C++ LPhi::numOperands方法代码示例

void
RegisterAllocator::dumpInstructions()
{
#ifdef DEBUG
    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());
            for (size_t j = 0; j < phi->numOperands(); j++)
                fprintf(stderr, " [use %s]", phi->getOperand(j)->toString());
            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());
                    fprintf(stderr, " -> %s]", group->getMove(i).to()->toString());
                }
                fprintf(stderr, "\n");
                continue;
            }

            for (size_t i = 0; i < ins->numDefs(); i++)
                fprintf(stderr, " [def %s]", ins->getDef(i)->toString());

            for (size_t i = 0; i < ins->numTemps(); i++) {
                LDefinition* temp = ins->getTemp(i);
                if (!temp->isBogusTemp())
                    fprintf(stderr, " [temp %s]", temp->toString());
            }

            for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next()) {
                if (!alloc->isBogus())
                    fprintf(stderr, " [use %s]", alloc->toString());
            }

            fprintf(stderr, "\n");
        }
    }
    fprintf(stderr, "\n");
#endif // DEBUG
}

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());
            for (size_t j = 0; j < phi->numOperands(); j++)
                fprintf(stderr, " [use %s]", info.inputs[j].toString());
            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--) {
                    // Use two printfs, as LAllocation::toString is not reentrant.
                    fprintf(stderr, " [%s", group->getMove(i).from()->toString());
                    fprintf(stderr, " -> %s]", group->getMove(i).to()->toString());
                }
                fprintf(stderr, "\n");
                continue;
            }

            for (size_t i = 0; i < ins->numDefs(); i++)
                fprintf(stderr, " [def %s]", ins->getDef(i)->toString());

            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());
            }

            size_t index = 0;
            for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next()) {
                fprintf(stderr, " [use %s", info.inputs[index++].toString());
                if (!alloc->isConstant())
                    fprintf(stderr, " %s", alloc->toString());
                fprintf(stderr, "]");
            }

            fprintf(stderr, "\n");
        }
    }

    // Print discovered allocations at the ends of blocks, in the order they
    // were discovered.

    Vector<IntegrityItem, 20, SystemAllocPolicy> seenOrdered;
    seenOrdered.appendN(IntegrityItem(), seen.count());

    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());
        }
    }

    fprintf(stderr, "\n");
#endif
}

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
GreedyAllocator::allocateRegisters()
{
    // Allocate registers bottom-up, such that we see all uses before their
    // definitions.
    for (size_t i = graph.numBlocks() - 1; i < graph.numBlocks(); i--) {
        LBlock *block = graph.getBlock(i);

        IonSpew(IonSpew_RegAlloc, "Allocating block %d", (uint32)i);

        // All registers should be free.
        JS_ASSERT(state.free == RegisterSet::All());

        // Allocate stack for any phis.
        for (size_t j = 0; j < block->numPhis(); j++) {
            LPhi *phi = block->getPhi(j);
            VirtualRegister *vreg = getVirtualRegister(phi->getDef(0));
            allocateStack(vreg);
        }

        // Allocate registers.
        if (!allocateRegistersInBlock(block))
            return false;

        LMoveGroup *entrySpills = block->getEntryMoveGroup();

        // We've reached the top of the block. Spill all registers by inserting
        // moves from their stack locations.
        for (AnyRegisterIterator iter(RegisterSet::All()); iter.more(); iter++) {
            VirtualRegister *vreg = state[*iter];
            if (!vreg) {
                JS_ASSERT(state.free.has(*iter));
                continue;
            }

            JS_ASSERT(vreg->reg() == *iter);
            JS_ASSERT(!state.free.has(vreg->reg()));
            allocateStack(vreg);

            LAllocation *from = LAllocation::New(vreg->backingStack());
            LAllocation *to = LAllocation::New(vreg->reg());
            if (!entrySpills->add(from, to))
                return false;

            killReg(vreg);
            vreg->unsetRegister();
        }

        // Before killing phis, ensure that each phi input has its own stack
        // allocation. This ensures we won't allocate the same slot for any phi
        // as its input, which technically may be legal (since the phi becomes
        // the last use of the slot), but we avoid for sanity.
        for (size_t i = 0; i < block->numPhis(); i++) {
            LPhi *phi = block->getPhi(i);
            for (size_t j = 0; j < phi->numOperands(); j++) {
                VirtualRegister *in = getVirtualRegister(phi->getOperand(j)->toUse());
                allocateStack(in);
            }
        }

        // Kill phis.
        for (size_t i = 0; i < block->numPhis(); i++) {
            LPhi *phi = block->getPhi(i);
            VirtualRegister *vr = getVirtualRegister(phi->getDef(0));
            JS_ASSERT(!vr->hasRegister());
            killStack(vr);
        }
    }
    return true;
}