 43 #include "utilities/checkedCast.hpp" 44 #include "utilities/globalDefinitions.hpp" 45 46 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register tmp, Label& slow_case) { 47 const int aligned_mask = BytesPerWord -1; 48 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 49 assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction"); 50 assert_different_registers(hdr, obj, disp_hdr, tmp); 51 int null_check_offset = -1; 52 53 verify_oop(obj); 54 55 // save object being locked into the BasicObjectLock 56 movptr(Address(disp_hdr, BasicObjectLock::obj_offset()), obj); 57 58 null_check_offset = offset(); 59 60 if (DiagnoseSyncOnValueBasedClasses != 0) { 61 load_klass(hdr, obj, rscratch1); 62 movl(hdr, Address(hdr, Klass::access_flags_offset())); 63 testl(hdr, JVM_ACC_IS_VALUE_BASED_CLASS); 64 jcc(Assembler::notZero, slow_case); 65 } 66 67 if (LockingMode == LM_LIGHTWEIGHT) { 68 #ifdef _LP64 69 const Register thread = r15_thread; 70 #else 71 const Register thread = disp_hdr; 72 get_thread(thread); 73 #endif 74 lightweight_lock(obj, hdr, thread, tmp, slow_case); 75 } else if (LockingMode == LM_LEGACY) { 76 Label done; 77 // Load object header 78 movptr(hdr, Address(obj, hdr_offset)); 79 // and mark it as unlocked 80 orptr(hdr, markWord::unlocked_value); 81 if (EnableValhalla) { 82 // Mask inline_type bit such that we go to the slow path if object is an inline type 83 andptr(hdr, ~((int) markWord::inline_type_bit_in_place)); 84 } 85 // save unlocked object header into the displaced header location on the stack 86 movptr(Address(disp_hdr, 0), hdr); 87 // test if object header is still the same (i.e. unlocked), and if so, store the 88 // displaced header address in the object header - if it is not the same, get the 89 // object header instead 90 MacroAssembler::lock(); // must be immediately before cmpxchg! 91 cmpxchgptr(disp_hdr, Address(obj, hdr_offset)); 92 // if the object header was the same, we're done 93 jcc(Assembler::equal, done); 94 // if the object header was not the same, it is now in the hdr register 95 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 96 // 97 // 1) (hdr & aligned_mask) == 0 98 // 2) rsp <= hdr 99 // 3) hdr <= rsp + page_size 100 // 101 // these 3 tests can be done by evaluating the following expression: 102 // 103 // (hdr - rsp) & (aligned_mask - page_size) 104 // 105 // assuming both the stack pointer and page_size have their least 106 // significant 2 bits cleared and page_size is a power of 2 107 subptr(hdr, rsp); 108 andptr(hdr, aligned_mask - (int)os::vm_page_size()); 109 // for recursive locking, the result is zero => save it in the displaced header 110 // location (null in the displaced hdr location indicates recursive locking) 111 movptr(Address(disp_hdr, 0), hdr); 112 // otherwise we don't care about the result and handle locking via runtime call 113 jcc(Assembler::notZero, slow_case); 114 // done 115 bind(done); 116 } 117 118 inc_held_monitor_count(); 119 120 return null_check_offset; 121 } 122 123 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 124 const int aligned_mask = BytesPerWord -1; 125 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 126 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction"); 127 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 128 Label done; 129 130 if (LockingMode != LM_LIGHTWEIGHT) { 131 // load displaced header 132 movptr(hdr, Address(disp_hdr, 0)); 133 // if the loaded hdr is null we had recursive locking 134 testptr(hdr, hdr); 135 // if we had recursive locking, we are done 136 jcc(Assembler::zero, done); 137 } 138 139 // load object 140 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset())); 141 verify_oop(obj); 142 143 if (LockingMode == LM_LIGHTWEIGHT) { 144 #ifdef _LP64 145 lightweight_unlock(obj, disp_hdr, r15_thread, hdr, slow_case); 146 #else 147 // This relies on the implementation of lightweight_unlock being able to handle 148 // that the reg_rax and thread Register parameters may alias each other. 149 get_thread(disp_hdr); 150 lightweight_unlock(obj, disp_hdr, disp_hdr, hdr, slow_case); 151 #endif 152 } else if (LockingMode == LM_LEGACY) { 153 // test if object header is pointing to the displaced header, and if so, restore 154 // the displaced header in the object - if the object header is not pointing to 155 // the displaced header, get the object header instead 156 MacroAssembler::lock(); // must be immediately before cmpxchg! 157 cmpxchgptr(hdr, Address(obj, hdr_offset)); 158 // if the object header was not pointing to the displaced header, 159 // we do unlocking via runtime call 160 jcc(Assembler::notEqual, slow_case); 161 // done 162 } 163 bind(done); 164 dec_held_monitor_count(); 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(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 172 } else { 173 jmp(slow_case); 174 } 175 } 176 177 178 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 179 assert_different_registers(obj, klass, len); 180 if (EnableValhalla) { 181 // Need to copy markWord::prototype header for klass 182 assert_different_registers(obj, klass, len, t1, t2); 183 movptr(t1, Address(klass, Klass::prototype_header_offset())); 184 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1); 185 } else { 186 // This assumes that all prototype bits fit in an int32_t 187 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value())); 188 } 189 #ifdef _LP64 190 if (UseCompressedClassPointers) { // Take care not to kill klass 191 movptr(t1, klass); 192 encode_klass_not_null(t1, rscratch1); 193 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1); 194 } else 195 #endif 196 { 197 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass); 198 } 199 200 if (len->is_valid()) { 201 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len); 202 #ifdef _LP64 203 int base_offset = arrayOopDesc::length_offset_in_bytes() + BytesPerInt; 204 if (!is_aligned(base_offset, BytesPerWord)) { 205 assert(is_aligned(base_offset, BytesPerInt), "must be 4-byte aligned"); 206 // Clear gap/first 4 bytes following the length field. 207 xorl(t1, t1); 208 movl(Address(obj, base_offset), t1); 209 } 210 #endif 211 } 212 #ifdef _LP64 213 else if (UseCompressedClassPointers) { 214 xorptr(t1, t1); 215 store_klass_gap(obj, t1); 216 } 217 #endif 218 } 219 220 221 // preserves obj, destroys len_in_bytes 222 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) { 223 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 224 Label done; 225 226 // len_in_bytes is positive and ptr sized 227 subptr(len_in_bytes, hdr_size_in_bytes); 228 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1); 229 bind(done); 230 } 231 232 233 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 234 assert(obj == rax, "obj must be in rax, for cmpxchg"); 235 assert_different_registers(obj, t1, t2); // XXX really? 236 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 237 238 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 239 240 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 241 } 242 243 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) { 244 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 245 "con_size_in_bytes is not multiple of alignment"); 246 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 247 248 initialize_header(obj, klass, noreg, t1, t2); 249 250 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 251 // clear rest of allocated space 252 const Register t1_zero = t1; 253 const Register index = t2; 254 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below) 255 if (var_size_in_bytes != noreg) { 256 mov(index, var_size_in_bytes); 257 initialize_body(obj, index, hdr_size_in_bytes, t1_zero); 258 } else if (con_size_in_bytes <= threshold) { 259 // use explicit null stores 260 // code size = 2 + 3*n bytes (n = number of fields to clear) 261 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code) 262 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord) 263 movptr(Address(obj, i), t1_zero); 264 } else if (con_size_in_bytes > hdr_size_in_bytes) { 265 // use loop to null out the fields 266 // code size = 16 bytes for even n (n = number of fields to clear) 267 // initialize last object field first if odd number of fields 268 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code) 269 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3); 270 // initialize last object field if constant size is odd 271 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0) 272 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero); 273 // initialize remaining object fields: rdx is a multiple of 2 274 { Label loop; 275 bind(loop); 276 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)), 277 t1_zero); 278 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)), 279 t1_zero);) 280 decrement(index); 281 jcc(Assembler::notZero, loop); 282 } 283 } 284 } 285 286 if (CURRENT_ENV->dtrace_alloc_probes()) { 287 assert(obj == rax, "must be"); 288 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 289 } 290 291 verify_oop(obj); 292 } 293 294 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, Address::ScaleFactor f, Register klass, Label& slow_case, bool zero_array) { 295 assert(obj == rax, "obj must be in rax, for cmpxchg"); 296 assert_different_registers(obj, len, t1, t2, klass); 297 298 // determine alignment mask 299 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 300 301 // check for negative or excessive length 302 cmpptr(len, checked_cast<int32_t>(max_array_allocation_length)); 303 jcc(Assembler::above, slow_case); 304 305 const Register arr_size = t2; // okay to be the same 306 // align object end 307 movptr(arr_size, base_offset_in_bytes + MinObjAlignmentInBytesMask); 308 lea(arr_size, Address(arr_size, len, f)); 309 andptr(arr_size, ~MinObjAlignmentInBytesMask); 310 311 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 312 313 initialize_header(obj, klass, len, t1, t2); 314 315 // clear rest of allocated space 316 if (zero_array) { 317 const Register len_zero = len; 318 // Align-up to word boundary, because we clear the 4 bytes potentially 319 // following the length field in initialize_header(). 320 int base_offset = align_up(base_offset_in_bytes, BytesPerWord); 321 initialize_body(obj, arr_size, base_offset, len_zero); 322 } 323 324 if (CURRENT_ENV->dtrace_alloc_probes()) { 325 assert(obj == rax, "must be"); 326 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 327 } 328 329 verify_oop(obj); 330 } 331 332 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) { 333 push(rbp); 334 if (PreserveFramePointer) { 335 mov(rbp, rsp); 336 } 337 #if !defined(_LP64) && defined(COMPILER2) 338 if (UseSSE < 2 && !CompilerConfig::is_c1_only_no_jvmci()) { 339 // c2 leaves fpu stack dirty. Clean it on entry 340 empty_FPU_stack(); 341 } 342 #endif // !_LP64 && COMPILER2 343 decrement(rsp, frame_size_in_bytes); 344 345 if (needs_stack_repair) { 346 // Save stack increment (also account for fixed framesize and rbp) 347 assert((sp_inc & (StackAlignmentInBytes-1)) == 0, "stack increment not aligned"); 348 int real_frame_size = sp_inc + frame_size_in_bytes + wordSize; 349 movptr(Address(rsp, frame_size_in_bytes - wordSize), real_frame_size); 350 } 351 if (reset_orig_pc) { 352 // Zero orig_pc to detect deoptimization during buffering in the entry points 353 movptr(Address(rsp, sp_offset_for_orig_pc), 0); 354 } 355 } 356 357 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) { 358 // Make sure there is enough stack space for this method's activation. 359 // Note that we do this before doing an enter(). This matches the 360 // ordering of C2's stack overflow check / rsp decrement and allows 361 // the SharedRuntime stack overflow handling to be consistent 362 // between the two compilers. 363 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 364 generate_stack_overflow_check(bang_size_in_bytes); 365 366 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, has_scalarized_args, needs_stack_repair); 367 368 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 369 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub 370 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */); 371 372 if (verified_inline_entry_label != nullptr) { 373 // Jump here from the scalarized entry points that already created the frame. 374 bind(*verified_inline_entry_label); 375 } 376 } 377 378 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 379 if (breakAtEntry || VerifyFPU) { 380 // Verified Entry first instruction should be 5 bytes long for correct 381 // patching by patch_verified_entry(). 382 // 383 // Breakpoint and VerifyFPU have one byte first instruction. 384 // Also first instruction will be one byte "push(rbp)" if stack banging 385 // code is not generated (see build_frame() above). 386 // For all these cases generate long instruction first. 387 fat_nop(); 388 } 389 if (breakAtEntry) int3(); 390 // build frame 391 IA32_ONLY( verify_FPU(0, "method_entry"); ) 392 } 393 394 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) { 395 assert(InlineTypePassFieldsAsArgs, "sanity"); 396 // Make sure there is enough stack space for this method's activation. 397 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 398 generate_stack_overflow_check(bang_size_in_bytes); 399 400 GrowableArray<SigEntry>* sig = ces->sig(); 401 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? ces->sig_cc_ro() : ces->sig_cc(); 402 VMRegPair* regs = ces->regs(); 403 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc(); 404 int args_on_stack = ces->args_on_stack(); 405 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc(); 406 407 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!"); 408 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length()); 409 int args_passed = sig->length(); 410 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt); 411 412 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC. 413 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, true, ces->c1_needs_stack_repair()); 414 415 // The runtime call might safepoint, make sure nmethod entry barrier is executed 416 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 417 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub 418 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */); 419 420 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args. 421 movptr(rbx, (intptr_t)(ces->method())); 422 if (is_inline_ro_entry) { 423 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id))); 424 } else { 425 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id))); 426 } 427 int rt_call_offset = offset(); 428 429 // Remove the temp frame 430 addptr(rsp, frame_size_in_bytes); 431 pop(rbp); 432 433 // Check if we need to extend the stack for packing 434 int sp_inc = 0; 435 if (args_on_stack > args_on_stack_cc) { 436 sp_inc = extend_stack_for_inline_args(args_on_stack); 437 } 438 439 shuffle_inline_args(true, is_inline_ro_entry, sig_cc, 440 args_passed_cc, args_on_stack_cc, regs_cc, // from 441 args_passed, args_on_stack, regs, // to 442 sp_inc, rax); 443 444 // Create the real frame. Below jump will then skip over the stack banging and frame 445 // setup code in the verified_inline_entry (which has a different real_frame_size). 446 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, sp_inc, false, ces->c1_needs_stack_repair()); 447 448 jmp(verified_inline_entry_label); 449 return rt_call_offset; 450 } 451 452 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 453 // rbp, + 0: link 454 // + 1: return address 455 // + 2: argument with offset 0 456 // + 3: argument with offset 1 457 // + 4: ... 458 459 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord)); 460 } 461 462 #ifndef PRODUCT 463 464 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 465 if (!VerifyOops) return; 466 verify_oop_addr(Address(rsp, stack_offset)); 467 } 468 469 void C1_MacroAssembler::verify_not_null_oop(Register r) { 470 if (!VerifyOops) return; 471 Label not_null; 472 testptr(r, r); 473 jcc(Assembler::notZero, not_null); 474 stop("non-null oop required"); 475 bind(not_null); 476 verify_oop(r); 477 } 478 479 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) { 480 #ifdef ASSERT 481 if (inv_rax) movptr(rax, 0xDEAD); 482 if (inv_rbx) movptr(rbx, 0xDEAD); 483 if (inv_rcx) movptr(rcx, 0xDEAD); 484 if (inv_rdx) movptr(rdx, 0xDEAD); 485 if (inv_rsi) movptr(rsi, 0xDEAD); 486 if (inv_rdi) movptr(rdi, 0xDEAD); 487 #endif 488 } 489 490 #endif // ifndef PRODUCT