1 /* 2 * Copyright (c) 1999, 2022, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2014, 2021, 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 "gc/shared/barrierSetAssembler.hpp" 30 #include "gc/shared/collectedHeap.hpp" 31 #include "gc/shared/tlab_globals.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "oops/arrayOop.hpp" 34 #include "oops/markWord.hpp" 35 #include "runtime/basicLock.hpp" 36 #include "runtime/os.hpp" 37 #include "runtime/sharedRuntime.hpp" 38 #include "runtime/stubRoutines.hpp" 39 40 void C1_MacroAssembler::float_cmp(bool is_float, int unordered_result, 41 FloatRegister f0, FloatRegister f1, 42 Register result) 43 { 44 Label done; 45 if (is_float) { 46 fcmps(f0, f1); 47 } else { 48 fcmpd(f0, f1); 49 } 50 if (unordered_result < 0) { 51 // we want -1 for unordered or less than, 0 for equal and 1 for 52 // greater than. 53 cset(result, NE); // Not equal or unordered 54 cneg(result, result, LT); // Less than or unordered 55 } else { 56 // we want -1 for less than, 0 for equal and 1 for unordered or 57 // greater than. 58 cset(result, NE); // Not equal or unordered 59 cneg(result, result, LO); // Less than 60 } 61 } 62 63 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 64 const int aligned_mask = BytesPerWord -1; 65 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 66 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 67 Label done; 68 int null_check_offset = -1; 69 70 verify_oop(obj); 71 72 // save object being locked into the BasicObjectLock 73 str(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 74 75 null_check_offset = offset(); 76 77 if (DiagnoseSyncOnValueBasedClasses != 0) { 78 load_klass(hdr, obj); 79 ldrw(hdr, Address(hdr, Klass::access_flags_offset())); 80 tstw(hdr, JVM_ACC_IS_VALUE_BASED_CLASS); 81 br(Assembler::NE, slow_case); 82 } 83 84 // Load object header 85 ldr(hdr, Address(obj, hdr_offset)); 86 // and mark it as unlocked 87 orr(hdr, hdr, markWord::unlocked_value); 88 // save unlocked object header into the displaced header location on the stack 89 str(hdr, Address(disp_hdr, 0)); 90 // test if object header is still the same (i.e. unlocked), and if so, store the 91 // displaced header address in the object header - if it is not the same, get the 92 // object header instead 93 lea(rscratch2, Address(obj, hdr_offset)); 94 cmpxchgptr(hdr, disp_hdr, rscratch2, rscratch1, done, /*fallthough*/NULL); 95 // if the object header was the same, we're done 96 // if the object header was not the same, it is now in the hdr register 97 // => test if it is a stack pointer into the same stack (recursive locking), i.e.: 98 // 99 // 1) (hdr & aligned_mask) == 0 100 // 2) sp <= hdr 101 // 3) hdr <= sp + page_size 102 // 103 // these 3 tests can be done by evaluating the following expression: 104 // 105 // (hdr - sp) & (aligned_mask - page_size) 106 // 107 // assuming both the stack pointer and page_size have their least 108 // significant 2 bits cleared and page_size is a power of 2 109 mov(rscratch1, sp); 110 sub(hdr, hdr, rscratch1); 111 ands(hdr, hdr, aligned_mask - os::vm_page_size()); 112 // for recursive locking, the result is zero => save it in the displaced header 113 // location (NULL in the displaced hdr location indicates recursive locking) 114 str(hdr, Address(disp_hdr, 0)); 115 // otherwise we don't care about the result and handle locking via runtime call 116 cbnz(hdr, slow_case); 117 // done 118 bind(done); 119 return null_check_offset; 120 } 121 122 123 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) { 124 const int aligned_mask = BytesPerWord -1; 125 const int hdr_offset = oopDesc::mark_offset_in_bytes(); 126 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different"); 127 Label done; 128 129 // load displaced header 130 ldr(hdr, Address(disp_hdr, 0)); 131 // if the loaded hdr is NULL we had recursive locking 132 // if we had recursive locking, we are done 133 cbz(hdr, done); 134 // load object 135 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes())); 136 verify_oop(obj); 137 // test if object header is pointing to the displaced header, and if so, restore 138 // the displaced header in the object - if the object header is not pointing to 139 // the displaced header, get the object header instead 140 // if the object header was not pointing to the displaced header, 141 // we do unlocking via runtime call 142 if (hdr_offset) { 143 lea(rscratch1, Address(obj, hdr_offset)); 144 cmpxchgptr(disp_hdr, hdr, rscratch1, rscratch2, done, &slow_case); 145 } else { 146 cmpxchgptr(disp_hdr, hdr, obj, rscratch2, done, &slow_case); 147 } 148 // done 149 bind(done); 150 } 151 152 153 // Defines obj, preserves var_size_in_bytes 154 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) { 155 if (UseTLAB) { 156 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case); 157 } else { 158 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case); 159 } 160 } 161 162 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) { 163 assert_different_registers(obj, klass, len); 164 ldr(t1, Address(klass, Klass::prototype_header_offset())); 165 str(t1, Address(obj, oopDesc::mark_offset_in_bytes())); 166 167 if (len->is_valid()) { 168 strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes())); 169 } 170 } 171 172 // preserves obj, destroys len_in_bytes 173 // 174 // Scratch registers: t1 = r10, t2 = r11 175 // 176 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1, Register t2) { 177 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0"); 178 assert(t1 == r10 && t2 == r11, "must be"); 179 180 Label done; 181 182 // len_in_bytes is positive and ptr sized 183 subs(len_in_bytes, len_in_bytes, hdr_size_in_bytes); 184 br(Assembler::EQ, done); 185 186 // Zero first 4 bytes, if start offset is not word aligned. 187 if (!is_aligned(hdr_size_in_bytes, BytesPerWord)) { 188 strw(zr, Address(obj, hdr_size_in_bytes)); 189 hdr_size_in_bytes += BytesPerInt; 190 } 191 192 // zero_words() takes ptr in r10 and count in words in r11 193 mov(rscratch1, len_in_bytes); 194 lea(t1, Address(obj, hdr_size_in_bytes)); 195 lsr(t2, rscratch1, LogBytesPerWord); 196 zero_words(t1, t2); 197 198 bind(done); 199 } 200 201 202 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) { 203 assert_different_registers(obj, t1, t2); // XXX really? 204 assert(header_size >= 0 && object_size >= header_size, "illegal sizes"); 205 206 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case); 207 208 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB); 209 } 210 211 // Scratch registers: t1 = r10, t2 = r11 212 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) { 213 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, 214 "con_size_in_bytes is not multiple of alignment"); 215 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize; 216 217 initialize_header(obj, klass, noreg, t1, t2); 218 219 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) { 220 // clear rest of allocated space 221 const Register index = t2; 222 if (var_size_in_bytes != noreg) { 223 mov(index, var_size_in_bytes); 224 initialize_body(obj, index, hdr_size_in_bytes, t1, t2); 225 } else if (con_size_in_bytes > hdr_size_in_bytes) { 226 con_size_in_bytes -= hdr_size_in_bytes; 227 lea(t1, Address(obj, hdr_size_in_bytes)); 228 zero_words(t1, con_size_in_bytes / BytesPerWord); 229 } 230 } 231 232 membar(StoreStore); 233 234 if (CURRENT_ENV->dtrace_alloc_probes()) { 235 assert(obj == r0, "must be"); 236 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 237 } 238 239 verify_oop(obj); 240 } 241 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, int f, Register klass, Label& slow_case) { 242 assert_different_registers(obj, len, t1, t2, klass); 243 244 // determine alignment mask 245 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work"); 246 247 // check for negative or excessive length 248 mov(rscratch1, (int32_t)max_array_allocation_length); 249 cmp(len, rscratch1); 250 br(Assembler::HS, slow_case); 251 252 const Register arr_size = t2; // okay to be the same 253 // align object end 254 mov(arr_size, (int32_t)base_offset_in_bytes + MinObjAlignmentInBytesMask); 255 add(arr_size, arr_size, len, ext::uxtw, f); 256 andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask); 257 258 try_allocate(obj, arr_size, 0, t1, t2, slow_case); 259 260 initialize_header(obj, klass, len, t1, t2); 261 262 // clear rest of allocated space 263 initialize_body(obj, arr_size, base_offset_in_bytes, t1, t2); 264 265 membar(StoreStore); 266 267 if (CURRENT_ENV->dtrace_alloc_probes()) { 268 assert(obj == r0, "must be"); 269 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id))); 270 } 271 272 verify_oop(obj); 273 } 274 275 276 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) { 277 verify_oop(receiver); 278 // explicit NULL check not needed since load from [klass_offset] causes a trap 279 // check against inline cache 280 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::mark_offset_in_bytes()), "must add explicit null check"); 281 282 cmp_klass(receiver, iCache, rscratch1); 283 } 284 285 286 void C1_MacroAssembler::build_frame(int framesize, int bang_size_in_bytes) { 287 assert(bang_size_in_bytes >= framesize, "stack bang size incorrect"); 288 // Make sure there is enough stack space for this method's activation. 289 // Note that we do this before creating a frame. 290 generate_stack_overflow_check(bang_size_in_bytes); 291 MacroAssembler::build_frame(framesize); 292 293 // Insert nmethod entry barrier into frame. 294 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 295 bs->nmethod_entry_barrier(this); 296 } 297 298 void C1_MacroAssembler::remove_frame(int framesize) { 299 MacroAssembler::remove_frame(framesize); 300 } 301 302 303 void C1_MacroAssembler::verified_entry(bool breakAtEntry) { 304 // If we have to make this method not-entrant we'll overwrite its 305 // first instruction with a jump. For this action to be legal we 306 // must ensure that this first instruction is a B, BL, NOP, BKPT, 307 // SVC, HVC, or SMC. Make it a NOP. 308 nop(); 309 } 310 311 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) { 312 // rbp, + 0: link 313 // + 1: return address 314 // + 2: argument with offset 0 315 // + 3: argument with offset 1 316 // + 4: ... 317 318 ldr(reg, Address(rfp, (offset_in_words + 2) * BytesPerWord)); 319 } 320 321 #ifndef PRODUCT 322 323 void C1_MacroAssembler::verify_stack_oop(int stack_offset) { 324 if (!VerifyOops) return; 325 verify_oop_addr(Address(sp, stack_offset)); 326 } 327 328 void C1_MacroAssembler::verify_not_null_oop(Register r) { 329 if (!VerifyOops) return; 330 Label not_null; 331 cbnz(r, not_null); 332 stop("non-null oop required"); 333 bind(not_null); 334 verify_oop(r); 335 } 336 337 void C1_MacroAssembler::invalidate_registers(bool inv_r0, bool inv_r19, bool inv_r2, bool inv_r3, bool inv_r4, bool inv_r5) { 338 #ifdef ASSERT 339 static int nn; 340 if (inv_r0) mov(r0, 0xDEAD); 341 if (inv_r19) mov(r19, 0xDEAD); 342 if (inv_r2) mov(r2, nn++); 343 if (inv_r3) mov(r3, 0xDEAD); 344 if (inv_r4) mov(r4, 0xDEAD); 345 if (inv_r5) mov(r5, 0xDEAD); 346 #endif 347 } 348 #endif // ifndef PRODUCT