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 * Copyright (c) 2015-2018, Azul Systems, Inc. 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_MacroAssembler.hpp" 29 #include "c1/c1_Runtime1.hpp" 30 #include "classfile/systemDictionary.hpp" 31 #include "gc/shared/collectedHeap.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "oops/arrayOop.hpp" 34 #include "oops/markOop.hpp" 35 #include "runtime/basicLock.hpp" 36 #include "runtime/biasedLocking.hpp" 37 #include "runtime/os.hpp" 38 #include "runtime/sharedRuntime.hpp" 39 #include "runtime/stubRoutines.hpp" 40 41 void C1_MacroAssembler::float_cmp(bool is_float, int unordered_result, 42 FloatRegister f0, FloatRegister f1, 43 Register result) 44 { 45 Label done; 46 if (is_float) { 47 vcmp_f32(f0, f1); 48 } else { 49 vcmp_f64(f0, f1); 50 } 51 52 get_fpsr(); 53 54 mov(result, 0); 55 if (unordered_result < 0) { 56 // we want -1 for unordered or less than, 0 for equal and 1 for 57 // greater than. 58 mov(result, 1, NE); // Not equal or unordered 59 neg(result, result, LT); // Less than or unordered 60 } else { 61 // we want -1 for less than, 0 for equal and 1 for unordered or 62 // greater than. 63 mov(result, 1, NE); // Not equal or unordered 64 neg(result, result, LO); // Less than 65 } 66 } 67 68 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case) { 69 const int aligned_mask = BytesPerWord -1; 70 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 71 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 72 Label done, fail; 73 int null_check_offset = -1; 74 75 verify_oop(obj); 76 77 // save object being locked into the BasicObjectLock 78 str(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 79 80 if (UseBiasedLocking) { 81 assert(scratch != noreg, "should have scratch register at this point"); 82 null_check_offset = biased_locking_enter(obj, hdr, scratch, rscratch1, false, done, &slow_case); 83 } else { 84 null_check_offset = offset(); 85 } 86 87 // Load object header 88 ldr(hdr, Address(obj, hdr_offset)); 89 // and mark it as unlocked 90 orr(hdr, hdr, markOopDesc::unlocked_value); 91 // save unlocked object header into the displaced header location on the stack 92 str(hdr, Address(disp_hdr, 0)); 93 // test if object header is still the same (i.e. unlocked), and if so, store the 94 // displaced header address in the object header - if it is not the same, get the 95 // object header instead 96 lea(rscratch2, Address(obj, hdr_offset)); 97 cmpxchgptr(hdr, disp_hdr, rscratch2, rscratch1, done, /*fallthough*/NULL); 98 // if the object header was the same, we're done 99 // if the object header was not the same, it is now in the hdr register 100 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 101 // 102 // 1) (hdr & aligned_mask) == 0 103 // 2) sp <= hdr 104 // 3) hdr <= sp + page_size 105 // 106 // these 3 tests can be done by evaluating the following expression: 107 // 108 // (hdr - sp) & (aligned_mask - page_size) 109 // 110 // assuming both the stack pointer and page_size have their least 111 // significant 2 bits cleared and page_size is a power of 2 112 mov(rscratch1, sp); 113 sub(hdr, hdr, rscratch1); 114 mov(rscratch2, aligned_mask - os::vm_page_size()); 115 ands(hdr, hdr, rscratch2); 116 // for recursive locking, the result is zero => save it in the displaced header 117 // location (NULL in the displaced hdr location indicates recursive locking) 118 str(hdr, Address(disp_hdr, 0)); 119 // otherwise we don't care about the result and handle locking via runtime call 120 cbnz(hdr, slow_case); 121 // done 122 bind(done); 123 if (PrintBiasedLockingStatistics) { 124 lea(rscratch2, ExternalAddress((address)BiasedLocking::fast_path_entry_count_addr())); 125 addmw(Address(rscratch2, 0), 1, rscratch1); 126 } 127 return null_check_offset; 128 } 129 130 131 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 132 const int aligned_mask = BytesPerWord -1; 133 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 134 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 135 Label done; 136 137 if (UseBiasedLocking) { 138 // load object 139 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 140 biased_locking_exit(obj, hdr, done); 141 } 142 143 // load displaced header 144 ldr(hdr, Address(disp_hdr, 0)); 145 // if the loaded hdr is NULL we had recursive locking 146 // if we had recursive locking, we are done 147 cbz(hdr, done); 148 if (!UseBiasedLocking) { 149 // load object 150 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 151 } 152 verify_oop(obj); 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 // if the object header was not pointing to the displaced header, 157 // we do unlocking via runtime call 158 if (hdr_offset) { 159 lea(rscratch1, Address(obj, hdr_offset)); 160 cmpxchgptr(disp_hdr, hdr, rscratch1, rscratch2, done, &slow_case); 161 } else { 162 cmpxchgptr(disp_hdr, hdr, obj, rscratch2, done, &slow_case); 163 } 164 // done 165 bind(done); 166 } 167 168 169 // Defines obj, preserves var_size_in_bytes 170 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) { 171 if (UseTLAB) { 172 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 173 } else { 174 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case); 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 (UseBiasedLocking && !len->is_valid()) { 181 assert_different_registers(obj, klass, len, t1, t2); 182 ldr(t1, Address(klass, Klass::prototype_header_offset())); 183 } else { 184 // This assumes that all prototype bits fit in an int32_t 185 mov(t1, (int32_t)(intptr_t)markOopDesc::prototype()); 186 } 187 str(t1, Address(obj, oopDesc::mark_offset_in_bytes())); 188 str(klass, Address(obj, oopDesc::klass_offset_in_bytes())); 189 190 if (len->is_valid()) { 191 str(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 192 } 193 } 194 195 // preserves obj, destroys len_in_bytes 196 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) { 197 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 198 Label done; 199 200 // len_in_bytes is positive and ptr sized 201 subs(len_in_bytes, len_in_bytes, hdr_size_in_bytes); 202 b(done, Assembler::EQ); 203 204 // Preserve obj 205 if (hdr_size_in_bytes) 206 add(obj, obj, hdr_size_in_bytes); 207 zero_memory(obj, len_in_bytes, t1); 208 if (hdr_size_in_bytes) 209 sub(obj, obj, hdr_size_in_bytes); 210 211 bind(done); 212 } 213 214 215 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 216 assert_different_registers(obj, t1, t2); // XXX really? 217 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 218 219 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 220 221 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 222 } 223 224 // This method clobbers t1, t2, and rscratch1 registers. 225 void C1_MacroAssembler::initialize_object(Register obj, Register klass, 226 Register var_size_in_bytes, 227 int con_size_in_bytes, 228 Register t1, Register t2, 229 bool is_tlab_allocated) { 230 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 231 "con_size_in_bytes is not multiple of alignment"); 232 233 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 234 235 initialize_header(obj, klass, noreg, t1, t2); 236 237 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 238 // Null out rest of allocated space 239 const Register index = t2; 240 const int threshold = 8 * BytesPerWord; 241 if (var_size_in_bytes != noreg) { 242 mov(index, var_size_in_bytes); 243 initialize_body(obj, index, hdr_size_in_bytes, t1); 244 } else if (con_size_in_bytes <= threshold) { 245 // Emit required number of str instructions (unroll loop completely) 246 mov(t1, 0); 247 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord) { 248 str(t1, Address(obj, i)); 249 } 250 } else if (con_size_in_bytes > hdr_size_in_bytes) { 251 block_comment("zero memory"); 252 // Use loop to null out fields 253 int words = (con_size_in_bytes - hdr_size_in_bytes) / BytesPerWord; 254 mov(t1, 0); 255 256 const int unroll = 4; // Number of str instructions we'll unroll 257 mov(index, words / unroll); 258 int remainder = words % unroll; 259 lea(rscratch1, Address(obj, hdr_size_in_bytes + remainder * BytesPerWord)); 260 261 Label entry_point, loop; 262 b(entry_point); 263 bind(loop); 264 sub(index, index, 1); 265 for (int i = -unroll; i < 0; i++) { 266 if (-i == remainder) { 267 bind(entry_point); 268 } 269 str(t1, Address(rscratch1, i * BytesPerWord)); 270 } 271 if (remainder == 0) { 272 bind(entry_point); 273 } 274 add(rscratch1, rscratch1, unroll * BytesPerWord); 275 cbnz(index, loop); 276 } 277 } 278 279 membar(StoreStore); 280 281 if (CURRENT_ENV->dtrace_alloc_probes()) { 282 assert(obj == r0, "must be"); 283 far_call(RuntimeAddress(Runtime1::entry_for( 284 Runtime1::dtrace_object_alloc_id))); 285 } 286 287 verify_oop(obj); 288 } 289 290 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, int f, Register klass, Label& slow_case) { 291 assert_different_registers(obj, len, t1, t2, klass); 292 293 // determine alignment mask 294 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 295 296 // check for negative or excessive length 297 mov(rscratch1, (int32_t)max_array_allocation_length); 298 cmp(len, rscratch1); 299 b(slow_case, Assembler::HS); 300 301 const Register arr_size = t2; // okay to be the same 302 // align object end 303 mov(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask); 304 add(arr_size, arr_size, len, Assembler::lsl(f)); 305 mov(t1, ~MinObjAlignmentInBytesMask); 306 andr(arr_size, arr_size, t1); 307 308 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 309 310 initialize_header(obj, klass, len, t1, t2); 311 312 // clear rest of allocated space 313 const Register len_zero = len; 314 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero); 315 316 membar(StoreStore); 317 318 if (CURRENT_ENV->dtrace_alloc_probes()) { 319 assert(obj == r0, "must be"); 320 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 321 } 322 323 verify_oop(obj); 324 } 325 326 327 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 328 verify_oop(receiver); 329 // explicit NULL check not needed since load from [klass_offset] causes a trap 330 // check against inline cache 331 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check"); 332 333 cmp_klass(receiver, iCache, rscratch1); 334 } 335 336 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, 337 int bang_size_in_bytes) { 338 assert(bang_size_in_bytes >= frame_size_in_bytes, 339 "stack bang size incorrect"); 340 341 // If we have to make this method not-entrant, we'll overwrite its first 342 // instruction with a jump. For this action to be legal we must ensure that 343 // this first instruction is a B, BL, NOP, BKPT, or SVC. Make it a NOP 344 nop(); 345 346 // Make sure there is enough stack space for this method's activation 347 generate_stack_overflow_check(bang_size_in_bytes); 348 349 // Push lr, rfp, and optionally update rfp. rfp points to the first stack 350 // word used by the new frame. 351 352 if (FrameAPCS) { 353 mov(rscratch2, sp); 354 stmdb(sp, RegSet::of(rfp, rscratch2, lr, r15_pc).bits()); 355 add(rfp, sp, 3 * wordSize); 356 } else { 357 stmdb(sp, RegSet::of(rfp, lr).bits()); 358 if (PreserveFramePointer) { 359 add(rfp, sp, BytesPerWord); 360 } 361 } 362 363 // Create frame. frame_size_in_bytes always comes from 364 // LIR_Assembler::initial_frame_size_in_bytes() method, and it already 365 // takes into account two stack words spent on saving lr and rfp. 366 decrement(sp, frame_size_in_bytes); 367 } 368 369 void C1_MacroAssembler::remove_frame(int frame_size_in_bytes) { 370 if (FrameAPCS) { 371 ldmea(rfp, RegSet::of(rfp, sp, lr).bits(), false/*wb*/); 372 } else { 373 // Remove frame. frame_size_in_bytes always comes from 374 // LIR_Assembler::initial_frame_size_in_bytes() method, and it already 375 // takes into account two stack words spent on saving lr and rfp. 376 increment(sp, frame_size_in_bytes); 377 // Pop rfp and lr 378 ldmia(sp, RegSet::of(rfp, lr).bits()); 379 } 380 } 381 382 void C1_MacroAssembler::verified_entry() { 383 } 384 385 void C1_MacroAssembler::patchable_load(Register reg, address addr) { 386 nop(); 387 membar(Assembler::LoadLoad); 388 far_load(reg, addr); 389 } 390 391 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 392 //// Not APCS 393 // - 1: link 394 // fp 0: return address 395 // + 1: argument with offset 0 396 // + 2: argument with offset 1 397 // + 3: ... 398 //// APCS 399 // - 3: link 400 // - 2: sp 401 // - 1: return address 402 // fp 0: pc 403 // + 1: argument with offset 0 404 // + 2: argument with offset 1 405 // + 3: ... 406 407 ldr(reg, Address(rfp, (offset_in_words + 1) * BytesPerWord)); 408 } 409 410 #ifndef PRODUCT 411 412 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 413 if (!VerifyOops) return; 414 verify_oop_addr(Address(sp, stack_offset), "oop"); 415 } 416 417 void C1_MacroAssembler::verify_not_null_oop(Register r) { 418 if (!VerifyOops) return; 419 Label not_null; 420 cbnz(r, not_null); 421 stop("non-null oop required"); 422 bind(not_null); 423 verify_oop(r); 424 } 425 426 void C1_MacroAssembler::invalidate_registers(bool inv_r0, bool inv_r2, bool inv_r3) { 427 #ifdef ASSERT 428 static int nn; 429 if (inv_r0) mov(r0, 0xDEAD); 430 if (inv_r2) mov(r2, nn++); 431 if (inv_r3) mov(r3, 0xDEAD); 432 #endif 433 } 434 #endif // ifndef PRODUCT