1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jit/Snapshots.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,495 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef jit_Snapshot_h
1.11 +#define jit_Snapshot_h
1.12 +
1.13 +#include "mozilla/Alignment.h"
1.14 +
1.15 +#include "jsalloc.h"
1.16 +#include "jsbytecode.h"
1.17 +
1.18 +#include "jit/CompactBuffer.h"
1.19 +#include "jit/IonTypes.h"
1.20 +#include "jit/Registers.h"
1.21 +
1.22 +#include "js/HashTable.h"
1.23 +
1.24 +namespace js {
1.25 +namespace jit {
1.26 +
1.27 +class RValueAllocation;
1.28 +
1.29 +// A Recover Value Allocation mirror what is known at compiled time as being the
1.30 +// MIRType and the LAllocation. This is read out of the snapshot to recover the
1.31 +// value which would be there if this frame was an interpreter frame instead of
1.32 +// an Ion frame.
1.33 +//
1.34 +// It is used with the SnapshotIterator to recover a Value from the stack,
1.35 +// spilled registers or the list of constant of the compiled script.
1.36 +//
1.37 +// Unit tests are located in jsapi-tests/testJitRValueAlloc.cpp.
1.38 +class RValueAllocation
1.39 +{
1.40 + public:
1.41 +
1.42 + // See RValueAllocation encoding in Snapshots.cpp
1.43 + enum Mode
1.44 + {
1.45 + CONSTANT = 0x00,
1.46 + CST_UNDEFINED = 0x01,
1.47 + CST_NULL = 0x02,
1.48 + DOUBLE_REG = 0x03,
1.49 + FLOAT32_REG = 0x04,
1.50 + FLOAT32_STACK = 0x05,
1.51 +#if defined(JS_NUNBOX32)
1.52 + UNTYPED_REG_REG = 0x06,
1.53 + UNTYPED_REG_STACK = 0x07,
1.54 + UNTYPED_STACK_REG = 0x08,
1.55 + UNTYPED_STACK_STACK = 0x09,
1.56 +#elif defined(JS_PUNBOX64)
1.57 + UNTYPED_REG = 0x06,
1.58 + UNTYPED_STACK = 0x07,
1.59 +#endif
1.60 + // The JSValueType is packed in the Mode.
1.61 + TYPED_REG_MIN = 0x10,
1.62 + TYPED_REG_MAX = 0x17,
1.63 + TYPED_REG = TYPED_REG_MIN,
1.64 +
1.65 + // The JSValueType is packed in the Mode.
1.66 + TYPED_STACK_MIN = 0x18,
1.67 + TYPED_STACK_MAX = 0x1f,
1.68 + TYPED_STACK = TYPED_STACK_MIN,
1.69 +
1.70 + INVALID = 0x100,
1.71 + };
1.72 +
1.73 + // See Payload encoding in Snapshots.cpp
1.74 + enum PayloadType {
1.75 + PAYLOAD_NONE,
1.76 + PAYLOAD_INDEX,
1.77 + PAYLOAD_STACK_OFFSET,
1.78 + PAYLOAD_GPR,
1.79 + PAYLOAD_FPU,
1.80 + PAYLOAD_PACKED_TAG
1.81 + };
1.82 +
1.83 + struct Layout {
1.84 + PayloadType type1;
1.85 + PayloadType type2;
1.86 + const char *name;
1.87 + };
1.88 +
1.89 + private:
1.90 + Mode mode_;
1.91 +
1.92 + // Additional information to recover the content of the allocation.
1.93 + union Payload {
1.94 + uint32_t index;
1.95 + int32_t stackOffset;
1.96 + Register gpr;
1.97 + FloatRegister fpu;
1.98 + JSValueType type;
1.99 + };
1.100 +
1.101 + Payload arg1_;
1.102 + Payload arg2_;
1.103 +
1.104 + static Payload payloadOfIndex(uint32_t index) {
1.105 + Payload p;
1.106 + p.index = index;
1.107 + return p;
1.108 + }
1.109 + static Payload payloadOfStackOffset(int32_t offset) {
1.110 + Payload p;
1.111 + p.stackOffset = offset;
1.112 + return p;
1.113 + }
1.114 + static Payload payloadOfRegister(Register reg) {
1.115 + Payload p;
1.116 + p.gpr = reg;
1.117 + return p;
1.118 + }
1.119 + static Payload payloadOfFloatRegister(FloatRegister reg) {
1.120 + Payload p;
1.121 + p.fpu = reg;
1.122 + return p;
1.123 + }
1.124 + static Payload payloadOfValueType(JSValueType type) {
1.125 + Payload p;
1.126 + p.type = type;
1.127 + return p;
1.128 + }
1.129 +
1.130 + static const Layout &layoutFromMode(Mode mode);
1.131 +
1.132 + static void readPayload(CompactBufferReader &reader, PayloadType t,
1.133 + uint8_t *mode, Payload *p);
1.134 + static void writePayload(CompactBufferWriter &writer, PayloadType t,
1.135 + Payload p);
1.136 + static void writePadding(CompactBufferWriter &writer);
1.137 + static void dumpPayload(FILE *fp, PayloadType t, Payload p);
1.138 + static bool equalPayloads(PayloadType t, Payload lhs, Payload rhs);
1.139 +
1.140 + RValueAllocation(Mode mode, Payload a1, Payload a2)
1.141 + : mode_(mode),
1.142 + arg1_(a1),
1.143 + arg2_(a2)
1.144 + {
1.145 + }
1.146 +
1.147 + RValueAllocation(Mode mode, Payload a1)
1.148 + : mode_(mode),
1.149 + arg1_(a1)
1.150 + {
1.151 + }
1.152 +
1.153 + RValueAllocation(Mode mode)
1.154 + : mode_(mode)
1.155 + {
1.156 + }
1.157 +
1.158 + public:
1.159 + RValueAllocation()
1.160 + : mode_(INVALID)
1.161 + { }
1.162 +
1.163 + // DOUBLE_REG
1.164 + static RValueAllocation Double(const FloatRegister ®) {
1.165 + return RValueAllocation(DOUBLE_REG, payloadOfFloatRegister(reg));
1.166 + }
1.167 +
1.168 + // FLOAT32_REG or FLOAT32_STACK
1.169 + static RValueAllocation Float32(const FloatRegister ®) {
1.170 + return RValueAllocation(FLOAT32_REG, payloadOfFloatRegister(reg));
1.171 + }
1.172 + static RValueAllocation Float32(int32_t offset) {
1.173 + return RValueAllocation(FLOAT32_STACK, payloadOfStackOffset(offset));
1.174 + }
1.175 +
1.176 + // TYPED_REG or TYPED_STACK
1.177 + static RValueAllocation Typed(JSValueType type, const Register ®) {
1.178 + JS_ASSERT(type != JSVAL_TYPE_DOUBLE &&
1.179 + type != JSVAL_TYPE_MAGIC &&
1.180 + type != JSVAL_TYPE_NULL &&
1.181 + type != JSVAL_TYPE_UNDEFINED);
1.182 + return RValueAllocation(TYPED_REG, payloadOfValueType(type),
1.183 + payloadOfRegister(reg));
1.184 + }
1.185 + static RValueAllocation Typed(JSValueType type, int32_t offset) {
1.186 + JS_ASSERT(type != JSVAL_TYPE_MAGIC &&
1.187 + type != JSVAL_TYPE_NULL &&
1.188 + type != JSVAL_TYPE_UNDEFINED);
1.189 + return RValueAllocation(TYPED_STACK, payloadOfValueType(type),
1.190 + payloadOfStackOffset(offset));
1.191 + }
1.192 +
1.193 + // UNTYPED
1.194 +#if defined(JS_NUNBOX32)
1.195 + static RValueAllocation Untyped(const Register &type, const Register &payload) {
1.196 + return RValueAllocation(UNTYPED_REG_REG,
1.197 + payloadOfRegister(type),
1.198 + payloadOfRegister(payload));
1.199 + }
1.200 +
1.201 + static RValueAllocation Untyped(const Register &type, int32_t payloadStackOffset) {
1.202 + return RValueAllocation(UNTYPED_REG_STACK,
1.203 + payloadOfRegister(type),
1.204 + payloadOfStackOffset(payloadStackOffset));
1.205 + }
1.206 +
1.207 + static RValueAllocation Untyped(int32_t typeStackOffset, const Register &payload) {
1.208 + return RValueAllocation(UNTYPED_STACK_REG,
1.209 + payloadOfStackOffset(typeStackOffset),
1.210 + payloadOfRegister(payload));
1.211 + }
1.212 +
1.213 + static RValueAllocation Untyped(int32_t typeStackOffset, int32_t payloadStackOffset) {
1.214 + return RValueAllocation(UNTYPED_STACK_STACK,
1.215 + payloadOfStackOffset(typeStackOffset),
1.216 + payloadOfStackOffset(payloadStackOffset));
1.217 + }
1.218 +
1.219 +#elif defined(JS_PUNBOX64)
1.220 + static RValueAllocation Untyped(const Register ®) {
1.221 + return RValueAllocation(UNTYPED_REG, payloadOfRegister(reg));
1.222 + }
1.223 +
1.224 + static RValueAllocation Untyped(int32_t stackOffset) {
1.225 + return RValueAllocation(UNTYPED_STACK, payloadOfStackOffset(stackOffset));
1.226 + }
1.227 +#endif
1.228 +
1.229 + // common constants.
1.230 + static RValueAllocation Undefined() {
1.231 + return RValueAllocation(CST_UNDEFINED);
1.232 + }
1.233 + static RValueAllocation Null() {
1.234 + return RValueAllocation(CST_NULL);
1.235 + }
1.236 +
1.237 + // CONSTANT's index
1.238 + static RValueAllocation ConstantPool(uint32_t index) {
1.239 + return RValueAllocation(CONSTANT, payloadOfIndex(index));
1.240 + }
1.241 +
1.242 + void writeHeader(CompactBufferWriter &writer, JSValueType type, uint32_t regCode) const;
1.243 + public:
1.244 + static RValueAllocation read(CompactBufferReader &reader);
1.245 + void write(CompactBufferWriter &writer) const;
1.246 +
1.247 + public:
1.248 + Mode mode() const {
1.249 + return mode_;
1.250 + }
1.251 +
1.252 + uint32_t index() const {
1.253 + JS_ASSERT(layoutFromMode(mode()).type1 == PAYLOAD_INDEX);
1.254 + return arg1_.index;
1.255 + }
1.256 + int32_t stackOffset() const {
1.257 + JS_ASSERT(layoutFromMode(mode()).type1 == PAYLOAD_STACK_OFFSET);
1.258 + return arg1_.stackOffset;
1.259 + }
1.260 + Register reg() const {
1.261 + JS_ASSERT(layoutFromMode(mode()).type1 == PAYLOAD_GPR);
1.262 + return arg1_.gpr;
1.263 + }
1.264 + FloatRegister fpuReg() const {
1.265 + JS_ASSERT(layoutFromMode(mode()).type1 == PAYLOAD_FPU);
1.266 + return arg1_.fpu;
1.267 + }
1.268 + JSValueType knownType() const {
1.269 + JS_ASSERT(layoutFromMode(mode()).type1 == PAYLOAD_PACKED_TAG);
1.270 + return arg1_.type;
1.271 + }
1.272 +
1.273 + int32_t stackOffset2() const {
1.274 + JS_ASSERT(layoutFromMode(mode()).type2 == PAYLOAD_STACK_OFFSET);
1.275 + return arg2_.stackOffset;
1.276 + }
1.277 + Register reg2() const {
1.278 + JS_ASSERT(layoutFromMode(mode()).type2 == PAYLOAD_GPR);
1.279 + return arg2_.gpr;
1.280 + }
1.281 +
1.282 + public:
1.283 + void dump(FILE *fp) const;
1.284 +
1.285 + public:
1.286 + bool operator==(const RValueAllocation &rhs) const {
1.287 + if (mode_ != rhs.mode_)
1.288 + return false;
1.289 +
1.290 + const Layout &layout = layoutFromMode(mode());
1.291 + return equalPayloads(layout.type1, arg1_, rhs.arg1_) &&
1.292 + equalPayloads(layout.type2, arg2_, rhs.arg2_);
1.293 + }
1.294 +
1.295 + HashNumber hash() const;
1.296 +
1.297 + struct Hasher
1.298 + {
1.299 + typedef RValueAllocation Key;
1.300 + typedef Key Lookup;
1.301 + static HashNumber hash(const Lookup &v) {
1.302 + return v.hash();
1.303 + }
1.304 + static bool match(const Key &k, const Lookup &l) {
1.305 + return k == l;
1.306 + }
1.307 + };
1.308 +};
1.309 +
1.310 +class RecoverWriter;
1.311 +
1.312 +// Collects snapshots in a contiguous buffer, which is copied into IonScript
1.313 +// memory after code generation.
1.314 +class SnapshotWriter
1.315 +{
1.316 + CompactBufferWriter writer_;
1.317 + CompactBufferWriter allocWriter_;
1.318 +
1.319 + // Map RValueAllocations to an offset in the allocWriter_ buffer. This is
1.320 + // useful as value allocations are repeated frequently.
1.321 + typedef RValueAllocation RVA;
1.322 + typedef HashMap<RVA, uint32_t, RVA::Hasher, SystemAllocPolicy> RValueAllocMap;
1.323 + RValueAllocMap allocMap_;
1.324 +
1.325 + // This is only used to assert sanity.
1.326 + uint32_t allocWritten_;
1.327 +
1.328 + // Used to report size of the snapshot in the spew messages.
1.329 + SnapshotOffset lastStart_;
1.330 +
1.331 + public:
1.332 + bool init();
1.333 +
1.334 + SnapshotOffset startSnapshot(RecoverOffset recoverOffset, BailoutKind kind);
1.335 +#ifdef TRACK_SNAPSHOTS
1.336 + void trackSnapshot(uint32_t pcOpcode, uint32_t mirOpcode, uint32_t mirId,
1.337 + uint32_t lirOpcode, uint32_t lirId);
1.338 +#endif
1.339 + bool add(const RValueAllocation &slot);
1.340 +
1.341 + uint32_t allocWritten() const {
1.342 + return allocWritten_;
1.343 + }
1.344 + void endSnapshot();
1.345 +
1.346 + bool oom() const {
1.347 + return writer_.oom() || writer_.length() >= MAX_BUFFER_SIZE ||
1.348 + allocWriter_.oom() || allocWriter_.length() >= MAX_BUFFER_SIZE;
1.349 + }
1.350 +
1.351 + size_t listSize() const {
1.352 + return writer_.length();
1.353 + }
1.354 + const uint8_t *listBuffer() const {
1.355 + return writer_.buffer();
1.356 + }
1.357 +
1.358 + size_t RVATableSize() const {
1.359 + return allocWriter_.length();
1.360 + }
1.361 + const uint8_t *RVATableBuffer() const {
1.362 + return allocWriter_.buffer();
1.363 + }
1.364 +};
1.365 +
1.366 +class MResumePoint;
1.367 +
1.368 +class RecoverWriter
1.369 +{
1.370 + CompactBufferWriter writer_;
1.371 +
1.372 + uint32_t nframes_;
1.373 + uint32_t framesWritten_;
1.374 +
1.375 + public:
1.376 + SnapshotOffset startRecover(uint32_t frameCount, bool resumeAfter);
1.377 +
1.378 + bool writeFrame(const MResumePoint *rp);
1.379 +
1.380 + void endRecover();
1.381 +
1.382 + size_t size() const {
1.383 + return writer_.length();
1.384 + }
1.385 + const uint8_t *buffer() const {
1.386 + return writer_.buffer();
1.387 + }
1.388 +
1.389 + bool oom() const {
1.390 + return writer_.oom() || writer_.length() >= MAX_BUFFER_SIZE;
1.391 + }
1.392 +};
1.393 +
1.394 +class RecoverReader;
1.395 +
1.396 +// A snapshot reader reads the entries out of the compressed snapshot buffer in
1.397 +// a script. These entries describe the equivalent interpreter frames at a given
1.398 +// position in JIT code. Each entry is an Ion's value allocations, used to
1.399 +// recover the corresponding Value from an Ion frame.
1.400 +class SnapshotReader
1.401 +{
1.402 + CompactBufferReader reader_;
1.403 + CompactBufferReader allocReader_;
1.404 + const uint8_t* allocTable_;
1.405 +
1.406 + BailoutKind bailoutKind_;
1.407 + uint32_t allocRead_; // Number of slots that have been read.
1.408 + RecoverOffset recoverOffset_; // Offset of the recover instructions.
1.409 +
1.410 +#ifdef TRACK_SNAPSHOTS
1.411 + private:
1.412 + uint32_t pcOpcode_;
1.413 + uint32_t mirOpcode_;
1.414 + uint32_t mirId_;
1.415 + uint32_t lirOpcode_;
1.416 + uint32_t lirId_;
1.417 +
1.418 + public:
1.419 + void readTrackSnapshot();
1.420 + void spewBailingFrom() const;
1.421 +#endif
1.422 +
1.423 + private:
1.424 + void readSnapshotHeader();
1.425 + uint32_t readAllocationIndex();
1.426 +
1.427 + public:
1.428 + SnapshotReader(const uint8_t *snapshots, uint32_t offset,
1.429 + uint32_t RVATableSize, uint32_t listSize);
1.430 +
1.431 + RValueAllocation readAllocation();
1.432 + void skipAllocation() {
1.433 + readAllocationIndex();
1.434 + }
1.435 +
1.436 + BailoutKind bailoutKind() const {
1.437 + return bailoutKind_;
1.438 + }
1.439 + RecoverOffset recoverOffset() const {
1.440 + return recoverOffset_;
1.441 + }
1.442 +
1.443 + uint32_t numAllocationsRead() const {
1.444 + return allocRead_;
1.445 + }
1.446 + void resetNumAllocationsRead() {
1.447 + allocRead_ = 0;
1.448 + }
1.449 +};
1.450 +
1.451 +typedef mozilla::AlignedStorage<4 * sizeof(uint32_t)> RInstructionStorage;
1.452 +class RInstruction;
1.453 +
1.454 +class RecoverReader
1.455 +{
1.456 + CompactBufferReader reader_;
1.457 +
1.458 + // Number of encoded instructions.
1.459 + uint32_t numInstructions_;
1.460 +
1.461 + // Number of instruction read.
1.462 + uint32_t numInstructionsRead_;
1.463 +
1.464 + // True if we need to resume after the Resume Point instruction of the
1.465 + // innermost frame.
1.466 + bool resumeAfter_;
1.467 +
1.468 + // Space is reserved as part of the RecoverReader to avoid allocations of
1.469 + // data which is needed to decode the current instruction.
1.470 + RInstructionStorage rawData_;
1.471 +
1.472 + private:
1.473 + void readRecoverHeader();
1.474 + void readInstruction();
1.475 +
1.476 + public:
1.477 + RecoverReader(SnapshotReader &snapshot, const uint8_t *recovers, uint32_t size);
1.478 +
1.479 + bool moreInstructions() const {
1.480 + return numInstructionsRead_ < numInstructions_;
1.481 + }
1.482 + void nextInstruction() {
1.483 + readInstruction();
1.484 + }
1.485 +
1.486 + const RInstruction *instruction() const {
1.487 + return reinterpret_cast<const RInstruction *>(rawData_.addr());
1.488 + }
1.489 +
1.490 + bool resumeAfter() const {
1.491 + return resumeAfter_;
1.492 + }
1.493 +};
1.494 +
1.495 +}
1.496 +}
1.497 +
1.498 +#endif /* jit_Snapshot_h */
