1 /* 2 * Copyright (c) 1999, 2021, 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/frame.inline.hpp" 37 #include "runtime/os.hpp" 38 #include "runtime/sharedRuntime.hpp" 39 #include "runtime/stubRoutines.hpp" 40 41 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 42 const Register rklass_decode_tmp = LP64_ONLY(rscratch1) NOT_LP64(noreg); 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, rklass_decode_tmp); 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 return null_check_offset; 104 } 105 106 107 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 108 const int aligned_mask = BytesPerWord -1; 109 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 110 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction"); 111 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 112 Label done; 113 114 // load displaced header 115 movptr(hdr, Address(disp_hdr, 0)); 116 // if the loaded hdr is NULL we had recursive locking 117 testptr(hdr, hdr); 118 // if we had recursive locking, we are done 119 jcc(Assembler::zero, done); 120 // load object 121 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 122 123 verify_oop(obj); 124 // test if object header is pointing to the displaced header, and if so, restore 125 // the displaced header in the object - if the object header is not pointing to 126 // the displaced header, get the object header instead 127 MacroAssembler::lock(); // must be immediately before cmpxchg! 128 cmpxchgptr(hdr, Address(obj, hdr_offset)); 129 // if the object header was not pointing to the displaced header, 130 // we do unlocking via runtime call 131 jcc(Assembler::notEqual, slow_case); 132 // done 133 bind(done); 134 } 135 136 137 // Defines obj, preserves var_size_in_bytes 138 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) { 139 if (UseTLAB) { 140 tlab_allocate(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 141 } else { 142 eden_allocate(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case); 143 } 144 } 145 146 147 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 148 assert_different_registers(obj, klass, len); 149 Register tmp_encode_klass = LP64_ONLY(rscratch1) NOT_LP64(noreg); 150 if (EnableValhalla) { 151 // Need to copy markWord::prototype header for klass 152 assert_different_registers(obj, klass, len, t1, t2); 153 movptr(t1, Address(klass, Klass::prototype_header_offset())); 154 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1); 155 } else { 156 // This assumes that all prototype bits fit in an int32_t 157 movptr(Address(obj, oopDesc::mark_offset_in_bytes ()), (int32_t)(intptr_t)markWord::prototype().value()); 158 } 159 #ifdef _LP64 160 if (UseCompressedClassPointers) { // Take care not to kill klass 161 movptr(t1, klass); 162 encode_klass_not_null(t1, tmp_encode_klass); 163 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1); 164 } else 165 #endif 166 { 167 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass); 168 } 169 170 if (len->is_valid()) { 171 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len); 172 } 173 #ifdef _LP64 174 else if (UseCompressedClassPointers) { 175 xorptr(t1, t1); 176 store_klass_gap(obj, t1); 177 } 178 #endif 179 } 180 181 182 // preserves obj, destroys len_in_bytes 183 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) { 184 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 185 Label done; 186 187 // len_in_bytes is positive and ptr sized 188 subptr(len_in_bytes, hdr_size_in_bytes); 189 jcc(Assembler::zero, done); 190 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1); 191 bind(done); 192 } 193 194 195 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 196 assert(obj == rax, "obj must be in rax, for cmpxchg"); 197 assert_different_registers(obj, t1, t2); // XXX really? 198 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 199 200 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 201 202 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 203 } 204 205 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) { 206 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 207 "con_size_in_bytes is not multiple of alignment"); 208 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 209 210 initialize_header(obj, klass, noreg, t1, t2); 211 212 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 213 // clear rest of allocated space 214 const Register t1_zero = t1; 215 const Register index = t2; 216 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below) 217 if (var_size_in_bytes != noreg) { 218 mov(index, var_size_in_bytes); 219 initialize_body(obj, index, hdr_size_in_bytes, t1_zero); 220 } else if (con_size_in_bytes <= threshold) { 221 // use explicit null stores 222 // code size = 2 + 3*n bytes (n = number of fields to clear) 223 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code) 224 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord) 225 movptr(Address(obj, i), t1_zero); 226 } else if (con_size_in_bytes > hdr_size_in_bytes) { 227 // use loop to null out the fields 228 // code size = 16 bytes for even n (n = number of fields to clear) 229 // initialize last object field first if odd number of fields 230 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code) 231 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3); 232 // initialize last object field if constant size is odd 233 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0) 234 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero); 235 // initialize remaining object fields: rdx is a multiple of 2 236 { Label loop; 237 bind(loop); 238 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)), 239 t1_zero); 240 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)), 241 t1_zero);) 242 decrement(index); 243 jcc(Assembler::notZero, loop); 244 } 245 } 246 } 247 248 if (CURRENT_ENV->dtrace_alloc_probes()) { 249 assert(obj == rax, "must be"); 250 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 251 } 252 253 verify_oop(obj); 254 } 255 256 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) { 257 assert(obj == rax, "obj must be in rax, for cmpxchg"); 258 assert_different_registers(obj, len, t1, t2, klass); 259 260 // determine alignment mask 261 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 262 263 // check for negative or excessive length 264 cmpptr(len, (int32_t)max_array_allocation_length); 265 jcc(Assembler::above, slow_case); 266 267 const Register arr_size = t2; // okay to be the same 268 // align object end 269 movptr(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask); 270 lea(arr_size, Address(arr_size, len, f)); 271 andptr(arr_size, ~MinObjAlignmentInBytesMask); 272 273 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 274 275 initialize_header(obj, klass, len, t1, t2); 276 277 // clear rest of allocated space 278 const Register len_zero = len; 279 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero); 280 281 if (CURRENT_ENV->dtrace_alloc_probes()) { 282 assert(obj == rax, "must be"); 283 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 284 } 285 286 verify_oop(obj); 287 } 288 289 290 291 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 292 verify_oop(receiver); 293 // explicit NULL check not needed since load from [klass_offset] causes a trap 294 // check against inline cache 295 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check"); 296 int start_offset = offset(); 297 Register tmp_load_klass = LP64_ONLY(rscratch2) NOT_LP64(noreg); 298 299 if (UseCompressedClassPointers) { 300 load_klass(rscratch1, receiver, tmp_load_klass); 301 cmpptr(rscratch1, iCache); 302 } else { 303 cmpptr(iCache, Address(receiver, oopDesc::klass_offset_in_bytes())); 304 } 305 // if icache check fails, then jump to runtime routine 306 // Note: RECEIVER must still contain the receiver! 307 jump_cc(Assembler::notEqual, 308 RuntimeAddress(SharedRuntime::get_ic_miss_stub())); 309 const int ic_cmp_size = LP64_ONLY(10) NOT_LP64(9); 310 assert(UseCompressedClassPointers || offset() - start_offset == ic_cmp_size, "check alignment in emit_method_entry"); 311 } 312 313 void C1_MacroAssembler::build_frame_helper(int frame_size_in_bytes, int sp_inc, bool needs_stack_repair) { 314 push(rbp); 315 if (PreserveFramePointer) { 316 mov(rbp, rsp); 317 } 318 #if !defined(_LP64) && defined(COMPILER2) 319 if (UseSSE < 2 && !CompilerConfig::is_c1_only_no_jvmci()) { 320 // c2 leaves fpu stack dirty. Clean it on entry 321 empty_FPU_stack(); 322 } 323 #endif // !_LP64 && COMPILER2 324 decrement(rsp, frame_size_in_bytes); 325 326 if (needs_stack_repair) { 327 // Save stack increment (also account for fixed framesize and rbp) 328 assert((sp_inc & (StackAlignmentInBytes-1)) == 0, "stack increment not aligned"); 329 int real_frame_size = sp_inc + frame_size_in_bytes + wordSize; 330 movptr(Address(rsp, frame_size_in_bytes - wordSize), real_frame_size); 331 } 332 } 333 334 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) { 335 if (has_scalarized_args) { 336 // Initialize orig_pc to detect deoptimization during buffering in the entry points 337 movptr(Address(rsp, sp_offset_for_orig_pc - frame_size_in_bytes - wordSize), 0); 338 } 339 if (!needs_stack_repair && verified_inline_entry_label != NULL) { 340 bind(*verified_inline_entry_label); 341 } 342 // Make sure there is enough stack space for this method's activation. 343 // Note that we do this before doing an enter(). This matches the 344 // ordering of C2's stack overflow check / rsp decrement and allows 345 // the SharedRuntime stack overflow handling to be consistent 346 // between the two compilers. 347 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 348 generate_stack_overflow_check(bang_size_in_bytes); 349 350 build_frame_helper(frame_size_in_bytes, 0, needs_stack_repair); 351 352 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 353 bs->nmethod_entry_barrier(this); 354 355 if (needs_stack_repair && verified_inline_entry_label != NULL) { 356 // Jump here from the scalarized entry points that require additional stack space 357 // for packing scalarized arguments and therefore already created the frame. 358 bind(*verified_inline_entry_label); 359 } 360 } 361 362 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 363 if (breakAtEntry || VerifyFPU) { 364 // Verified Entry first instruction should be 5 bytes long for correct 365 // patching by patch_verified_entry(). 366 // 367 // Breakpoint and VerifyFPU have one byte first instruction. 368 // Also first instruction will be one byte "push(rbp)" if stack banging 369 // code is not generated (see build_frame() above). 370 // For all these cases generate long instruction first. 371 fat_nop(); 372 } 373 if (breakAtEntry) int3(); 374 // build frame 375 IA32_ONLY( verify_FPU(0, "method_entry"); ) 376 } 377 378 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) { 379 assert(InlineTypePassFieldsAsArgs, "sanity"); 380 // Make sure there is enough stack space for this method's activation. 381 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 382 generate_stack_overflow_check(bang_size_in_bytes); 383 384 GrowableArray<SigEntry>* sig = &ces->sig(); 385 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? &ces->sig_cc_ro() : &ces->sig_cc(); 386 VMRegPair* regs = ces->regs(); 387 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc(); 388 int args_on_stack = ces->args_on_stack(); 389 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc(); 390 391 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!"); 392 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length()); 393 int args_passed = sig->length(); 394 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt); 395 396 // Check if we need to extend the stack for packing 397 int sp_inc = 0; 398 if (args_on_stack > args_on_stack_cc) { 399 sp_inc = extend_stack_for_inline_args(args_on_stack); 400 } 401 402 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC. 403 build_frame_helper(frame_size_in_bytes, sp_inc, ces->c1_needs_stack_repair()); 404 405 // Initialize orig_pc to detect deoptimization during buffering in below runtime call 406 movptr(Address(rsp, sp_offset_for_orig_pc), 0); 407 408 // The runtime call might safepoint, make sure nmethod entry barrier is executed 409 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 410 bs->nmethod_entry_barrier(this); 411 412 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args. 413 movptr(rbx, (intptr_t)(ces->method())); 414 if (is_inline_ro_entry) { 415 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id))); 416 } else { 417 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id))); 418 } 419 int rt_call_offset = offset(); 420 421 // Remove the temp frame 422 addptr(rsp, frame_size_in_bytes); 423 pop(rbp); 424 425 shuffle_inline_args(true, is_inline_ro_entry, sig_cc, 426 args_passed_cc, args_on_stack_cc, regs_cc, // from 427 args_passed, args_on_stack, regs, // to 428 sp_inc, rax); 429 430 if (ces->c1_needs_stack_repair()) { 431 // Create the real frame. Below jump will then skip over the stack banging and frame 432 // setup code in the verified_inline_entry (which has a different real_frame_size). 433 build_frame_helper(frame_size_in_bytes, sp_inc, true); 434 } 435 436 jmp(verified_inline_entry_label); 437 return rt_call_offset; 438 } 439 440 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 441 // rbp, + 0: link 442 // + 1: return address 443 // + 2: argument with offset 0 444 // + 3: argument with offset 1 445 // + 4: ... 446 447 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord)); 448 } 449 450 #ifndef PRODUCT 451 452 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 453 if (!VerifyOops) return; 454 verify_oop_addr(Address(rsp, stack_offset)); 455 } 456 457 void C1_MacroAssembler::verify_not_null_oop(Register r) { 458 if (!VerifyOops) return; 459 Label not_null; 460 testptr(r, r); 461 jcc(Assembler::notZero, not_null); 462 stop("non-null oop required"); 463 bind(not_null); 464 verify_oop(r); 465 } 466 467 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) { 468 #ifdef ASSERT 469 if (inv_rax) movptr(rax, 0xDEAD); 470 if (inv_rbx) movptr(rbx, 0xDEAD); 471 if (inv_rcx) movptr(rcx, 0xDEAD); 472 if (inv_rdx) movptr(rdx, 0xDEAD); 473 if (inv_rsi) movptr(rsi, 0xDEAD); 474 if (inv_rdi) movptr(rdi, 0xDEAD); 475 #endif 476 } 477 478 #endif // ifndef PRODUCT