1 /* 2 * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2014, Red Hat Inc. All rights reserved. 4 * Copyright (c) 2020, 2022, Huawei Technologies Co., Ltd. All rights reserved. 5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 6 * 7 * This code is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License version 2 only, as 9 * published by the Free Software Foundation. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 * 25 */ 26 27 #include "precompiled.hpp" 28 #include "c1/c1_LIR.hpp" 29 #include "c1/c1_MacroAssembler.hpp" 30 #include "c1/c1_Runtime1.hpp" 31 #include "classfile/systemDictionary.hpp" 32 #include "gc/shared/barrierSetAssembler.hpp" 33 #include "gc/shared/collectedHeap.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 freg0, FloatRegister freg1, 44 Register result) { 45 if (is_float) { 46 float_compare(result, freg0, freg1, unordered_result); 47 } else { 48 double_compare(result, freg0, freg1, unordered_result); 49 } 50 } 51 52 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register temp, Label& slow_case) { 53 const int aligned_mask = BytesPerWord - 1; 54 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 55 assert_different_registers(hdr, obj, disp_hdr, temp, t0, t1); 56 int null_check_offset = -1; 57 58 verify_oop(obj); 59 60 // save object being locked into the BasicObjectLock 61 sd(obj, Address(disp_hdr, BasicObjectLock::obj_offset())); 62 63 null_check_offset = offset(); 64 65 if (DiagnoseSyncOnValueBasedClasses != 0) { 66 load_klass(hdr, obj); 67 lbu(hdr, Address(hdr, Klass::misc_flags_offset())); 68 test_bit(temp, hdr, exact_log2(KlassFlags::_misc_is_value_based_class)); 69 bnez(temp, slow_case, true /* is_far */); 70 } 71 72 if (LockingMode == LM_LIGHTWEIGHT) { 73 lightweight_lock(disp_hdr, obj, hdr, temp, t1, slow_case); 74 } else if (LockingMode == LM_LEGACY) { 75 Label done; 76 // Load object header 77 ld(hdr, Address(obj, hdr_offset)); 78 // and mark it as unlocked 79 ori(hdr, hdr, markWord::unlocked_value); 80 // save unlocked object header into the displaced header location on the stack 81 sd(hdr, Address(disp_hdr, 0)); 82 // test if object header is still the same (i.e. unlocked), and if so, store the 83 // displaced header address in the object header - if it is not the same, get the 84 // object header instead 85 la(temp, Address(obj, hdr_offset)); 86 cmpxchgptr(hdr, disp_hdr, temp, t1, done, /*fallthough*/nullptr); 87 // if the object header was the same, we're done 88 // if the object header was not the same, it is now in the hdr register 89 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 90 // 91 // 1) (hdr & aligned_mask) == 0 92 // 2) sp <= hdr 93 // 3) hdr <= sp + page_size 94 // 95 // these 3 tests can be done by evaluating the following expression: 96 // 97 // (hdr -sp) & (aligned_mask - page_size) 98 // 99 // assuming both the stack pointer and page_size have their least 100 // significant 2 bits cleared and page_size is a power of 2 101 sub(hdr, hdr, sp); 102 mv(temp, aligned_mask - (int)os::vm_page_size()); 103 andr(hdr, hdr, temp); 104 // for recursive locking, the result is zero => save it in the displaced header 105 // location (null in the displaced hdr location indicates recursive locking) 106 sd(hdr, Address(disp_hdr, 0)); 107 // otherwise we don't care about the result and handle locking via runtime call 108 bnez(hdr, slow_case, /* is_far */ true); 109 // done 110 bind(done); 111 } 112 113 increment(Address(xthread, JavaThread::held_monitor_count_offset())); 114 return null_check_offset; 115 } 116 117 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Register temp, Label& slow_case) { 118 const int aligned_mask = BytesPerWord - 1; 119 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 120 assert_different_registers(hdr, obj, disp_hdr, temp, t0, t1); 121 Label done; 122 123 if (LockingMode != LM_LIGHTWEIGHT) { 124 // load displaced header 125 ld(hdr, Address(disp_hdr, 0)); 126 // if the loaded hdr is null we had recursive locking 127 // if we had recursive locking, we are done 128 beqz(hdr, done); 129 } 130 131 // load object 132 ld(obj, Address(disp_hdr, BasicObjectLock::obj_offset())); 133 verify_oop(obj); 134 135 if (LockingMode == LM_LIGHTWEIGHT) { 136 lightweight_unlock(obj, hdr, temp, t1, slow_case); 137 } else if (LockingMode == LM_LEGACY) { 138 // test if object header is pointing to the displaced header, and if so, restore 139 // the displaced header in the object - if the object header is not pointing to 140 // the displaced header, get the object header instead 141 // if the object header was not pointing to the displaced header, 142 // we do unlocking via runtime call 143 if (hdr_offset) { 144 la(temp, Address(obj, hdr_offset)); 145 cmpxchgptr(disp_hdr, hdr, temp, t1, done, &slow_case); 146 } else { 147 cmpxchgptr(disp_hdr, hdr, obj, t1, done, &slow_case); 148 } 149 // done 150 bind(done); 151 } 152 153 decrement(Address(xthread, JavaThread::held_monitor_count_offset())); 154 } 155 156 // Defines obj, preserves var_size_in_bytes 157 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register tmp1, Register tmp2, Label& slow_case) { 158 if (UseTLAB) { 159 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, tmp1, tmp2, slow_case, /* is_far */ true); 160 } else { 161 j(slow_case); 162 } 163 } 164 165 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register tmp1, Register tmp2) { 166 assert_different_registers(obj, klass, len, tmp1, tmp2); 167 // This assumes that all prototype bits fitr in an int32_t 168 mv(tmp1, (int32_t)(intptr_t)markWord::prototype().value()); 169 sd(tmp1, Address(obj, oopDesc::mark_offset_in_bytes())); 170 171 if (UseCompressedClassPointers) { // Take care not to kill klass 172 encode_klass_not_null(tmp1, klass, tmp2); 173 sw(tmp1, Address(obj, oopDesc::klass_offset_in_bytes())); 174 } else { 175 sd(klass, Address(obj, oopDesc::klass_offset_in_bytes())); 176 } 177 178 if (len->is_valid()) { 179 sw(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 180 int base_offset = arrayOopDesc::length_offset_in_bytes() + BytesPerInt; 181 if (!is_aligned(base_offset, BytesPerWord)) { 182 assert(is_aligned(base_offset, BytesPerInt), "must be 4-byte aligned"); 183 // Clear gap/first 4 bytes following the length field. 184 sw(zr, Address(obj, base_offset)); 185 } 186 } else if (UseCompressedClassPointers) { 187 store_klass_gap(obj, zr); 188 } 189 } 190 191 // preserves obj, destroys len_in_bytes 192 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register tmp) { 193 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 194 Label done; 195 196 // len_in_bytes is positive and ptr sized 197 sub(len_in_bytes, len_in_bytes, hdr_size_in_bytes); 198 beqz(len_in_bytes, done); 199 200 // Preserve obj 201 if (hdr_size_in_bytes) { 202 add(obj, obj, hdr_size_in_bytes); 203 } 204 zero_memory(obj, len_in_bytes, tmp); 205 if (hdr_size_in_bytes) { 206 sub(obj, obj, hdr_size_in_bytes); 207 } 208 209 bind(done); 210 } 211 212 void C1_MacroAssembler::allocate_object(Register obj, Register tmp1, Register tmp2, int header_size, int object_size, Register klass, Label& slow_case) { 213 assert_different_registers(obj, tmp1, tmp2); 214 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 215 216 try_allocate(obj, noreg, object_size * BytesPerWord, tmp1, tmp2, slow_case); 217 218 initialize_object(obj, klass, noreg, object_size * HeapWordSize, tmp1, tmp2, UseTLAB); 219 } 220 221 void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register tmp1, Register tmp2, bool is_tlab_allocated) { 222 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 223 "con_size_in_bytes is not multiple of alignment"); 224 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 225 226 initialize_header(obj, klass, noreg, tmp1, tmp2); 227 228 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 229 // clear rest of allocated space 230 const Register index = tmp2; 231 // 16: multiplier for threshold 232 const int threshold = 16 * BytesPerWord; // approximate break even point for code size (see comments below) 233 if (var_size_in_bytes != noreg) { 234 mv(index, var_size_in_bytes); 235 initialize_body(obj, index, hdr_size_in_bytes, tmp1); 236 } else if (con_size_in_bytes <= threshold) { 237 // use explicit null stores 238 int i = hdr_size_in_bytes; 239 if (i < con_size_in_bytes && (con_size_in_bytes % (2 * BytesPerWord))) { // 2: multiplier for BytesPerWord 240 sd(zr, Address(obj, i)); 241 i += BytesPerWord; 242 } 243 for (; i < con_size_in_bytes; i += BytesPerWord) { 244 sd(zr, Address(obj, i)); 245 } 246 } else if (con_size_in_bytes > hdr_size_in_bytes) { 247 block_comment("zero memory"); 248 // use loop to null out the fields 249 int words = (con_size_in_bytes - hdr_size_in_bytes) / BytesPerWord; 250 mv(index, words / 8); // 8: byte size 251 252 const int unroll = 8; // Number of sd(zr) instructions we'll unroll 253 int remainder = words % unroll; 254 la(t0, Address(obj, hdr_size_in_bytes + remainder * BytesPerWord)); 255 256 Label entry_point, loop; 257 j(entry_point); 258 259 bind(loop); 260 sub(index, index, 1); 261 for (int i = -unroll; i < 0; i++) { 262 if (-i == remainder) { 263 bind(entry_point); 264 } 265 sd(zr, Address(t0, i * wordSize)); 266 } 267 if (remainder == 0) { 268 bind(entry_point); 269 } 270 add(t0, t0, unroll * wordSize); 271 bnez(index, loop); 272 } 273 } 274 275 membar(MacroAssembler::StoreStore); 276 277 if (CURRENT_ENV->dtrace_alloc_probes()) { 278 assert(obj == x10, "must be"); 279 far_call(RuntimeAddress(Runtime1::entry_for(C1StubId::dtrace_object_alloc_id))); 280 } 281 282 verify_oop(obj); 283 } 284 285 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register tmp1, Register tmp2, int base_offset_in_bytes, int f, Register klass, Label& slow_case, bool zero_array) { 286 assert_different_registers(obj, len, tmp1, tmp2, klass); 287 288 // determine alignment mask 289 assert(!(BytesPerWord & 1), "must be multiple of 2 for masking code to work"); 290 291 // check for negative or excessive length 292 mv(t0, (int32_t)max_array_allocation_length); 293 bgeu(len, t0, slow_case, /* is_far */ true); 294 295 const Register arr_size = tmp2; // okay to be the same 296 // align object end 297 mv(arr_size, (int32_t)base_offset_in_bytes + MinObjAlignmentInBytesMask); 298 shadd(arr_size, len, arr_size, t0, f); 299 andi(arr_size, arr_size, ~(uint)MinObjAlignmentInBytesMask); 300 301 try_allocate(obj, arr_size, 0, tmp1, tmp2, slow_case); 302 303 initialize_header(obj, klass, len, tmp1, tmp2); 304 305 // Align-up to word boundary, because we clear the 4 bytes potentially 306 // following the length field in initialize_header(). 307 int base_offset = align_up(base_offset_in_bytes, BytesPerWord); 308 309 // clear rest of allocated space 310 const Register len_zero = len; 311 if (zero_array) { 312 initialize_body(obj, arr_size, base_offset, len_zero); 313 } 314 315 membar(MacroAssembler::StoreStore); 316 317 if (CURRENT_ENV->dtrace_alloc_probes()) { 318 assert(obj == x10, "must be"); 319 far_call(RuntimeAddress(Runtime1::entry_for(C1StubId::dtrace_object_alloc_id))); 320 } 321 322 verify_oop(obj); 323 } 324 325 void C1_MacroAssembler::build_frame(int framesize, int bang_size_in_bytes) { 326 assert(bang_size_in_bytes >= framesize, "stack bang size incorrect"); 327 // Make sure there is enough stack space for this method's activation. 328 // Note that we do this before creating a frame. 329 generate_stack_overflow_check(bang_size_in_bytes); 330 MacroAssembler::build_frame(framesize); 331 332 // Insert nmethod entry barrier into frame. 333 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 334 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */, nullptr /* guard */); 335 } 336 337 void C1_MacroAssembler::remove_frame(int framesize) { 338 MacroAssembler::remove_frame(framesize); 339 } 340 341 342 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 343 // If we have to make this method not-entrant we'll overwrite its 344 // first instruction with a jump. For this action to be legal we 345 // must ensure that this first instruction is a J, JAL or NOP. 346 // Make it a NOP. 347 IncompressibleRegion ir(this); // keep the nop as 4 bytes for patching. 348 assert_alignment(pc()); 349 nop(); // 4 bytes 350 } 351 352 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 353 // fp + -2: link 354 // + -1: return address 355 // + 0: argument with offset 0 356 // + 1: argument with offset 1 357 // + 2: ... 358 ld(reg, Address(fp, offset_in_words * BytesPerWord)); 359 } 360 361 #ifndef PRODUCT 362 363 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 364 if (!VerifyOops) { 365 return; 366 } 367 verify_oop_addr(Address(sp, stack_offset)); 368 } 369 370 void C1_MacroAssembler::verify_not_null_oop(Register r) { 371 if (!VerifyOops) return; 372 Label not_null; 373 bnez(r, not_null); 374 stop("non-null oop required"); 375 bind(not_null); 376 verify_oop(r); 377 } 378 379 void C1_MacroAssembler::invalidate_registers(bool inv_x10, bool inv_x9, bool inv_x12, bool inv_x13, bool inv_x14, bool inv_x15) { 380 #ifdef ASSERT 381 static int nn; 382 if (inv_x10) { mv(x10, 0xDEAD); } 383 if (inv_x9) { mv(x9, 0xDEAD); } 384 if (inv_x12) { mv(x12, nn++); } 385 if (inv_x13) { mv(x13, 0xDEAD); } 386 if (inv_x14) { mv(x14, 0xDEAD); } 387 if (inv_x15) { mv(x15, 0xDEAD); } 388 #endif // ASSERT 389 } 390 #endif // ifndef PRODUCT 391 392 typedef void (C1_MacroAssembler::*c1_cond_branch_insn)(Register op1, Register op2, Label& label, bool is_far); 393 typedef void (C1_MacroAssembler::*c1_float_cond_branch_insn)(FloatRegister op1, FloatRegister op2, 394 Label& label, bool is_far, bool is_unordered); 395 396 static c1_cond_branch_insn c1_cond_branch[] = 397 { 398 /* SHORT branches */ 399 (c1_cond_branch_insn)&MacroAssembler::beq, 400 (c1_cond_branch_insn)&MacroAssembler::bne, 401 (c1_cond_branch_insn)&MacroAssembler::blt, 402 (c1_cond_branch_insn)&MacroAssembler::ble, 403 (c1_cond_branch_insn)&MacroAssembler::bge, 404 (c1_cond_branch_insn)&MacroAssembler::bgt, 405 (c1_cond_branch_insn)&MacroAssembler::bleu, // lir_cond_belowEqual 406 (c1_cond_branch_insn)&MacroAssembler::bgeu // lir_cond_aboveEqual 407 }; 408 409 static c1_float_cond_branch_insn c1_float_cond_branch[] = 410 { 411 /* FLOAT branches */ 412 (c1_float_cond_branch_insn)&MacroAssembler::float_beq, 413 (c1_float_cond_branch_insn)&MacroAssembler::float_bne, 414 (c1_float_cond_branch_insn)&MacroAssembler::float_blt, 415 (c1_float_cond_branch_insn)&MacroAssembler::float_ble, 416 (c1_float_cond_branch_insn)&MacroAssembler::float_bge, 417 (c1_float_cond_branch_insn)&MacroAssembler::float_bgt, 418 nullptr, // lir_cond_belowEqual 419 nullptr, // lir_cond_aboveEqual 420 421 /* DOUBLE branches */ 422 (c1_float_cond_branch_insn)&MacroAssembler::double_beq, 423 (c1_float_cond_branch_insn)&MacroAssembler::double_bne, 424 (c1_float_cond_branch_insn)&MacroAssembler::double_blt, 425 (c1_float_cond_branch_insn)&MacroAssembler::double_ble, 426 (c1_float_cond_branch_insn)&MacroAssembler::double_bge, 427 (c1_float_cond_branch_insn)&MacroAssembler::double_bgt, 428 nullptr, // lir_cond_belowEqual 429 nullptr // lir_cond_aboveEqual 430 }; 431 432 void C1_MacroAssembler::c1_cmp_branch(int cmpFlag, Register op1, Register op2, Label& label, 433 BasicType type, bool is_far) { 434 if (type == T_OBJECT || type == T_ARRAY) { 435 assert(cmpFlag == lir_cond_equal || cmpFlag == lir_cond_notEqual, "Should be equal or notEqual"); 436 if (cmpFlag == lir_cond_equal) { 437 beq(op1, op2, label, is_far); 438 } else { 439 bne(op1, op2, label, is_far); 440 } 441 } else { 442 assert(cmpFlag >= 0 && cmpFlag < (int)(sizeof(c1_cond_branch) / sizeof(c1_cond_branch[0])), 443 "invalid c1 conditional branch index"); 444 (this->*c1_cond_branch[cmpFlag])(op1, op2, label, is_far); 445 } 446 } 447 448 void C1_MacroAssembler::c1_float_cmp_branch(int cmpFlag, FloatRegister op1, FloatRegister op2, Label& label, 449 bool is_far, bool is_unordered) { 450 assert(cmpFlag >= 0 && 451 cmpFlag < (int)(sizeof(c1_float_cond_branch) / sizeof(c1_float_cond_branch[0])), 452 "invalid c1 float conditional branch index"); 453 (this->*c1_float_cond_branch[cmpFlag])(op1, op2, label, is_far, is_unordered); 454 }