Beispiel #1
0
//------------------------------------------------------------------------
// TreeNodeInfoInitPutArgStk: Set the NodeInfo for a GT_PUTARG_STK node
//
// Arguments:
//    argNode - a GT_PUTARG_STK node
//
// Return Value:
//    None.
//
// Notes:
//    Set the child node(s) to be contained when we have a multireg arg
//
void Lowering::TreeNodeInfoInitPutArgStk(GenTreePutArgStk* argNode, fgArgTabEntryPtr info)
{
    assert(argNode->gtOper == GT_PUTARG_STK);

    GenTreePtr putArgChild = argNode->gtOp.gtOp1;

    // Initialize 'argNode' as not contained, as this is both the default case
    //  and how MakeSrcContained expects to find things setup.
    //
    argNode->gtLsraInfo.srcCount = 1;
    argNode->gtLsraInfo.dstCount = 0;

    // Do we have a TYP_STRUCT argument (or a GT_FIELD_LIST), if so it must be a multireg pass-by-value struct
    if ((putArgChild->TypeGet() == TYP_STRUCT) || (putArgChild->OperGet() == GT_FIELD_LIST))
    {
        // We will use store instructions that each write a register sized value

        if (putArgChild->OperGet() == GT_FIELD_LIST)
        {
            // We consume all of the items in the GT_FIELD_LIST
            argNode->gtLsraInfo.srcCount = info->numSlots;
            putArgChild->SetContained();
        }
        else
        {
#ifdef _TARGET_ARM64_
            // We could use a ldp/stp sequence so we need two internal registers
            argNode->gtLsraInfo.internalIntCount = 2;
#else  // _TARGET_ARM_
            // We could use a ldr/str sequence so we need a internal register
            argNode->gtLsraInfo.internalIntCount = 1;
#endif // _TARGET_ARM_

            if (putArgChild->OperGet() == GT_OBJ)
            {
                GenTreePtr objChild = putArgChild->gtOp.gtOp1;
                if (objChild->OperGet() == GT_LCL_VAR_ADDR)
                {
                    // We will generate all of the code for the GT_PUTARG_STK, the GT_OBJ and the GT_LCL_VAR_ADDR
                    // as one contained operation
                    //
                    MakeSrcContained(putArgChild, objChild);
                }
            }

            // We will generate all of the code for the GT_PUTARG_STK and it's child node
            // as one contained operation
            //
            MakeSrcContained(argNode, putArgChild);
        }
    }
    else
    {
        // We must not have a multi-reg struct
        assert(info->numSlots == 1);
    }
}
Beispiel #2
0
//------------------------------------------------------------------------
// TreeNodeInfoInitShiftRotate: Set the NodeInfo for a shift or rotate.
//
// Arguments:
//    tree      - The node of interest
//
// Return Value:
//    None.
//
void Lowering::TreeNodeInfoInitShiftRotate(GenTree* tree)
{
    TreeNodeInfo* info = &(tree->gtLsraInfo);
    LinearScan*   l    = m_lsra;

    info->srcCount = 2;
    info->dstCount = 1;

    GenTreePtr shiftBy = tree->gtOp.gtOp2;
    GenTreePtr source  = tree->gtOp.gtOp1;
    if (shiftBy->IsCnsIntOrI())
    {
        MakeSrcContained(tree, shiftBy);
    }

#ifdef _TARGET_ARM_

    // The first operand of a GT_LSH_HI and GT_RSH_LO oper is a GT_LONG so that
    // we can have a three operand form. Increment the srcCount.
    if (tree->OperGet() == GT_LSH_HI || tree->OperGet() == GT_RSH_LO)
    {
        assert(source->OperGet() == GT_LONG);
        source->SetContained();

        info->srcCount++;

        if (tree->OperGet() == GT_LSH_HI)
        {
            GenTreePtr sourceLo              = source->gtOp.gtOp1;
            sourceLo->gtLsraInfo.isDelayFree = true;
        }
        else
        {
            GenTreePtr sourceHi              = source->gtOp.gtOp2;
            sourceHi->gtLsraInfo.isDelayFree = true;
        }

        source->gtLsraInfo.hasDelayFreeSrc = true;
        info->hasDelayFreeSrc              = true;
    }

#endif // _TARGET_ARM_
}
Beispiel #3
0
//------------------------------------------------------------------------
// TreeNodeInfoInitBlockStore: Set the NodeInfo for a block store.
//
// Arguments:
//    blkNode       - The block store node of interest
//
// Return Value:
//    None.
//
void Lowering::TreeNodeInfoInitBlockStore(GenTreeBlk* blkNode)
{
    GenTree*    dstAddr  = blkNode->Addr();
    unsigned    size     = blkNode->gtBlkSize;
    GenTree*    source   = blkNode->Data();
    LinearScan* l        = m_lsra;
    Compiler*   compiler = comp;

    // Sources are dest address and initVal or source.
    // We may require an additional source or temp register for the size.
    blkNode->gtLsraInfo.srcCount = 2;
    blkNode->gtLsraInfo.dstCount = 0;
    GenTreePtr srcAddrOrFill     = nullptr;
    bool       isInitBlk         = blkNode->OperIsInitBlkOp();

    if (!isInitBlk)
    {
        // CopyObj or CopyBlk
        if (source->gtOper == GT_IND)
        {
            srcAddrOrFill = blkNode->Data()->gtGetOp1();
            // We're effectively setting source as contained, but can't call MakeSrcContained, because the
            // "inheritance" of the srcCount is to a child not a parent - it would "just work" but could be misleading.
            // If srcAddr is already non-contained, we don't need to change it.
            if (srcAddrOrFill->gtLsraInfo.getDstCount() == 0)
            {
                srcAddrOrFill->gtLsraInfo.setDstCount(1);
                srcAddrOrFill->gtLsraInfo.setSrcCount(source->gtLsraInfo.srcCount);
            }
            m_lsra->clearOperandCounts(source);
            source->SetContained();
            source->AsIndir()->Addr()->ClearContained();
        }
        else if (!source->IsMultiRegCall() && !source->OperIsSIMD())
        {
            assert(source->IsLocal());
            MakeSrcContained(blkNode, source);
            blkNode->gtLsraInfo.srcCount--;
        }
    }

    if (isInitBlk)
    {
        GenTreePtr initVal = source;
        if (initVal->OperIsInitVal())
        {
            initVal->SetContained();
            initVal = initVal->gtGetOp1();
        }
        srcAddrOrFill = initVal;

        if (blkNode->gtBlkOpKind == GenTreeBlk::BlkOpKindUnroll)
        {
            // TODO-ARM-CQ: Currently we generate a helper call for every
            // initblk we encounter.  Later on we should implement loop unrolling
            // code sequences to improve CQ.
            // For reference see the code in lsraxarch.cpp.
            NYI_ARM("initblk loop unrolling is currently not implemented.");

#ifdef _TARGET_ARM64_
            // No additional temporaries required
            ssize_t fill = initVal->gtIntCon.gtIconVal & 0xFF;
            if (fill == 0)
            {
                MakeSrcContained(blkNode, source);
                blkNode->gtLsraInfo.srcCount--;
            }
#endif // _TARGET_ARM64_
        }
        else
        {
            assert(blkNode->gtBlkOpKind == GenTreeBlk::BlkOpKindHelper);
            // The helper follows the regular ABI.
            dstAddr->gtLsraInfo.setSrcCandidates(l, RBM_ARG_0);
            initVal->gtLsraInfo.setSrcCandidates(l, RBM_ARG_1);
            if (size != 0)
            {
                // Reserve a temp register for the block size argument.
                blkNode->gtLsraInfo.setInternalCandidates(l, RBM_ARG_2);
                blkNode->gtLsraInfo.internalIntCount = 1;
            }
            else
            {
                // The block size argument is a third argument to GT_STORE_DYN_BLK
                noway_assert(blkNode->gtOper == GT_STORE_DYN_BLK);
                blkNode->gtLsraInfo.setSrcCount(3);
                GenTree* sizeNode = blkNode->AsDynBlk()->gtDynamicSize;
                sizeNode->gtLsraInfo.setSrcCandidates(l, RBM_ARG_2);
            }
        }
    }
    else
    {
        // CopyObj or CopyBlk
        // Sources are src and dest and size if not constant.
        if (blkNode->OperGet() == GT_STORE_OBJ)
        {
            // CopyObj
            // We don't need to materialize the struct size but we still need
            // a temporary register to perform the sequence of loads and stores.
            blkNode->gtLsraInfo.internalIntCount = 1;

            if (size >= 2 * REGSIZE_BYTES)
            {
                // We will use ldp/stp to reduce code size and improve performance
                // so we need to reserve an extra internal register
                blkNode->gtLsraInfo.internalIntCount++;
            }

            // We can't use the special Write Barrier registers, so exclude them from the mask
            regMaskTP internalIntCandidates = RBM_ALLINT & ~(RBM_WRITE_BARRIER_DST_BYREF | RBM_WRITE_BARRIER_SRC_BYREF);
            blkNode->gtLsraInfo.setInternalCandidates(l, internalIntCandidates);

            // If we have a dest address we want it in RBM_WRITE_BARRIER_DST_BYREF.
            dstAddr->gtLsraInfo.setSrcCandidates(l, RBM_WRITE_BARRIER_DST_BYREF);

            // If we have a source address we want it in REG_WRITE_BARRIER_SRC_BYREF.
            // Otherwise, if it is a local, codegen will put its address in REG_WRITE_BARRIER_SRC_BYREF,
            // which is killed by a StoreObj (and thus needn't be reserved).
            if (srcAddrOrFill != nullptr)
            {
                srcAddrOrFill->gtLsraInfo.setSrcCandidates(l, RBM_WRITE_BARRIER_SRC_BYREF);
            }
        }
        else
        {
            // CopyBlk
            short     internalIntCount      = 0;
            regMaskTP internalIntCandidates = RBM_NONE;

            if (blkNode->gtBlkOpKind == GenTreeBlk::BlkOpKindUnroll)
            {
                // TODO-ARM-CQ: cpblk loop unrolling is currently not implemented.
                // In case of a CpBlk with a constant size and less than CPBLK_UNROLL_LIMIT size
                // we should unroll the loop to improve CQ.
                // For reference see the code in lsraxarch.cpp.
                NYI_ARM("cpblk loop unrolling is currently not implemented.");

#ifdef _TARGET_ARM64_

                internalIntCount      = 1;
                internalIntCandidates = RBM_ALLINT;

                if (size >= 2 * REGSIZE_BYTES)
                {
                    // We will use ldp/stp to reduce code size and improve performance
                    // so we need to reserve an extra internal register
                    internalIntCount++;
                }

#endif // _TARGET_ARM64_
            }
            else
            {
                assert(blkNode->gtBlkOpKind == GenTreeBlk::BlkOpKindHelper);
                dstAddr->gtLsraInfo.setSrcCandidates(l, RBM_ARG_0);
                // The srcAddr goes in arg1.
                if (srcAddrOrFill != nullptr)
                {
                    srcAddrOrFill->gtLsraInfo.setSrcCandidates(l, RBM_ARG_1);
                }
                if (size != 0)
                {
                    // Reserve a temp register for the block size argument.
                    internalIntCandidates |= RBM_ARG_2;
                    internalIntCount++;
                }
                else
                {
                    // The block size argument is a third argument to GT_STORE_DYN_BLK
                    noway_assert(blkNode->gtOper == GT_STORE_DYN_BLK);
                    blkNode->gtLsraInfo.setSrcCount(3);
                    GenTree* blockSize = blkNode->AsDynBlk()->gtDynamicSize;
                    blockSize->gtLsraInfo.setSrcCandidates(l, RBM_ARG_2);
                }
            }
            if (internalIntCount != 0)
            {
                blkNode->gtLsraInfo.internalIntCount = internalIntCount;
                blkNode->gtLsraInfo.setInternalCandidates(l, internalIntCandidates);
            }
        }
    }
}
Beispiel #4
0
//------------------------------------------------------------------------
// TreeNodeInfoInitPutArgSplit: Set the NodeInfo for a GT_PUTARG_SPLIT node
//
// Arguments:
//    argNode - a GT_PUTARG_SPLIT node
//
// Return Value:
//    None.
//
// Notes:
//    Set the child node(s) to be contained
//
void Lowering::TreeNodeInfoInitPutArgSplit(GenTreePutArgSplit* argNode, TreeNodeInfo& info, fgArgTabEntryPtr argInfo)
{
    assert(argNode->gtOper == GT_PUTARG_SPLIT);

    GenTreePtr putArgChild = argNode->gtOp.gtOp1;

    // Registers for split argument corresponds to source
    argNode->gtLsraInfo.dstCount = argInfo->numRegs;
    info.srcCount += argInfo->numRegs;

    regNumber argReg  = argInfo->regNum;
    regMaskTP argMask = RBM_NONE;
    for (unsigned i = 0; i < argInfo->numRegs; i++)
    {
        argMask |= genRegMask((regNumber)((unsigned)argReg + i));
    }
    argNode->gtLsraInfo.setDstCandidates(m_lsra, argMask);

    if (putArgChild->OperGet() == GT_FIELD_LIST)
    {
        // Generated code:
        // 1. Consume all of the items in the GT_FIELD_LIST (source)
        // 2. Store to target slot and move to target registers (destination) from source
        //
        argNode->gtLsraInfo.srcCount = argInfo->numRegs + argInfo->numSlots;

        // To avoid redundant moves, have the argument operand computed in the
        // register in which the argument is passed to the call.
        GenTreeFieldList* fieldListPtr = putArgChild->AsFieldList();
        for (unsigned idx = 0; fieldListPtr != nullptr; fieldListPtr = fieldListPtr->Rest(), idx++)
        {
            if (idx < argInfo->numRegs)
            {
                GenTreePtr node = fieldListPtr->gtGetOp1();
                node->gtLsraInfo.setSrcCandidates(m_lsra, genRegMask((regNumber)((unsigned)argReg + idx)));
            }
        }

        putArgChild->SetContained();
    }
    else
    {
        assert(putArgChild->TypeGet() == TYP_STRUCT);
        assert(putArgChild->OperGet() == GT_OBJ);

        // We could use a ldr/str sequence so we need a internal register
        argNode->gtLsraInfo.srcCount         = 1;
        argNode->gtLsraInfo.internalIntCount = 1;
        regMaskTP internalMask               = RBM_ALLINT & ~argMask;
        argNode->gtLsraInfo.setInternalCandidates(m_lsra, internalMask);

        GenTreePtr objChild = putArgChild->gtOp.gtOp1;
        if (objChild->OperGet() == GT_LCL_VAR_ADDR)
        {
            // We will generate all of the code for the GT_PUTARG_SPLIT, the GT_OBJ and the GT_LCL_VAR_ADDR
            // as one contained operation
            //
            MakeSrcContained(putArgChild, objChild);
            putArgChild->gtLsraInfo.srcCount--;
        }
        argNode->gtLsraInfo.srcCount = putArgChild->gtLsraInfo.srcCount;
        MakeSrcContained(argNode, putArgChild);
    }
}
Beispiel #5
0
//------------------------------------------------------------------------
// TreeNodeInfoInitCall: Set the NodeInfo for a call.
//
// Arguments:
//    call - The call node of interest
//
// Return Value:
//    None.
//
void Lowering::TreeNodeInfoInitCall(GenTreeCall* call)
{
    TreeNodeInfo*   info              = &(call->gtLsraInfo);
    LinearScan*     l                 = m_lsra;
    Compiler*       compiler          = comp;
    bool            hasMultiRegRetVal = false;
    ReturnTypeDesc* retTypeDesc       = nullptr;

    info->srcCount = 0;
    if (call->TypeGet() != TYP_VOID)
    {
        hasMultiRegRetVal = call->HasMultiRegRetVal();
        if (hasMultiRegRetVal)
        {
            // dst count = number of registers in which the value is returned by call
            retTypeDesc    = call->GetReturnTypeDesc();
            info->dstCount = retTypeDesc->GetReturnRegCount();
        }
        else
        {
            info->dstCount = 1;
        }
    }
    else
    {
        info->dstCount = 0;
    }

    GenTree* ctrlExpr = call->gtControlExpr;
    if (call->gtCallType == CT_INDIRECT)
    {
        // either gtControlExpr != null or gtCallAddr != null.
        // Both cannot be non-null at the same time.
        assert(ctrlExpr == nullptr);
        assert(call->gtCallAddr != nullptr);
        ctrlExpr = call->gtCallAddr;
    }

    // set reg requirements on call target represented as control sequence.
    if (ctrlExpr != nullptr)
    {
        // we should never see a gtControlExpr whose type is void.
        assert(ctrlExpr->TypeGet() != TYP_VOID);

        info->srcCount++;

        // In case of fast tail implemented as jmp, make sure that gtControlExpr is
        // computed into a register.
        if (call->IsFastTailCall())
        {
            NYI_ARM("tail call");

#ifdef _TARGET_ARM64_
            // Fast tail call - make sure that call target is always computed in IP0
            // so that epilog sequence can generate "br xip0" to achieve fast tail call.
            ctrlExpr->gtLsraInfo.setSrcCandidates(l, genRegMask(REG_IP0));
#endif // _TARGET_ARM64_
        }
    }
#ifdef _TARGET_ARM_
    else
    {
        info->internalIntCount = 1;
    }
#endif // _TARGET_ARM_

    RegisterType registerType = call->TypeGet();

// Set destination candidates for return value of the call.

#ifdef _TARGET_ARM_
    if (call->IsHelperCall(compiler, CORINFO_HELP_INIT_PINVOKE_FRAME))
    {
        // The ARM CORINFO_HELP_INIT_PINVOKE_FRAME helper uses a custom calling convention that returns with
        // TCB in REG_PINVOKE_TCB. fgMorphCall() sets the correct argument registers.
        info->setDstCandidates(l, RBM_PINVOKE_TCB);
    }
    else
#endif // _TARGET_ARM_
        if (hasMultiRegRetVal)
    {
        assert(retTypeDesc != nullptr);
        info->setDstCandidates(l, retTypeDesc->GetABIReturnRegs());
    }
    else if (varTypeIsFloating(registerType))
    {
        info->setDstCandidates(l, RBM_FLOATRET);
    }
    else if (registerType == TYP_LONG)
    {
        info->setDstCandidates(l, RBM_LNGRET);
    }
    else
    {
        info->setDstCandidates(l, RBM_INTRET);
    }

    // If there is an explicit this pointer, we don't want that node to produce anything
    // as it is redundant
    if (call->gtCallObjp != nullptr)
    {
        GenTreePtr thisPtrNode = call->gtCallObjp;

        if (thisPtrNode->gtOper == GT_PUTARG_REG)
        {
            l->clearOperandCounts(thisPtrNode);
            thisPtrNode->SetContained();
            l->clearDstCount(thisPtrNode->gtOp.gtOp1);
        }
        else
        {
            l->clearDstCount(thisPtrNode);
        }
    }

    // First, count reg args
    bool callHasFloatRegArgs = false;

    for (GenTreePtr list = call->gtCallLateArgs; list; list = list->MoveNext())
    {
        assert(list->OperIsList());

        GenTreePtr argNode = list->Current();

        fgArgTabEntryPtr curArgTabEntry = compiler->gtArgEntryByNode(call, argNode);
        assert(curArgTabEntry);

        if (curArgTabEntry->regNum == REG_STK)
        {
            // late arg that is not passed in a register
            assert(argNode->gtOper == GT_PUTARG_STK);

            TreeNodeInfoInitPutArgStk(argNode->AsPutArgStk(), curArgTabEntry);
            continue;
        }

        // A GT_FIELD_LIST has a TYP_VOID, but is used to represent a multireg struct
        if (argNode->OperGet() == GT_FIELD_LIST)
        {
            argNode->SetContained();

            // There could be up to 2-4 PUTARG_REGs in the list (3 or 4 can only occur for HFAs)
            regNumber argReg = curArgTabEntry->regNum;
            for (GenTreeFieldList* entry = argNode->AsFieldList(); entry != nullptr; entry = entry->Rest())
            {
                TreeNodeInfoInitPutArgReg(entry->Current()->AsUnOp(), argReg, *info, false, &callHasFloatRegArgs);

                // Update argReg for the next putarg_reg (if any)
                argReg = genRegArgNext(argReg);

#if defined(_TARGET_ARM_)
                // A double register is modelled as an even-numbered single one
                if (entry->Current()->TypeGet() == TYP_DOUBLE)
                {
                    argReg = genRegArgNext(argReg);
                }
#endif // _TARGET_ARM_
            }
        }
#ifdef _TARGET_ARM_
        else if (argNode->OperGet() == GT_PUTARG_SPLIT)
        {
            fgArgTabEntryPtr curArgTabEntry = compiler->gtArgEntryByNode(call, argNode);
            TreeNodeInfoInitPutArgSplit(argNode->AsPutArgSplit(), *info, curArgTabEntry);
        }
#endif
        else
        {
            TreeNodeInfoInitPutArgReg(argNode->AsUnOp(), curArgTabEntry->regNum, *info, false, &callHasFloatRegArgs);
        }
    }

    // Now, count stack args
    // Note that these need to be computed into a register, but then
    // they're just stored to the stack - so the reg doesn't
    // need to remain live until the call.  In fact, it must not
    // because the code generator doesn't actually consider it live,
    // so it can't be spilled.

    GenTreePtr args = call->gtCallArgs;
    while (args)
    {
        GenTreePtr arg = args->gtOp.gtOp1;

        // Skip arguments that have been moved to the Late Arg list
        if (!(args->gtFlags & GTF_LATE_ARG))
        {
            if (arg->gtOper == GT_PUTARG_STK)
            {
                fgArgTabEntryPtr curArgTabEntry = compiler->gtArgEntryByNode(call, arg);
                assert(curArgTabEntry);

                assert(curArgTabEntry->regNum == REG_STK);

                TreeNodeInfoInitPutArgStk(arg->AsPutArgStk(), curArgTabEntry);
            }
#ifdef _TARGET_ARM_
            else if (arg->OperGet() == GT_PUTARG_SPLIT)
            {
                fgArgTabEntryPtr curArgTabEntry = compiler->gtArgEntryByNode(call, arg);
                TreeNodeInfoInitPutArgSplit(arg->AsPutArgSplit(), *info, curArgTabEntry);
            }
#endif
            else
            {
                TreeNodeInfo* argInfo = &(arg->gtLsraInfo);
                if (argInfo->dstCount != 0)
                {
                    argInfo->isLocalDefUse = true;
                }

                argInfo->dstCount = 0;
            }
        }
        args = args->gtOp.gtOp2;
    }

    // If it is a fast tail call, it is already preferenced to use IP0.
    // Therefore, no need set src candidates on call tgt again.
    if (call->IsVarargs() && callHasFloatRegArgs && !call->IsFastTailCall() && (ctrlExpr != nullptr))
    {
        NYI_ARM("float reg varargs");

        // Don't assign the call target to any of the argument registers because
        // we will use them to also pass floating point arguments as required
        // by Arm64 ABI.
        ctrlExpr->gtLsraInfo.setSrcCandidates(l, l->allRegs(TYP_INT) & ~(RBM_ARG_REGS));
    }

#ifdef _TARGET_ARM_

    if (call->NeedsNullCheck())
    {
        info->internalIntCount++;
    }

#endif // _TARGET_ARM_
}
Beispiel #6
0
//------------------------------------------------------------------------
// TreeNodeInfoInitIndir: Specify register requirements for address expression
//                       of an indirection operation.
//
// Arguments:
//    indirTree - GT_IND, GT_STOREIND, block node or GT_NULLCHECK gentree node
//
void Lowering::TreeNodeInfoInitIndir(GenTreePtr indirTree)
{
    assert(indirTree->OperIsIndir());
    // If this is the rhs of a block copy (i.e. non-enregisterable struct),
    // it has no register requirements.
    if (indirTree->TypeGet() == TYP_STRUCT)
    {
        return;
    }

    GenTreePtr    addr = indirTree->gtGetOp1();
    TreeNodeInfo* info = &(indirTree->gtLsraInfo);

    GenTreePtr base  = nullptr;
    GenTreePtr index = nullptr;
    unsigned   cns   = 0;
    unsigned   mul;
    bool       rev;
    bool       modifiedSources = false;
    bool       makeContained   = true;

    if ((addr->OperGet() == GT_LEA) && IsSafeToContainMem(indirTree, addr))
    {
        GenTreeAddrMode* lea = addr->AsAddrMode();
        base                 = lea->Base();
        index                = lea->Index();
        cns                  = lea->gtOffset;

#ifdef _TARGET_ARM_
        // ARM floating-point load/store doesn't support a form similar to integer
        // ldr Rdst, [Rbase + Roffset] with offset in a register. The only supported
        // form is vldr Rdst, [Rbase + imm] with a more limited constraint on the imm.
        if (lea->HasIndex() || !emitter::emitIns_valid_imm_for_vldst_offset(cns))
        {
            if (indirTree->OperGet() == GT_STOREIND)
            {
                if (varTypeIsFloating(indirTree->AsStoreInd()->Data()))
                {
                    makeContained = false;
                }
            }
            else if (indirTree->OperGet() == GT_IND)
            {
                if (varTypeIsFloating(indirTree))
                {
                    makeContained = false;
                }
            }
        }
#endif

        if (makeContained)
        {
            m_lsra->clearOperandCounts(addr);
            addr->SetContained();
            // The srcCount is decremented because addr is now "contained",
            // then we account for the base and index below, if they are non-null.
            info->srcCount--;
        }
    }
    else if (comp->codeGen->genCreateAddrMode(addr, -1, true, 0, &rev, &base, &index, &mul, &cns, true /*nogen*/) &&
             !(modifiedSources = AreSourcesPossiblyModifiedLocals(indirTree, base, index)))
    {
        // An addressing mode will be constructed that may cause some
        // nodes to not need a register, and cause others' lifetimes to be extended
        // to the GT_IND or even its parent if it's an assignment

        assert(base != addr);
        m_lsra->clearOperandCounts(addr);
        addr->SetContained();

        // Traverse the computation below GT_IND to find the operands
        // for the addressing mode, marking the various constants and
        // intermediate results as not consuming/producing.
        // If the traversal were more complex, we might consider using
        // a traversal function, but the addressing mode is only made
        // up of simple arithmetic operators, and the code generator
        // only traverses one leg of each node.

        bool       foundBase  = (base == nullptr);
        bool       foundIndex = (index == nullptr);
        GenTreePtr nextChild  = nullptr;
        for (GenTreePtr child = addr; child != nullptr && !child->OperIsLeaf(); child = nextChild)
        {
            nextChild      = nullptr;
            GenTreePtr op1 = child->gtOp.gtOp1;
            GenTreePtr op2 = (child->OperIsBinary()) ? child->gtOp.gtOp2 : nullptr;

            if (op1 == base)
            {
                foundBase = true;
            }
            else if (op1 == index)
            {
                foundIndex = true;
            }
            else
            {
                m_lsra->clearOperandCounts(op1);
                op1->SetContained();
                if (!op1->OperIsLeaf())
                {
                    nextChild = op1;
                }
            }

            if (op2 != nullptr)
            {
                if (op2 == base)
                {
                    foundBase = true;
                }
                else if (op2 == index)
                {
                    foundIndex = true;
                }
                else
                {
                    m_lsra->clearOperandCounts(op2);
                    op2->SetContained();
                    if (!op2->OperIsLeaf())
                    {
                        assert(nextChild == nullptr);
                        nextChild = op2;
                    }
                }
            }
        }
        assert(foundBase && foundIndex);
        info->srcCount--; // it gets incremented below.
    }
    else if (addr->gtOper == GT_ARR_ELEM)
    {
        // The GT_ARR_ELEM consumes all the indices and produces the offset.
        // The array object lives until the mem access.
        // We also consume the target register to which the address is
        // computed

        info->srcCount++;
        assert(addr->gtLsraInfo.srcCount >= 2);
        addr->gtLsraInfo.srcCount -= 1;
    }
    else
    {
        // it is nothing but a plain indir
        info->srcCount--; // base gets added in below
        base = addr;
    }

    if (!makeContained)
    {
        return;
    }

    if (base != nullptr)
    {
        info->srcCount++;
    }
    if (index != nullptr && !modifiedSources)
    {
        info->srcCount++;
    }

    // On ARM we may need a single internal register
    // (when both conditions are true then we still only need a single internal register)
    if ((index != nullptr) && (cns != 0))
    {
        // ARM does not support both Index and offset so we need an internal register
        info->internalIntCount = 1;
    }
    else if (!emitter::emitIns_valid_imm_for_ldst_offset(cns, emitTypeSize(indirTree)))
    {
        // This offset can't be contained in the ldr/str instruction, so we need an internal register
        info->internalIntCount = 1;
    }
}
Beispiel #7
0
//------------------------------------------------------------------------
// LowerBlockStore: Set block store type
//
// Arguments:
//    blkNode       - The block store node of interest
//
// Return Value:
//    None.
//
void Lowering::LowerBlockStore(GenTreeBlk* blkNode)
{
    GenTree*  dstAddr  = blkNode->Addr();
    unsigned  size     = blkNode->gtBlkSize;
    GenTree*  source   = blkNode->Data();
    Compiler* compiler = comp;

    // Sources are dest address and initVal or source.
    GenTreePtr srcAddrOrFill = nullptr;
    bool       isInitBlk     = blkNode->OperIsInitBlkOp();

    if (!isInitBlk)
    {
        // CopyObj or CopyBlk
        if ((blkNode->OperGet() == GT_STORE_OBJ) && ((blkNode->AsObj()->gtGcPtrCount == 0) || blkNode->gtBlkOpGcUnsafe))
        {
            blkNode->SetOper(GT_STORE_BLK);
        }
        if (source->gtOper == GT_IND)
        {
            srcAddrOrFill = blkNode->Data()->gtGetOp1();
        }
    }

    if (isInitBlk)
    {
        GenTreePtr initVal = source;
        if (initVal->OperIsInitVal())
        {
            initVal->SetContained();
            initVal = initVal->gtGetOp1();
        }
        srcAddrOrFill = initVal;

#ifdef _TARGET_ARM64_
        if ((size != 0) && (size <= INITBLK_UNROLL_LIMIT) && initVal->IsCnsIntOrI())
        {
            // TODO-ARM-CQ: Currently we generate a helper call for every
            // initblk we encounter.  Later on we should implement loop unrolling
            // code sequences to improve CQ.
            // For reference see the code in LowerXArch.cpp.
            NYI_ARM("initblk loop unrolling is currently not implemented.");

            // The fill value of an initblk is interpreted to hold a
            // value of (unsigned int8) however a constant of any size
            // may practically reside on the evaluation stack. So extract
            // the lower byte out of the initVal constant and replicate
            // it to a larger constant whose size is sufficient to support
            // the largest width store of the desired inline expansion.

            ssize_t fill = initVal->gtIntCon.gtIconVal & 0xFF;
            if (fill == 0)
            {
                MakeSrcContained(blkNode, source);
            }
            else if (size < REGSIZE_BYTES)
            {
                initVal->gtIntCon.gtIconVal = 0x01010101 * fill;
            }
            else
            {
                initVal->gtIntCon.gtIconVal = 0x0101010101010101LL * fill;
                initVal->gtType             = TYP_LONG;
            }
            blkNode->gtBlkOpKind = GenTreeBlk::BlkOpKindUnroll;
        }
        else
#endif // _TARGET_ARM64_
        {
            blkNode->gtBlkOpKind = GenTreeBlk::BlkOpKindHelper;
        }
    }
    else
    {
        // CopyObj or CopyBlk
        // Sources are src and dest and size if not constant.

        if (blkNode->OperGet() == GT_STORE_OBJ)
        {
            // CopyObj
            GenTreeObj* objNode = blkNode->AsObj();

            unsigned slots = objNode->gtSlots;

#ifdef DEBUG
            // CpObj must always have at least one GC-Pointer as a member.
            assert(objNode->gtGcPtrCount > 0);

            assert(dstAddr->gtType == TYP_BYREF || dstAddr->gtType == TYP_I_IMPL);

            CORINFO_CLASS_HANDLE clsHnd    = objNode->gtClass;
            size_t               classSize = compiler->info.compCompHnd->getClassSize(clsHnd);
            size_t               blkSize   = roundUp(classSize, TARGET_POINTER_SIZE);

            // Currently, the EE always round up a class data structure so
            // we are not handling the case where we have a non multiple of pointer sized
            // struct. This behavior may change in the future so in order to keeps things correct
            // let's assert it just to be safe. Going forward we should simply
            // handle this case.
            assert(classSize == blkSize);
            assert((blkSize / TARGET_POINTER_SIZE) == slots);
            assert(objNode->HasGCPtr());
#endif

            blkNode->gtBlkOpKind = GenTreeBlk::BlkOpKindUnroll;
        }
        else // CopyBlk
        {
            // In case of a CpBlk with a constant size and less than CPBLK_UNROLL_LIMIT size
            // we should unroll the loop to improve CQ.
            // For reference see the code in lowerxarch.cpp.

            if ((size != 0) && (size <= INITBLK_UNROLL_LIMIT))
            {
                blkNode->gtBlkOpKind = GenTreeBlk::BlkOpKindUnroll;
            }
            else
            {
                // In case we have a constant integer this means we went beyond
                // CPBLK_UNROLL_LIMIT bytes of size, still we should never have the case of
                // any GC-Pointers in the src struct.
                blkNode->gtBlkOpKind = GenTreeBlk::BlkOpKindHelper;
            }
        }
        // CopyObj or CopyBlk
        if (source->gtOper == GT_IND)
        {
            MakeSrcContained(blkNode, source);
        }
        else if (!source->IsMultiRegCall() && !source->OperIsSIMD())
        {
            assert(source->IsLocal());
            MakeSrcContained(blkNode, source);
        }
    }
}