Add m-esr52 at 52.6.0

1 files changed, 614 insertions, 0 deletions

diff --git a/js/src/jit/RegisterAllocator.cpp b/js/src/jit/RegisterAllocator.cpp
new file mode 100644
index 000000000..0ed1480fe
--- /dev/null
+++ b/js/src/jit/RegisterAllocator.cpp
@@ -0,0 +1,614 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/RegisterAllocator.h"
+
+using namespace js;
+using namespace js::jit;
+
+bool
+AllocationIntegrityState::record()
+{
+    // Ignore repeated record() calls.
+    if (!instructions.empty())
+        return true;
+
+    if (!instructions.appendN(InstructionInfo(), graph.numInstructions()))
+        return false;
+
+    if (!virtualRegisters.appendN((LDefinition*)nullptr, graph.numVirtualRegisters()))
+        return false;
+
+    if (!blocks.reserve(graph.numBlocks()))
+        return false;
+    for (size_t i = 0; i < graph.numBlocks(); i++) {
+        blocks.infallibleAppend(BlockInfo());
+        LBlock* block = graph.getBlock(i);
+        MOZ_ASSERT(block->mir()->id() == i);
+
+        BlockInfo& blockInfo = blocks[i];
+        if (!blockInfo.phis.reserve(block->numPhis()))
+            return false;
+
+        for (size_t j = 0; j < block->numPhis(); j++) {
+            blockInfo.phis.infallibleAppend(InstructionInfo());
+            InstructionInfo& info = blockInfo.phis[j];
+            LPhi* phi = block->getPhi(j);
+            MOZ_ASSERT(phi->numDefs() == 1);
+            uint32_t vreg = phi->getDef(0)->virtualRegister();
+            virtualRegisters[vreg] = phi->getDef(0);
+            if (!info.outputs.append(*phi->getDef(0)))
+                return false;
+            for (size_t k = 0, kend = phi->numOperands(); k < kend; k++) {
+                if (!info.inputs.append(*phi->getOperand(k)))
+                    return false;
+            }
+        }
+
+        for (LInstructionIterator iter = block->begin(); iter != block->end(); iter++) {
+            LInstruction* ins = *iter;
+            InstructionInfo& info = instructions[ins->id()];
+
+            for (size_t k = 0; k < ins->numTemps(); k++) {
+                if (!ins->getTemp(k)->isBogusTemp()) {
+                    uint32_t vreg = ins->getTemp(k)->virtualRegister();
+                    virtualRegisters[vreg] = ins->getTemp(k);
+                }
+                if (!info.temps.append(*ins->getTemp(k)))
+                    return false;
+            }
+            for (size_t k = 0; k < ins->numDefs(); k++) {
+                if (!ins->getDef(k)->isBogusTemp()) {
+                    uint32_t vreg = ins->getDef(k)->virtualRegister();
+                    virtualRegisters[vreg] = ins->getDef(k);
+                }
+                if (!info.outputs.append(*ins->getDef(k)))
+                    return false;
+            }
+            for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next()) {
+                if (!info.inputs.append(**alloc))
+                    return false;
+            }
+        }
+    }
+
+    return seen.init();
+}
+
+bool
+AllocationIntegrityState::check(bool populateSafepoints)
+{
+    MOZ_ASSERT(!instructions.empty());
+
+#ifdef JS_JITSPEW
+    if (JitSpewEnabled(JitSpew_RegAlloc))
+        dump();
+#endif
+#ifdef DEBUG
+    for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); blockIndex++) {
+        LBlock* block = graph.getBlock(blockIndex);
+
+        // Check that all instruction inputs and outputs have been assigned an allocation.
+        for (LInstructionIterator iter = block->begin(); iter != block->end(); iter++) {
+            LInstruction* ins = *iter;
+
+            for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next())
+                MOZ_ASSERT(!alloc->isUse());
+
+            for (size_t i = 0; i < ins->numDefs(); i++) {
+                LDefinition* def = ins->getDef(i);
+                MOZ_ASSERT(!def->output()->isUse());
+
+                LDefinition oldDef = instructions[ins->id()].outputs[i];
+                MOZ_ASSERT_IF(oldDef.policy() == LDefinition::MUST_REUSE_INPUT,
+                              *def->output() == *ins->getOperand(oldDef.getReusedInput()));
+            }
+
+            for (size_t i = 0; i < ins->numTemps(); i++) {
+                LDefinition* temp = ins->getTemp(i);
+                MOZ_ASSERT_IF(!temp->isBogusTemp(), temp->output()->isRegister());
+
+                LDefinition oldTemp = instructions[ins->id()].temps[i];
+                MOZ_ASSERT_IF(oldTemp.policy() == LDefinition::MUST_REUSE_INPUT,
+                              *temp->output() == *ins->getOperand(oldTemp.getReusedInput()));
+            }
+        }
+    }
+#endif
+
+    // Check that the register assignment and move groups preserve the original
+    // semantics of the virtual registers. Each virtual register has a single
+    // write (owing to the SSA representation), but the allocation may move the
+    // written value around between registers and memory locations along
+    // different paths through the script.
+    //
+    // For each use of an allocation, follow the physical value which is read
+    // backward through the script, along all paths to the value's virtual
+    // register's definition.
+    for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); blockIndex++) {
+        LBlock* block = graph.getBlock(blockIndex);
+        for (LInstructionIterator iter = block->begin(); iter != block->end(); iter++) {
+            LInstruction* ins = *iter;
+            const InstructionInfo& info = instructions[ins->id()];
+
+            LSafepoint* safepoint = ins->safepoint();
+            if (safepoint) {
+                for (size_t i = 0; i < ins->numTemps(); i++) {
+                    if (ins->getTemp(i)->isBogusTemp())
+                        continue;
+                    uint32_t vreg = info.temps[i].virtualRegister();
+                    LAllocation* alloc = ins->getTemp(i)->output();
+                    if (!checkSafepointAllocation(ins, vreg, *alloc, populateSafepoints))
+                        return false;
+                }
+                MOZ_ASSERT_IF(ins->isCall() && !populateSafepoints,
+                              safepoint->liveRegs().emptyFloat() &&
+                              safepoint->liveRegs().emptyGeneral());
+            }
+
+            size_t inputIndex = 0;
+            for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next()) {
+                LAllocation oldInput = info.inputs[inputIndex++];
+                if (!oldInput.isUse())
+                    continue;
+
+                uint32_t vreg = oldInput.toUse()->virtualRegister();
+
+                if (safepoint && !oldInput.toUse()->usedAtStart()) {
+                    if (!checkSafepointAllocation(ins, vreg, **alloc, populateSafepoints))
+                        return false;
+                }
+
+                // Start checking at the previous instruction, in case this
+                // instruction reuses its input register for an output.
+                LInstructionReverseIterator riter = block->rbegin(ins);
+                riter++;
+                if (!checkIntegrity(block, *riter, vreg, **alloc, populateSafepoints))
+                    return false;
+
+                while (!worklist.empty()) {
+                    IntegrityItem item = worklist.popCopy();
+                    if (!checkIntegrity(item.block, *item.block->rbegin(), item.vreg, item.alloc,
+                                        populateSafepoints)) {
+                        return false;
+                    }
+                }
+            }
+        }
+    }
+
+    return true;
+}
+
+bool
+AllocationIntegrityState::checkIntegrity(LBlock* block, LInstruction* ins,
+                                         uint32_t vreg, LAllocation alloc, bool populateSafepoints)
+{
+    for (LInstructionReverseIterator iter(block->rbegin(ins)); iter != block->rend(); iter++) {
+        ins = *iter;
+
+        // Follow values through assignments in move groups. All assignments in
+        // a move group are considered to happen simultaneously, so stop after
+        // the first matching move is found.
+        if (ins->isMoveGroup()) {
+            LMoveGroup* group = ins->toMoveGroup();
+            for (int i = group->numMoves() - 1; i >= 0; i--) {
+                if (group->getMove(i).to() == alloc) {
+                    alloc = group->getMove(i).from();
+                    break;
+                }
+            }
+        }
+
+        const InstructionInfo& info = instructions[ins->id()];
+
+        // Make sure the physical location being tracked is not clobbered by
+        // another instruction, and that if the originating vreg definition is
+        // found that it is writing to the tracked location.
+
+        for (size_t i = 0; i < ins->numDefs(); i++) {
+            LDefinition* def = ins->getDef(i);
+            if (def->isBogusTemp())
+                continue;
+            if (info.outputs[i].virtualRegister() == vreg) {
+                MOZ_ASSERT(*def->output() == alloc);
+
+                // Found the original definition, done scanning.
+                return true;
+            } else {
+                MOZ_ASSERT(*def->output() != alloc);
+            }
+        }
+
+        for (size_t i = 0; i < ins->numTemps(); i++) {
+            LDefinition* temp = ins->getTemp(i);
+            if (!temp->isBogusTemp())
+                MOZ_ASSERT(*temp->output() != alloc);
+        }
+
+        if (ins->safepoint()) {
+            if (!checkSafepointAllocation(ins, vreg, alloc, populateSafepoints))
+                return false;
+        }
+    }
+
+    // Phis are effectless, but change the vreg we are tracking. Check if there
+    // is one which produced this vreg. We need to follow back through the phi
+    // inputs as it is not guaranteed the register allocator filled in physical
+    // allocations for the inputs and outputs of the phis.
+    for (size_t i = 0; i < block->numPhis(); i++) {
+        const InstructionInfo& info = blocks[block->mir()->id()].phis[i];
+        LPhi* phi = block->getPhi(i);
+        if (info.outputs[0].virtualRegister() == vreg) {
+            for (size_t j = 0, jend = phi->numOperands(); j < jend; j++) {
+                uint32_t newvreg = info.inputs[j].toUse()->virtualRegister();
+                LBlock* predecessor = block->mir()->getPredecessor(j)->lir();
+                if (!addPredecessor(predecessor, newvreg, alloc))
+                    return false;
+            }
+            return true;
+        }
+    }
+
+    // No phi which defined the vreg we are tracking, follow back through all
+    // predecessors with the existing vreg.
+    for (size_t i = 0, iend = block->mir()->numPredecessors(); i < iend; i++) {
+        LBlock* predecessor = block->mir()->getPredecessor(i)->lir();
+        if (!addPredecessor(predecessor, vreg, alloc))
+            return false;
+    }
+
+    return true;
+}
+
+bool
+AllocationIntegrityState::checkSafepointAllocation(LInstruction* ins,
+                                                   uint32_t vreg, LAllocation alloc,
+                                                   bool populateSafepoints)
+{
+    LSafepoint* safepoint = ins->safepoint();
+    MOZ_ASSERT(safepoint);
+
+    if (ins->isCall() && alloc.isRegister())
+        return true;
+
+    if (alloc.isRegister()) {
+        AnyRegister reg = alloc.toRegister();
+        if (populateSafepoints)
+            safepoint->addLiveRegister(reg);
+
+        MOZ_ASSERT(safepoint->liveRegs().has(reg));
+    }
+
+    // The |this| argument slot is implicitly included in all safepoints.
+    if (alloc.isArgument() && alloc.toArgument()->index() < THIS_FRAME_ARGSLOT + sizeof(Value))
+        return true;
+
+    LDefinition::Type type = virtualRegisters[vreg]
+                             ? virtualRegisters[vreg]->type()
+                             : LDefinition::GENERAL;
+
+    switch (type) {
+      case LDefinition::OBJECT:
+        if (populateSafepoints) {
+            JitSpew(JitSpew_RegAlloc, "Safepoint object v%u i%u %s",
+                    vreg, ins->id(), alloc.toString().get());
+            if (!safepoint->addGcPointer(alloc))
+                return false;
+        }
+        MOZ_ASSERT(safepoint->hasGcPointer(alloc));
+        break;
+      case LDefinition::SLOTS:
+        if (populateSafepoints) {
+            JitSpew(JitSpew_RegAlloc, "Safepoint slots v%u i%u %s",
+                    vreg, ins->id(), alloc.toString().get());
+            if (!safepoint->addSlotsOrElementsPointer(alloc))
+                return false;
+        }
+        MOZ_ASSERT(safepoint->hasSlotsOrElementsPointer(alloc));
+        break;
+#ifdef JS_NUNBOX32
+      // Do not assert that safepoint information for nunbox types is complete,
+      // as if a vreg for a value's components are copied in multiple places
+      // then the safepoint information may not reflect all copies. All copies
+      // of payloads must be reflected, however, for generational GC.
+      case LDefinition::TYPE:
+        if (populateSafepoints) {
+            JitSpew(JitSpew_RegAlloc, "Safepoint type v%u i%u %s",
+                    vreg, ins->id(), alloc.toString().get());
+            if (!safepoint->addNunboxType(vreg, alloc))
+                return false;
+        }
+        break;
+      case LDefinition::PAYLOAD:
+        if (populateSafepoints) {
+            JitSpew(JitSpew_RegAlloc, "Safepoint payload v%u i%u %s",
+                    vreg, ins->id(), alloc.toString().get());
+            if (!safepoint->addNunboxPayload(vreg, alloc))
+                return false;
+        }
+        MOZ_ASSERT(safepoint->hasNunboxPayload(alloc));
+        break;
+#else
+      case LDefinition::BOX:
+        if (populateSafepoints) {
+            JitSpew(JitSpew_RegAlloc, "Safepoint boxed value v%u i%u %s",
+                    vreg, ins->id(), alloc.toString().get());
+            if (!safepoint->addBoxedValue(alloc))
+                return false;
+        }
+        MOZ_ASSERT(safepoint->hasBoxedValue(alloc));
+        break;
+#endif
+      default:
+        break;
+    }
+
+    return true;
+}
+
+bool
+AllocationIntegrityState::addPredecessor(LBlock* block, uint32_t vreg, LAllocation alloc)
+{
+    // There is no need to reanalyze if we have already seen this predecessor.
+    // We share the seen allocations across analysis of each use, as there will
+    // likely be common ground between different uses of the same vreg.
+    IntegrityItem item;
+    item.block = block;
+    item.vreg = vreg;
+    item.alloc = alloc;
+    item.index = seen.count();
+
+    IntegrityItemSet::AddPtr p = seen.lookupForAdd(item);
+    if (p)
+        return true;
+    if (!seen.add(p, item))
+        return false;
+
+    return worklist.append(item);
+}
+
+void
+AllocationIntegrityState::dump()
+{
+#ifdef DEBUG
+    fprintf(stderr, "Register Allocation Integrity State:\n");
+
+    for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); blockIndex++) {
+        LBlock* block = graph.getBlock(blockIndex);
+        MBasicBlock* mir = block->mir();
+
+        fprintf(stderr, "\nBlock %lu", static_cast<unsigned long>(blockIndex));
+        for (size_t i = 0; i < mir->numSuccessors(); i++)
+            fprintf(stderr, " [successor %u]", mir->getSuccessor(i)->id());
+        fprintf(stderr, "\n");
+
+        for (size_t i = 0; i < block->numPhis(); i++) {
+            const InstructionInfo& info = blocks[blockIndex].phis[i];
+            LPhi* phi = block->getPhi(i);
+            CodePosition input(block->getPhi(0)->id(), CodePosition::INPUT);
+            CodePosition output(block->getPhi(block->numPhis() - 1)->id(), CodePosition::OUTPUT);
+
+            fprintf(stderr, "[%u,%u Phi] [def %s] ",
+                    input.bits(),
+                    output.bits(),
+                    phi->getDef(0)->toString().get());
+            for (size_t j = 0; j < phi->numOperands(); j++)
+                fprintf(stderr, " [use %s]", info.inputs[j].toString().get());
+            fprintf(stderr, "\n");
+        }
+
+        for (LInstructionIterator iter = block->begin(); iter != block->end(); iter++) {
+            LInstruction* ins = *iter;
+            const InstructionInfo& info = instructions[ins->id()];
+
+            CodePosition input(ins->id(), CodePosition::INPUT);
+            CodePosition output(ins->id(), CodePosition::OUTPUT);
+
+            fprintf(stderr, "[");
+            if (input != CodePosition::MIN)
+                fprintf(stderr, "%u,%u ", input.bits(), output.bits());
+            fprintf(stderr, "%s]", ins->opName());
+
+            if (ins->isMoveGroup()) {
+                LMoveGroup* group = ins->toMoveGroup();
+                for (int i = group->numMoves() - 1; i >= 0; i--) {
+                    fprintf(stderr, " [%s -> %s]",
+                            group->getMove(i).from().toString().get(),
+                            group->getMove(i).to().toString().get());
+                }
+                fprintf(stderr, "\n");
+                continue;
+            }
+
+            for (size_t i = 0; i < ins->numDefs(); i++)
+                fprintf(stderr, " [def %s]", ins->getDef(i)->toString().get());
+
+            for (size_t i = 0; i < ins->numTemps(); i++) {
+                LDefinition* temp = ins->getTemp(i);
+                if (!temp->isBogusTemp())
+                    fprintf(stderr, " [temp v%u %s]", info.temps[i].virtualRegister(),
+                            temp->toString().get());
+            }
+
+            size_t index = 0;
+            for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next()) {
+                fprintf(stderr, " [use %s", info.inputs[index++].toString().get());
+                if (!alloc->isConstant())
+                    fprintf(stderr, " %s", alloc->toString().get());
+                fprintf(stderr, "]");
+            }
+
+            fprintf(stderr, "\n");
+        }
+    }
+
+    // Print discovered allocations at the ends of blocks, in the order they
+    // were discovered.
+
+    Vector<IntegrityItem, 20, SystemAllocPolicy> seenOrdered;
+    if (!seenOrdered.appendN(IntegrityItem(), seen.count())) {
+        fprintf(stderr, "OOM while dumping allocations\n");
+        return;
+    }
+
+    for (IntegrityItemSet::Enum iter(seen); !iter.empty(); iter.popFront()) {
+        IntegrityItem item = iter.front();
+        seenOrdered[item.index] = item;
+    }
+
+    if (!seenOrdered.empty()) {
+        fprintf(stderr, "Intermediate Allocations:\n");
+
+        for (size_t i = 0; i < seenOrdered.length(); i++) {
+            IntegrityItem item = seenOrdered[i];
+            fprintf(stderr, "  block %u reg v%u alloc %s\n",
+                    item.block->mir()->id(), item.vreg, item.alloc.toString().get());
+        }
+    }
+
+    fprintf(stderr, "\n");
+#endif
+}
+
+const CodePosition CodePosition::MAX(UINT_MAX);
+const CodePosition CodePosition::MIN(0);
+
+bool
+RegisterAllocator::init()
+{
+    if (!insData.init(mir, graph.numInstructions()))
+        return false;
+
+    if (!entryPositions.reserve(graph.numBlocks()) || !exitPositions.reserve(graph.numBlocks()))
+        return false;
+
+    for (size_t i = 0; i < graph.numBlocks(); i++) {
+        LBlock* block = graph.getBlock(i);
+        for (LInstructionIterator ins = block->begin(); ins != block->end(); ins++)
+            insData[ins->id()] = *ins;
+        for (size_t j = 0; j < block->numPhis(); j++) {
+            LPhi* phi = block->getPhi(j);
+            insData[phi->id()] = phi;
+        }
+
+        CodePosition entry = block->numPhis() != 0
+                             ? CodePosition(block->getPhi(0)->id(), CodePosition::INPUT)
+                             : inputOf(block->firstInstructionWithId());
+        CodePosition exit = outputOf(block->lastInstructionWithId());
+
+        MOZ_ASSERT(block->mir()->id() == i);
+        entryPositions.infallibleAppend(entry);
+        exitPositions.infallibleAppend(exit);
+    }
+
+    return true;
+}
+
+LMoveGroup*
+RegisterAllocator::getInputMoveGroup(LInstruction* ins)
+{
+    MOZ_ASSERT(!ins->fixReuseMoves());
+    if (ins->inputMoves())
+        return ins->inputMoves();
+
+    LMoveGroup* moves = LMoveGroup::New(alloc());
+    ins->setInputMoves(moves);
+    ins->block()->insertBefore(ins, moves);
+    return moves;
+}
+
+LMoveGroup*
+RegisterAllocator::getFixReuseMoveGroup(LInstruction* ins)
+{
+    if (ins->fixReuseMoves())
+        return ins->fixReuseMoves();
+
+    LMoveGroup* moves = LMoveGroup::New(alloc());
+    ins->setFixReuseMoves(moves);
+    ins->block()->insertBefore(ins, moves);
+    return moves;
+}
+
+LMoveGroup*
+RegisterAllocator::getMoveGroupAfter(LInstruction* ins)
+{
+    if (ins->movesAfter())
+        return ins->movesAfter();
+
+    LMoveGroup* moves = LMoveGroup::New(alloc());
+    ins->setMovesAfter(moves);
+
+    ins->block()->insertAfter(ins, moves);
+    return moves;
+}
+
+void
+RegisterAllocator::dumpInstructions()
+{
+#ifdef JS_JITSPEW
+    fprintf(stderr, "Instructions:\n");
+
+    for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); blockIndex++) {
+        LBlock* block = graph.getBlock(blockIndex);
+        MBasicBlock* mir = block->mir();
+
+        fprintf(stderr, "\nBlock %lu", static_cast<unsigned long>(blockIndex));
+        for (size_t i = 0; i < mir->numSuccessors(); i++)
+            fprintf(stderr, " [successor %u]", mir->getSuccessor(i)->id());
+        fprintf(stderr, "\n");
+
+        for (size_t i = 0; i < block->numPhis(); i++) {
+            LPhi* phi = block->getPhi(i);
+
+            fprintf(stderr, "[%u,%u Phi] [def %s]",
+                    inputOf(phi).bits(),
+                    outputOf(phi).bits(),
+                    phi->getDef(0)->toString().get());
+            for (size_t j = 0; j < phi->numOperands(); j++)
+                fprintf(stderr, " [use %s]", phi->getOperand(j)->toString().get());
+            fprintf(stderr, "\n");
+        }
+
+        for (LInstructionIterator iter = block->begin(); iter != block->end(); iter++) {
+            LInstruction* ins = *iter;
+
+            fprintf(stderr, "[");
+            if (ins->id() != 0)
+                fprintf(stderr, "%u,%u ", inputOf(ins).bits(), outputOf(ins).bits());
+            fprintf(stderr, "%s]", ins->opName());
+
+            if (ins->isMoveGroup()) {
+                LMoveGroup* group = ins->toMoveGroup();
+                for (int i = group->numMoves() - 1; i >= 0; i--) {
+                    // Use two printfs, as LAllocation::toString is not reentant.
+                    fprintf(stderr, " [%s", group->getMove(i).from().toString().get());
+                    fprintf(stderr, " -> %s]", group->getMove(i).to().toString().get());
+                }
+                fprintf(stderr, "\n");
+                continue;
+            }
+
+            for (size_t i = 0; i < ins->numDefs(); i++)
+                fprintf(stderr, " [def %s]", ins->getDef(i)->toString().get());
+
+            for (size_t i = 0; i < ins->numTemps(); i++) {
+                LDefinition* temp = ins->getTemp(i);
+                if (!temp->isBogusTemp())
+                    fprintf(stderr, " [temp %s]", temp->toString().get());
+            }
+
+            for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next()) {
+                if (!alloc->isBogus())
+                    fprintf(stderr, " [use %s]", alloc->toString().get());
+            }
+
+            fprintf(stderr, "\n");
+        }
+    }
+    fprintf(stderr, "\n");
+#endif // JS_JITSPEW
+}