1 /* 2 * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2016 SAP SE. 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 "asm/macroAssembler.inline.hpp" 28 #include "c1/c1_MacroAssembler.hpp" 29 #include "c1/c1_Runtime1.hpp" 30 #include "gc/shared/barrierSet.hpp" 31 #include "gc/shared/barrierSetAssembler.hpp" 32 #include "gc/shared/collectedHeap.hpp" 33 #include "gc/shared/tlab_globals.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 #include "utilities/macros.hpp" 42 43 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 44 Label ic_miss, ic_hit; 45 verify_oop(receiver, FILE_AND_LINE); 46 int klass_offset = oopDesc::klass_offset_in_bytes(); 47 48 if (!ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(klass_offset)) { 49 if (VM_Version::has_CompareBranch()) { 50 z_cgij(receiver, 0, Assembler::bcondEqual, ic_miss); 51 } else { 52 z_ltgr(receiver, receiver); 53 z_bre(ic_miss); 54 } 55 } 56 57 compare_klass_ptr(iCache, klass_offset, receiver, false); 58 z_bre(ic_hit); 59 60 // If icache check fails, then jump to runtime routine. 61 // Note: RECEIVER must still contain the receiver! 62 load_const_optimized(Z_R1_scratch, AddressLiteral(SharedRuntime::get_ic_miss_stub())); 63 z_br(Z_R1_scratch); 64 align(CodeEntryAlignment); 65 bind(ic_hit); 66 } 67 68 void C1_MacroAssembler::explicit_null_check(Register base) { 69 ShouldNotCallThis(); // unused 70 } 71 72 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) { 73 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect"); 74 generate_stack_overflow_check(bang_size_in_bytes); 75 save_return_pc(); 76 push_frame(frame_size_in_bytes); 77 78 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 79 bs->nmethod_entry_barrier(this); 80 } 81 82 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 83 if (breakAtEntry) z_illtrap(0xC1); 84 } 85 86 void C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 87 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 88 assert_different_registers(hdr, obj, disp_hdr); 89 90 verify_oop(obj, FILE_AND_LINE); 91 92 // Load object header. 93 z_lg(hdr, Address(obj, hdr_offset)); 94 95 // Save object being locked into the BasicObjectLock... 96 z_stg(obj, Address(disp_hdr, BasicObjectLock::obj_offset())); 97 98 if (DiagnoseSyncOnValueBasedClasses != 0) { 99 load_klass(Z_R1_scratch, obj); 100 testbit(Address(Z_R1_scratch, Klass::access_flags_offset()), exact_log2(JVM_ACC_IS_VALUE_BASED_CLASS)); 101 z_btrue(slow_case); 102 } 103 104 assert(LockingMode != LM_MONITOR, "LM_MONITOR is already handled, by emit_lock()"); 105 106 if (LockingMode == LM_LIGHTWEIGHT) { 107 Unimplemented(); 108 } else if (LockingMode == LM_LEGACY) { 109 NearLabel done; 110 // and mark it as unlocked. 111 z_oill(hdr, markWord::unlocked_value); 112 // Save unlocked object header into the displaced header location on the stack. 113 z_stg(hdr, Address(disp_hdr, (intptr_t) 0)); 114 // Test if object header is still the same (i.e. unlocked), and if so, store the 115 // displaced header address in the object header. If it is not the same, get the 116 // object header instead. 117 z_csg(hdr, disp_hdr, hdr_offset, obj); 118 // If the object header was the same, we're done. 119 branch_optimized(Assembler::bcondEqual, done); 120 // If the object header was not the same, it is now in the hdr register. 121 // => Test if it is a stack pointer into the same stack (recursive locking), i.e.: 122 // 123 // 1) (hdr & markWord::lock_mask_in_place) == 0 124 // 2) rsp <= hdr 125 // 3) hdr <= rsp + page_size 126 // 127 // These 3 tests can be done by evaluating the following expression: 128 // 129 // (hdr - Z_SP) & (~(page_size-1) | markWord::lock_mask_in_place) 130 // 131 // assuming both the stack pointer and page_size have their least 132 // significant 2 bits cleared and page_size is a power of 2 133 z_sgr(hdr, Z_SP); 134 135 load_const_optimized(Z_R0_scratch, (~(os::vm_page_size() - 1) | markWord::lock_mask_in_place)); 136 z_ngr(hdr, Z_R0_scratch); // AND sets CC (result eq/ne 0). 137 // For recursive locking, the result is zero. => Save it in the displaced header 138 // location (null in the displaced hdr location indicates recursive locking). 139 z_stg(hdr, Address(disp_hdr, (intptr_t) 0)); 140 // Otherwise we don't care about the result and handle locking via runtime call. 141 branch_optimized(Assembler::bcondNotZero, slow_case); 142 // done 143 bind(done); 144 } 145 } 146 147 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 148 const int aligned_mask = BytesPerWord -1; 149 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 150 assert_different_registers(hdr, obj, disp_hdr); 151 NearLabel done; 152 153 if (LockingMode != LM_LIGHTWEIGHT) { 154 // Load displaced header. 155 z_ltg(hdr, Address(disp_hdr, (intptr_t) 0)); 156 // If the loaded hdr is null we had recursive locking, and we are done. 157 z_bre(done); 158 } 159 160 // Load object. 161 z_lg(obj, Address(disp_hdr, BasicObjectLock::obj_offset())); 162 verify_oop(obj, FILE_AND_LINE); 163 164 if (LockingMode == LM_LIGHTWEIGHT) { 165 Unimplemented(); 166 } else { 167 // Test if object header is pointing to the displaced header, and if so, restore 168 // the displaced header in the object. If the object header is not pointing to 169 // the displaced header, get the object header instead. 170 z_csg(disp_hdr, hdr, hdr_offset, obj); 171 // If the object header was not pointing to the displaced header, 172 // we do unlocking via runtime call. 173 branch_optimized(Assembler::bcondNotEqual, slow_case); 174 // done 175 } 176 bind(done); 177 } 178 179 void C1_MacroAssembler::try_allocate( 180 Register obj, // result: Pointer to object after successful allocation. 181 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise. 182 int con_size_in_bytes, // Object size in bytes if known at compile time. 183 Register t1, // Temp register: Must be global register for incr_allocated_bytes. 184 Label& slow_case // Continuation point if fast allocation fails. 185 ) { 186 if (UseTLAB) { 187 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case); 188 } else { 189 // Allocation in shared Eden not implemented, because sapjvm allocation trace does not allow it. 190 z_brul(slow_case); 191 } 192 } 193 194 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register Rzero, Register t1) { 195 assert_different_registers(obj, klass, len, t1, Rzero); 196 // This assumes that all prototype bits fit in an int32_t. 197 load_const_optimized(t1, (intx)markWord::prototype().value()); 198 z_stg(t1, Address(obj, oopDesc::mark_offset_in_bytes())); 199 200 if (len->is_valid()) { 201 // Length will be in the klass gap, if one exists. 202 z_st(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 203 } else if (UseCompressedClassPointers) { 204 store_klass_gap(Rzero, obj); // Zero klass gap for compressed oops. 205 } 206 store_klass(klass, obj, t1); 207 } 208 209 void C1_MacroAssembler::initialize_body(Register objectFields, Register len_in_bytes, Register Rzero) { 210 Label done; 211 assert_different_registers(objectFields, len_in_bytes, Rzero); 212 213 // Initialize object fields. 214 // See documentation for MVCLE instruction!!! 215 assert(objectFields->encoding()%2==0, "objectFields must be an even register"); 216 assert(len_in_bytes->encoding() == (objectFields->encoding()+1), "objectFields and len_in_bytes must be a register pair"); 217 assert(Rzero->encoding()%2==1, "Rzero must be an odd register"); 218 219 // Use Rzero as src length, then mvcle will copy nothing 220 // and fill the object with the padding value 0. 221 move_long_ext(objectFields, as_Register(Rzero->encoding()-1), 0); 222 bind(done); 223 } 224 225 void C1_MacroAssembler::allocate_object( 226 Register obj, // Result: pointer to object after successful allocation. 227 Register t1, // temp register 228 Register t2, // temp register: Must be a global register for try_allocate. 229 int hdr_size, // object header size in words 230 int obj_size, // object size in words 231 Register klass, // object klass 232 Label& slow_case // Continuation point if fast allocation fails. 233 ) { 234 assert_different_registers(obj, t1, t2, klass); 235 236 // Allocate space and initialize header. 237 try_allocate(obj, noreg, obj_size * wordSize, t1, slow_case); 238 239 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2); 240 } 241 242 void C1_MacroAssembler::initialize_object( 243 Register obj, // result: Pointer to object after successful allocation. 244 Register klass, // object klass 245 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise. 246 int con_size_in_bytes, // Object size in bytes if known at compile time. 247 Register t1, // temp register 248 Register t2 // temp register 249 ) { 250 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 251 "con_size_in_bytes is not multiple of alignment"); 252 assert(var_size_in_bytes == noreg, "not implemented"); 253 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 254 255 const Register Rzero = t2; 256 257 z_xgr(Rzero, Rzero); 258 initialize_header(obj, klass, noreg, Rzero, t1); 259 260 // Clear rest of allocated space. 261 const int threshold = 4 * BytesPerWord; 262 if (con_size_in_bytes <= threshold) { 263 // Use explicit null stores. 264 // code size = 6*n bytes (n = number of fields to clear) 265 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord) 266 z_stg(Rzero, Address(obj, i)); 267 } else { 268 // Code size generated by initialize_body() is 16. 269 Register object_fields = Z_R0_scratch; 270 Register len_in_bytes = Z_R1_scratch; 271 z_la(object_fields, hdr_size_in_bytes, obj); 272 load_const_optimized(len_in_bytes, con_size_in_bytes - hdr_size_in_bytes); 273 initialize_body(object_fields, len_in_bytes, Rzero); 274 } 275 276 // Dtrace support is unimplemented. 277 // if (CURRENT_ENV->dtrace_alloc_probes()) { 278 // assert(obj == rax, "must be"); 279 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id))); 280 // } 281 282 verify_oop(obj, FILE_AND_LINE); 283 } 284 285 void C1_MacroAssembler::allocate_array( 286 Register obj, // result: Pointer to array after successful allocation. 287 Register len, // array length 288 Register t1, // temp register 289 Register t2, // temp register 290 int hdr_size, // object header size in words 291 int elt_size, // element size in bytes 292 Register klass, // object klass 293 Label& slow_case // Continuation point if fast allocation fails. 294 ) { 295 assert_different_registers(obj, len, t1, t2, klass); 296 297 // Determine alignment mask. 298 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 299 300 // Check for negative or excessive length. 301 compareU64_and_branch(len, (int32_t)max_array_allocation_length, bcondHigh, slow_case); 302 303 // Compute array size. 304 // Note: If 0 <= len <= max_length, len*elt_size + header + alignment is 305 // smaller or equal to the largest integer. Also, since top is always 306 // aligned, we can do the alignment here instead of at the end address 307 // computation. 308 const Register arr_size = t2; 309 switch (elt_size) { 310 case 1: lgr_if_needed(arr_size, len); break; 311 case 2: z_sllg(arr_size, len, 1); break; 312 case 4: z_sllg(arr_size, len, 2); break; 313 case 8: z_sllg(arr_size, len, 3); break; 314 default: ShouldNotReachHere(); 315 } 316 add2reg(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment. 317 z_nill(arr_size, (~MinObjAlignmentInBytesMask) & 0xffff); // Align array size. 318 319 try_allocate(obj, arr_size, 0, t1, slow_case); 320 321 initialize_header(obj, klass, len, noreg, t1); 322 323 // Clear rest of allocated space. 324 Label done; 325 Register object_fields = t1; 326 Register Rzero = Z_R1_scratch; 327 z_aghi(arr_size, -(hdr_size * BytesPerWord)); 328 z_bre(done); // Jump if size of fields is zero. 329 z_la(object_fields, hdr_size * BytesPerWord, obj); 330 z_xgr(Rzero, Rzero); 331 initialize_body(object_fields, arr_size, Rzero); 332 bind(done); 333 334 // Dtrace support is unimplemented. 335 // if (CURRENT_ENV->dtrace_alloc_probes()) { 336 // assert(obj == rax, "must be"); 337 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id))); 338 // } 339 340 verify_oop(obj, FILE_AND_LINE); 341 } 342 343 344 #ifndef PRODUCT 345 346 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 347 if (!VerifyOops) return; 348 verify_oop_addr(Address(Z_SP, stack_offset), FILE_AND_LINE); 349 } 350 351 void C1_MacroAssembler::verify_not_null_oop(Register r) { 352 if (!VerifyOops) return; 353 NearLabel not_null; 354 compareU64_and_branch(r, (intptr_t)0, bcondNotEqual, not_null); 355 stop("non-null oop required"); 356 bind(not_null); 357 verify_oop(r, FILE_AND_LINE); 358 } 359 360 void C1_MacroAssembler::invalidate_registers(Register preserve1, 361 Register preserve2, 362 Register preserve3) { 363 Register dead_value = noreg; 364 for (int i = 0; i < FrameMap::nof_cpu_regs; i++) { 365 Register r = as_Register(i); 366 if (r != preserve1 && r != preserve2 && r != preserve3 && r != Z_SP && r != Z_thread) { 367 if (dead_value == noreg) { 368 load_const_optimized(r, 0xc1dead); 369 dead_value = r; 370 } else { 371 z_lgr(r, dead_value); 372 } 373 } 374 } 375 } 376 377 #endif // !PRODUCT