1 /* 2 * Copyright (c) 1999, 2022, 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 "compiler/compilerDefinitions.inline.hpp" 29 #include "gc/shared/barrierSet.hpp" 30 #include "gc/shared/barrierSetAssembler.hpp" 31 #include "gc/shared/collectedHeap.hpp" 32 #include "gc/shared/tlab_globals.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "oops/arrayOop.hpp" 35 #include "oops/markWord.hpp" 36 #include "runtime/basicLock.hpp" 37 #include "runtime/frame.inline.hpp" 38 #include "runtime/os.hpp" 39 #include "runtime/sharedRuntime.hpp" 40 #include "runtime/stubRoutines.hpp" 41 42 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 43 const int aligned_mask = BytesPerWord -1; 44 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 45 assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction"); 46 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 47 Label done; 48 int null_check_offset = -1; 49 50 verify_oop(obj); 51 52 // save object being locked into the BasicObjectLock 53 movptr(Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()), obj); 54 55 null_check_offset = offset(); 56 57 if (DiagnoseSyncOnValueBasedClasses != 0) { 58 load_klass(hdr, obj, rscratch1); 59 movl(hdr, Address(hdr, Klass::access_flags_offset())); 60 testl(hdr, JVM_ACC_IS_VALUE_BASED_CLASS); 61 jcc(Assembler::notZero, slow_case); 62 } 63 64 // Load object header 65 movptr(hdr, Address(obj, hdr_offset)); 66 // and mark it as unlocked 67 orptr(hdr, markWord::unlocked_value); 68 if (EnableValhalla) { 69 // Mask inline_type bit such that we go to the slow path if object is an inline type 70 andptr(hdr, ~((int) markWord::inline_type_bit_in_place)); 71 } 72 // save unlocked object header into the displaced header location on the stack 73 movptr(Address(disp_hdr, 0), hdr); 74 // test if object header is still the same (i.e. unlocked), and if so, store the 75 // displaced header address in the object header - if it is not the same, get the 76 // object header instead 77 MacroAssembler::lock(); // must be immediately before cmpxchg! 78 cmpxchgptr(disp_hdr, Address(obj, hdr_offset)); 79 // if the object header was the same, we're done 80 jcc(Assembler::equal, done); 81 // if the object header was not the same, it is now in the hdr register 82 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 83 // 84 // 1) (hdr & aligned_mask) == 0 85 // 2) rsp <= hdr 86 // 3) hdr <= rsp + page_size 87 // 88 // these 3 tests can be done by evaluating the following expression: 89 // 90 // (hdr - rsp) & (aligned_mask - page_size) 91 // 92 // assuming both the stack pointer and page_size have their least 93 // significant 2 bits cleared and page_size is a power of 2 94 subptr(hdr, rsp); 95 andptr(hdr, aligned_mask - os::vm_page_size()); 96 // for recursive locking, the result is zero => save it in the displaced header 97 // location (NULL in the displaced hdr location indicates recursive locking) 98 movptr(Address(disp_hdr, 0), hdr); 99 // otherwise we don't care about the result and handle locking via runtime call 100 jcc(Assembler::notZero, slow_case); 101 // done 102 bind(done); 103 104 inc_held_monitor_count(); 105 106 return null_check_offset; 107 } 108 109 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 110 const int aligned_mask = BytesPerWord -1; 111 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 112 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction"); 113 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 114 Label done; 115 116 // load displaced header 117 movptr(hdr, Address(disp_hdr, 0)); 118 // if the loaded hdr is NULL we had recursive locking 119 testptr(hdr, hdr); 120 // if we had recursive locking, we are done 121 jcc(Assembler::zero, done); 122 // load object 123 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 124 125 verify_oop(obj); 126 // test if object header is pointing to the displaced header, and if so, restore 127 // the displaced header in the object - if the object header is not pointing to 128 // the displaced header, get the object header instead 129 MacroAssembler::lock(); // must be immediately before cmpxchg! 130 cmpxchgptr(hdr, Address(obj, hdr_offset)); 131 // if the object header was not pointing to the displaced header, 132 // we do unlocking via runtime call 133 jcc(Assembler::notEqual, slow_case); 134 // done 135 bind(done); 136 137 dec_held_monitor_count(); 138 } 139 140 141 // Defines obj, preserves var_size_in_bytes 142 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) { 143 if (UseTLAB) { 144 tlab_allocate(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 145 } else { 146 jmp(slow_case); 147 } 148 } 149 150 151 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 152 assert_different_registers(obj, klass, len); 153 if (EnableValhalla) { 154 // Need to copy markWord::prototype header for klass 155 assert_different_registers(obj, klass, len, t1, t2); 156 movptr(t1, Address(klass, Klass::prototype_header_offset())); 157 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1); 158 } else { 159 // This assumes that all prototype bits fit in an int32_t 160 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value())); 161 } 162 #ifdef _LP64 163 if (UseCompressedClassPointers) { // Take care not to kill klass 164 movptr(t1, klass); 165 encode_klass_not_null(t1, rscratch1); 166 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1); 167 } else 168 #endif 169 { 170 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass); 171 } 172 173 if (len->is_valid()) { 174 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len); 175 } 176 #ifdef _LP64 177 else if (UseCompressedClassPointers) { 178 xorptr(t1, t1); 179 store_klass_gap(obj, t1); 180 } 181 #endif 182 } 183 184 185 // preserves obj, destroys len_in_bytes 186 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) { 187 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 188 Label done; 189 190 // len_in_bytes is positive and ptr sized 191 subptr(len_in_bytes, hdr_size_in_bytes); 192 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1); 193 bind(done); 194 } 195 196 197 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 198 assert(obj == rax, "obj must be in rax, for cmpxchg"); 199 assert_different_registers(obj, t1, t2); // XXX really? 200 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 201 202 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 203 204 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 205 } 206 207 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) { 208 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 209 "con_size_in_bytes is not multiple of alignment"); 210 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 211 212 initialize_header(obj, klass, noreg, t1, t2); 213 214 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 215 // clear rest of allocated space 216 const Register t1_zero = t1; 217 const Register index = t2; 218 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below) 219 if (var_size_in_bytes != noreg) { 220 mov(index, var_size_in_bytes); 221 initialize_body(obj, index, hdr_size_in_bytes, t1_zero); 222 } else if (con_size_in_bytes <= threshold) { 223 // use explicit null stores 224 // code size = 2 + 3*n bytes (n = number of fields to clear) 225 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code) 226 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord) 227 movptr(Address(obj, i), t1_zero); 228 } else if (con_size_in_bytes > hdr_size_in_bytes) { 229 // use loop to null out the fields 230 // code size = 16 bytes for even n (n = number of fields to clear) 231 // initialize last object field first if odd number of fields 232 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code) 233 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3); 234 // initialize last object field if constant size is odd 235 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0) 236 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero); 237 // initialize remaining object fields: rdx is a multiple of 2 238 { Label loop; 239 bind(loop); 240 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)), 241 t1_zero); 242 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)), 243 t1_zero);) 244 decrement(index); 245 jcc(Assembler::notZero, loop); 246 } 247 } 248 } 249 250 if (CURRENT_ENV->dtrace_alloc_probes()) { 251 assert(obj == rax, "must be"); 252 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 253 } 254 255 verify_oop(obj); 256 } 257 258 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) { 259 assert(obj == rax, "obj must be in rax, for cmpxchg"); 260 assert_different_registers(obj, len, t1, t2, klass); 261 262 // determine alignment mask 263 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 264 265 // check for negative or excessive length 266 cmpptr(len, checked_cast<int32_t>(max_array_allocation_length)); 267 jcc(Assembler::above, slow_case); 268 269 const Register arr_size = t2; // okay to be the same 270 // align object end 271 movptr(arr_size, header_size * BytesPerWord + MinObjAlignmentInBytesMask); 272 lea(arr_size, Address(arr_size, len, f)); 273 andptr(arr_size, ~MinObjAlignmentInBytesMask); 274 275 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 276 277 initialize_header(obj, klass, len, t1, t2); 278 279 // clear rest of allocated space 280 const Register len_zero = len; 281 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero); 282 283 if (CURRENT_ENV->dtrace_alloc_probes()) { 284 assert(obj == rax, "must be"); 285 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 286 } 287 288 verify_oop(obj); 289 } 290 291 292 293 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 294 verify_oop(receiver); 295 // explicit NULL check not needed since load from [klass_offset] causes a trap 296 // check against inline cache 297 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check"); 298 int start_offset = offset(); 299 300 if (UseCompressedClassPointers) { 301 load_klass(rscratch1, receiver, rscratch2); 302 cmpptr(rscratch1, iCache); 303 } else { 304 cmpptr(iCache, Address(receiver, oopDesc::klass_offset_in_bytes())); 305 } 306 // if icache check fails, then jump to runtime routine 307 // Note: RECEIVER must still contain the receiver! 308 jump_cc(Assembler::notEqual, 309 RuntimeAddress(SharedRuntime::get_ic_miss_stub())); 310 const int ic_cmp_size = LP64_ONLY(10) NOT_LP64(9); 311 assert(UseCompressedClassPointers || offset() - start_offset == ic_cmp_size, "check alignment in emit_method_entry"); 312 } 313 314 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) { 315 push(rbp); 316 if (PreserveFramePointer) { 317 mov(rbp, rsp); 318 } 319 #if !defined(_LP64) && defined(COMPILER2) 320 if (UseSSE < 2 && !CompilerConfig::is_c1_only_no_jvmci()) { 321 // c2 leaves fpu stack dirty. Clean it on entry 322 empty_FPU_stack(); 323 } 324 #endif // !_LP64 && COMPILER2 325 decrement(rsp, frame_size_in_bytes); 326 327 if (needs_stack_repair) { 328 // Save stack increment (also account for fixed framesize and rbp) 329 assert((sp_inc & (StackAlignmentInBytes-1)) == 0, "stack increment not aligned"); 330 int real_frame_size = sp_inc + frame_size_in_bytes + wordSize; 331 movptr(Address(rsp, frame_size_in_bytes - wordSize), real_frame_size); 332 } 333 if (reset_orig_pc) { 334 // Zero orig_pc to detect deoptimization during buffering in the entry points 335 movptr(Address(rsp, sp_offset_for_orig_pc), 0); 336 } 337 } 338 339 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) { 340 // Make sure there is enough stack space for this method's activation. 341 // Note that we do this before doing an enter(). This matches the 342 // ordering of C2's stack overflow check / rsp decrement and allows 343 // the SharedRuntime stack overflow handling to be consistent 344 // between the two compilers. 345 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 346 generate_stack_overflow_check(bang_size_in_bytes); 347 348 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, has_scalarized_args, needs_stack_repair); 349 350 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 351 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub 352 bs->nmethod_entry_barrier(this, NULL /* slow_path */, NULL /* continuation */); 353 354 if (verified_inline_entry_label != NULL) { 355 // Jump here from the scalarized entry points that already created the frame. 356 bind(*verified_inline_entry_label); 357 } 358 } 359 360 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 361 if (breakAtEntry || VerifyFPU) { 362 // Verified Entry first instruction should be 5 bytes long for correct 363 // patching by patch_verified_entry(). 364 // 365 // Breakpoint and VerifyFPU have one byte first instruction. 366 // Also first instruction will be one byte "push(rbp)" if stack banging 367 // code is not generated (see build_frame() above). 368 // For all these cases generate long instruction first. 369 fat_nop(); 370 } 371 if (breakAtEntry) int3(); 372 // build frame 373 IA32_ONLY( verify_FPU(0, "method_entry"); ) 374 } 375 376 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) { 377 assert(InlineTypePassFieldsAsArgs, "sanity"); 378 // Make sure there is enough stack space for this method's activation. 379 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 380 generate_stack_overflow_check(bang_size_in_bytes); 381 382 GrowableArray<SigEntry>* sig = &ces->sig(); 383 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? &ces->sig_cc_ro() : &ces->sig_cc(); 384 VMRegPair* regs = ces->regs(); 385 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc(); 386 int args_on_stack = ces->args_on_stack(); 387 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc(); 388 389 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!"); 390 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length()); 391 int args_passed = sig->length(); 392 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt); 393 394 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC. 395 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, true, ces->c1_needs_stack_repair()); 396 397 // The runtime call might safepoint, make sure nmethod entry barrier is executed 398 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 399 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub 400 bs->nmethod_entry_barrier(this, NULL /* slow_path */, NULL /* continuation */); 401 402 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args. 403 movptr(rbx, (intptr_t)(ces->method())); 404 if (is_inline_ro_entry) { 405 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id))); 406 } else { 407 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id))); 408 } 409 int rt_call_offset = offset(); 410 411 // Remove the temp frame 412 addptr(rsp, frame_size_in_bytes); 413 pop(rbp); 414 415 // Check if we need to extend the stack for packing 416 int sp_inc = 0; 417 if (args_on_stack > args_on_stack_cc) { 418 sp_inc = extend_stack_for_inline_args(args_on_stack); 419 } 420 421 shuffle_inline_args(true, is_inline_ro_entry, sig_cc, 422 args_passed_cc, args_on_stack_cc, regs_cc, // from 423 args_passed, args_on_stack, regs, // to 424 sp_inc, rax); 425 426 // Create the real frame. Below jump will then skip over the stack banging and frame 427 // setup code in the verified_inline_entry (which has a different real_frame_size). 428 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, sp_inc, false, ces->c1_needs_stack_repair()); 429 430 jmp(verified_inline_entry_label); 431 return rt_call_offset; 432 } 433 434 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 435 // rbp, + 0: link 436 // + 1: return address 437 // + 2: argument with offset 0 438 // + 3: argument with offset 1 439 // + 4: ... 440 441 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord)); 442 } 443 444 #ifndef PRODUCT 445 446 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 447 if (!VerifyOops) return; 448 verify_oop_addr(Address(rsp, stack_offset)); 449 } 450 451 void C1_MacroAssembler::verify_not_null_oop(Register r) { 452 if (!VerifyOops) return; 453 Label not_null; 454 testptr(r, r); 455 jcc(Assembler::notZero, not_null); 456 stop("non-null oop required"); 457 bind(not_null); 458 verify_oop(r); 459 } 460 461 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) { 462 #ifdef ASSERT 463 if (inv_rax) movptr(rax, 0xDEAD); 464 if (inv_rbx) movptr(rbx, 0xDEAD); 465 if (inv_rcx) movptr(rcx, 0xDEAD); 466 if (inv_rdx) movptr(rdx, 0xDEAD); 467 if (inv_rsi) movptr(rsi, 0xDEAD); 468 if (inv_rdi) movptr(rdi, 0xDEAD); 469 #endif 470 } 471 472 #endif // ifndef PRODUCT