1 /* 2 * Copyright (c) 1999, 2018, 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 "asm/macroAssembler.inline.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 "interpreter/interpreter.hpp" 32 #include "oops/arrayOop.hpp" 33 #include "oops/markWord.hpp" 34 #include "runtime/basicLock.hpp" 35 #include "runtime/biasedLocking.hpp" 36 #include "runtime/os.hpp" 37 #include "runtime/sharedRuntime.hpp" 38 #include "runtime/stubRoutines.hpp" 39 40 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 41 Label L; 42 const Register temp_reg = G3_scratch; 43 // Note: needs more testing of out-of-line vs. inline slow case 44 verify_oop(receiver); 45 load_klass(receiver, temp_reg); 46 cmp_and_brx_short(temp_reg, iCache, Assembler::equal, Assembler::pt, L); 47 AddressLiteral ic_miss(SharedRuntime::get_ic_miss_stub()); 48 jump_to(ic_miss, temp_reg); 49 delayed()->nop(); 50 align(CodeEntryAlignment); 51 bind(L); 52 } 53 54 55 void C1_MacroAssembler::explicit_null_check(Register base) { 56 Unimplemented(); 57 } 58 59 60 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) { 61 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 62 generate_stack_overflow_check(bang_size_in_bytes); 63 // Create the frame. 64 save_frame_c1(frame_size_in_bytes); 65 } 66 67 68 void C1_MacroAssembler::verified_entry() { 69 if (C1Breakpoint) { 70 breakpoint_trap(); 71 } 72 } 73 74 75 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) { 76 assert_different_registers(Rmark, Roop, Rbox, Rscratch); 77 78 Label done; 79 80 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes()); 81 82 // The following move must be the first instruction of emitted since debug 83 // information may be generated for it. 84 // Load object header 85 ld_ptr(mark_addr, Rmark); 86 87 verify_oop(Roop); 88 89 // save object being locked into the BasicObjectLock 90 st_ptr(Roop, Rbox, BasicObjectLock::obj_offset_in_bytes()); 91 92 if (UseBiasedLocking) { 93 biased_locking_enter(Roop, Rmark, Rscratch, done, &slow_case); 94 } 95 96 // Save Rbox in Rscratch to be used for the cas operation 97 mov(Rbox, Rscratch); 98 99 // and mark it unlocked 100 or3(Rmark, markWord::unlocked_value, Rmark); 101 102 // save unlocked object header into the displaced header location on the stack 103 st_ptr(Rmark, Rbox, BasicLock::displaced_header_offset_in_bytes()); 104 105 // compare object markWord with Rmark and if equal exchange Rscratch with object markWord 106 assert(mark_addr.disp() == 0, "cas must take a zero displacement"); 107 cas_ptr(mark_addr.base(), Rmark, Rscratch); 108 // if compare/exchange succeeded we found an unlocked object and we now have locked it 109 // hence we are done 110 cmp(Rmark, Rscratch); 111 brx(Assembler::equal, false, Assembler::pt, done); 112 delayed()->sub(Rscratch, SP, Rscratch); //pull next instruction into delay slot 113 // we did not find an unlocked object so see if this is a recursive case 114 // sub(Rscratch, SP, Rscratch); 115 assert(os::vm_page_size() > 0xfff, "page size too small - change the constant"); 116 andcc(Rscratch, 0xfffff003, Rscratch); 117 brx(Assembler::notZero, false, Assembler::pn, slow_case); 118 delayed()->st_ptr(Rscratch, Rbox, BasicLock::displaced_header_offset_in_bytes()); 119 bind(done); 120 } 121 122 123 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) { 124 assert_different_registers(Rmark, Roop, Rbox); 125 126 Label done; 127 128 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes()); 129 assert(mark_addr.disp() == 0, "cas must take a zero displacement"); 130 131 if (UseBiasedLocking) { 132 // load the object out of the BasicObjectLock 133 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop); 134 verify_oop(Roop); 135 biased_locking_exit(mark_addr, Rmark, done); 136 } 137 // Test first it it is a fast recursive unlock 138 ld_ptr(Rbox, BasicLock::displaced_header_offset_in_bytes(), Rmark); 139 br_null_short(Rmark, Assembler::pt, done); 140 if (!UseBiasedLocking) { 141 // load object 142 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop); 143 verify_oop(Roop); 144 } 145 146 // Check if it is still a light weight lock, this is is true if we see 147 // the stack address of the basicLock in the markWord of the object 148 cas_ptr(mark_addr.base(), Rbox, Rmark); 149 cmp(Rbox, Rmark); 150 151 brx(Assembler::notEqual, false, Assembler::pn, slow_case); 152 delayed()->nop(); 153 // Done 154 bind(done); 155 } 156 157 158 void C1_MacroAssembler::try_allocate( 159 Register obj, // result: pointer to object after successful allocation 160 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise 161 int con_size_in_bytes, // object size in bytes if known at compile time 162 Register t1, // temp register, must be global register for incr_allocated_bytes 163 Register t2, // temp register 164 Label& slow_case // continuation point if fast allocation fails 165 ) { 166 RegisterOrConstant size_in_bytes = var_size_in_bytes->is_valid() 167 ? RegisterOrConstant(var_size_in_bytes) : RegisterOrConstant(con_size_in_bytes); 168 if (UseTLAB) { 169 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case); 170 } else { 171 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 172 incr_allocated_bytes(size_in_bytes, t1, t2); 173 } 174 } 175 176 177 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 178 assert_different_registers(obj, klass, len, t1, t2); 179 if (UseBiasedLocking && !len->is_valid()) { 180 ld_ptr(klass, in_bytes(Klass::prototype_header_offset()), t1); 181 } else { 182 set((intx)markWord::prototype().value(), t1); 183 } 184 st_ptr(t1, obj, oopDesc::mark_offset_in_bytes()); 185 if (UseCompressedClassPointers) { 186 // Save klass 187 mov(klass, t1); 188 encode_klass_not_null(t1); 189 stw(t1, obj, oopDesc::klass_offset_in_bytes()); 190 } else { 191 st_ptr(klass, obj, oopDesc::klass_offset_in_bytes()); 192 } 193 if (len->is_valid()) { 194 st(len, obj, arrayOopDesc::length_offset_in_bytes()); 195 } else if (UseCompressedClassPointers) { 196 // otherwise length is in the class gap 197 store_klass_gap(G0, obj); 198 } 199 } 200 201 202 void C1_MacroAssembler::initialize_body(Register base, Register index) { 203 zero_memory(base, index); 204 } 205 206 207 void C1_MacroAssembler::allocate_object( 208 Register obj, // result: pointer to object after successful allocation 209 Register t1, // temp register 210 Register t2, // temp register, must be a global register for try_allocate 211 Register t3, // temp register 212 int hdr_size, // object header size in words 213 int obj_size, // object size in words 214 Register klass, // object klass 215 Label& slow_case // continuation point if fast allocation fails 216 ) { 217 assert_different_registers(obj, t1, t2, t3, klass); 218 assert(klass == G5, "must be G5"); 219 220 // allocate space & initialize header 221 if (!is_simm13(obj_size * wordSize)) { 222 // would need to use extra register to load 223 // object size => go the slow case for now 224 ba(slow_case); 225 delayed()->nop(); 226 return; 227 } 228 try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case); 229 230 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2, /* is_tlab_allocated */ UseTLAB); 231 } 232 233 void C1_MacroAssembler::initialize_object( 234 Register obj, // result: pointer to object after successful allocation 235 Register klass, // object klass 236 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise 237 int con_size_in_bytes, // object size in bytes if known at compile time 238 Register t1, // temp register 239 Register t2, // temp register 240 bool is_tlab_allocated // the object was allocated in a TLAB; relevant for the implementation of ZeroTLAB 241 ) { 242 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 243 244 initialize_header(obj, klass, noreg, t1, t2); 245 246 #ifdef ASSERT 247 { 248 Label ok; 249 ld(klass, in_bytes(Klass::layout_helper_offset()), t1); 250 if (var_size_in_bytes != noreg) { 251 cmp_and_brx_short(t1, var_size_in_bytes, Assembler::equal, Assembler::pt, ok); 252 } else { 253 cmp_and_brx_short(t1, con_size_in_bytes, Assembler::equal, Assembler::pt, ok); 254 } 255 stop("bad size in initialize_object"); 256 should_not_reach_here(); 257 258 bind(ok); 259 } 260 261 #endif 262 263 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 264 // initialize body 265 const int threshold = 5 * HeapWordSize; // approximate break even point for code size 266 if (var_size_in_bytes != noreg) { 267 // use a loop 268 add(obj, hdr_size_in_bytes, t1); // compute address of first element 269 sub(var_size_in_bytes, hdr_size_in_bytes, t2); // compute size of body 270 initialize_body(t1, t2); 271 } else if (con_size_in_bytes <= threshold) { 272 // use explicit NULL stores 273 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += HeapWordSize) st_ptr(G0, obj, i); 274 } else if (con_size_in_bytes > hdr_size_in_bytes) { 275 // use a loop 276 const Register base = t1; 277 const Register index = t2; 278 add(obj, hdr_size_in_bytes, base); // compute address of first element 279 // compute index = number of words to clear 280 set(con_size_in_bytes - hdr_size_in_bytes, index); 281 initialize_body(base, index); 282 } 283 } 284 285 if (CURRENT_ENV->dtrace_alloc_probes()) { 286 assert(obj == O0, "must be"); 287 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)), 288 relocInfo::runtime_call_type); 289 delayed()->nop(); 290 } 291 292 verify_oop(obj); 293 } 294 295 296 void C1_MacroAssembler::allocate_array( 297 Register obj, // result: pointer to array after successful allocation 298 Register len, // array length 299 Register t1, // temp register 300 Register t2, // temp register 301 Register t3, // temp register 302 int hdr_size, // object header size in words 303 int elt_size, // element size in bytes 304 Register klass, // object klass 305 Label& slow_case // continuation point if fast allocation fails 306 ) { 307 assert_different_registers(obj, len, t1, t2, t3, klass); 308 assert(klass == G5, "must be G5"); 309 assert(t1 == G1, "must be G1"); 310 311 // determine alignment mask 312 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 313 314 // check for negative or excessive length 315 // note: the maximum length allowed is chosen so that arrays of any 316 // element size with this length are always smaller or equal 317 // to the largest integer (i.e., array size computation will 318 // not overflow) 319 set(max_array_allocation_length, t1); 320 cmp(len, t1); 321 br(Assembler::greaterUnsigned, false, Assembler::pn, slow_case); 322 323 // compute array size 324 // note: if 0 <= len <= max_length, len*elt_size + header + alignment is 325 // smaller or equal to the largest integer; also, since top is always 326 // aligned, we can do the alignment here instead of at the end address 327 // computation 328 const Register arr_size = t1; 329 switch (elt_size) { 330 case 1: delayed()->mov(len, arr_size); break; 331 case 2: delayed()->sll(len, 1, arr_size); break; 332 case 4: delayed()->sll(len, 2, arr_size); break; 333 case 8: delayed()->sll(len, 3, arr_size); break; 334 default: ShouldNotReachHere(); 335 } 336 add(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask, arr_size); // add space for header & alignment 337 and3(arr_size, ~MinObjAlignmentInBytesMask, arr_size); // align array size 338 339 // allocate space & initialize header 340 if (UseTLAB) { 341 tlab_allocate(obj, arr_size, 0, t2, slow_case); 342 } else { 343 eden_allocate(obj, arr_size, 0, t2, t3, slow_case); 344 } 345 initialize_header(obj, klass, len, t2, t3); 346 347 // initialize body 348 const Register base = t2; 349 const Register index = t3; 350 add(obj, hdr_size * wordSize, base); // compute address of first element 351 sub(arr_size, hdr_size * wordSize, index); // compute index = number of words to clear 352 initialize_body(base, index); 353 354 if (CURRENT_ENV->dtrace_alloc_probes()) { 355 assert(obj == O0, "must be"); 356 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)), 357 relocInfo::runtime_call_type); 358 delayed()->nop(); 359 } 360 361 verify_oop(obj); 362 } 363 364 365 #ifndef PRODUCT 366 367 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 368 if (!VerifyOops) return; 369 verify_oop_addr(Address(SP, stack_offset + STACK_BIAS)); 370 } 371 372 void C1_MacroAssembler::verify_not_null_oop(Register r) { 373 Label not_null; 374 br_notnull_short(r, Assembler::pt, not_null); 375 stop("non-null oop required"); 376 bind(not_null); 377 if (!VerifyOops) return; 378 verify_oop(r); 379 } 380 381 void C1_MacroAssembler::invalidate_registers(bool iregisters, bool lregisters, bool oregisters, 382 Register preserve1, Register preserve2) { 383 if (iregisters) { 384 for (int i = 0; i < 6; i++) { 385 Register r = as_iRegister(i); 386 if (r != preserve1 && r != preserve2) set(0xdead, r); 387 } 388 } 389 if (oregisters) { 390 for (int i = 0; i < 6; i++) { 391 Register r = as_oRegister(i); 392 if (r != preserve1 && r != preserve2) set(0xdead, r); 393 } 394 } 395 if (lregisters) { 396 for (int i = 0; i < 8; i++) { 397 Register r = as_lRegister(i); 398 if (r != preserve1 && r != preserve2) set(0xdead, r); 399 } 400 } 401 } 402 403 404 #endif