1 /* 2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2014, 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 "classfile/systemDictionary.hpp" 30 #include "gc/shared/collectedHeap.hpp" 31 #include "gc/shared/barrierSet.hpp" 32 #include "gc/shared/barrierSetAssembler.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "oops/arrayOop.hpp" 35 #include "oops/markOop.hpp" 36 #include "runtime/basicLock.hpp" 37 #include "runtime/biasedLocking.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, Register scratch, Label& slow_case) { 66 const int aligned_mask = BytesPerWord -1; 67 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 68 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 69 Label done; 70 int null_check_offset = -1; 71 72 verify_oop(obj); 73 74 // save object being locked into the BasicObjectLock 75 str(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 76 77 if (UseBiasedLocking) { 78 assert(scratch != noreg, "should have scratch register at this point"); 79 null_check_offset = biased_locking_enter(disp_hdr, obj, hdr, scratch, false, done, &slow_case); 80 } else { 81 null_check_offset = offset(); 82 } 83 84 // Load object header 85 ldr(hdr, Address(obj, hdr_offset)); 86 // and mark it as unlocked 87 orr(hdr, hdr, markOopDesc::unlocked_value); 88 89 if (EnableValhalla && !UseBiasedLocking) { 90 // Mask always_locked bit such that we go to the slow path if object is a value type 91 andr(hdr, hdr, ~markOopDesc::biased_lock_bit_in_place); 92 } 93 94 // save unlocked object header into the displaced header location on the stack 95 str(hdr, Address(disp_hdr, 0)); 96 // test if object header is still the same (i.e. unlocked), and if so, store the 97 // displaced header address in the object header - if it is not the same, get the 98 // object header instead 99 lea(rscratch2, Address(obj, hdr_offset)); 100 cmpxchgptr(hdr, disp_hdr, rscratch2, rscratch1, done, /*fallthough*/NULL); 101 // if the object header was the same, we're done 102 // if the object header was not the same, it is now in the hdr register 103 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 104 // 105 // 1) (hdr & aligned_mask) == 0 106 // 2) sp <= hdr 107 // 3) hdr <= sp + page_size 108 // 109 // these 3 tests can be done by evaluating the following expression: 110 // 111 // (hdr - sp) & (aligned_mask - page_size) 112 // 113 // assuming both the stack pointer and page_size have their least 114 // significant 2 bits cleared and page_size is a power of 2 115 mov(rscratch1, sp); 116 sub(hdr, hdr, rscratch1); 117 ands(hdr, hdr, aligned_mask - os::vm_page_size()); 118 // for recursive locking, the result is zero => save it in the displaced header 119 // location (NULL in the displaced hdr location indicates recursive locking) 120 str(hdr, Address(disp_hdr, 0)); 121 // otherwise we don't care about the result and handle locking via runtime call 122 cbnz(hdr, slow_case); 123 // done 124 bind(done); 125 if (PrintBiasedLockingStatistics) { 126 lea(rscratch2, ExternalAddress((address)BiasedLocking::fast_path_entry_count_addr())); 127 addmw(Address(rscratch2, 0), 1, rscratch1); 128 } 129 return null_check_offset; 130 } 131 132 133 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 134 const int aligned_mask = BytesPerWord -1; 135 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 136 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 137 Label done; 138 139 if (UseBiasedLocking) { 140 // load object 141 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 142 biased_locking_exit(obj, hdr, done); 143 } 144 145 // load displaced header 146 ldr(hdr, Address(disp_hdr, 0)); 147 // if the loaded hdr is NULL we had recursive locking 148 // if we had recursive locking, we are done 149 cbz(hdr, done); 150 if (!UseBiasedLocking) { 151 // load object 152 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 153 } 154 verify_oop(obj); 155 // test if object header is pointing to the displaced header, and if so, restore 156 // the displaced header in the object - if the object header is not pointing to 157 // the displaced header, get the object header instead 158 // if the object header was not pointing to the displaced header, 159 // we do unlocking via runtime call 160 if (hdr_offset) { 161 lea(rscratch1, Address(obj, hdr_offset)); 162 cmpxchgptr(disp_hdr, hdr, rscratch1, rscratch2, done, &slow_case); 163 } else { 164 cmpxchgptr(disp_hdr, hdr, obj, rscratch2, done, &slow_case); 165 } 166 // done 167 bind(done); 168 } 169 170 171 // Defines obj, preserves var_size_in_bytes 172 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) { 173 if (UseTLAB) { 174 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 175 } else { 176 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case); 177 } 178 } 179 180 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 181 assert_different_registers(obj, klass, len); 182 if (UseBiasedLocking && !len->is_valid()) { 183 assert_different_registers(obj, klass, len, t1, t2); 184 ldr(t1, Address(klass, Klass::prototype_header_offset())); 185 } else { 186 // This assumes that all prototype bits fit in an int32_t 187 mov(t1, (int32_t)(intptr_t)markOopDesc::prototype()); 188 } 189 str(t1, Address(obj, oopDesc::mark_offset_in_bytes())); 190 191 if (UseCompressedClassPointers) { // Take care not to kill klass 192 encode_klass_not_null(t1, klass); 193 strw(t1, Address(obj, oopDesc::klass_offset_in_bytes())); 194 } else { 195 str(klass, Address(obj, oopDesc::klass_offset_in_bytes())); 196 } 197 198 if (len->is_valid()) { 199 strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 200 } else if (UseCompressedClassPointers) { 201 store_klass_gap(obj, zr); 202 } 203 } 204 205 // preserves obj, destroys len_in_bytes 206 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) { 207 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 208 Label done; 209 210 // len_in_bytes is positive and ptr sized 211 subs(len_in_bytes, len_in_bytes, hdr_size_in_bytes); 212 br(Assembler::EQ, done); 213 214 // Preserve obj 215 if (hdr_size_in_bytes) 216 add(obj, obj, hdr_size_in_bytes); 217 zero_memory(obj, len_in_bytes, t1); 218 if (hdr_size_in_bytes) 219 sub(obj, obj, hdr_size_in_bytes); 220 221 bind(done); 222 } 223 224 225 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 226 assert_different_registers(obj, t1, t2); // XXX really? 227 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 228 229 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 230 231 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 232 } 233 234 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) { 235 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 236 "con_size_in_bytes is not multiple of alignment"); 237 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 238 239 initialize_header(obj, klass, noreg, t1, t2); 240 241 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 242 // clear rest of allocated space 243 const Register index = t2; 244 const int threshold = 16 * BytesPerWord; // approximate break even point for code size (see comments below) 245 if (var_size_in_bytes != noreg) { 246 mov(index, var_size_in_bytes); 247 initialize_body(obj, index, hdr_size_in_bytes, t1); 248 } else if (con_size_in_bytes <= threshold) { 249 // use explicit null stores 250 int i = hdr_size_in_bytes; 251 if (i < con_size_in_bytes && (con_size_in_bytes % (2 * BytesPerWord))) { 252 str(zr, Address(obj, i)); 253 i += BytesPerWord; 254 } 255 for (; i < con_size_in_bytes; i += 2 * BytesPerWord) 256 stp(zr, zr, Address(obj, i)); 257 } else if (con_size_in_bytes > hdr_size_in_bytes) { 258 block_comment("zero memory"); 259 // use loop to null out the fields 260 261 int words = (con_size_in_bytes - hdr_size_in_bytes) / BytesPerWord; 262 mov(index, words / 8); 263 264 const int unroll = 8; // Number of str(zr) instructions we'll unroll 265 int remainder = words % unroll; 266 lea(rscratch1, Address(obj, hdr_size_in_bytes + remainder * BytesPerWord)); 267 268 Label entry_point, loop; 269 b(entry_point); 270 271 bind(loop); 272 sub(index, index, 1); 273 for (int i = -unroll; i < 0; i++) { 274 if (-i == remainder) 275 bind(entry_point); 276 str(zr, Address(rscratch1, i * wordSize)); 277 } 278 if (remainder == 0) 279 bind(entry_point); 280 add(rscratch1, rscratch1, unroll * wordSize); 281 cbnz(index, loop); 282 283 } 284 } 285 286 membar(StoreStore); 287 288 if (CURRENT_ENV->dtrace_alloc_probes()) { 289 assert(obj == r0, "must be"); 290 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 291 } 292 293 verify_oop(obj); 294 } 295 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, int f, Register klass, Label& slow_case) { 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 mov(rscratch1, (int32_t)max_array_allocation_length); 303 cmp(len, rscratch1); 304 br(Assembler::HS, slow_case); 305 306 const Register arr_size = t2; // okay to be the same 307 // align object end 308 mov(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask); 309 add(arr_size, arr_size, len, ext::uxtw, f); 310 andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask); 311 312 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 313 314 initialize_header(obj, klass, len, t1, t2); 315 316 // clear rest of allocated space 317 const Register len_zero = len; 318 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero); 319 320 membar(StoreStore); 321 322 if (CURRENT_ENV->dtrace_alloc_probes()) { 323 assert(obj == r0, "must be"); 324 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 325 } 326 327 verify_oop(obj); 328 } 329 330 331 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 332 verify_oop(receiver); 333 // explicit NULL check not needed since load from [klass_offset] causes a trap 334 // check against inline cache 335 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check"); 336 337 cmp_klass(receiver, iCache, rscratch1); 338 } 339 340 341 void C1_MacroAssembler::build_frame(int framesize, int bang_size_in_bytes, bool needs_stack_repair, Label* verified_value_entry_label) { 342 343 344 // If we have to make this method not-entrant we'll overwrite its 345 // first instruction with a jump. For this action to be legal we 346 // must ensure that this first instruction is a B, BL, NOP, BKPT, 347 // SVC, HVC, or SMC. Make it a NOP. 348 nop(); 349 assert(bang_size_in_bytes >= framesize, "stack bang size incorrect"); 350 // Make sure there is enough stack space for this method's activation. 351 // Note that we do this before doing an enter(). 352 generate_stack_overflow_check(bang_size_in_bytes); 353 354 guarantee(needs_stack_repair == false, "Stack repair should not be true"); 355 if (verified_value_entry_label != NULL) { 356 bind(*verified_value_entry_label); 357 } 358 359 MacroAssembler::build_frame(framesize + 2 * wordSize); 360 if (NotifySimulator) { 361 notify(Assembler::method_entry); 362 } 363 } 364 365 void C1_MacroAssembler::remove_frame(int framesize, bool needs_stack_repair) { 366 367 guarantee(needs_stack_repair == false, "Stack repair should not be true"); 368 369 MacroAssembler::remove_frame(framesize + 2 * wordSize); 370 if (NotifySimulator) { 371 notify(Assembler::method_reentry); 372 } 373 } 374 375 void C1_MacroAssembler::verified_value_entry() { 376 if (C1Breakpoint || VerifyFPU || !UseStackBanging) { 377 // Verified Entry first instruction should be 5 bytes long for correct 378 // patching by patch_verified_entry(). 379 // 380 // C1Breakpoint and VerifyFPU have one byte first instruction. 381 // Also first instruction will be one byte "push(rbp)" if stack banging 382 // code is not generated (see build_frame() above). 383 // For all these cases generate long instruction first. 384 nop(); 385 } 386 387 // build frame 388 // DMS CHECK: is it nop? 389 // verify_FPU(0, "method_entry"); 390 391 } 392 393 int C1_MacroAssembler::scalarized_entry(const CompiledEntrySignature *ces, int frame_size_in_bytes, int bang_size_in_bytes, Label& verified_value_entry_label, bool is_value_ro_entry) { 394 guarantee(false, "Support for ValueTypePassFieldsAsArgs and ValueTypeReturnedAsFields is not implemented"); 395 return 0; 396 } 397 398 399 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 400 // rbp, + 0: link 401 // + 1: return address 402 // + 2: argument with offset 0 403 // + 3: argument with offset 1 404 // + 4: ... 405 406 ldr(reg, Address(rfp, (offset_in_words + 2) * BytesPerWord)); 407 } 408 409 #ifndef PRODUCT 410 411 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 412 if (!VerifyOops) return; 413 verify_oop_addr(Address(sp, stack_offset), "oop"); 414 } 415 416 void C1_MacroAssembler::verify_not_null_oop(Register r) { 417 if (!VerifyOops) return; 418 Label not_null; 419 cbnz(r, not_null); 420 stop("non-null oop required"); 421 bind(not_null); 422 verify_oop(r); 423 } 424 425 void C1_MacroAssembler::invalidate_registers(bool inv_r0, bool inv_r19, bool inv_r2, bool inv_r3, bool inv_r4, bool inv_r5) { 426 #ifdef ASSERT 427 static int nn; 428 if (inv_r0) mov(r0, 0xDEAD); 429 if (inv_r19) mov(r19, 0xDEAD); 430 if (inv_r2) mov(r2, nn++); 431 if (inv_r3) mov(r3, 0xDEAD); 432 if (inv_r4) mov(r4, 0xDEAD); 433 if (inv_r5) mov(r5, 0xDEAD); 434 #endif 435 } 436 #endif // ifndef PRODUCT