src/cpu/x86/vm/c1_MacroAssembler_x86.cpp

Mon, 10 Jan 2011 18:46:29 -0800

author
iveresov
date
Mon, 10 Jan 2011 18:46:29 -0800
changeset 2438
dd031b2226de
parent 2344
ac637b7220d1
child 2423
b1a2afa37ec4
permissions
-rw-r--r--

4930919: race condition in MDO creation at back branch locations
Summary: Reuse set_method_data_for_bcp() to setup mdp after MDO creation.
Reviewed-by: kvn, never

duke@435 1 /*
trims@1907 2 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "c1/c1_MacroAssembler.hpp"
stefank@2314 27 #include "c1/c1_Runtime1.hpp"
stefank@2314 28 #include "classfile/systemDictionary.hpp"
stefank@2314 29 #include "gc_interface/collectedHeap.hpp"
stefank@2314 30 #include "interpreter/interpreter.hpp"
stefank@2314 31 #include "oops/arrayOop.hpp"
stefank@2314 32 #include "oops/markOop.hpp"
stefank@2314 33 #include "runtime/basicLock.hpp"
stefank@2314 34 #include "runtime/biasedLocking.hpp"
stefank@2314 35 #include "runtime/os.hpp"
stefank@2314 36 #include "runtime/stubRoutines.hpp"
duke@435 37
duke@435 38 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case) {
never@739 39 const int aligned_mask = BytesPerWord -1;
duke@435 40 const int hdr_offset = oopDesc::mark_offset_in_bytes();
duke@435 41 assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
duke@435 42 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
duke@435 43 Label done;
duke@435 44 int null_check_offset = -1;
duke@435 45
duke@435 46 verify_oop(obj);
duke@435 47
duke@435 48 // save object being locked into the BasicObjectLock
never@739 49 movptr(Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()), obj);
duke@435 50
duke@435 51 if (UseBiasedLocking) {
duke@435 52 assert(scratch != noreg, "should have scratch register at this point");
duke@435 53 null_check_offset = biased_locking_enter(disp_hdr, obj, hdr, scratch, false, done, &slow_case);
duke@435 54 } else {
duke@435 55 null_check_offset = offset();
duke@435 56 }
duke@435 57
duke@435 58 // Load object header
never@739 59 movptr(hdr, Address(obj, hdr_offset));
duke@435 60 // and mark it as unlocked
never@739 61 orptr(hdr, markOopDesc::unlocked_value);
duke@435 62 // save unlocked object header into the displaced header location on the stack
never@739 63 movptr(Address(disp_hdr, 0), hdr);
duke@435 64 // test if object header is still the same (i.e. unlocked), and if so, store the
duke@435 65 // displaced header address in the object header - if it is not the same, get the
duke@435 66 // object header instead
duke@435 67 if (os::is_MP()) MacroAssembler::lock(); // must be immediately before cmpxchg!
never@739 68 cmpxchgptr(disp_hdr, Address(obj, hdr_offset));
duke@435 69 // if the object header was the same, we're done
duke@435 70 if (PrintBiasedLockingStatistics) {
duke@435 71 cond_inc32(Assembler::equal,
duke@435 72 ExternalAddress((address)BiasedLocking::fast_path_entry_count_addr()));
duke@435 73 }
duke@435 74 jcc(Assembler::equal, done);
duke@435 75 // if the object header was not the same, it is now in the hdr register
duke@435 76 // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
duke@435 77 //
duke@435 78 // 1) (hdr & aligned_mask) == 0
duke@435 79 // 2) rsp <= hdr
duke@435 80 // 3) hdr <= rsp + page_size
duke@435 81 //
duke@435 82 // these 3 tests can be done by evaluating the following expression:
duke@435 83 //
duke@435 84 // (hdr - rsp) & (aligned_mask - page_size)
duke@435 85 //
duke@435 86 // assuming both the stack pointer and page_size have their least
duke@435 87 // significant 2 bits cleared and page_size is a power of 2
never@739 88 subptr(hdr, rsp);
never@739 89 andptr(hdr, aligned_mask - os::vm_page_size());
duke@435 90 // for recursive locking, the result is zero => save it in the displaced header
duke@435 91 // location (NULL in the displaced hdr location indicates recursive locking)
never@739 92 movptr(Address(disp_hdr, 0), hdr);
duke@435 93 // otherwise we don't care about the result and handle locking via runtime call
duke@435 94 jcc(Assembler::notZero, slow_case);
duke@435 95 // done
duke@435 96 bind(done);
duke@435 97 return null_check_offset;
duke@435 98 }
duke@435 99
duke@435 100
duke@435 101 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
never@739 102 const int aligned_mask = BytesPerWord -1;
duke@435 103 const int hdr_offset = oopDesc::mark_offset_in_bytes();
duke@435 104 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
duke@435 105 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
duke@435 106 Label done;
duke@435 107
duke@435 108 if (UseBiasedLocking) {
duke@435 109 // load object
never@739 110 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
duke@435 111 biased_locking_exit(obj, hdr, done);
duke@435 112 }
duke@435 113
duke@435 114 // load displaced header
never@739 115 movptr(hdr, Address(disp_hdr, 0));
duke@435 116 // if the loaded hdr is NULL we had recursive locking
never@739 117 testptr(hdr, hdr);
duke@435 118 // if we had recursive locking, we are done
duke@435 119 jcc(Assembler::zero, done);
duke@435 120 if (!UseBiasedLocking) {
duke@435 121 // load object
never@739 122 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
duke@435 123 }
duke@435 124 verify_oop(obj);
duke@435 125 // test if object header is pointing to the displaced header, and if so, restore
duke@435 126 // the displaced header in the object - if the object header is not pointing to
duke@435 127 // the displaced header, get the object header instead
duke@435 128 if (os::is_MP()) MacroAssembler::lock(); // must be immediately before cmpxchg!
never@739 129 cmpxchgptr(hdr, Address(obj, hdr_offset));
duke@435 130 // if the object header was not pointing to the displaced header,
duke@435 131 // we do unlocking via runtime call
duke@435 132 jcc(Assembler::notEqual, slow_case);
duke@435 133 // done
duke@435 134 bind(done);
duke@435 135 }
duke@435 136
duke@435 137
duke@435 138 // Defines obj, preserves var_size_in_bytes
duke@435 139 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
duke@435 140 if (UseTLAB) {
duke@435 141 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
duke@435 142 } else {
duke@435 143 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
duke@435 144 }
duke@435 145 }
duke@435 146
duke@435 147
duke@435 148 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
duke@435 149 assert_different_registers(obj, klass, len);
duke@435 150 if (UseBiasedLocking && !len->is_valid()) {
duke@435 151 assert_different_registers(obj, klass, len, t1, t2);
never@739 152 movptr(t1, Address(klass, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
never@739 153 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
duke@435 154 } else {
never@739 155 // This assumes that all prototype bits fit in an int32_t
never@739 156 movptr(Address(obj, oopDesc::mark_offset_in_bytes ()), (int32_t)(intptr_t)markOopDesc::prototype());
duke@435 157 }
iveresov@2344 158 #ifdef _LP64
iveresov@2344 159 if (UseCompressedOops) { // Take care not to kill klass
iveresov@2344 160 movptr(t1, klass);
iveresov@2344 161 encode_heap_oop_not_null(t1);
iveresov@2344 162 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
iveresov@2344 163 } else
iveresov@2344 164 #endif
iveresov@2344 165 {
iveresov@2344 166 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
iveresov@2344 167 }
duke@435 168
duke@435 169 if (len->is_valid()) {
duke@435 170 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
duke@435 171 }
iveresov@2344 172 #ifdef _LP64
iveresov@2344 173 else if (UseCompressedOops) {
iveresov@2344 174 xorptr(t1, t1);
iveresov@2344 175 store_klass_gap(obj, t1);
iveresov@2344 176 }
iveresov@2344 177 #endif
duke@435 178 }
duke@435 179
duke@435 180
duke@435 181 // preserves obj, destroys len_in_bytes
duke@435 182 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
duke@435 183 Label done;
duke@435 184 assert(obj != len_in_bytes && obj != t1 && t1 != len_in_bytes, "registers must be different");
duke@435 185 assert((hdr_size_in_bytes & (BytesPerWord - 1)) == 0, "header size is not a multiple of BytesPerWord");
duke@435 186 Register index = len_in_bytes;
never@739 187 // index is positive and ptr sized
never@739 188 subptr(index, hdr_size_in_bytes);
duke@435 189 jcc(Assembler::zero, done);
duke@435 190 // initialize topmost word, divide index by 2, check if odd and test if zero
duke@435 191 // note: for the remaining code to work, index must be a multiple of BytesPerWord
duke@435 192 #ifdef ASSERT
duke@435 193 { Label L;
never@739 194 testptr(index, BytesPerWord - 1);
duke@435 195 jcc(Assembler::zero, L);
duke@435 196 stop("index is not a multiple of BytesPerWord");
duke@435 197 bind(L);
duke@435 198 }
duke@435 199 #endif
never@739 200 xorptr(t1, t1); // use _zero reg to clear memory (shorter code)
duke@435 201 if (UseIncDec) {
never@739 202 shrptr(index, 3); // divide by 8/16 and set carry flag if bit 2 was set
duke@435 203 } else {
never@739 204 shrptr(index, 2); // use 2 instructions to avoid partial flag stall
never@739 205 shrptr(index, 1);
duke@435 206 }
never@739 207 #ifndef _LP64
duke@435 208 // index could have been not a multiple of 8 (i.e., bit 2 was set)
duke@435 209 { Label even;
duke@435 210 // note: if index was a multiple of 8, than it cannot
duke@435 211 // be 0 now otherwise it must have been 0 before
duke@435 212 // => if it is even, we don't need to check for 0 again
duke@435 213 jcc(Assembler::carryClear, even);
duke@435 214 // clear topmost word (no jump needed if conditional assignment would work here)
never@739 215 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - 0*BytesPerWord), t1);
duke@435 216 // index could be 0 now, need to check again
duke@435 217 jcc(Assembler::zero, done);
duke@435 218 bind(even);
duke@435 219 }
never@739 220 #endif // !_LP64
duke@435 221 // initialize remaining object fields: rdx is a multiple of 2 now
duke@435 222 { Label loop;
duke@435 223 bind(loop);
never@739 224 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - 1*BytesPerWord), t1);
never@739 225 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - 2*BytesPerWord), t1);)
duke@435 226 decrement(index);
duke@435 227 jcc(Assembler::notZero, loop);
duke@435 228 }
duke@435 229
duke@435 230 // done
duke@435 231 bind(done);
duke@435 232 }
duke@435 233
duke@435 234
duke@435 235 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
duke@435 236 assert(obj == rax, "obj must be in rax, for cmpxchg");
duke@435 237 assert(obj != t1 && obj != t2 && t1 != t2, "registers must be different"); // XXX really?
duke@435 238 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
duke@435 239
duke@435 240 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
duke@435 241
duke@435 242 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2);
duke@435 243 }
duke@435 244
duke@435 245 void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2) {
duke@435 246 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
duke@435 247 "con_size_in_bytes is not multiple of alignment");
iveresov@2344 248 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
duke@435 249
duke@435 250 initialize_header(obj, klass, noreg, t1, t2);
duke@435 251
duke@435 252 // clear rest of allocated space
duke@435 253 const Register t1_zero = t1;
duke@435 254 const Register index = t2;
duke@435 255 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
duke@435 256 if (var_size_in_bytes != noreg) {
never@739 257 mov(index, var_size_in_bytes);
duke@435 258 initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
duke@435 259 } else if (con_size_in_bytes <= threshold) {
duke@435 260 // use explicit null stores
duke@435 261 // code size = 2 + 3*n bytes (n = number of fields to clear)
never@739 262 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
duke@435 263 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
never@739 264 movptr(Address(obj, i), t1_zero);
duke@435 265 } else if (con_size_in_bytes > hdr_size_in_bytes) {
duke@435 266 // use loop to null out the fields
duke@435 267 // code size = 16 bytes for even n (n = number of fields to clear)
duke@435 268 // initialize last object field first if odd number of fields
never@739 269 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
never@739 270 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
duke@435 271 // initialize last object field if constant size is odd
duke@435 272 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
never@739 273 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
duke@435 274 // initialize remaining object fields: rdx is a multiple of 2
duke@435 275 { Label loop;
duke@435 276 bind(loop);
never@739 277 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)),
never@739 278 t1_zero);
never@739 279 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)),
never@739 280 t1_zero);)
duke@435 281 decrement(index);
duke@435 282 jcc(Assembler::notZero, loop);
duke@435 283 }
duke@435 284 }
duke@435 285
kvn@1215 286 if (CURRENT_ENV->dtrace_alloc_probes()) {
duke@435 287 assert(obj == rax, "must be");
duke@435 288 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
duke@435 289 }
duke@435 290
duke@435 291 verify_oop(obj);
duke@435 292 }
duke@435 293
duke@435 294 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) {
duke@435 295 assert(obj == rax, "obj must be in rax, for cmpxchg");
duke@435 296 assert_different_registers(obj, len, t1, t2, klass);
duke@435 297
duke@435 298 // determine alignment mask
never@739 299 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
duke@435 300
duke@435 301 // check for negative or excessive length
never@739 302 cmpptr(len, (int32_t)max_array_allocation_length);
duke@435 303 jcc(Assembler::above, slow_case);
duke@435 304
duke@435 305 const Register arr_size = t2; // okay to be the same
duke@435 306 // align object end
never@739 307 movptr(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask);
never@739 308 lea(arr_size, Address(arr_size, len, f));
never@739 309 andptr(arr_size, ~MinObjAlignmentInBytesMask);
duke@435 310
duke@435 311 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
duke@435 312
duke@435 313 initialize_header(obj, klass, len, t1, t2);
duke@435 314
duke@435 315 // clear rest of allocated space
duke@435 316 const Register len_zero = len;
duke@435 317 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero);
duke@435 318
kvn@1215 319 if (CURRENT_ENV->dtrace_alloc_probes()) {
duke@435 320 assert(obj == rax, "must be");
duke@435 321 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
duke@435 322 }
duke@435 323
duke@435 324 verify_oop(obj);
duke@435 325 }
duke@435 326
duke@435 327
duke@435 328
duke@435 329 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
duke@435 330 verify_oop(receiver);
duke@435 331 // explicit NULL check not needed since load from [klass_offset] causes a trap
duke@435 332 // check against inline cache
duke@435 333 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
duke@435 334 int start_offset = offset();
iveresov@2344 335
iveresov@2344 336 if (UseCompressedOops) {
iveresov@2344 337 load_klass(rscratch1, receiver);
iveresov@2344 338 cmpptr(rscratch1, iCache);
iveresov@2344 339 } else {
iveresov@2344 340 cmpptr(iCache, Address(receiver, oopDesc::klass_offset_in_bytes()));
iveresov@2344 341 }
duke@435 342 // if icache check fails, then jump to runtime routine
duke@435 343 // Note: RECEIVER must still contain the receiver!
duke@435 344 jump_cc(Assembler::notEqual,
duke@435 345 RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
never@739 346 const int ic_cmp_size = LP64_ONLY(10) NOT_LP64(9);
iveresov@2344 347 assert(UseCompressedOops || offset() - start_offset == ic_cmp_size, "check alignment in emit_method_entry");
duke@435 348 }
duke@435 349
duke@435 350
duke@435 351 void C1_MacroAssembler::build_frame(int frame_size_in_bytes) {
duke@435 352 // Make sure there is enough stack space for this method's activation.
duke@435 353 // Note that we do this before doing an enter(). This matches the
duke@435 354 // ordering of C2's stack overflow check / rsp decrement and allows
duke@435 355 // the SharedRuntime stack overflow handling to be consistent
duke@435 356 // between the two compilers.
duke@435 357 generate_stack_overflow_check(frame_size_in_bytes);
duke@435 358
twisti@1730 359 push(rbp);
duke@435 360 #ifdef TIERED
duke@435 361 // c2 leaves fpu stack dirty. Clean it on entry
duke@435 362 if (UseSSE < 2 ) {
duke@435 363 empty_FPU_stack();
duke@435 364 }
duke@435 365 #endif // TIERED
duke@435 366 decrement(rsp, frame_size_in_bytes); // does not emit code for frame_size == 0
duke@435 367 }
duke@435 368
duke@435 369
twisti@1730 370 void C1_MacroAssembler::remove_frame(int frame_size_in_bytes) {
twisti@1730 371 increment(rsp, frame_size_in_bytes); // Does not emit code for frame_size == 0
twisti@1730 372 pop(rbp);
twisti@1730 373 }
twisti@1730 374
twisti@1730 375
duke@435 376 void C1_MacroAssembler::unverified_entry(Register receiver, Register ic_klass) {
duke@435 377 if (C1Breakpoint) int3();
duke@435 378 inline_cache_check(receiver, ic_klass);
duke@435 379 }
duke@435 380
duke@435 381
duke@435 382 void C1_MacroAssembler::verified_entry() {
duke@435 383 if (C1Breakpoint)int3();
duke@435 384 // build frame
duke@435 385 verify_FPU(0, "method_entry");
duke@435 386 }
duke@435 387
duke@435 388
duke@435 389 #ifndef PRODUCT
duke@435 390
duke@435 391 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
duke@435 392 if (!VerifyOops) return;
duke@435 393 verify_oop_addr(Address(rsp, stack_offset));
duke@435 394 }
duke@435 395
duke@435 396 void C1_MacroAssembler::verify_not_null_oop(Register r) {
duke@435 397 if (!VerifyOops) return;
duke@435 398 Label not_null;
never@739 399 testptr(r, r);
duke@435 400 jcc(Assembler::notZero, not_null);
duke@435 401 stop("non-null oop required");
duke@435 402 bind(not_null);
duke@435 403 verify_oop(r);
duke@435 404 }
duke@435 405
duke@435 406 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
duke@435 407 #ifdef ASSERT
never@739 408 if (inv_rax) movptr(rax, 0xDEAD);
never@739 409 if (inv_rbx) movptr(rbx, 0xDEAD);
never@739 410 if (inv_rcx) movptr(rcx, 0xDEAD);
never@739 411 if (inv_rdx) movptr(rdx, 0xDEAD);
never@739 412 if (inv_rsi) movptr(rsi, 0xDEAD);
never@739 413 if (inv_rdi) movptr(rdi, 0xDEAD);
duke@435 414 #endif
duke@435 415 }
duke@435 416
duke@435 417 #endif // ifndef PRODUCT

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