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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /js/src/jit/MIRGraph.cpp
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/jit/MIRGraph.cpp')
-rw-r--r--js/src/jit/MIRGraph.cpp1414
1 files changed, 1414 insertions, 0 deletions
diff --git a/js/src/jit/MIRGraph.cpp b/js/src/jit/MIRGraph.cpp
new file mode 100644
index 0000000000..86a2bf4ad3
--- /dev/null
+++ b/js/src/jit/MIRGraph.cpp
@@ -0,0 +1,1414 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jit/MIRGraph.h"
+
+#include "jit/CompileInfo.h"
+#include "jit/InlineScriptTree.h"
+#include "jit/IonOptimizationLevels.h"
+#include "jit/JitSpewer.h"
+#include "jit/MIR.h"
+#include "jit/MIRGenerator.h"
+
+using namespace js;
+using namespace js::jit;
+
+MIRGenerator::MIRGenerator(CompileRealm* realm,
+ const JitCompileOptions& options,
+ TempAllocator* alloc, MIRGraph* graph,
+ const CompileInfo* info,
+ const OptimizationInfo* optimizationInfo)
+ : realm(realm),
+ runtime(realm ? realm->runtime() : nullptr),
+ outerInfo_(info),
+ optimizationInfo_(optimizationInfo),
+ alloc_(alloc),
+ graph_(graph),
+ offThreadStatus_(Ok()),
+ cancelBuild_(false),
+ wasmMaxStackArgBytes_(0),
+ needsOverrecursedCheck_(false),
+ needsStaticStackAlignment_(false),
+ instrumentedProfiling_(false),
+ instrumentedProfilingIsCached_(false),
+ stringsCanBeInNursery_(realm ? realm->zone()->canNurseryAllocateStrings()
+ : false),
+ bigIntsCanBeInNursery_(realm ? realm->zone()->canNurseryAllocateBigInts()
+ : false),
+ minWasmHeapLength_(0),
+ options(options),
+ gs_(alloc) {}
+
+bool MIRGenerator::licmEnabled() const {
+ return optimizationInfo().licmEnabled() && !disableLICM_ &&
+ !outerInfo().hadLICMInvalidation();
+}
+
+mozilla::GenericErrorResult<AbortReason> MIRGenerator::abort(AbortReason r) {
+ if (JitSpewEnabled(JitSpew_IonAbort)) {
+ switch (r) {
+ case AbortReason::Alloc:
+ JitSpew(JitSpew_IonAbort, "AbortReason::Alloc");
+ break;
+ case AbortReason::Disable:
+ JitSpew(JitSpew_IonAbort, "AbortReason::Disable");
+ break;
+ case AbortReason::Error:
+ JitSpew(JitSpew_IonAbort, "AbortReason::Error");
+ break;
+ case AbortReason::NoAbort:
+ MOZ_CRASH("Abort with AbortReason::NoAbort");
+ break;
+ }
+ }
+ return Err(std::move(r));
+}
+
+mozilla::GenericErrorResult<AbortReason> MIRGenerator::abortFmt(
+ AbortReason r, const char* message, va_list ap) {
+ JitSpewVA(JitSpew_IonAbort, message, ap);
+ return Err(std::move(r));
+}
+
+mozilla::GenericErrorResult<AbortReason> MIRGenerator::abort(
+ AbortReason r, const char* message, ...) {
+ va_list ap;
+ va_start(ap, message);
+ auto forward = abortFmt(r, message, ap);
+ va_end(ap);
+ return forward;
+}
+
+void MIRGraph::addBlock(MBasicBlock* block) {
+ MOZ_ASSERT(block);
+ block->setId(blockIdGen_++);
+ blocks_.pushBack(block);
+ numBlocks_++;
+}
+
+void MIRGraph::insertBlockAfter(MBasicBlock* at, MBasicBlock* block) {
+ block->setId(blockIdGen_++);
+ blocks_.insertAfter(at, block);
+ numBlocks_++;
+}
+
+void MIRGraph::insertBlockBefore(MBasicBlock* at, MBasicBlock* block) {
+ block->setId(blockIdGen_++);
+ blocks_.insertBefore(at, block);
+ numBlocks_++;
+}
+
+void MIRGraph::removeBlock(MBasicBlock* block) {
+ // Remove a block from the graph. It will also cleanup the block.
+
+ if (block == osrBlock_) {
+ osrBlock_ = nullptr;
+ }
+
+ if (returnAccumulator_) {
+ size_t i = 0;
+ while (i < returnAccumulator_->length()) {
+ if ((*returnAccumulator_)[i] == block) {
+ returnAccumulator_->erase(returnAccumulator_->begin() + i);
+ } else {
+ i++;
+ }
+ }
+ }
+
+ block->clear();
+ block->markAsDead();
+
+ if (block->isInList()) {
+ blocks_.remove(block);
+ numBlocks_--;
+ }
+}
+
+void MIRGraph::unmarkBlocks() {
+ for (MBasicBlockIterator i(blocks_.begin()); i != blocks_.end(); i++) {
+ i->unmark();
+ }
+}
+
+MBasicBlock* MBasicBlock::New(MIRGraph& graph, size_t stackDepth,
+ const CompileInfo& info, MBasicBlock* maybePred,
+ BytecodeSite* site, Kind kind) {
+ MOZ_ASSERT(site->pc() != nullptr);
+
+ MBasicBlock* block = new (graph.alloc()) MBasicBlock(graph, info, site, kind);
+ if (!block->init()) {
+ return nullptr;
+ }
+
+ if (!block->inherit(graph.alloc(), stackDepth, maybePred, 0)) {
+ return nullptr;
+ }
+
+ return block;
+}
+
+MBasicBlock* MBasicBlock::NewPopN(MIRGraph& graph, const CompileInfo& info,
+ MBasicBlock* pred, BytecodeSite* site,
+ Kind kind, uint32_t popped) {
+ MOZ_ASSERT(site->pc() != nullptr);
+
+ MBasicBlock* block = new (graph.alloc()) MBasicBlock(graph, info, site, kind);
+ if (!block->init()) {
+ return nullptr;
+ }
+
+ if (!block->inherit(graph.alloc(), pred->stackDepth(), pred, popped)) {
+ return nullptr;
+ }
+
+ return block;
+}
+
+MBasicBlock* MBasicBlock::NewPendingLoopHeader(MIRGraph& graph,
+ const CompileInfo& info,
+ MBasicBlock* pred,
+ BytecodeSite* site) {
+ MOZ_ASSERT(site->pc() != nullptr);
+
+ MBasicBlock* block =
+ new (graph.alloc()) MBasicBlock(graph, info, site, PENDING_LOOP_HEADER);
+ if (!block->init()) {
+ return nullptr;
+ }
+
+ if (!block->inherit(graph.alloc(), pred->stackDepth(), pred, 0)) {
+ return nullptr;
+ }
+
+ return block;
+}
+
+MBasicBlock* MBasicBlock::NewSplitEdge(MIRGraph& graph, MBasicBlock* pred,
+ size_t predEdgeIdx, MBasicBlock* succ) {
+ MBasicBlock* split = nullptr;
+ if (!succ->pc()) {
+ // The predecessor does not have a PC, this is a Wasm compilation.
+ split = MBasicBlock::New(graph, succ->info(), pred, SPLIT_EDGE);
+ if (!split) {
+ return nullptr;
+ }
+
+ // Insert the split edge block in-between.
+ split->end(MGoto::New(graph.alloc(), succ));
+ } else {
+ // The predecessor has a PC, this is a Warp compilation.
+ MResumePoint* succEntry = succ->entryResumePoint();
+
+ BytecodeSite* site =
+ new (graph.alloc()) BytecodeSite(succ->trackedTree(), succEntry->pc());
+ split =
+ new (graph.alloc()) MBasicBlock(graph, succ->info(), site, SPLIT_EDGE);
+
+ if (!split->init()) {
+ return nullptr;
+ }
+
+ // A split edge is used to simplify the graph to avoid having a
+ // predecessor with multiple successors as well as a successor with
+ // multiple predecessors. As instructions can be moved in this
+ // split-edge block, we need to give this block a resume point. To do
+ // so, we copy the entry resume points of the successor and filter the
+ // phis to keep inputs from the current edge.
+
+ // Propagate the caller resume point from the inherited block.
+ split->callerResumePoint_ = succ->callerResumePoint();
+
+ // Split-edge are created after the interpreter stack emulation. Thus,
+ // there is no need for creating slots.
+ split->stackPosition_ = succEntry->stackDepth();
+
+ // Create a resume point using our initial stack position.
+ MResumePoint* splitEntry = new (graph.alloc())
+ MResumePoint(split, succEntry->pc(), ResumeMode::ResumeAt);
+ if (!splitEntry->init(graph.alloc())) {
+ return nullptr;
+ }
+ split->entryResumePoint_ = splitEntry;
+
+ // Insert the split edge block in-between.
+ split->end(MGoto::New(graph.alloc(), succ));
+
+ // The target entry resume point might have phi operands, keep the
+ // operands of the phi coming from our edge.
+ size_t succEdgeIdx = succ->indexForPredecessor(pred);
+
+ for (size_t i = 0, e = splitEntry->numOperands(); i < e; i++) {
+ MDefinition* def = succEntry->getOperand(i);
+ // This early in the pipeline, we have no recover instructions in
+ // any entry resume point.
+ if (def->block() == succ) {
+ if (def->isPhi()) {
+ def = def->toPhi()->getOperand(succEdgeIdx);
+ } else {
+ // The phi-operand may already have been optimized out.
+ MOZ_ASSERT(def->isConstant());
+ MOZ_ASSERT(def->type() == MIRType::MagicOptimizedOut);
+
+ def = split->optimizedOutConstant(graph.alloc());
+ }
+ }
+
+ splitEntry->initOperand(i, def);
+ }
+
+ // This is done in the New variant for wasm, so we cannot keep this
+ // line below, where the rest of the graph is modified.
+ if (!split->predecessors_.append(pred)) {
+ return nullptr;
+ }
+ }
+
+ split->setLoopDepth(succ->loopDepth());
+
+ graph.insertBlockAfter(pred, split);
+
+ pred->replaceSuccessor(predEdgeIdx, split);
+ succ->replacePredecessor(pred, split);
+ return split;
+}
+
+void MBasicBlock::moveToNewBlock(MInstruction* ins, MBasicBlock* dst) {
+ MOZ_ASSERT(ins->block() == this);
+ MOZ_ASSERT(!dst->hasLastIns());
+ instructions_.remove(ins);
+ ins->setInstructionBlock(dst, dst->trackedSite());
+ if (MResumePoint* rp = ins->resumePoint()) {
+ removeResumePoint(rp);
+ dst->addResumePoint(rp);
+ rp->setBlock(dst);
+ }
+ dst->instructions_.pushBack(ins);
+}
+
+void MBasicBlock::moveOuterResumePointTo(MBasicBlock* dest) {
+ if (MResumePoint* outer = outerResumePoint()) {
+ removeResumePoint(outer);
+ outerResumePoint_ = nullptr;
+ dest->setOuterResumePoint(outer);
+ dest->addResumePoint(outer);
+ outer->setBlock(dest);
+ }
+}
+
+bool MBasicBlock::wrapInstructionInFastpath(MInstruction* ins,
+ MInstruction* fastpath,
+ MInstruction* condition) {
+ MOZ_ASSERT(ins->block() == this);
+ MOZ_ASSERT(!ins->isControlInstruction());
+
+ MInstructionIterator rest(begin(ins));
+ rest++;
+
+ MResumePoint* resumeBeforeIns = activeResumePoint(ins);
+ MResumePoint* resumeAfterIns = activeResumePoint(*rest);
+
+ // Create the join block.
+ MBasicBlock* join = MBasicBlock::NewInternal(graph_, this, resumeAfterIns);
+ if (!join) {
+ return false;
+ }
+
+ // Update the successors of the current block.
+ for (uint32_t i = 0; i < numSuccessors(); i++) {
+ getSuccessor(i)->replacePredecessor(this, join);
+ }
+ if (successorWithPhis()) {
+ join->setSuccessorWithPhis(successorWithPhis(), positionInPhiSuccessor());
+ clearSuccessorWithPhis();
+ }
+
+ // Copy all instructions after |ins| into the join block.
+ while (rest != end()) {
+ MInstruction* ins = *rest++;
+ moveToNewBlock(ins, join);
+ }
+ MOZ_ASSERT(!hasLastIns());
+ MOZ_ASSERT(join->hasLastIns());
+
+ graph_.insertBlockAfter(this, join);
+
+ // Create the fast path block.
+ MBasicBlock* fastpathBlock =
+ MBasicBlock::NewInternal(graph_, this, resumeBeforeIns);
+ if (!fastpathBlock) {
+ return false;
+ }
+ graph_.insertBlockAfter(this, fastpathBlock);
+ fastpathBlock->add(fastpath);
+ fastpathBlock->end(MGoto::New(graph_.alloc(), join));
+
+ // Create the slowpath block.
+ MBasicBlock* slowpathBlock =
+ MBasicBlock::NewInternal(graph_, this, resumeBeforeIns);
+ if (!slowpathBlock) {
+ return false;
+ }
+ graph_.insertBlockAfter(fastpathBlock, slowpathBlock);
+ moveToNewBlock(ins, slowpathBlock);
+ slowpathBlock->end(MGoto::New(graph_.alloc(), join));
+
+ // Connect current block to fastpath and slowpath.
+ add(condition);
+ end(MTest::New(graph_.alloc(), condition, fastpathBlock, slowpathBlock));
+
+ // Update predecessors.
+ if (!fastpathBlock->addPredecessorWithoutPhis(this) ||
+ !slowpathBlock->addPredecessorWithoutPhis(this) ||
+ !join->addPredecessorWithoutPhis(fastpathBlock) ||
+ !join->addPredecessorWithoutPhis(slowpathBlock)) {
+ return false;
+ }
+
+ if (ins->hasUses()) {
+ // Insert phi.
+ MPhi* phi = MPhi::New(graph_.alloc());
+ if (!phi->reserveLength(2)) {
+ return false;
+ }
+ phi->addInput(fastpath);
+ fastpathBlock->setSuccessorWithPhis(join, 0);
+ phi->addInput(ins);
+ slowpathBlock->setSuccessorWithPhis(join, 1);
+ join->addPhi(phi);
+
+ for (MUseIterator i(ins->usesBegin()), e(ins->usesEnd()); i != e;) {
+ MUse* use = *i++;
+ if (use->consumer() != phi && use->consumer() != ins->resumePoint()) {
+ use->replaceProducer(phi);
+ }
+ }
+ }
+
+ moveOuterResumePointTo(join);
+
+ return true;
+}
+
+MBasicBlock* MBasicBlock::NewInternal(MIRGraph& graph, MBasicBlock* orig,
+ MResumePoint* resumePoint) {
+ jsbytecode* pc = IsResumeAfter(resumePoint->mode())
+ ? GetNextPc(resumePoint->pc())
+ : resumePoint->pc();
+
+ BytecodeSite* site =
+ new (graph.alloc()) BytecodeSite(orig->trackedTree(), pc);
+ MBasicBlock* block =
+ new (graph.alloc()) MBasicBlock(graph, orig->info(), site, INTERNAL);
+ if (!block->init()) {
+ return nullptr;
+ }
+
+ // Propagate the caller resume point from the original block.
+ block->callerResumePoint_ = orig->callerResumePoint();
+
+ // Copy the resume point.
+ block->stackPosition_ = resumePoint->stackDepth();
+ MResumePoint* entryResumePoint =
+ new (graph.alloc()) MResumePoint(block, pc, ResumeMode::ResumeAt);
+ if (!entryResumePoint->init(graph.alloc())) {
+ return nullptr;
+ }
+ for (size_t i = 0; i < resumePoint->stackDepth(); i++) {
+ entryResumePoint->initOperand(i, resumePoint->getOperand(i));
+ }
+ block->entryResumePoint_ = entryResumePoint;
+
+ block->setLoopDepth(orig->loopDepth());
+
+ return block;
+}
+
+MBasicBlock* MBasicBlock::New(MIRGraph& graph, const CompileInfo& info,
+ MBasicBlock* pred, Kind kind) {
+ BytecodeSite* site = new (graph.alloc()) BytecodeSite();
+ MBasicBlock* block = new (graph.alloc()) MBasicBlock(graph, info, site, kind);
+ if (!block->init()) {
+ return nullptr;
+ }
+
+ if (pred) {
+ block->stackPosition_ = pred->stackPosition_;
+
+ if (block->kind_ == PENDING_LOOP_HEADER) {
+ size_t nphis = block->stackPosition_;
+
+ size_t nfree = graph.phiFreeListLength();
+
+ TempAllocator& alloc = graph.alloc();
+ MPhi* phis = nullptr;
+ if (nphis > nfree) {
+ phis = alloc.allocateArray<MPhi>(nphis - nfree);
+ if (!phis) {
+ return nullptr;
+ }
+ }
+
+ // Note: Phis are inserted in the same order as the slots.
+ for (size_t i = 0; i < nphis; i++) {
+ MDefinition* predSlot = pred->getSlot(i);
+
+ MOZ_ASSERT(predSlot->type() != MIRType::Value);
+
+ MPhi* phi;
+ if (i < nfree) {
+ phi = graph.takePhiFromFreeList();
+ } else {
+ phi = phis + (i - nfree);
+ }
+ new (phi) MPhi(alloc, predSlot->type());
+
+ phi->addInlineInput(predSlot);
+
+ // Add append Phis in the block.
+ block->addPhi(phi);
+ block->setSlot(i, phi);
+ }
+ } else {
+ if (!block->ensureHasSlots(0)) {
+ return nullptr;
+ }
+ block->copySlots(pred);
+ }
+
+ if (!block->predecessors_.append(pred)) {
+ return nullptr;
+ }
+ }
+
+ return block;
+}
+
+// Create an empty and unreachable block which jumps to |header|. Used
+// when the normal entry into a loop is removed (but the loop is still
+// reachable due to OSR) to preserve the invariant that every loop
+// header has two predecessors, which is needed for building the
+// dominator tree. The new block is inserted immediately before the
+// header, which preserves the graph ordering (post-order/RPO). These
+// blocks will all be removed before lowering.
+MBasicBlock* MBasicBlock::NewFakeLoopPredecessor(MIRGraph& graph,
+ MBasicBlock* header) {
+ MOZ_ASSERT(graph.osrBlock());
+
+ MBasicBlock* backedge = header->backedge();
+ MBasicBlock* fake = MBasicBlock::New(graph, header->info(), nullptr,
+ MBasicBlock::FAKE_LOOP_PRED);
+ if (!fake) {
+ return nullptr;
+ }
+
+ graph.insertBlockBefore(header, fake);
+ fake->setUnreachable();
+
+ // Create fake defs to use as inputs for any phis in |header|.
+ for (MPhiIterator iter(header->phisBegin()), end(header->phisEnd());
+ iter != end; ++iter) {
+ if (!graph.alloc().ensureBallast()) {
+ return nullptr;
+ }
+ MPhi* phi = *iter;
+ auto* fakeDef = MUnreachableResult::New(graph.alloc(), phi->type());
+ fake->add(fakeDef);
+ if (!phi->addInputSlow(fakeDef)) {
+ return nullptr;
+ }
+ }
+
+ fake->end(MGoto::New(graph.alloc(), header));
+
+ if (!header->addPredecessorWithoutPhis(fake)) {
+ return nullptr;
+ }
+
+ // The backedge is always the last predecessor, but we have added a
+ // new pred. Restore |backedge| as |header|'s loop backedge.
+ header->clearLoopHeader();
+ header->setLoopHeader(backedge);
+
+ return fake;
+}
+
+void MIRGraph::removeFakeLoopPredecessors() {
+ MOZ_ASSERT(osrBlock());
+ size_t id = 0;
+ for (ReversePostorderIterator it = rpoBegin(); it != rpoEnd();) {
+ MBasicBlock* block = *it++;
+ if (block->isFakeLoopPred()) {
+ MOZ_ASSERT(block->unreachable());
+ MBasicBlock* succ = block->getSingleSuccessor();
+ succ->removePredecessor(block);
+ removeBlock(block);
+ } else {
+ block->setId(id++);
+ }
+ }
+#ifdef DEBUG
+ canBuildDominators_ = false;
+#endif
+}
+
+MBasicBlock::MBasicBlock(MIRGraph& graph, const CompileInfo& info,
+ BytecodeSite* site, Kind kind)
+ : graph_(graph),
+ info_(info),
+ predecessors_(graph.alloc()),
+ stackPosition_(info_.firstStackSlot()),
+ id_(0),
+ domIndex_(0),
+ numDominated_(0),
+ lir_(nullptr),
+ callerResumePoint_(nullptr),
+ entryResumePoint_(nullptr),
+ outerResumePoint_(nullptr),
+ successorWithPhis_(nullptr),
+ positionInPhiSuccessor_(0),
+ loopDepth_(0),
+ kind_(kind),
+ mark_(false),
+ immediatelyDominated_(graph.alloc()),
+ immediateDominator_(nullptr),
+ trackedSite_(site),
+ lineno_(0u),
+ columnIndex_(0u) {
+ MOZ_ASSERT(trackedSite_, "trackedSite_ is non-nullptr");
+}
+
+bool MBasicBlock::init() { return slots_.init(graph_.alloc(), info_.nslots()); }
+
+bool MBasicBlock::increaseSlots(size_t num) {
+ return slots_.growBy(graph_.alloc(), num);
+}
+
+bool MBasicBlock::ensureHasSlots(size_t num) {
+ size_t depth = stackDepth() + num;
+ if (depth > nslots()) {
+ if (!increaseSlots(depth - nslots())) {
+ return false;
+ }
+ }
+ return true;
+}
+
+void MBasicBlock::copySlots(MBasicBlock* from) {
+ MOZ_ASSERT(stackPosition_ <= from->stackPosition_);
+ MOZ_ASSERT(stackPosition_ <= nslots());
+
+ MDefinition** thisSlots = slots_.begin();
+ MDefinition** fromSlots = from->slots_.begin();
+ for (size_t i = 0, e = stackPosition_; i < e; ++i) {
+ thisSlots[i] = fromSlots[i];
+ }
+}
+
+bool MBasicBlock::inherit(TempAllocator& alloc, size_t stackDepth,
+ MBasicBlock* maybePred, uint32_t popped) {
+ MOZ_ASSERT_IF(maybePred, maybePred->stackDepth() == stackDepth);
+
+ MOZ_ASSERT(stackDepth >= popped);
+ stackDepth -= popped;
+ stackPosition_ = stackDepth;
+
+ if (maybePred && kind_ != PENDING_LOOP_HEADER) {
+ copySlots(maybePred);
+ }
+
+ MOZ_ASSERT(info_.nslots() >= stackPosition_);
+ MOZ_ASSERT(!entryResumePoint_);
+
+ // Propagate the caller resume point from the inherited block.
+ callerResumePoint_ = maybePred ? maybePred->callerResumePoint() : nullptr;
+
+ // Create a resume point using our initial stack state.
+ entryResumePoint_ =
+ new (alloc) MResumePoint(this, pc(), ResumeMode::ResumeAt);
+ if (!entryResumePoint_->init(alloc)) {
+ return false;
+ }
+
+ if (maybePred) {
+ if (!predecessors_.append(maybePred)) {
+ return false;
+ }
+
+ if (kind_ == PENDING_LOOP_HEADER) {
+ for (size_t i = 0; i < stackDepth; i++) {
+ MPhi* phi = MPhi::New(alloc.fallible());
+ if (!phi) {
+ return false;
+ }
+ phi->addInlineInput(maybePred->getSlot(i));
+ addPhi(phi);
+ setSlot(i, phi);
+ entryResumePoint()->initOperand(i, phi);
+ }
+ } else {
+ for (size_t i = 0; i < stackDepth; i++) {
+ entryResumePoint()->initOperand(i, getSlot(i));
+ }
+ }
+ } else {
+ /*
+ * Don't leave the operands uninitialized for the caller, as it may not
+ * initialize them later on.
+ */
+ for (size_t i = 0; i < stackDepth; i++) {
+ entryResumePoint()->clearOperand(i);
+ }
+ }
+
+ return true;
+}
+
+void MBasicBlock::inheritSlots(MBasicBlock* parent) {
+ stackPosition_ = parent->stackPosition_;
+ copySlots(parent);
+}
+
+bool MBasicBlock::initEntrySlots(TempAllocator& alloc) {
+ // Remove the previous resume point.
+ discardResumePoint(entryResumePoint_);
+
+ // Create a resume point using our initial stack state.
+ entryResumePoint_ =
+ MResumePoint::New(alloc, this, pc(), ResumeMode::ResumeAt);
+ if (!entryResumePoint_) {
+ return false;
+ }
+ return true;
+}
+
+MDefinition* MBasicBlock::environmentChain() {
+ return getSlot(info().environmentChainSlot());
+}
+
+MDefinition* MBasicBlock::argumentsObject() {
+ return getSlot(info().argsObjSlot());
+}
+
+void MBasicBlock::setEnvironmentChain(MDefinition* scopeObj) {
+ setSlot(info().environmentChainSlot(), scopeObj);
+}
+
+void MBasicBlock::setArgumentsObject(MDefinition* argsObj) {
+ setSlot(info().argsObjSlot(), argsObj);
+}
+
+void MBasicBlock::pick(int32_t depth) {
+ // pick takes a value and moves it to the top.
+ // pick(-2):
+ // A B C D E
+ // A B D C E [ swapAt(-2) ]
+ // A B D E C [ swapAt(-1) ]
+ for (; depth < 0; depth++) {
+ swapAt(depth);
+ }
+}
+
+void MBasicBlock::unpick(int32_t depth) {
+ // unpick takes the value on top of the stack and moves it under the depth-th
+ // element;
+ // unpick(-2):
+ // A B C D E
+ // A B C E D [ swapAt(-1) ]
+ // A B E C D [ swapAt(-2) ]
+ for (int32_t n = -1; n >= depth; n--) {
+ swapAt(n);
+ }
+}
+
+void MBasicBlock::swapAt(int32_t depth) {
+ uint32_t lhsDepth = stackPosition_ + depth - 1;
+ uint32_t rhsDepth = stackPosition_ + depth;
+
+ MDefinition* temp = slots_[lhsDepth];
+ slots_[lhsDepth] = slots_[rhsDepth];
+ slots_[rhsDepth] = temp;
+}
+
+void MBasicBlock::discardLastIns() { discard(lastIns()); }
+
+MConstant* MBasicBlock::optimizedOutConstant(TempAllocator& alloc) {
+ // If the first instruction is a MConstant(MagicValue(JS_OPTIMIZED_OUT))
+ // then reuse it.
+ MInstruction* ins = *begin();
+ if (ins->type() == MIRType::MagicOptimizedOut) {
+ return ins->toConstant();
+ }
+
+ MConstant* constant = MConstant::New(alloc, MagicValue(JS_OPTIMIZED_OUT));
+ insertBefore(ins, constant);
+ return constant;
+}
+
+void MBasicBlock::moveBefore(MInstruction* at, MInstruction* ins) {
+ // Remove |ins| from the current block.
+ MOZ_ASSERT(ins->block() == this);
+ instructions_.remove(ins);
+
+ // Insert into new block, which may be distinct.
+ // Uses and operands are untouched.
+ ins->setInstructionBlock(at->block(), at->trackedSite());
+ at->block()->instructions_.insertBefore(at, ins);
+}
+
+MInstruction* MBasicBlock::safeInsertTop(MDefinition* ins, IgnoreTop ignore) {
+ MOZ_ASSERT(graph().osrBlock() != this,
+ "We are not supposed to add any instruction in OSR blocks.");
+
+ // Beta nodes and interrupt checks are required to be located at the
+ // beginnings of basic blocks, so we must insert new instructions after any
+ // such instructions.
+ MInstructionIterator insertIter =
+ !ins || ins->isPhi() ? begin() : begin(ins->toInstruction());
+ while (insertIter->isBeta() || insertIter->isInterruptCheck() ||
+ insertIter->isConstant() || insertIter->isParameter() ||
+ (!(ignore & IgnoreRecover) && insertIter->isRecoveredOnBailout())) {
+ insertIter++;
+ }
+
+ return *insertIter;
+}
+
+void MBasicBlock::discardResumePoint(
+ MResumePoint* rp, ReferencesType refType /* = RefType_Default */) {
+ if (refType & RefType_DiscardOperands) {
+ rp->releaseUses();
+ }
+ rp->setDiscarded();
+ removeResumePoint(rp);
+}
+
+void MBasicBlock::removeResumePoint(MResumePoint* rp) {
+#ifdef DEBUG
+ MResumePointIterator iter = resumePointsBegin();
+ while (*iter != rp) {
+ // We should reach it before reaching the end.
+ MOZ_ASSERT(iter != resumePointsEnd());
+ iter++;
+ }
+ resumePoints_.removeAt(iter);
+#endif
+}
+
+void MBasicBlock::prepareForDiscard(
+ MInstruction* ins, ReferencesType refType /* = RefType_Default */) {
+ // Only remove instructions from the same basic block. This is needed for
+ // correctly removing the resume point if any.
+ MOZ_ASSERT(ins->block() == this);
+
+ MResumePoint* rp = ins->resumePoint();
+ if ((refType & RefType_DiscardResumePoint) && rp) {
+ discardResumePoint(rp, refType);
+ }
+
+ // We need to assert that instructions have no uses after removing the their
+ // resume points operands as they could be captured by their own resume
+ // point.
+ MOZ_ASSERT_IF(refType & RefType_AssertNoUses, !ins->hasUses());
+
+ const uint32_t InstructionOperands =
+ RefType_DiscardOperands | RefType_DiscardInstruction;
+ if ((refType & InstructionOperands) == InstructionOperands) {
+ for (size_t i = 0, e = ins->numOperands(); i < e; i++) {
+ ins->releaseOperand(i);
+ }
+ }
+
+ ins->setDiscarded();
+}
+
+void MBasicBlock::discard(MInstruction* ins) {
+ prepareForDiscard(ins);
+ instructions_.remove(ins);
+}
+
+void MBasicBlock::discardIgnoreOperands(MInstruction* ins) {
+#ifdef DEBUG
+ for (size_t i = 0, e = ins->numOperands(); i < e; i++) {
+ MOZ_ASSERT(!ins->hasOperand(i));
+ }
+#endif
+
+ prepareForDiscard(ins, RefType_IgnoreOperands);
+ instructions_.remove(ins);
+}
+
+void MBasicBlock::discardAllInstructions() {
+ MInstructionIterator iter = begin();
+ discardAllInstructionsStartingAt(iter);
+}
+
+void MBasicBlock::discardAllInstructionsStartingAt(MInstructionIterator iter) {
+ while (iter != end()) {
+ // Discard operands and resume point operands and flag the instruction
+ // as discarded. Also we do not assert that we have no uses as blocks
+ // might be removed in reverse post order.
+ MInstruction* ins = *iter++;
+ prepareForDiscard(ins, RefType_DefaultNoAssert);
+ instructions_.remove(ins);
+ }
+}
+
+void MBasicBlock::discardAllPhis() {
+ for (MPhiIterator iter = phisBegin(); iter != phisEnd(); iter++) {
+ iter->removeAllOperands();
+ }
+
+ for (MBasicBlock** pred = predecessors_.begin(); pred != predecessors_.end();
+ pred++) {
+ (*pred)->clearSuccessorWithPhis();
+ }
+
+ phis_.clear();
+}
+
+void MBasicBlock::discardAllResumePoints(bool discardEntry) {
+ if (outerResumePoint_) {
+ clearOuterResumePoint();
+ }
+
+ if (discardEntry && entryResumePoint_) {
+ clearEntryResumePoint();
+ }
+
+#ifdef DEBUG
+ if (!entryResumePoint()) {
+ MOZ_ASSERT(resumePointsEmpty());
+ } else {
+ MResumePointIterator iter(resumePointsBegin());
+ MOZ_ASSERT(iter != resumePointsEnd());
+ iter++;
+ MOZ_ASSERT(iter == resumePointsEnd());
+ }
+#endif
+}
+
+void MBasicBlock::clear() {
+ discardAllInstructions();
+ discardAllResumePoints();
+ discardAllPhis();
+}
+
+void MBasicBlock::insertBefore(MInstruction* at, MInstruction* ins) {
+ MOZ_ASSERT(at->block() == this);
+ ins->setInstructionBlock(this, at->trackedSite());
+ graph().allocDefinitionId(ins);
+ instructions_.insertBefore(at, ins);
+}
+
+void MBasicBlock::insertAfter(MInstruction* at, MInstruction* ins) {
+ MOZ_ASSERT(at->block() == this);
+ ins->setInstructionBlock(this, at->trackedSite());
+ graph().allocDefinitionId(ins);
+ instructions_.insertAfter(at, ins);
+}
+
+void MBasicBlock::insertAtEnd(MInstruction* ins) {
+ if (hasLastIns()) {
+ insertBefore(lastIns(), ins);
+ } else {
+ add(ins);
+ }
+}
+
+void MBasicBlock::addPhi(MPhi* phi) {
+ phis_.pushBack(phi);
+ phi->setPhiBlock(this);
+ graph().allocDefinitionId(phi);
+}
+
+void MBasicBlock::discardPhi(MPhi* phi) {
+ MOZ_ASSERT(!phis_.empty());
+
+ phi->removeAllOperands();
+ phi->setDiscarded();
+
+ phis_.remove(phi);
+
+ if (phis_.empty()) {
+ for (MBasicBlock* pred : predecessors_) {
+ pred->clearSuccessorWithPhis();
+ }
+ }
+}
+
+MResumePoint* MBasicBlock::activeResumePoint(MInstruction* ins) {
+ for (MInstructionReverseIterator iter = rbegin(ins); iter != rend(); iter++) {
+ if (iter->resumePoint() && *iter != ins) {
+ return iter->resumePoint();
+ }
+ }
+
+ // If none, take the entry resume point.
+ return entryResumePoint();
+}
+
+void MBasicBlock::flagOperandsOfPrunedBranches(MInstruction* ins) {
+ MResumePoint* rp = activeResumePoint(ins);
+
+ // The only blocks which do not have any entryResumePoint in Ion, are the
+ // SplitEdge blocks. SplitEdge blocks only have a Goto instruction before
+ // Range Analysis phase. In adjustInputs, we are manipulating instructions
+ // which have a TypePolicy. So, as a Goto has no operand and no type
+ // policy, the entry resume point should exist.
+ MOZ_ASSERT(rp);
+
+ // Flag all operands as being potentially used.
+ while (rp) {
+ for (size_t i = 0, end = rp->numOperands(); i < end; i++) {
+ rp->getOperand(i)->setImplicitlyUsedUnchecked();
+ }
+ rp = rp->caller();
+ }
+}
+
+bool MBasicBlock::addPredecessor(TempAllocator& alloc, MBasicBlock* pred) {
+ return addPredecessorPopN(alloc, pred, 0);
+}
+
+bool MBasicBlock::addPredecessorPopN(TempAllocator& alloc, MBasicBlock* pred,
+ uint32_t popped) {
+ MOZ_ASSERT(pred);
+ MOZ_ASSERT(predecessors_.length() > 0);
+
+ // Predecessors must be finished, and at the correct stack depth.
+ MOZ_ASSERT(pred->hasLastIns());
+ MOZ_ASSERT(pred->stackPosition_ == stackPosition_ + popped);
+
+ for (uint32_t i = 0, e = stackPosition_; i < e; ++i) {
+ MDefinition* mine = getSlot(i);
+ MDefinition* other = pred->getSlot(i);
+
+ if (mine != other) {
+ MIRType phiType = mine->type();
+ if (phiType != other->type()) {
+ phiType = MIRType::Value;
+ }
+
+ // If the current instruction is a phi, and it was created in this
+ // basic block, then we have already placed this phi and should
+ // instead append to its operands.
+ if (mine->isPhi() && mine->block() == this) {
+ MOZ_ASSERT(predecessors_.length());
+ MOZ_ASSERT(!mine->hasDefUses(),
+ "should only change type of newly created phis");
+ mine->setResultType(phiType);
+ if (!mine->toPhi()->addInputSlow(other)) {
+ return false;
+ }
+ } else {
+ // Otherwise, create a new phi node.
+ MPhi* phi = MPhi::New(alloc.fallible(), phiType);
+ if (!phi) {
+ return false;
+ }
+ addPhi(phi);
+
+ // Prime the phi for each predecessor, so input(x) comes from
+ // predecessor(x).
+ if (!phi->reserveLength(predecessors_.length() + 1)) {
+ return false;
+ }
+
+ for (size_t j = 0, numPreds = predecessors_.length(); j < numPreds;
+ ++j) {
+ MOZ_ASSERT(predecessors_[j]->getSlot(i) == mine);
+ phi->addInput(mine);
+ }
+ phi->addInput(other);
+
+ setSlot(i, phi);
+ if (entryResumePoint()) {
+ entryResumePoint()->replaceOperand(i, phi);
+ }
+ }
+ }
+ }
+
+ return predecessors_.append(pred);
+}
+
+bool MBasicBlock::addPredecessorSameInputsAs(MBasicBlock* pred,
+ MBasicBlock* existingPred) {
+ MOZ_ASSERT(pred);
+ MOZ_ASSERT(predecessors_.length() > 0);
+
+ // Predecessors must be finished, and at the correct stack depth.
+ MOZ_ASSERT(pred->hasLastIns());
+ MOZ_ASSERT(!pred->successorWithPhis());
+
+ if (!phisEmpty()) {
+ size_t existingPosition = indexForPredecessor(existingPred);
+ for (MPhiIterator iter = phisBegin(); iter != phisEnd(); iter++) {
+ if (!iter->addInputSlow(iter->getOperand(existingPosition))) {
+ return false;
+ }
+ }
+ }
+
+ if (!predecessors_.append(pred)) {
+ return false;
+ }
+ return true;
+}
+
+bool MBasicBlock::addPredecessorWithoutPhis(MBasicBlock* pred) {
+ // Predecessors must be finished.
+ MOZ_ASSERT(pred && pred->hasLastIns());
+ return predecessors_.append(pred);
+}
+
+bool MBasicBlock::addImmediatelyDominatedBlock(MBasicBlock* child) {
+ return immediatelyDominated_.append(child);
+}
+
+void MBasicBlock::removeImmediatelyDominatedBlock(MBasicBlock* child) {
+ for (size_t i = 0;; ++i) {
+ MOZ_ASSERT(i < immediatelyDominated_.length(),
+ "Dominated block to remove not present");
+ if (immediatelyDominated_[i] == child) {
+ immediatelyDominated_[i] = immediatelyDominated_.back();
+ immediatelyDominated_.popBack();
+ return;
+ }
+ }
+}
+
+bool MBasicBlock::setBackedge(MBasicBlock* pred) {
+ // Predecessors must be finished, and at the correct stack depth.
+ MOZ_ASSERT(hasLastIns());
+ MOZ_ASSERT(pred->hasLastIns());
+ MOZ_ASSERT(pred->stackDepth() == entryResumePoint()->stackDepth());
+
+ // We must be a pending loop header
+ MOZ_ASSERT(kind_ == PENDING_LOOP_HEADER);
+
+ // Add exit definitions to each corresponding phi at the entry.
+ if (!inheritPhisFromBackedge(pred)) {
+ return false;
+ }
+
+ // We are now a loop header proper
+ kind_ = LOOP_HEADER;
+
+ return predecessors_.append(pred);
+}
+
+bool MBasicBlock::setBackedgeWasm(MBasicBlock* pred, size_t paramCount) {
+ // Predecessors must be finished, and at the correct stack depth.
+ MOZ_ASSERT(hasLastIns());
+ MOZ_ASSERT(pred->hasLastIns());
+ MOZ_ASSERT(stackDepth() + paramCount == pred->stackDepth());
+
+ // We must be a pending loop header
+ MOZ_ASSERT(kind_ == PENDING_LOOP_HEADER);
+
+ // Add exit definitions to each corresponding phi at the entry.
+ // Note: Phis are inserted in the same order as the slots. (see
+ // MBasicBlock::New)
+ size_t slot = 0;
+ for (MPhiIterator phi = phisBegin(); phi != phisEnd(); phi++, slot++) {
+ MPhi* entryDef = *phi;
+ MDefinition* exitDef = pred->getSlot(slot);
+
+ // Assert that we already placed phis for each slot.
+ MOZ_ASSERT(entryDef->block() == this);
+
+ // Assert that the phi already has the correct type.
+ MOZ_ASSERT(entryDef->type() == exitDef->type());
+ MOZ_ASSERT(entryDef->type() != MIRType::Value);
+
+ if (entryDef == exitDef) {
+ // If the exit def is the same as the entry def, make a redundant
+ // phi. Since loop headers have exactly two incoming edges, we
+ // know that that's just the first input.
+ //
+ // Note that we eliminate later rather than now, to avoid any
+ // weirdness around pending continue edges which might still hold
+ // onto phis.
+ exitDef = entryDef->getOperand(0);
+ }
+
+ // Phis always have room for 2 operands, so this can't fail.
+ MOZ_ASSERT(phi->numOperands() == 1);
+ entryDef->addInlineInput(exitDef);
+
+ // Two cases here: phis that correspond to locals, and phis that correspond
+ // to loop parameters. Only phis for locals go in slots.
+ if (slot < stackDepth()) {
+ setSlot(slot, entryDef);
+ }
+ }
+
+ // We are now a loop header proper
+ kind_ = LOOP_HEADER;
+
+ return predecessors_.append(pred);
+}
+
+void MBasicBlock::clearLoopHeader() {
+ MOZ_ASSERT(isLoopHeader());
+ kind_ = NORMAL;
+}
+
+void MBasicBlock::setLoopHeader(MBasicBlock* newBackedge) {
+ MOZ_ASSERT(!isLoopHeader());
+ kind_ = LOOP_HEADER;
+
+ size_t numPreds = numPredecessors();
+ MOZ_ASSERT(numPreds != 0);
+
+ size_t lastIndex = numPreds - 1;
+ size_t oldIndex = 0;
+ for (;; ++oldIndex) {
+ MOZ_ASSERT(oldIndex < numPreds);
+ MBasicBlock* pred = getPredecessor(oldIndex);
+ if (pred == newBackedge) {
+ break;
+ }
+ }
+
+ // Set the loop backedge to be the last element in predecessors_.
+ std::swap(predecessors_[oldIndex], predecessors_[lastIndex]);
+
+ // If we have phis, reorder their operands accordingly.
+ if (!phisEmpty()) {
+ getPredecessor(oldIndex)->setSuccessorWithPhis(this, oldIndex);
+ getPredecessor(lastIndex)->setSuccessorWithPhis(this, lastIndex);
+ for (MPhiIterator iter(phisBegin()), end(phisEnd()); iter != end; ++iter) {
+ MPhi* phi = *iter;
+ MDefinition* last = phi->getOperand(oldIndex);
+ MDefinition* old = phi->getOperand(lastIndex);
+ phi->replaceOperand(oldIndex, old);
+ phi->replaceOperand(lastIndex, last);
+ }
+ }
+
+ MOZ_ASSERT(newBackedge->loopHeaderOfBackedge() == this);
+ MOZ_ASSERT(backedge() == newBackedge);
+}
+
+size_t MBasicBlock::getSuccessorIndex(MBasicBlock* block) const {
+ MOZ_ASSERT(lastIns());
+ for (size_t i = 0; i < numSuccessors(); i++) {
+ if (getSuccessor(i) == block) {
+ return i;
+ }
+ }
+ MOZ_CRASH("Invalid successor");
+}
+
+size_t MBasicBlock::getPredecessorIndex(MBasicBlock* block) const {
+ for (size_t i = 0, e = numPredecessors(); i < e; ++i) {
+ if (getPredecessor(i) == block) {
+ return i;
+ }
+ }
+ MOZ_CRASH("Invalid predecessor");
+}
+
+void MBasicBlock::replaceSuccessor(size_t pos, MBasicBlock* split) {
+ MOZ_ASSERT(lastIns());
+
+ // Note, during split-critical-edges, successors-with-phis is not yet set.
+ // During PAA, this case is handled before we enter.
+ MOZ_ASSERT_IF(successorWithPhis_, successorWithPhis_ != getSuccessor(pos));
+
+ lastIns()->replaceSuccessor(pos, split);
+}
+
+void MBasicBlock::replacePredecessor(MBasicBlock* old, MBasicBlock* split) {
+ for (size_t i = 0; i < numPredecessors(); i++) {
+ if (getPredecessor(i) == old) {
+ predecessors_[i] = split;
+
+#ifdef DEBUG
+ // The same block should not appear twice in the predecessor list.
+ for (size_t j = i; j < numPredecessors(); j++) {
+ MOZ_ASSERT(predecessors_[j] != old);
+ }
+#endif
+
+ return;
+ }
+ }
+
+ MOZ_CRASH("predecessor was not found");
+}
+
+void MBasicBlock::clearDominatorInfo() {
+ setImmediateDominator(nullptr);
+ immediatelyDominated_.clear();
+ numDominated_ = 0;
+}
+
+void MBasicBlock::removePredecessorWithoutPhiOperands(MBasicBlock* pred,
+ size_t predIndex) {
+ // If we're removing the last backedge, this is no longer a loop.
+ if (isLoopHeader() && hasUniqueBackedge() && backedge() == pred) {
+ clearLoopHeader();
+ }
+
+ // Adjust phis. Note that this can leave redundant phis behind.
+ // Don't adjust successorWithPhis() if we haven't constructed this
+ // information yet.
+ if (pred->successorWithPhis()) {
+ MOZ_ASSERT(pred->positionInPhiSuccessor() == predIndex);
+ pred->clearSuccessorWithPhis();
+ for (size_t j = predIndex + 1; j < numPredecessors(); j++) {
+ getPredecessor(j)->setSuccessorWithPhis(this, j - 1);
+ }
+ }
+
+ // Remove from pred list.
+ predecessors_.erase(predecessors_.begin() + predIndex);
+}
+
+void MBasicBlock::removePredecessor(MBasicBlock* pred) {
+ size_t predIndex = getPredecessorIndex(pred);
+
+ // Remove the phi operands.
+ for (MPhiIterator iter(phisBegin()), end(phisEnd()); iter != end; ++iter) {
+ iter->removeOperand(predIndex);
+ }
+
+ // Now we can call the underlying function, which expects that phi
+ // operands have been removed.
+ removePredecessorWithoutPhiOperands(pred, predIndex);
+}
+
+bool MBasicBlock::inheritPhisFromBackedge(MBasicBlock* backedge) {
+ // We must be a pending loop header
+ MOZ_ASSERT(kind_ == PENDING_LOOP_HEADER);
+
+ size_t stackDepth = entryResumePoint()->stackDepth();
+ for (size_t slot = 0; slot < stackDepth; slot++) {
+ // Get the value stack-slot of the back edge.
+ MDefinition* exitDef = backedge->getSlot(slot);
+
+ // Get the value of the loop header.
+ MDefinition* loopDef = entryResumePoint()->getOperand(slot);
+ if (loopDef->block() != this) {
+ // If we are finishing a pending loop header, then we need to ensure
+ // that all operands are phis. This is usualy the case, except for
+ // object/arrays build with generators, in which case we share the
+ // same allocations across all blocks.
+ MOZ_ASSERT(loopDef->block()->id() < id());
+ MOZ_ASSERT(loopDef == exitDef);
+ continue;
+ }
+
+ // Phis are allocated by NewPendingLoopHeader.
+ MPhi* entryDef = loopDef->toPhi();
+ MOZ_ASSERT(entryDef->block() == this);
+
+ if (entryDef == exitDef) {
+ // If the exit def is the same as the entry def, make a redundant
+ // phi. Since loop headers have exactly two incoming edges, we
+ // know that that's just the first input.
+ //
+ // Note that we eliminate later rather than now, to avoid any
+ // weirdness around pending continue edges which might still hold
+ // onto phis.
+ exitDef = entryDef->getOperand(0);
+ }
+
+ if (!entryDef->addInputSlow(exitDef)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+MTest* MBasicBlock::immediateDominatorBranch(BranchDirection* pdirection) {
+ *pdirection = FALSE_BRANCH;
+
+ if (numPredecessors() != 1) {
+ return nullptr;
+ }
+
+ MBasicBlock* dom = immediateDominator();
+ if (dom != getPredecessor(0)) {
+ return nullptr;
+ }
+
+ // Look for a trailing MTest branching to this block.
+ MInstruction* ins = dom->lastIns();
+ if (ins->isTest()) {
+ MTest* test = ins->toTest();
+
+ MOZ_ASSERT(test->ifTrue() == this || test->ifFalse() == this);
+ if (test->ifTrue() == this && test->ifFalse() == this) {
+ return nullptr;
+ }
+
+ *pdirection = (test->ifTrue() == this) ? TRUE_BRANCH : FALSE_BRANCH;
+ return test;
+ }
+
+ return nullptr;
+}
+
+void MBasicBlock::dumpStack(GenericPrinter& out) {
+#ifdef DEBUG
+ out.printf(" %-3s %-16s %-6s %-10s\n", "#", "name", "copyOf", "first/next");
+ out.printf("-------------------------------------------\n");
+ for (uint32_t i = 0; i < stackPosition_; i++) {
+ out.printf(" %-3u", i);
+ out.printf(" %-16p\n", (void*)slots_[i]);
+ }
+#endif
+}
+
+void MBasicBlock::dumpStack() {
+ Fprinter out(stderr);
+ dumpStack(out);
+ out.finish();
+}
+
+void MIRGraph::dump(GenericPrinter& out) {
+#ifdef JS_JITSPEW
+ for (MBasicBlockIterator iter(begin()); iter != end(); iter++) {
+ iter->dump(out);
+ out.printf("\n");
+ }
+#endif
+}
+
+void MIRGraph::dump() {
+ Fprinter out(stderr);
+ dump(out);
+ out.finish();
+}
+
+void MBasicBlock::dump(GenericPrinter& out) {
+#ifdef JS_JITSPEW
+ out.printf("block%u:%s%s%s\n", id(), isLoopHeader() ? " (loop header)" : "",
+ unreachable() ? " (unreachable)" : "",
+ isMarked() ? " (marked)" : "");
+ if (MResumePoint* resume = entryResumePoint()) {
+ resume->dump(out);
+ }
+ for (MPhiIterator iter(phisBegin()); iter != phisEnd(); iter++) {
+ iter->dump(out);
+ }
+ for (MInstructionIterator iter(begin()); iter != end(); iter++) {
+ iter->dump(out);
+ }
+#endif
+}
+
+void MBasicBlock::dump() {
+ Fprinter out(stderr);
+ dump(out);
+ out.finish();
+}