1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #ifdef WITH_JIT 17 18 /* 19 * Target independent portion of Android's Jit 20 */ 21 22 #include "Dalvik.h" 23 #include "Jit.h" 24 25 #include "libdex/DexOpcodes.h" 26 #include <unistd.h> 27 #include <pthread.h> 28 #include <sys/time.h> 29 #include <signal.h> 30 #include "compiler/Compiler.h" 31 #include "compiler/CompilerUtility.h" 32 #include "compiler/CompilerIR.h" 33 #include <errno.h> 34 35 #if defined(WITH_SELF_VERIFICATION) 36 /* Allocate space for per-thread ShadowSpace data structures */ 37 void* dvmSelfVerificationShadowSpaceAlloc(Thread* self) 38 { 39 self->shadowSpace = (ShadowSpace*) calloc(1, sizeof(ShadowSpace)); 40 if (self->shadowSpace == NULL) 41 return NULL; 42 43 self->shadowSpace->registerSpaceSize = REG_SPACE; 44 self->shadowSpace->registerSpace = 45 (int*) calloc(self->shadowSpace->registerSpaceSize, sizeof(int)); 46 47 return self->shadowSpace->registerSpace; 48 } 49 50 /* Free per-thread ShadowSpace data structures */ 51 void dvmSelfVerificationShadowSpaceFree(Thread* self) 52 { 53 free(self->shadowSpace->registerSpace); 54 free(self->shadowSpace); 55 } 56 57 /* 58 * Save out PC, FP, thread state, and registers to shadow space. 59 * Return a pointer to the shadow space for JIT to use. 60 * 61 * The set of saved state from the Thread structure is: 62 * pc (Dalvik PC) 63 * fp (Dalvik FP) 64 * retval 65 * method 66 * methodClassDex 67 * interpStackEnd 68 */ 69 void* dvmSelfVerificationSaveState(const u2* pc, u4* fp, 70 Thread* self, int targetTrace) 71 { 72 ShadowSpace *shadowSpace = self->shadowSpace; 73 unsigned preBytes = self->interpSave.method->outsSize*4 + 74 sizeof(StackSaveArea); 75 unsigned postBytes = self->interpSave.method->registersSize*4; 76 77 //ALOGD("### selfVerificationSaveState(%d) pc: %#x fp: %#x", 78 // self->threadId, (int)pc, (int)fp); 79 80 if (shadowSpace->selfVerificationState != kSVSIdle) { 81 ALOGD("~~~ Save: INCORRECT PREVIOUS STATE(%d): %d", 82 self->threadId, shadowSpace->selfVerificationState); 83 ALOGD("********** SHADOW STATE DUMP **********"); 84 ALOGD("PC: %#x FP: %#x", (int)pc, (int)fp); 85 } 86 shadowSpace->selfVerificationState = kSVSStart; 87 88 // Dynamically grow shadow register space if necessary 89 if (preBytes + postBytes > shadowSpace->registerSpaceSize * sizeof(u4)) { 90 free(shadowSpace->registerSpace); 91 shadowSpace->registerSpaceSize = (preBytes + postBytes) / sizeof(u4); 92 shadowSpace->registerSpace = 93 (int*) calloc(shadowSpace->registerSpaceSize, sizeof(u4)); 94 } 95 96 // Remember original state 97 shadowSpace->startPC = pc; 98 shadowSpace->fp = fp; 99 shadowSpace->retval = self->interpSave.retval; 100 shadowSpace->interpStackEnd = self->interpStackEnd; 101 102 /* 103 * Store the original method here in case the trace ends with a 104 * return/invoke, the last method. 105 */ 106 shadowSpace->method = self->interpSave.method; 107 shadowSpace->methodClassDex = self->interpSave.methodClassDex; 108 109 shadowSpace->shadowFP = shadowSpace->registerSpace + 110 shadowSpace->registerSpaceSize - postBytes/4; 111 112 self->interpSave.curFrame = (u4*)shadowSpace->shadowFP; 113 self->interpStackEnd = (u1*)shadowSpace->registerSpace; 114 115 // Create a copy of the stack 116 memcpy(((char*)shadowSpace->shadowFP)-preBytes, ((char*)fp)-preBytes, 117 preBytes+postBytes); 118 119 // Setup the shadowed heap space 120 shadowSpace->heapSpaceTail = shadowSpace->heapSpace; 121 122 // Reset trace length 123 shadowSpace->traceLength = 0; 124 125 return shadowSpace; 126 } 127 128 /* 129 * Save ending PC, FP and compiled code exit point to shadow space. 130 * Return a pointer to the shadow space for JIT to restore state. 131 */ 132 void* dvmSelfVerificationRestoreState(const u2* pc, u4* fp, 133 SelfVerificationState exitState, 134 Thread* self) 135 { 136 ShadowSpace *shadowSpace = self->shadowSpace; 137 shadowSpace->endPC = pc; 138 shadowSpace->endShadowFP = fp; 139 shadowSpace->jitExitState = exitState; 140 141 //ALOGD("### selfVerificationRestoreState(%d) pc: %#x fp: %#x endPC: %#x", 142 // self->threadId, (int)shadowSpace->startPC, (int)shadowSpace->fp, 143 // (int)pc); 144 145 if (shadowSpace->selfVerificationState != kSVSStart) { 146 ALOGD("~~~ Restore: INCORRECT PREVIOUS STATE(%d): %d", 147 self->threadId, shadowSpace->selfVerificationState); 148 ALOGD("********** SHADOW STATE DUMP **********"); 149 ALOGD("Dalvik PC: %#x endPC: %#x", (int)shadowSpace->startPC, 150 (int)shadowSpace->endPC); 151 ALOGD("Interp FP: %#x", (int)shadowSpace->fp); 152 ALOGD("Shadow FP: %#x endFP: %#x", (int)shadowSpace->shadowFP, 153 (int)shadowSpace->endShadowFP); 154 } 155 156 // Special case when punting after a single instruction 157 if (exitState == kSVSPunt && pc == shadowSpace->startPC) { 158 shadowSpace->selfVerificationState = kSVSIdle; 159 } else { 160 shadowSpace->selfVerificationState = exitState; 161 } 162 163 /* Restore state before returning */ 164 self->interpSave.pc = shadowSpace->startPC; 165 self->interpSave.curFrame = shadowSpace->fp; 166 self->interpSave.method = shadowSpace->method; 167 self->interpSave.methodClassDex = shadowSpace->methodClassDex; 168 self->interpSave.retval = shadowSpace->retval; 169 self->interpStackEnd = shadowSpace->interpStackEnd; 170 171 return shadowSpace; 172 } 173 174 /* Print contents of virtual registers */ 175 static void selfVerificationPrintRegisters(int* addr, int* addrRef, 176 int numWords) 177 { 178 int i; 179 for (i = 0; i < numWords; i++) { 180 ALOGD("(v%d) 0x%8x%s", i, addr[i], addr[i] != addrRef[i] ? " X" : ""); 181 } 182 } 183 184 /* Print values maintained in shadowSpace */ 185 static void selfVerificationDumpState(const u2* pc, Thread* self) 186 { 187 ShadowSpace* shadowSpace = self->shadowSpace; 188 StackSaveArea* stackSave = SAVEAREA_FROM_FP(self->interpSave.curFrame); 189 int frameBytes = (int) shadowSpace->registerSpace + 190 shadowSpace->registerSpaceSize*4 - 191 (int) shadowSpace->shadowFP; 192 int localRegs = 0; 193 int frameBytes2 = 0; 194 if ((uintptr_t)self->interpSave.curFrame < (uintptr_t)shadowSpace->fp) { 195 localRegs = (stackSave->method->registersSize - 196 stackSave->method->insSize)*4; 197 frameBytes2 = (int) shadowSpace->fp - 198 (int)self->interpSave.curFrame - localRegs; 199 } 200 ALOGD("********** SHADOW STATE DUMP **********"); 201 ALOGD("CurrentPC: %#x, Offset: 0x%04x", (int)pc, 202 (int)(pc - stackSave->method->insns)); 203 ALOGD("Class: %s", shadowSpace->method->clazz->descriptor); 204 ALOGD("Method: %s", shadowSpace->method->name); 205 ALOGD("Dalvik PC: %#x endPC: %#x", (int)shadowSpace->startPC, 206 (int)shadowSpace->endPC); 207 ALOGD("Interp FP: %#x endFP: %#x", (int)shadowSpace->fp, 208 (int)self->interpSave.curFrame); 209 ALOGD("Shadow FP: %#x endFP: %#x", (int)shadowSpace->shadowFP, 210 (int)shadowSpace->endShadowFP); 211 ALOGD("Frame1 Bytes: %d Frame2 Local: %d Bytes: %d", frameBytes, 212 localRegs, frameBytes2); 213 ALOGD("Trace length: %d State: %d", shadowSpace->traceLength, 214 shadowSpace->selfVerificationState); 215 } 216 217 /* Print decoded instructions in the current trace */ 218 static void selfVerificationDumpTrace(const u2* pc, Thread* self) 219 { 220 ShadowSpace* shadowSpace = self->shadowSpace; 221 StackSaveArea* stackSave = SAVEAREA_FROM_FP(self->interpSave.curFrame); 222 int i, addr, offset; 223 DecodedInstruction *decInsn; 224 225 ALOGD("********** SHADOW TRACE DUMP **********"); 226 for (i = 0; i < shadowSpace->traceLength; i++) { 227 addr = shadowSpace->trace[i].addr; 228 offset = (int)((u2*)addr - stackSave->method->insns); 229 decInsn = &(shadowSpace->trace[i].decInsn); 230 /* Not properly decoding instruction, some registers may be garbage */ 231 ALOGD("%#x: (0x%04x) %s", 232 addr, offset, dexGetOpcodeName(decInsn->opcode)); 233 } 234 } 235 236 /* Code is forced into this spin loop when a divergence is detected */ 237 static void selfVerificationSpinLoop(ShadowSpace *shadowSpace) 238 { 239 const u2 *startPC = shadowSpace->startPC; 240 JitTraceDescription* desc = dvmCopyTraceDescriptor(startPC, NULL); 241 if (desc) { 242 dvmCompilerWorkEnqueue(startPC, kWorkOrderTraceDebug, desc); 243 /* 244 * This function effectively terminates the VM right here, so not 245 * freeing the desc pointer when the enqueuing fails is acceptable. 246 */ 247 } 248 gDvmJit.selfVerificationSpin = true; 249 while(gDvmJit.selfVerificationSpin) sleep(10); 250 } 251 252 /* 253 * If here, we're re-interpreting an instruction that was included 254 * in a trace that was just executed. This routine is called for 255 * each instruction in the original trace, and compares state 256 * when it reaches the end point. 257 * 258 * TUNING: the interpretation mechanism now supports a counted 259 * single-step mechanism. If we were to associate an instruction 260 * count with each trace exit, we could just single-step the right 261 * number of cycles and then compare. This would improve detection 262 * of control divergences, as well as (slightly) simplify this code. 263 */ 264 void dvmCheckSelfVerification(const u2* pc, Thread* self) 265 { 266 ShadowSpace *shadowSpace = self->shadowSpace; 267 SelfVerificationState state = shadowSpace->selfVerificationState; 268 269 DecodedInstruction decInsn; 270 dexDecodeInstruction(pc, &decInsn); 271 272 //ALOGD("### DbgIntp(%d): PC: %#x endPC: %#x state: %d len: %d %s", 273 // self->threadId, (int)pc, (int)shadowSpace->endPC, state, 274 // shadowSpace->traceLength, dexGetOpcodeName(decInsn.opcode)); 275 276 if (state == kSVSIdle || state == kSVSStart) { 277 ALOGD("~~~ DbgIntrp: INCORRECT PREVIOUS STATE(%d): %d", 278 self->threadId, state); 279 selfVerificationDumpState(pc, self); 280 selfVerificationDumpTrace(pc, self); 281 } 282 283 /* 284 * Generalize the self verification state to kSVSDebugInterp unless the 285 * entry reason is kSVSBackwardBranch or kSVSSingleStep. 286 */ 287 if (state != kSVSBackwardBranch && state != kSVSSingleStep) { 288 shadowSpace->selfVerificationState = kSVSDebugInterp; 289 } 290 291 /* 292 * Check if the current pc matches the endPC. Only check for non-zero 293 * trace length when backward branches are involved. 294 */ 295 if (pc == shadowSpace->endPC && 296 (state == kSVSDebugInterp || state == kSVSSingleStep || 297 (state == kSVSBackwardBranch && shadowSpace->traceLength != 0))) { 298 299 shadowSpace->selfVerificationState = kSVSIdle; 300 301 /* Check register space */ 302 int frameBytes = (int) shadowSpace->registerSpace + 303 shadowSpace->registerSpaceSize*4 - 304 (int) shadowSpace->shadowFP; 305 if (memcmp(shadowSpace->fp, shadowSpace->shadowFP, frameBytes)) { 306 if (state == kSVSBackwardBranch) { 307 /* State mismatch on backward branch - try one more iteration */ 308 shadowSpace->selfVerificationState = kSVSDebugInterp; 309 goto log_and_continue; 310 } 311 ALOGD("~~~ DbgIntp(%d): REGISTERS DIVERGENCE!", self->threadId); 312 selfVerificationDumpState(pc, self); 313 selfVerificationDumpTrace(pc, self); 314 ALOGD("*** Interp Registers: addr: %#x bytes: %d", 315 (int)shadowSpace->fp, frameBytes); 316 selfVerificationPrintRegisters((int*)shadowSpace->fp, 317 (int*)shadowSpace->shadowFP, 318 frameBytes/4); 319 ALOGD("*** Shadow Registers: addr: %#x bytes: %d", 320 (int)shadowSpace->shadowFP, frameBytes); 321 selfVerificationPrintRegisters((int*)shadowSpace->shadowFP, 322 (int*)shadowSpace->fp, 323 frameBytes/4); 324 selfVerificationSpinLoop(shadowSpace); 325 } 326 /* Check new frame if it exists (invokes only) */ 327 if ((uintptr_t)self->interpSave.curFrame < (uintptr_t)shadowSpace->fp) { 328 StackSaveArea* stackSave = 329 SAVEAREA_FROM_FP(self->interpSave.curFrame); 330 int localRegs = (stackSave->method->registersSize - 331 stackSave->method->insSize)*4; 332 int frameBytes2 = (int) shadowSpace->fp - 333 (int) self->interpSave.curFrame - localRegs; 334 if (memcmp(((char*)self->interpSave.curFrame)+localRegs, 335 ((char*)shadowSpace->endShadowFP)+localRegs, frameBytes2)) { 336 if (state == kSVSBackwardBranch) { 337 /* 338 * State mismatch on backward branch - try one more 339 * iteration. 340 */ 341 shadowSpace->selfVerificationState = kSVSDebugInterp; 342 goto log_and_continue; 343 } 344 ALOGD("~~~ DbgIntp(%d): REGISTERS (FRAME2) DIVERGENCE!", 345 self->threadId); 346 selfVerificationDumpState(pc, self); 347 selfVerificationDumpTrace(pc, self); 348 ALOGD("*** Interp Registers: addr: %#x l: %d bytes: %d", 349 (int)self->interpSave.curFrame, localRegs, frameBytes2); 350 selfVerificationPrintRegisters((int*)self->interpSave.curFrame, 351 (int*)shadowSpace->endShadowFP, 352 (frameBytes2+localRegs)/4); 353 ALOGD("*** Shadow Registers: addr: %#x l: %d bytes: %d", 354 (int)shadowSpace->endShadowFP, localRegs, frameBytes2); 355 selfVerificationPrintRegisters((int*)shadowSpace->endShadowFP, 356 (int*)self->interpSave.curFrame, 357 (frameBytes2+localRegs)/4); 358 selfVerificationSpinLoop(shadowSpace); 359 } 360 } 361 362 /* Check memory space */ 363 bool memDiff = false; 364 ShadowHeap* heapSpacePtr; 365 for (heapSpacePtr = shadowSpace->heapSpace; 366 heapSpacePtr != shadowSpace->heapSpaceTail; heapSpacePtr++) { 367 int memData = *((unsigned int*) heapSpacePtr->addr); 368 if (heapSpacePtr->data != memData) { 369 if (state == kSVSBackwardBranch) { 370 /* 371 * State mismatch on backward branch - try one more 372 * iteration. 373 */ 374 shadowSpace->selfVerificationState = kSVSDebugInterp; 375 goto log_and_continue; 376 } 377 ALOGD("~~~ DbgIntp(%d): MEMORY DIVERGENCE!", self->threadId); 378 ALOGD("Addr: %#x Intrp Data: %#x Jit Data: %#x", 379 heapSpacePtr->addr, memData, heapSpacePtr->data); 380 selfVerificationDumpState(pc, self); 381 selfVerificationDumpTrace(pc, self); 382 memDiff = true; 383 } 384 } 385 if (memDiff) selfVerificationSpinLoop(shadowSpace); 386 387 388 /* 389 * Success. If this shadowed trace included a single-stepped 390 * instruction, we need to stay in the interpreter for one 391 * more interpretation before resuming. 392 */ 393 if (state == kSVSSingleStep) { 394 assert(self->jitResumeNPC != NULL); 395 assert(self->singleStepCount == 0); 396 self->singleStepCount = 1; 397 dvmEnableSubMode(self, kSubModeCountedStep); 398 } 399 400 /* 401 * Switch off shadow replay mode. The next shadowed trace 402 * execution will turn it back on. 403 */ 404 dvmDisableSubMode(self, kSubModeJitSV); 405 406 self->jitState = kJitDone; 407 return; 408 } 409 log_and_continue: 410 /* If end not been reached, make sure max length not exceeded */ 411 if (shadowSpace->traceLength >= JIT_MAX_TRACE_LEN) { 412 ALOGD("~~~ DbgIntp(%d): CONTROL DIVERGENCE!", self->threadId); 413 ALOGD("startPC: %#x endPC: %#x currPC: %#x", 414 (int)shadowSpace->startPC, (int)shadowSpace->endPC, (int)pc); 415 selfVerificationDumpState(pc, self); 416 selfVerificationDumpTrace(pc, self); 417 selfVerificationSpinLoop(shadowSpace); 418 return; 419 } 420 /* Log the instruction address and decoded instruction for debug */ 421 shadowSpace->trace[shadowSpace->traceLength].addr = (int)pc; 422 shadowSpace->trace[shadowSpace->traceLength].decInsn = decInsn; 423 shadowSpace->traceLength++; 424 } 425 #endif 426 427 /* 428 * If one of our fixed tables or the translation buffer fills up, 429 * call this routine to avoid wasting cycles on future translation requests. 430 */ 431 void dvmJitStopTranslationRequests() 432 { 433 /* 434 * Note 1: This won't necessarily stop all translation requests, and 435 * operates on a delayed mechanism. Running threads look to the copy 436 * of this value in their private thread structures and won't see 437 * this change until it is refreshed (which happens on interpreter 438 * entry). 439 * Note 2: This is a one-shot memory leak on this table. Because this is a 440 * permanent off switch for Jit profiling, it is a one-time leak of 1K 441 * bytes, and no further attempt will be made to re-allocate it. Can't 442 * free it because some thread may be holding a reference. 443 */ 444 gDvmJit.pProfTable = NULL; 445 dvmJitUpdateThreadStateAll(); 446 } 447 448 #if defined(WITH_JIT_TUNING) 449 /* Convenience function to increment counter from assembly code */ 450 void dvmBumpNoChain(int from) 451 { 452 gDvmJit.noChainExit[from]++; 453 } 454 455 /* Convenience function to increment counter from assembly code */ 456 void dvmBumpNormal() 457 { 458 gDvmJit.normalExit++; 459 } 460 461 /* Convenience function to increment counter from assembly code */ 462 void dvmBumpPunt(int from) 463 { 464 gDvmJit.puntExit++; 465 } 466 #endif 467 468 /* Dumps debugging & tuning stats to the log */ 469 void dvmJitStats() 470 { 471 int i; 472 int hit; 473 int not_hit; 474 int chains; 475 int stubs; 476 if (gDvmJit.pJitEntryTable) { 477 for (i=0, stubs=chains=hit=not_hit=0; 478 i < (int) gDvmJit.jitTableSize; 479 i++) { 480 if (gDvmJit.pJitEntryTable[i].dPC != 0) { 481 hit++; 482 if (gDvmJit.pJitEntryTable[i].codeAddress == 483 dvmCompilerGetInterpretTemplate()) 484 stubs++; 485 } else 486 not_hit++; 487 if (gDvmJit.pJitEntryTable[i].u.info.chain != gDvmJit.jitTableSize) 488 chains++; 489 } 490 ALOGD("JIT: table size is %d, entries used is %d", 491 gDvmJit.jitTableSize, gDvmJit.jitTableEntriesUsed); 492 ALOGD("JIT: %d traces, %d slots, %d chains, %d thresh, %s", 493 hit, not_hit + hit, chains, gDvmJit.threshold, 494 gDvmJit.blockingMode ? "Blocking" : "Non-blocking"); 495 496 #if defined(WITH_JIT_TUNING) 497 ALOGD("JIT: Code cache patches: %d", gDvmJit.codeCachePatches); 498 499 ALOGD("JIT: Lookups: %d hits, %d misses; %d normal, %d punt", 500 gDvmJit.addrLookupsFound, gDvmJit.addrLookupsNotFound, 501 gDvmJit.normalExit, gDvmJit.puntExit); 502 503 ALOGD("JIT: ICHits: %d", gDvmICHitCount); 504 505 ALOGD("JIT: noChainExit: %d IC miss, %d interp callsite, " 506 "%d switch overflow", 507 gDvmJit.noChainExit[kInlineCacheMiss], 508 gDvmJit.noChainExit[kCallsiteInterpreted], 509 gDvmJit.noChainExit[kSwitchOverflow]); 510 511 ALOGD("JIT: ICPatch: %d init, %d rejected, %d lock-free, %d queued, " 512 "%d dropped", 513 gDvmJit.icPatchInit, gDvmJit.icPatchRejected, 514 gDvmJit.icPatchLockFree, gDvmJit.icPatchQueued, 515 gDvmJit.icPatchDropped); 516 517 ALOGD("JIT: Invoke: %d mono, %d poly, %d native, %d return", 518 gDvmJit.invokeMonomorphic, gDvmJit.invokePolymorphic, 519 gDvmJit.invokeNative, gDvmJit.returnOp); 520 ALOGD("JIT: Inline: %d mgetter, %d msetter, %d pgetter, %d psetter", 521 gDvmJit.invokeMonoGetterInlined, gDvmJit.invokeMonoSetterInlined, 522 gDvmJit.invokePolyGetterInlined, gDvmJit.invokePolySetterInlined); 523 ALOGD("JIT: Total compilation time: %llu ms", gDvmJit.jitTime / 1000); 524 ALOGD("JIT: Avg unit compilation time: %llu us", 525 gDvmJit.numCompilations == 0 ? 0 : 526 gDvmJit.jitTime / gDvmJit.numCompilations); 527 ALOGD("JIT: Potential GC blocked by compiler: max %llu us / " 528 "avg %llu us (%d)", 529 gDvmJit.maxCompilerThreadBlockGCTime, 530 gDvmJit.numCompilerThreadBlockGC == 0 ? 531 0 : gDvmJit.compilerThreadBlockGCTime / 532 gDvmJit.numCompilerThreadBlockGC, 533 gDvmJit.numCompilerThreadBlockGC); 534 #endif 535 536 ALOGD("JIT: %d Translation chains, %d interp stubs", 537 gDvmJit.translationChains, stubs); 538 if (gDvmJit.profileMode == kTraceProfilingContinuous) { 539 dvmCompilerSortAndPrintTraceProfiles(); 540 } 541 } 542 } 543 544 545 /* End current trace now & don't include current instruction */ 546 void dvmJitEndTraceSelect(Thread* self, const u2* dPC) 547 { 548 if (self->jitState == kJitTSelect) { 549 self->jitState = kJitTSelectEnd; 550 } 551 if (self->jitState == kJitTSelectEnd) { 552 // Clean up and finish now. 553 dvmCheckJit(dPC, self); 554 } 555 } 556 557 /* 558 * Find an entry in the JitTable, creating if necessary. 559 * Returns null if table is full. 560 */ 561 static JitEntry *lookupAndAdd(const u2* dPC, bool callerLocked, 562 bool isMethodEntry) 563 { 564 u4 chainEndMarker = gDvmJit.jitTableSize; 565 u4 idx = dvmJitHash(dPC); 566 567 /* 568 * Walk the bucket chain to find an exact match for our PC and trace/method 569 * type 570 */ 571 while ((gDvmJit.pJitEntryTable[idx].u.info.chain != chainEndMarker) && 572 ((gDvmJit.pJitEntryTable[idx].dPC != dPC) || 573 (gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry != 574 isMethodEntry))) { 575 idx = gDvmJit.pJitEntryTable[idx].u.info.chain; 576 } 577 578 if (gDvmJit.pJitEntryTable[idx].dPC != dPC || 579 gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry != isMethodEntry) { 580 /* 581 * No match. Aquire jitTableLock and find the last 582 * slot in the chain. Possibly continue the chain walk in case 583 * some other thread allocated the slot we were looking 584 * at previuosly (perhaps even the dPC we're trying to enter). 585 */ 586 if (!callerLocked) 587 dvmLockMutex(&gDvmJit.tableLock); 588 /* 589 * At this point, if .dPC is NULL, then the slot we're 590 * looking at is the target slot from the primary hash 591 * (the simple, and common case). Otherwise we're going 592 * to have to find a free slot and chain it. 593 */ 594 ANDROID_MEMBAR_FULL(); /* Make sure we reload [].dPC after lock */ 595 if (gDvmJit.pJitEntryTable[idx].dPC != NULL) { 596 u4 prev; 597 while (gDvmJit.pJitEntryTable[idx].u.info.chain != chainEndMarker) { 598 if (gDvmJit.pJitEntryTable[idx].dPC == dPC && 599 gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry == 600 isMethodEntry) { 601 /* Another thread got there first for this dPC */ 602 if (!callerLocked) 603 dvmUnlockMutex(&gDvmJit.tableLock); 604 return &gDvmJit.pJitEntryTable[idx]; 605 } 606 idx = gDvmJit.pJitEntryTable[idx].u.info.chain; 607 } 608 /* Here, idx should be pointing to the last cell of an 609 * active chain whose last member contains a valid dPC */ 610 assert(gDvmJit.pJitEntryTable[idx].dPC != NULL); 611 /* Linear walk to find a free cell and add it to the end */ 612 prev = idx; 613 while (true) { 614 idx++; 615 if (idx == chainEndMarker) 616 idx = 0; /* Wraparound */ 617 if ((gDvmJit.pJitEntryTable[idx].dPC == NULL) || 618 (idx == prev)) 619 break; 620 } 621 if (idx != prev) { 622 JitEntryInfoUnion oldValue; 623 JitEntryInfoUnion newValue; 624 /* 625 * Although we hold the lock so that noone else will 626 * be trying to update a chain field, the other fields 627 * packed into the word may be in use by other threads. 628 */ 629 do { 630 oldValue = gDvmJit.pJitEntryTable[prev].u; 631 newValue = oldValue; 632 newValue.info.chain = idx; 633 } while (android_atomic_release_cas(oldValue.infoWord, 634 newValue.infoWord, 635 &gDvmJit.pJitEntryTable[prev].u.infoWord) != 0); 636 } 637 } 638 if (gDvmJit.pJitEntryTable[idx].dPC == NULL) { 639 gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry = isMethodEntry; 640 /* 641 * Initialize codeAddress and allocate the slot. Must 642 * happen in this order (since dPC is set, the entry is live. 643 */ 644 android_atomic_release_store((int32_t)dPC, 645 (volatile int32_t *)(void *)&gDvmJit.pJitEntryTable[idx].dPC); 646 /* for simulator mode, we need to initialized codeAddress to null */ 647 gDvmJit.pJitEntryTable[idx].codeAddress = NULL; 648 gDvmJit.pJitEntryTable[idx].dPC = dPC; 649 gDvmJit.jitTableEntriesUsed++; 650 } else { 651 /* Table is full */ 652 idx = chainEndMarker; 653 } 654 if (!callerLocked) 655 dvmUnlockMutex(&gDvmJit.tableLock); 656 } 657 return (idx == chainEndMarker) ? NULL : &gDvmJit.pJitEntryTable[idx]; 658 } 659 660 /* Dump a trace description */ 661 void dvmJitDumpTraceDesc(JitTraceDescription *trace) 662 { 663 int i; 664 bool done = false; 665 const u2* dpc; 666 const u2* dpcBase; 667 int curFrag = 0; 668 ALOGD("==========================================="); 669 ALOGD("Trace dump %#x, Method %s off %#x",(int)trace, 670 trace->method->name,trace->trace[curFrag].info.frag.startOffset); 671 dpcBase = trace->method->insns; 672 while (!done) { 673 DecodedInstruction decInsn; 674 if (trace->trace[curFrag].isCode) { 675 ALOGD("Frag[%d]- Insts: %d, start: %#x, hint: %#x, end: %d", 676 curFrag, trace->trace[curFrag].info.frag.numInsts, 677 trace->trace[curFrag].info.frag.startOffset, 678 trace->trace[curFrag].info.frag.hint, 679 trace->trace[curFrag].info.frag.runEnd); 680 dpc = dpcBase + trace->trace[curFrag].info.frag.startOffset; 681 for (i=0; i<trace->trace[curFrag].info.frag.numInsts; i++) { 682 dexDecodeInstruction(dpc, &decInsn); 683 ALOGD(" 0x%04x - %s %#x",(dpc-dpcBase), 684 dexGetOpcodeName(decInsn.opcode),(int)dpc); 685 dpc += dexGetWidthFromOpcode(decInsn.opcode); 686 } 687 if (trace->trace[curFrag].info.frag.runEnd) { 688 done = true; 689 } 690 } else { 691 ALOGD("Frag[%d]- META info: 0x%08x", curFrag, 692 (int)trace->trace[curFrag].info.meta); 693 } 694 curFrag++; 695 } 696 ALOGD("-------------------------------------------"); 697 } 698 699 /* 700 * Append the class ptr of "this" and the current method ptr to the current 701 * trace. That is, the trace runs will contain the following components: 702 * + trace run that ends with an invoke (existing entry) 703 * + thisClass (new) 704 * + calleeMethod (new) 705 */ 706 static void insertClassMethodInfo(Thread* self, 707 const ClassObject* thisClass, 708 const Method* calleeMethod, 709 const DecodedInstruction* insn) 710 { 711 int currTraceRun = ++self->currTraceRun; 712 self->trace[currTraceRun].info.meta = thisClass ? 713 (void *) thisClass->descriptor : NULL; 714 self->trace[currTraceRun].isCode = false; 715 716 currTraceRun = ++self->currTraceRun; 717 self->trace[currTraceRun].info.meta = thisClass ? 718 (void *) thisClass->classLoader : NULL; 719 self->trace[currTraceRun].isCode = false; 720 721 currTraceRun = ++self->currTraceRun; 722 self->trace[currTraceRun].info.meta = (void *) calleeMethod; 723 self->trace[currTraceRun].isCode = false; 724 } 725 726 /* 727 * Check if the next instruction following the invoke is a move-result and if 728 * so add it to the trace. That is, this will add the trace run that includes 729 * the move-result to the trace list. 730 * 731 * + trace run that ends with an invoke (existing entry) 732 * + thisClass (existing entry) 733 * + calleeMethod (existing entry) 734 * + move result (new) 735 * 736 * lastPC, len, offset are all from the preceding invoke instruction 737 */ 738 static void insertMoveResult(const u2 *lastPC, int len, int offset, 739 Thread *self) 740 { 741 DecodedInstruction nextDecInsn; 742 const u2 *moveResultPC = lastPC + len; 743 744 dexDecodeInstruction(moveResultPC, &nextDecInsn); 745 if ((nextDecInsn.opcode != OP_MOVE_RESULT) && 746 (nextDecInsn.opcode != OP_MOVE_RESULT_WIDE) && 747 (nextDecInsn.opcode != OP_MOVE_RESULT_OBJECT)) 748 return; 749 750 /* We need to start a new trace run */ 751 int currTraceRun = ++self->currTraceRun; 752 self->currRunHead = moveResultPC; 753 self->trace[currTraceRun].info.frag.startOffset = offset + len; 754 self->trace[currTraceRun].info.frag.numInsts = 1; 755 self->trace[currTraceRun].info.frag.runEnd = false; 756 self->trace[currTraceRun].info.frag.hint = kJitHintNone; 757 self->trace[currTraceRun].isCode = true; 758 self->totalTraceLen++; 759 760 self->currRunLen = dexGetWidthFromInstruction(moveResultPC); 761 } 762 763 /* 764 * Adds to the current trace request one instruction at a time, just 765 * before that instruction is interpreted. This is the primary trace 766 * selection function. NOTE: return instruction are handled a little 767 * differently. In general, instructions are "proposed" to be added 768 * to the current trace prior to interpretation. If the interpreter 769 * then successfully completes the instruction, is will be considered 770 * part of the request. This allows us to examine machine state prior 771 * to interpretation, and also abort the trace request if the instruction 772 * throws or does something unexpected. However, return instructions 773 * will cause an immediate end to the translation request - which will 774 * be passed to the compiler before the return completes. This is done 775 * in response to special handling of returns by the interpreter (and 776 * because returns cannot throw in a way that causes problems for the 777 * translated code. 778 */ 779 void dvmCheckJit(const u2* pc, Thread* self) 780 { 781 const ClassObject *thisClass = self->callsiteClass; 782 const Method* curMethod = self->methodToCall; 783 int flags, len; 784 int allDone = false; 785 /* Stay in break/single-stop mode for the next instruction */ 786 bool stayOneMoreInst = false; 787 788 /* Prepare to handle last PC and stage the current PC & method*/ 789 const u2 *lastPC = self->lastPC; 790 791 self->lastPC = pc; 792 793 switch (self->jitState) { 794 int offset; 795 DecodedInstruction decInsn; 796 case kJitTSelect: 797 /* First instruction - just remember the PC and exit */ 798 if (lastPC == NULL) break; 799 /* Grow the trace around the last PC if jitState is kJitTSelect */ 800 dexDecodeInstruction(lastPC, &decInsn); 801 #if TRACE_OPCODE_FILTER 802 /* Only add JIT support opcode to trace. End the trace if 803 * this opcode is not supported. 804 */ 805 if (!dvmIsOpcodeSupportedByJit(decInsn.opcode)) { 806 self->jitState = kJitTSelectEnd; 807 break; 808 } 809 #endif 810 /* 811 * Treat {PACKED,SPARSE}_SWITCH as trace-ending instructions due 812 * to the amount of space it takes to generate the chaining 813 * cells. 814 */ 815 if (self->totalTraceLen != 0 && 816 (decInsn.opcode == OP_PACKED_SWITCH || 817 decInsn.opcode == OP_SPARSE_SWITCH)) { 818 self->jitState = kJitTSelectEnd; 819 break; 820 } 821 822 #if defined(SHOW_TRACE) 823 ALOGD("TraceGen: adding %s. lpc:%#x, pc:%#x", 824 dexGetOpcodeName(decInsn.opcode), (int)lastPC, (int)pc); 825 #endif 826 flags = dexGetFlagsFromOpcode(decInsn.opcode); 827 len = dexGetWidthFromInstruction(lastPC); 828 offset = lastPC - self->traceMethod->insns; 829 assert((unsigned) offset < 830 dvmGetMethodInsnsSize(self->traceMethod)); 831 if (lastPC != self->currRunHead + self->currRunLen) { 832 int currTraceRun; 833 /* We need to start a new trace run */ 834 currTraceRun = ++self->currTraceRun; 835 self->currRunLen = 0; 836 self->currRunHead = (u2*)lastPC; 837 self->trace[currTraceRun].info.frag.startOffset = offset; 838 self->trace[currTraceRun].info.frag.numInsts = 0; 839 self->trace[currTraceRun].info.frag.runEnd = false; 840 self->trace[currTraceRun].info.frag.hint = kJitHintNone; 841 self->trace[currTraceRun].isCode = true; 842 } 843 self->trace[self->currTraceRun].info.frag.numInsts++; 844 self->totalTraceLen++; 845 self->currRunLen += len; 846 847 /* 848 * If the last instruction is an invoke, we will try to sneak in 849 * the move-result* (if existent) into a separate trace run. 850 */ 851 { 852 int needReservedRun = (flags & kInstrInvoke) ? 1 : 0; 853 854 /* Will probably never hit this with the current trace builder */ 855 if (self->currTraceRun == 856 (MAX_JIT_RUN_LEN - 1 - needReservedRun)) { 857 self->jitState = kJitTSelectEnd; 858 } 859 } 860 861 if (!dexIsGoto(flags) && 862 ((flags & (kInstrCanBranch | 863 kInstrCanSwitch | 864 kInstrCanReturn | 865 kInstrInvoke)) != 0)) { 866 self->jitState = kJitTSelectEnd; 867 #if defined(SHOW_TRACE) 868 ALOGD("TraceGen: ending on %s, basic block end", 869 dexGetOpcodeName(decInsn.opcode)); 870 #endif 871 872 /* 873 * If the current invoke is a {virtual,interface}, get the 874 * current class/method pair into the trace as well. 875 * If the next instruction is a variant of move-result, insert 876 * it to the trace too. 877 */ 878 if (flags & kInstrInvoke) { 879 insertClassMethodInfo(self, thisClass, curMethod, 880 &decInsn); 881 insertMoveResult(lastPC, len, offset, self); 882 } 883 } 884 /* Break on throw or self-loop */ 885 if ((decInsn.opcode == OP_THROW) || (lastPC == pc)){ 886 self->jitState = kJitTSelectEnd; 887 } 888 if (self->totalTraceLen >= JIT_MAX_TRACE_LEN) { 889 self->jitState = kJitTSelectEnd; 890 } 891 if ((flags & kInstrCanReturn) != kInstrCanReturn) { 892 break; 893 } 894 else { 895 /* 896 * Last instruction is a return - stay in the dbg interpreter 897 * for one more instruction if it is a non-void return, since 898 * we don't want to start a trace with move-result as the first 899 * instruction (which is already included in the trace 900 * containing the invoke. 901 */ 902 if (decInsn.opcode != OP_RETURN_VOID) { 903 stayOneMoreInst = true; 904 } 905 } 906 /* NOTE: intentional fallthrough for returns */ 907 case kJitTSelectEnd: 908 { 909 /* Empty trace - set to bail to interpreter */ 910 if (self->totalTraceLen == 0) { 911 dvmJitSetCodeAddr(self->currTraceHead, 912 dvmCompilerGetInterpretTemplate(), 913 dvmCompilerGetInterpretTemplateSet(), 914 false /* Not method entry */, 0); 915 self->jitState = kJitDone; 916 allDone = true; 917 break; 918 } 919 920 int lastTraceDesc = self->currTraceRun; 921 922 /* Extend a new empty desc if the last slot is meta info */ 923 if (!self->trace[lastTraceDesc].isCode) { 924 lastTraceDesc = ++self->currTraceRun; 925 self->trace[lastTraceDesc].info.frag.startOffset = 0; 926 self->trace[lastTraceDesc].info.frag.numInsts = 0; 927 self->trace[lastTraceDesc].info.frag.hint = kJitHintNone; 928 self->trace[lastTraceDesc].isCode = true; 929 } 930 931 /* Mark the end of the trace runs */ 932 self->trace[lastTraceDesc].info.frag.runEnd = true; 933 934 JitTraceDescription* desc = 935 (JitTraceDescription*)malloc(sizeof(JitTraceDescription) + 936 sizeof(JitTraceRun) * (self->currTraceRun+1)); 937 938 if (desc == NULL) { 939 ALOGE("Out of memory in trace selection"); 940 dvmJitStopTranslationRequests(); 941 self->jitState = kJitDone; 942 allDone = true; 943 break; 944 } 945 946 desc->method = self->traceMethod; 947 memcpy((char*)&(desc->trace[0]), 948 (char*)&(self->trace[0]), 949 sizeof(JitTraceRun) * (self->currTraceRun+1)); 950 #if defined(SHOW_TRACE) 951 ALOGD("TraceGen: trace done, adding to queue"); 952 dvmJitDumpTraceDesc(desc); 953 #endif 954 if (dvmCompilerWorkEnqueue( 955 self->currTraceHead,kWorkOrderTrace,desc)) { 956 /* Work order successfully enqueued */ 957 if (gDvmJit.blockingMode) { 958 dvmCompilerDrainQueue(); 959 } 960 } else { 961 /* 962 * Make sure the descriptor for the abandoned work order is 963 * freed. 964 */ 965 free(desc); 966 } 967 self->jitState = kJitDone; 968 allDone = true; 969 } 970 break; 971 case kJitDone: 972 allDone = true; 973 break; 974 case kJitNot: 975 allDone = true; 976 break; 977 default: 978 ALOGE("Unexpected JIT state: %d", self->jitState); 979 dvmAbort(); 980 break; 981 } 982 983 /* 984 * If we're done with trace selection, switch off the control flags. 985 */ 986 if (allDone) { 987 dvmDisableSubMode(self, kSubModeJitTraceBuild); 988 if (stayOneMoreInst) { 989 // Clear jitResumeNPC explicitly since we know we don't need it 990 // here. 991 self->jitResumeNPC = NULL; 992 // Keep going in single-step mode for at least one more inst 993 if (self->singleStepCount == 0) 994 self->singleStepCount = 1; 995 dvmEnableSubMode(self, kSubModeCountedStep); 996 } 997 } 998 return; 999 } 1000 1001 JitEntry *dvmJitFindEntry(const u2* pc, bool isMethodEntry) 1002 { 1003 int idx = dvmJitHash(pc); 1004 1005 /* Expect a high hit rate on 1st shot */ 1006 if ((gDvmJit.pJitEntryTable[idx].dPC == pc) && 1007 (gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry == isMethodEntry)) 1008 return &gDvmJit.pJitEntryTable[idx]; 1009 else { 1010 int chainEndMarker = gDvmJit.jitTableSize; 1011 while (gDvmJit.pJitEntryTable[idx].u.info.chain != chainEndMarker) { 1012 idx = gDvmJit.pJitEntryTable[idx].u.info.chain; 1013 if ((gDvmJit.pJitEntryTable[idx].dPC == pc) && 1014 (gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry == 1015 isMethodEntry)) 1016 return &gDvmJit.pJitEntryTable[idx]; 1017 } 1018 } 1019 return NULL; 1020 } 1021 1022 /* 1023 * Walk through the JIT profile table and find the corresponding JIT code, in 1024 * the specified format (ie trace vs method). This routine needs to be fast. 1025 */ 1026 void* getCodeAddrCommon(const u2* dPC, bool methodEntry) 1027 { 1028 int idx = dvmJitHash(dPC); 1029 const u2* pc = gDvmJit.pJitEntryTable[idx].dPC; 1030 if (pc != NULL) { 1031 bool hideTranslation = dvmJitHideTranslation(); 1032 if (pc == dPC && 1033 gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry == methodEntry) { 1034 int offset = (gDvmJit.profileMode >= kTraceProfilingContinuous) ? 1035 0 : gDvmJit.pJitEntryTable[idx].u.info.profileOffset; 1036 intptr_t codeAddress = 1037 (intptr_t)gDvmJit.pJitEntryTable[idx].codeAddress; 1038 #if defined(WITH_JIT_TUNING) 1039 gDvmJit.addrLookupsFound++; 1040 #endif 1041 return hideTranslation || !codeAddress ? NULL : 1042 (void *)(codeAddress + offset); 1043 } else { 1044 int chainEndMarker = gDvmJit.jitTableSize; 1045 while (gDvmJit.pJitEntryTable[idx].u.info.chain != chainEndMarker) { 1046 idx = gDvmJit.pJitEntryTable[idx].u.info.chain; 1047 if (gDvmJit.pJitEntryTable[idx].dPC == dPC && 1048 gDvmJit.pJitEntryTable[idx].u.info.isMethodEntry == 1049 methodEntry) { 1050 int offset = (gDvmJit.profileMode >= 1051 kTraceProfilingContinuous) ? 0 : 1052 gDvmJit.pJitEntryTable[idx].u.info.profileOffset; 1053 intptr_t codeAddress = 1054 (intptr_t)gDvmJit.pJitEntryTable[idx].codeAddress; 1055 #if defined(WITH_JIT_TUNING) 1056 gDvmJit.addrLookupsFound++; 1057 #endif 1058 return hideTranslation || !codeAddress ? NULL : 1059 (void *)(codeAddress + offset); 1060 } 1061 } 1062 } 1063 } 1064 #if defined(WITH_JIT_TUNING) 1065 gDvmJit.addrLookupsNotFound++; 1066 #endif 1067 return NULL; 1068 } 1069 1070 /* 1071 * If a translated code address, in trace format, exists for the davik byte code 1072 * pointer return it. 1073 */ 1074 void* dvmJitGetTraceAddr(const u2* dPC) 1075 { 1076 return getCodeAddrCommon(dPC, false /* method entry */); 1077 } 1078 1079 /* 1080 * If a translated code address, in whole-method format, exists for the davik 1081 * byte code pointer return it. 1082 */ 1083 void* dvmJitGetMethodAddr(const u2* dPC) 1084 { 1085 return getCodeAddrCommon(dPC, true /* method entry */); 1086 } 1087 1088 /* 1089 * Similar to dvmJitGetTraceAddr, but returns null if the calling 1090 * thread is in a single-step mode. 1091 */ 1092 void* dvmJitGetTraceAddrThread(const u2* dPC, Thread* self) 1093 { 1094 return (self->interpBreak.ctl.breakFlags != 0) ? NULL : 1095 getCodeAddrCommon(dPC, false /* method entry */); 1096 } 1097 1098 /* 1099 * Similar to dvmJitGetMethodAddr, but returns null if the calling 1100 * thread is in a single-step mode. 1101 */ 1102 void* dvmJitGetMethodAddrThread(const u2* dPC, Thread* self) 1103 { 1104 return (self->interpBreak.ctl.breakFlags != 0) ? NULL : 1105 getCodeAddrCommon(dPC, true /* method entry */); 1106 } 1107 1108 /* 1109 * Register the translated code pointer into the JitTable. 1110 * NOTE: Once a codeAddress field transitions from initial state to 1111 * JIT'd code, it must not be altered without first halting all 1112 * threads. We defer the setting of the profile prefix size until 1113 * after the new code address is set to ensure that the prefix offset 1114 * is never applied to the initial interpret-only translation. All 1115 * translations with non-zero profile prefixes will still be correct 1116 * if entered as if the profile offset is 0, but the interpret-only 1117 * template cannot handle a non-zero prefix. 1118 * NOTE: JitTable must not be in danger of reset while this 1119 * code is executing. see Issue 4271784 for details. 1120 */ 1121 void dvmJitSetCodeAddr(const u2* dPC, void *nPC, JitInstructionSetType set, 1122 bool isMethodEntry, int profilePrefixSize) 1123 { 1124 JitEntryInfoUnion oldValue; 1125 JitEntryInfoUnion newValue; 1126 /* 1127 * Get the JitTable slot for this dPC (or create one if JitTable 1128 * has been reset between the time the trace was requested and 1129 * now. 1130 */ 1131 JitEntry *jitEntry = isMethodEntry ? 1132 lookupAndAdd(dPC, false /* caller holds tableLock */, isMethodEntry) : 1133 dvmJitFindEntry(dPC, isMethodEntry); 1134 assert(jitEntry); 1135 /* Note: order of update is important */ 1136 do { 1137 oldValue = jitEntry->u; 1138 newValue = oldValue; 1139 newValue.info.isMethodEntry = isMethodEntry; 1140 newValue.info.instructionSet = set; 1141 newValue.info.profileOffset = profilePrefixSize; 1142 } while (android_atomic_release_cas( 1143 oldValue.infoWord, newValue.infoWord, 1144 &jitEntry->u.infoWord) != 0); 1145 jitEntry->codeAddress = nPC; 1146 } 1147 1148 /* 1149 * Determine if valid trace-bulding request is active. If so, set 1150 * the proper flags in interpBreak and return. Trace selection will 1151 * then begin normally via dvmCheckBefore. 1152 */ 1153 void dvmJitCheckTraceRequest(Thread* self) 1154 { 1155 int i; 1156 /* 1157 * A note on trace "hotness" filtering: 1158 * 1159 * Our first level trigger is intentionally loose - we need it to 1160 * fire easily not just to identify potential traces to compile, but 1161 * also to allow re-entry into the code cache. 1162 * 1163 * The 2nd level filter (done here) exists to be selective about 1164 * what we actually compile. It works by requiring the same 1165 * trace head "key" (defined as filterKey below) to appear twice in 1166 * a relatively short period of time. The difficulty is defining the 1167 * shape of the filterKey. Unfortunately, there is no "one size fits 1168 * all" approach. 1169 * 1170 * For spiky execution profiles dominated by a smallish 1171 * number of very hot loops, we would want the second-level filter 1172 * to be very selective. A good selective filter is requiring an 1173 * exact match of the Dalvik PC. In other words, defining filterKey as: 1174 * intptr_t filterKey = (intptr_t)self->interpSave.pc 1175 * 1176 * However, for flat execution profiles we do best when aggressively 1177 * translating. A heuristically decent proxy for this is to use 1178 * the value of the method pointer containing the trace as the filterKey. 1179 * Intuitively, this is saying that once any trace in a method appears hot, 1180 * immediately translate any other trace from that same method that 1181 * survives the first-level filter. Here, filterKey would be defined as: 1182 * intptr_t filterKey = (intptr_t)self->interpSave.method 1183 * 1184 * The problem is that we can't easily detect whether we're dealing 1185 * with a spiky or flat profile. If we go with the "pc" match approach, 1186 * flat profiles perform poorly. If we go with the loose "method" match, 1187 * we end up generating a lot of useless translations. Probably the 1188 * best approach in the future will be to retain profile information 1189 * across runs of each application in order to determine it's profile, 1190 * and then choose once we have enough history. 1191 * 1192 * However, for now we've decided to chose a compromise filter scheme that 1193 * includes elements of both. The high order bits of the filter key 1194 * are drawn from the enclosing method, and are combined with a slice 1195 * of the low-order bits of the Dalvik pc of the trace head. The 1196 * looseness of the filter can be adjusted by changing with width of 1197 * the Dalvik pc slice (JIT_TRACE_THRESH_FILTER_PC_BITS). The wider 1198 * the slice, the tighter the filter. 1199 * 1200 * Note: the fixed shifts in the function below reflect assumed word 1201 * alignment for method pointers, and half-word alignment of the Dalvik pc. 1202 * for method pointers and half-word alignment for dalvik pc. 1203 */ 1204 u4 methodKey = (u4)self->interpSave.method << 1205 (JIT_TRACE_THRESH_FILTER_PC_BITS - 2); 1206 u4 pcKey = ((u4)self->interpSave.pc >> 1) & 1207 ((1 << JIT_TRACE_THRESH_FILTER_PC_BITS) - 1); 1208 intptr_t filterKey = (intptr_t)(methodKey | pcKey); 1209 1210 // Shouldn't be here if already building a trace. 1211 assert((self->interpBreak.ctl.subMode & kSubModeJitTraceBuild)==0); 1212 1213 /* Check if the JIT request can be handled now */ 1214 if ((gDvmJit.pJitEntryTable != NULL) && 1215 ((self->interpBreak.ctl.breakFlags & kInterpSingleStep) == 0)){ 1216 /* Bypass the filter for hot trace requests or during stress mode */ 1217 if (self->jitState == kJitTSelectRequest && 1218 gDvmJit.threshold > 6) { 1219 /* Two-level filtering scheme */ 1220 for (i=0; i< JIT_TRACE_THRESH_FILTER_SIZE; i++) { 1221 if (filterKey == self->threshFilter[i]) { 1222 self->threshFilter[i] = 0; // Reset filter entry 1223 break; 1224 } 1225 } 1226 if (i == JIT_TRACE_THRESH_FILTER_SIZE) { 1227 /* 1228 * Use random replacement policy - otherwise we could miss a 1229 * large loop that contains more traces than the size of our 1230 * filter array. 1231 */ 1232 i = rand() % JIT_TRACE_THRESH_FILTER_SIZE; 1233 self->threshFilter[i] = filterKey; 1234 self->jitState = kJitDone; 1235 } 1236 } 1237 1238 /* If the compiler is backlogged, cancel any JIT actions */ 1239 if (gDvmJit.compilerQueueLength >= gDvmJit.compilerHighWater) { 1240 self->jitState = kJitDone; 1241 } 1242 1243 /* 1244 * Check for additional reasons that might force the trace select 1245 * request to be dropped 1246 */ 1247 if (self->jitState == kJitTSelectRequest || 1248 self->jitState == kJitTSelectRequestHot) { 1249 if (dvmJitFindEntry(self->interpSave.pc, false)) { 1250 /* In progress - nothing do do */ 1251 self->jitState = kJitDone; 1252 } else { 1253 JitEntry *slot = lookupAndAdd(self->interpSave.pc, 1254 false /* lock */, 1255 false /* method entry */); 1256 if (slot == NULL) { 1257 /* 1258 * Table is full. This should have been 1259 * detected by the compiler thread and the table 1260 * resized before we run into it here. Assume bad things 1261 * are afoot and disable profiling. 1262 */ 1263 self->jitState = kJitDone; 1264 ALOGD("JIT: JitTable full, disabling profiling"); 1265 dvmJitStopTranslationRequests(); 1266 } 1267 } 1268 } 1269 1270 switch (self->jitState) { 1271 case kJitTSelectRequest: 1272 case kJitTSelectRequestHot: 1273 self->jitState = kJitTSelect; 1274 self->traceMethod = self->interpSave.method; 1275 self->currTraceHead = self->interpSave.pc; 1276 self->currTraceRun = 0; 1277 self->totalTraceLen = 0; 1278 self->currRunHead = self->interpSave.pc; 1279 self->currRunLen = 0; 1280 self->trace[0].info.frag.startOffset = 1281 self->interpSave.pc - self->interpSave.method->insns; 1282 self->trace[0].info.frag.numInsts = 0; 1283 self->trace[0].info.frag.runEnd = false; 1284 self->trace[0].info.frag.hint = kJitHintNone; 1285 self->trace[0].isCode = true; 1286 self->lastPC = 0; 1287 /* Turn on trace selection mode */ 1288 dvmEnableSubMode(self, kSubModeJitTraceBuild); 1289 #if defined(SHOW_TRACE) 1290 ALOGD("Starting trace for %s at %#x", 1291 self->interpSave.method->name, (int)self->interpSave.pc); 1292 #endif 1293 break; 1294 case kJitDone: 1295 break; 1296 default: 1297 ALOGE("Unexpected JIT state: %d", self->jitState); 1298 dvmAbort(); 1299 } 1300 } else { 1301 /* Cannot build trace this time */ 1302 self->jitState = kJitDone; 1303 } 1304 } 1305 1306 /* 1307 * Resizes the JitTable. Must be a power of 2, and returns true on failure. 1308 * Stops all threads, and thus is a heavyweight operation. May only be called 1309 * by the compiler thread. 1310 */ 1311 bool dvmJitResizeJitTable( unsigned int size ) 1312 { 1313 JitEntry *pNewTable; 1314 JitEntry *pOldTable; 1315 JitEntry tempEntry; 1316 unsigned int oldSize; 1317 unsigned int i; 1318 1319 assert(gDvmJit.pJitEntryTable != NULL); 1320 assert(size && !(size & (size - 1))); /* Is power of 2? */ 1321 1322 ALOGI("Jit: resizing JitTable from %d to %d", gDvmJit.jitTableSize, size); 1323 1324 if (size <= gDvmJit.jitTableSize) { 1325 return true; 1326 } 1327 1328 /* Make sure requested size is compatible with chain field width */ 1329 tempEntry.u.info.chain = size; 1330 if (tempEntry.u.info.chain != size) { 1331 ALOGD("Jit: JitTable request of %d too big", size); 1332 return true; 1333 } 1334 1335 pNewTable = (JitEntry*)calloc(size, sizeof(*pNewTable)); 1336 if (pNewTable == NULL) { 1337 return true; 1338 } 1339 for (i=0; i< size; i++) { 1340 pNewTable[i].u.info.chain = size; /* Initialize chain termination */ 1341 } 1342 1343 /* Stop all other interpreting/jit'ng threads */ 1344 dvmSuspendAllThreads(SUSPEND_FOR_TBL_RESIZE); 1345 1346 pOldTable = gDvmJit.pJitEntryTable; 1347 oldSize = gDvmJit.jitTableSize; 1348 1349 dvmLockMutex(&gDvmJit.tableLock); 1350 gDvmJit.pJitEntryTable = pNewTable; 1351 gDvmJit.jitTableSize = size; 1352 gDvmJit.jitTableMask = size - 1; 1353 gDvmJit.jitTableEntriesUsed = 0; 1354 1355 for (i=0; i < oldSize; i++) { 1356 if (pOldTable[i].dPC) { 1357 JitEntry *p; 1358 u2 chain; 1359 p = lookupAndAdd(pOldTable[i].dPC, true /* holds tableLock*/, 1360 pOldTable[i].u.info.isMethodEntry); 1361 p->codeAddress = pOldTable[i].codeAddress; 1362 /* We need to preserve the new chain field, but copy the rest */ 1363 chain = p->u.info.chain; 1364 p->u = pOldTable[i].u; 1365 p->u.info.chain = chain; 1366 } 1367 } 1368 1369 dvmUnlockMutex(&gDvmJit.tableLock); 1370 1371 free(pOldTable); 1372 1373 /* Restart the world */ 1374 dvmResumeAllThreads(SUSPEND_FOR_TBL_RESIZE); 1375 1376 return false; 1377 } 1378 1379 /* 1380 * Reset the JitTable to the initial clean state. 1381 */ 1382 void dvmJitResetTable() 1383 { 1384 JitEntry *jitEntry = gDvmJit.pJitEntryTable; 1385 unsigned int size = gDvmJit.jitTableSize; 1386 unsigned int i; 1387 1388 dvmLockMutex(&gDvmJit.tableLock); 1389 1390 /* Note: If need to preserve any existing counts. Do so here. */ 1391 if (gDvmJit.pJitTraceProfCounters) { 1392 for (i=0; i < JIT_PROF_BLOCK_BUCKETS; i++) { 1393 if (gDvmJit.pJitTraceProfCounters->buckets[i]) 1394 memset((void *) gDvmJit.pJitTraceProfCounters->buckets[i], 1395 0, sizeof(JitTraceCounter_t) * JIT_PROF_BLOCK_ENTRIES); 1396 } 1397 gDvmJit.pJitTraceProfCounters->next = 0; 1398 } 1399 1400 memset((void *) jitEntry, 0, sizeof(JitEntry) * size); 1401 for (i=0; i< size; i++) { 1402 jitEntry[i].u.info.chain = size; /* Initialize chain termination */ 1403 } 1404 gDvmJit.jitTableEntriesUsed = 0; 1405 dvmUnlockMutex(&gDvmJit.tableLock); 1406 } 1407 1408 /* 1409 * Return the address of the next trace profile counter. This address 1410 * will be embedded in the generated code for the trace, and thus cannot 1411 * change while the trace exists. 1412 */ 1413 JitTraceCounter_t *dvmJitNextTraceCounter() 1414 { 1415 int idx = gDvmJit.pJitTraceProfCounters->next / JIT_PROF_BLOCK_ENTRIES; 1416 int elem = gDvmJit.pJitTraceProfCounters->next % JIT_PROF_BLOCK_ENTRIES; 1417 JitTraceCounter_t *res; 1418 /* Lazily allocate blocks of counters */ 1419 if (!gDvmJit.pJitTraceProfCounters->buckets[idx]) { 1420 JitTraceCounter_t *p = 1421 (JitTraceCounter_t*) calloc(JIT_PROF_BLOCK_ENTRIES, sizeof(*p)); 1422 if (!p) { 1423 ALOGE("Failed to allocate block of trace profile counters"); 1424 dvmAbort(); 1425 } 1426 gDvmJit.pJitTraceProfCounters->buckets[idx] = p; 1427 } 1428 res = &gDvmJit.pJitTraceProfCounters->buckets[idx][elem]; 1429 gDvmJit.pJitTraceProfCounters->next++; 1430 return res; 1431 } 1432 1433 /* 1434 * Float/double conversion requires clamping to min and max of integer form. If 1435 * target doesn't support this normally, use these. 1436 */ 1437 s8 dvmJitd2l(double d) 1438 { 1439 static const double kMaxLong = (double)(s8)0x7fffffffffffffffULL; 1440 static const double kMinLong = (double)(s8)0x8000000000000000ULL; 1441 if (d >= kMaxLong) 1442 return (s8)0x7fffffffffffffffULL; 1443 else if (d <= kMinLong) 1444 return (s8)0x8000000000000000ULL; 1445 else if (d != d) // NaN case 1446 return 0; 1447 else 1448 return (s8)d; 1449 } 1450 1451 s8 dvmJitf2l(float f) 1452 { 1453 static const float kMaxLong = (float)(s8)0x7fffffffffffffffULL; 1454 static const float kMinLong = (float)(s8)0x8000000000000000ULL; 1455 if (f >= kMaxLong) 1456 return (s8)0x7fffffffffffffffULL; 1457 else if (f <= kMinLong) 1458 return (s8)0x8000000000000000ULL; 1459 else if (f != f) // NaN case 1460 return 0; 1461 else 1462 return (s8)f; 1463 } 1464 1465 /* Should only be called by the compiler thread */ 1466 void dvmJitChangeProfileMode(TraceProfilingModes newState) 1467 { 1468 if (gDvmJit.profileMode != newState) { 1469 gDvmJit.profileMode = newState; 1470 dvmJitUnchainAll(); 1471 } 1472 } 1473 1474 void dvmJitTraceProfilingOn() 1475 { 1476 if (gDvmJit.profileMode == kTraceProfilingPeriodicOff) 1477 dvmCompilerForceWorkEnqueue(NULL, kWorkOrderProfileMode, 1478 (void*) kTraceProfilingPeriodicOn); 1479 else if (gDvmJit.profileMode == kTraceProfilingDisabled) 1480 dvmCompilerForceWorkEnqueue(NULL, kWorkOrderProfileMode, 1481 (void*) kTraceProfilingContinuous); 1482 } 1483 1484 void dvmJitTraceProfilingOff() 1485 { 1486 if (gDvmJit.profileMode == kTraceProfilingPeriodicOn) 1487 dvmCompilerForceWorkEnqueue(NULL, kWorkOrderProfileMode, 1488 (void*) kTraceProfilingPeriodicOff); 1489 else if (gDvmJit.profileMode == kTraceProfilingContinuous) 1490 dvmCompilerForceWorkEnqueue(NULL, kWorkOrderProfileMode, 1491 (void*) kTraceProfilingDisabled); 1492 } 1493 1494 /* 1495 * Update JIT-specific info in Thread structure for a single thread 1496 */ 1497 void dvmJitUpdateThreadStateSingle(Thread* thread) 1498 { 1499 thread->pJitProfTable = gDvmJit.pProfTable; 1500 thread->jitThreshold = gDvmJit.threshold; 1501 } 1502 1503 /* 1504 * Walk through the thread list and refresh all local copies of 1505 * JIT global state (which was placed there for fast access). 1506 */ 1507 void dvmJitUpdateThreadStateAll() 1508 { 1509 Thread* self = dvmThreadSelf(); 1510 Thread* thread; 1511 1512 dvmLockThreadList(self); 1513 for (thread = gDvm.threadList; thread != NULL; thread = thread->next) { 1514 dvmJitUpdateThreadStateSingle(thread); 1515 } 1516 dvmUnlockThreadList(); 1517 1518 } 1519 #endif /* WITH_JIT */ 1520
