//------------------------------------------------------------------------
// DecomposeLclFld: Decompose GT_LCL_FLD.
//
// Arguments:
// use - the LIR::Use object for the def that needs to be decomposed.
//
// Return Value:
// The next node to process.
//
GenTree* DecomposeLongs::DecomposeLclFld(LIR::Use& use)
{
assert(use.IsInitialized());
assert(use.Def()->OperGet() == GT_LCL_FLD);
GenTree* tree = use.Def();
GenTreeLclFld* loResult = tree->AsLclFld();
loResult->gtType = TYP_INT;
GenTree* hiResult = m_compiler->gtNewLclFldNode(loResult->gtLclNum, TYP_INT, loResult->gtLclOffs + 4);
hiResult->CopyCosts(loResult);
BlockRange().InsertAfter(loResult, hiResult);
return FinalizeDecomposition(use, loResult, hiResult);
}
//------------------------------------------------------------------------
// DecomposeCnsLng: Decompose GT_CNS_LNG.
//
// Arguments:
// use - the LIR::Use object for the def that needs to be decomposed.
//
// Return Value:
// The next node to process.
//
GenTree* DecomposeLongs::DecomposeCnsLng(LIR::Use& use)
{
assert(use.IsInitialized());
assert(use.Def()->OperGet() == GT_CNS_LNG);
GenTree* tree = use.Def();
INT32 hiVal = tree->AsLngCon()->HiVal();
GenTree* loResult = tree;
loResult->ChangeOperConst(GT_CNS_INT);
loResult->gtType = TYP_INT;
GenTree* hiResult = new (m_compiler, GT_CNS_INT) GenTreeIntCon(TYP_INT, hiVal);
hiResult->CopyCosts(loResult);
BlockRange().InsertAfter(loResult, hiResult);
return FinalizeDecomposition(use, loResult, hiResult);
}
//------------------------------------------------------------------------
// DecomposeLclVar: Decompose GT_LCL_VAR.
//
// Arguments:
// use - the LIR::Use object for the def that needs to be decomposed.
//
// Return Value:
// The next node to process.
//
GenTree* DecomposeLongs::DecomposeLclVar(LIR::Use& use)
{
assert(use.IsInitialized());
assert(use.Def()->OperGet() == GT_LCL_VAR);
GenTree* tree = use.Def();
unsigned varNum = tree->AsLclVarCommon()->gtLclNum;
LclVarDsc* varDsc = m_compiler->lvaTable + varNum;
m_compiler->lvaDecRefCnts(tree);
GenTree* loResult = tree;
loResult->gtType = TYP_INT;
GenTree* hiResult = m_compiler->gtNewLclLNode(varNum, TYP_INT);
hiResult->CopyCosts(loResult);
BlockRange().InsertAfter(loResult, hiResult);
if (varDsc->lvPromoted)
{
assert(varDsc->lvFieldCnt == 2);
unsigned loVarNum = varDsc->lvFieldLclStart;
unsigned hiVarNum = loVarNum + 1;
loResult->AsLclVarCommon()->SetLclNum(loVarNum);
hiResult->AsLclVarCommon()->SetLclNum(hiVarNum);
}
else
{
noway_assert(varDsc->lvLRACandidate == false);
loResult->SetOper(GT_LCL_FLD);
loResult->AsLclFld()->gtLclOffs = 0;
loResult->AsLclFld()->gtFieldSeq = FieldSeqStore::NotAField();
hiResult->SetOper(GT_LCL_FLD);
hiResult->AsLclFld()->gtLclOffs = 4;
hiResult->AsLclFld()->gtFieldSeq = FieldSeqStore::NotAField();
}
m_compiler->lvaIncRefCnts(loResult);
m_compiler->lvaIncRefCnts(hiResult);
return FinalizeDecomposition(use, loResult, hiResult);
}
//------------------------------------------------------------------------
// FinalizeDecomposition: A helper function to finalize LONG decomposition by
// taking the resulting two halves of the decomposition, and tie them together
// with a new GT_LONG node that will replace the original node.
//
// Arguments:
// ppTree - the original tree node
// data - tree walk context
// loResult - the decomposed low part
// hiResult - the decomposed high part
//
// Return Value:
// None.
//
void DecomposeLongs::FinalizeDecomposition(GenTree** ppTree, Compiler::fgWalkData* data, GenTree* loResult, GenTree* hiResult)
{
assert(ppTree != nullptr);
assert(*ppTree != nullptr);
assert(data != nullptr);
assert(loResult != nullptr);
assert(hiResult != nullptr);
assert(m_compiler->compCurStmt != nullptr);
GenTree* tree = *ppTree;
m_compiler->fgInsertTreeInListAfter(hiResult, loResult, m_compiler->compCurStmt->AsStmt());
hiResult->CopyCosts(tree);
GenTree* newTree = new (m_compiler, GT_LONG) GenTreeOp(GT_LONG, TYP_LONG, loResult, hiResult);
SimpleLinkNodeAfter(hiResult, newTree);
m_compiler->fgFixupIfCallArg(data->parentStack, tree, newTree);
newTree->CopyCosts(tree);
*ppTree = newTree;
}
//------------------------------------------------------------------------
// DecomposeNot: Decompose GT_NOT.
//
// Arguments:
// use - the LIR::Use object for the def that needs to be decomposed.
//
// Return Value:
// The next node to process.
//
GenTree* DecomposeLongs::DecomposeNot(LIR::Use& use)
{
assert(use.IsInitialized());
assert(use.Def()->OperGet() == GT_NOT);
GenTree* tree = use.Def();
GenTree* gtLong = tree->gtGetOp1();
noway_assert(gtLong->OperGet() == GT_LONG);
GenTree* loOp1 = gtLong->gtGetOp1();
GenTree* hiOp1 = gtLong->gtGetOp2();
BlockRange().Remove(gtLong);
GenTree* loResult = tree;
loResult->gtType = TYP_INT;
loResult->gtOp.gtOp1 = loOp1;
GenTree* hiResult = new (m_compiler, GT_NOT) GenTreeOp(GT_NOT, TYP_INT, hiOp1, nullptr);
hiResult->CopyCosts(loResult);
BlockRange().InsertAfter(loResult, hiResult);
return FinalizeDecomposition(use, loResult, hiResult);
}
//------------------------------------------------------------------------
// DecomposeCast: Decompose GT_CAST.
//
// Arguments:
// use - the LIR::Use object for the def that needs to be decomposed.
//
// Return Value:
// The next node to process.
//
GenTree* DecomposeLongs::DecomposeCast(LIR::Use& use)
{
assert(use.IsInitialized());
assert(use.Def()->OperGet() == GT_CAST);
GenTree* tree = use.Def();
GenTree* loResult = nullptr;
GenTree* hiResult = nullptr;
assert(tree->gtPrev == tree->gtGetOp1());
NYI_IF(tree->gtOverflow(), "TYP_LONG cast with overflow");
switch (tree->AsCast()->CastFromType())
{
case TYP_INT:
if (tree->gtFlags & GTF_UNSIGNED)
{
loResult = tree->gtGetOp1();
BlockRange().Remove(tree);
hiResult = new (m_compiler, GT_CNS_INT) GenTreeIntCon(TYP_INT, 0);
hiResult->CopyCosts(loResult);
BlockRange().InsertAfter(loResult, hiResult);
}
else
{
NYI("Lowering of signed cast TYP_INT->TYP_LONG");
}
break;
default:
NYI("Unimplemented type for Lowering of cast to TYP_LONG");
break;
}
return FinalizeDecomposition(use, loResult, hiResult);
}
//------------------------------------------------------------------------
// DecomposeStoreInd: Decompose GT_STOREIND.
//
// Arguments:
// tree - the tree to decompose
//
// Return Value:
// None.
//
void DecomposeLongs::DecomposeStoreInd(GenTree** ppTree, Compiler::fgWalkData* data)
{
assert(ppTree != nullptr);
assert(*ppTree != nullptr);
assert(data != nullptr);
assert((*ppTree)->OperGet() == GT_STOREIND);
assert(m_compiler->compCurStmt != nullptr);
GenTree* tree = *ppTree;
assert(tree->gtOp.gtOp2->OperGet() == GT_LONG);
GenTreeStmt* curStmt = m_compiler->compCurStmt->AsStmt();
bool isEmbeddedStmt = !curStmt->gtStmtIsTopLevel();
// Example input trees (a nested embedded statement case)
//
// <linkBegin Node>
// * stmtExpr void (top level) (IL ???... ???)
// | /--* argPlace ref $280
// | +--* argPlace int $4a
// | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | /--* lclVar ref V11 tmp9 u:3 $21c
// | | { | +--* const int 4 $44
// | | { | /--* + byref $2c8
// | | { | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | | { | /--* lclFld long V01 arg1 u:2[+8] Fseq[i] $380
// | | { | | { \--* st.lclVar long (P) V21 cse8
// | | { | | { \--* int V21.hi (offs=0x00) -> V22 rat0
// | | { | | { \--* int V21.hi (offs=0x04) -> V23 rat1
// | | { | | /--* lclVar int V22 rat0 $380
// | | { | | +--* lclVar int V23 rat1
// | | { | +--* gt_long long
// | | { \--* storeIndir long
// | +--* lclVar ref V11 tmp9 u:3 (last use) $21c
// | +--* lclVar ref V02 tmp0 u:3 $280
// | +--* const int 8 $4a
// \--* call help void HELPER.CORINFO_HELP_ARRADDR_ST $205
// <linkEndNode>
//
// (editor brace matching compensation: }}}}}}}}}}}}}}}}}})
GenTree* linkBegin = m_compiler->fgGetFirstNode(tree)->gtPrev;
GenTree* linkEnd = tree->gtNext;
GenTree* gtLong = tree->gtOp.gtOp2;
// Save address to a temp. It is used in storeIndLow and storeIndHigh trees.
GenTreeStmt* addrStmt = CreateTemporary(&tree->gtOp.gtOp1);
JITDUMP("[DecomposeStoreInd]: Saving address tree to a temp var:\n");
DISPTREE(addrStmt);
if (!gtLong->gtOp.gtOp1->OperIsLeaf())
{
GenTreeStmt* dataLowStmt = CreateTemporary(>Long->gtOp.gtOp1);
JITDUMP("[DecomposeStoreInd]: Saving low data tree to a temp var:\n");
DISPTREE(dataLowStmt);
}
if (!gtLong->gtOp.gtOp2->OperIsLeaf())
{
GenTreeStmt* dataHighStmt = CreateTemporary(>Long->gtOp.gtOp2);
JITDUMP("[DecomposeStoreInd]: Saving high data tree to a temp var:\n");
DISPTREE(dataHighStmt);
}
// Example trees after embedded statements for address and data are added.
// This example saves all address and data trees into temp variables
// to show how those embedded statements are created.
//
// * stmtExpr void (top level) (IL ???... ???)
// | /--* argPlace ref $280
// | +--* argPlace int $4a
// | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | /--* lclVar ref V11 tmp9 u:3 $21c
// | | { | +--* const int 4 $44
// | | { | /--* + byref $2c8
// | | { \--* st.lclVar byref V24 rat2
// | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | /--* lclVar byref V24 rat2
// | | { | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | | { | /--* lclFld long V01 arg1 u:2[+8] Fseq[i] $380380
// | | { | | { \--* st.lclVar long (P) V21 cse8
// | | { | | { \--* int V21.hi (offs=0x00) -> V22 rat0
// | | { | | { \--* int V21.hi (offs=0x04) -> V23 rat1
// | | { | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | | { | /--* lclVar int V22 rat0 $380
// | | { | | { \--* st.lclVar int V25 rat3
// | | { | | /--* lclVar int V25 rat3
// | | { | | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | | | { | /--* lclVar int V23 rat1
// | | { | | | { \--* st.lclVar int V26 rat4
// | | { | | +--* lclVar int V26 rat4
// | | { | +--* gt_long long
// | | { \--* storeIndir long
// | +--* lclVar ref V11 tmp9 u:3 (last use) $21c
// | +--* lclVar ref V02 tmp0 u:3 $280
// | +--* const int 8 $4a
// \--* call help void HELPER.CORINFO_HELP_ARRADDR_ST $205
//
// (editor brace matching compensation: }}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}})
GenTree* addrBase = tree->gtOp.gtOp1;
GenTree* dataHigh = gtLong->gtOp.gtOp2;
GenTree* dataLow = gtLong->gtOp.gtOp1;
GenTree* storeIndLow = tree;
// Rewrite storeIndLow tree to save only lower 32-bit data.
//
// | | { | /--* lclVar byref V24 rat2 (address)
// ...
// | | { | +--* lclVar int V25 rat3 (lower 32-bit data)
// | | { | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | { | /--* lclVar int V23 rat1
// | | { | { \--* st.lclVar int V26 rat4
// | | { \--* storeIndir int
//
// (editor brace matching compensation: }}}}}}}}})
m_compiler->fgSnipNode(curStmt, gtLong);
m_compiler->fgSnipNode(curStmt, dataHigh);
storeIndLow->gtOp.gtOp2 = dataLow;
storeIndLow->gtType = TYP_INT;
// Construct storeIndHigh tree
//
// | | { *stmtExpr void (embedded)(IL ? ? ? ... ? ? ? )
// | | { | / --* lclVar int V26 rat4
// | | { | | / --* lclVar byref V24 rat2
// | | { | +--* lea(b + 4) ref
// | | { \--* storeIndir int
//
// (editor brace matching compensation: }}}}})
GenTree* addrBaseHigh = new(m_compiler, GT_LCL_VAR) GenTreeLclVar(GT_LCL_VAR,
addrBase->TypeGet(), addrBase->AsLclVarCommon()->GetLclNum(), BAD_IL_OFFSET);
GenTree* addrHigh = new(m_compiler, GT_LEA) GenTreeAddrMode(TYP_REF, addrBaseHigh, nullptr, 0, genTypeSize(TYP_INT));
GenTree* storeIndHigh = new(m_compiler, GT_STOREIND) GenTreeStoreInd(TYP_INT, addrHigh, dataHigh);
storeIndHigh->gtFlags = (storeIndLow->gtFlags & (GTF_ALL_EFFECT | GTF_LIVENESS_MASK));
storeIndHigh->gtFlags |= GTF_REVERSE_OPS;
storeIndHigh->CopyCosts(storeIndLow);
// Internal links of storeIndHigh tree
dataHigh->gtPrev = nullptr;
dataHigh->gtNext = nullptr;
SimpleLinkNodeAfter(dataHigh, addrBaseHigh);
SimpleLinkNodeAfter(addrBaseHigh, addrHigh);
SimpleLinkNodeAfter(addrHigh, storeIndHigh);
// External links of storeIndHigh tree
//dataHigh->gtPrev = nullptr;
if (isEmbeddedStmt)
{
// If storeIndTree is an embedded statement, connect storeIndLow
// and dataHigh
storeIndLow->gtNext = dataHigh;
dataHigh->gtPrev = storeIndLow;
}
storeIndHigh->gtNext = linkEnd;
if (linkEnd != nullptr)
{
linkEnd->gtPrev = storeIndHigh;
}
InsertNodeAsStmt(storeIndHigh);
// Example final output
//
// * stmtExpr void (top level) (IL ???... ???)
// | /--* argPlace ref $280
// | +--* argPlace int $4a
// | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | /--* lclVar ref V11 tmp9 u:3 $21c
// | | { | +--* const int 4 $44
// | | { | /--* + byref $2c8
// | | { \--* st.lclVar byref V24 rat2
// | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | /--* lclVar byref V24 rat2
// | | { | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | | { | /--* lclFld int V01 arg1 u:2[+8] Fseq[i] $380
// | | { | | { | +--* lclFld int V01 arg1 [+12]
// | | { | | { | /--* gt_long long
// | | { | | { \--* st.lclVar long (P) V21 cse8
// | | { | | { \--* int V21.hi (offs=0x00) -> V22 rat0
// | | { | | { \--* int V21.hi (offs=0x04) -> V23 rat1
// | | { | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | | { | /--* lclVar int V22 rat0 $380
// | | { | | { \--* st.lclVar int V25 rat3
// | | { | +--* lclVar int V25 rat3
// | | { | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | { | /--* lclVar int V23 rat1
// | | { | { \--* st.lclVar int V26 rat4
// | | { \--* storeIndir int
// | | { * stmtExpr void (embedded) (IL ???... ???)
// | | { | /--* lclVar int V26 rat4
// | | { | | /--* lclVar byref V24 rat2
// | | { | +--* lea(b+4) ref
// | | { \--* storeIndir int
// | | /--* lclVar ref V11 tmp9 u:3 (last use) $21c
// | +--* putarg_stk [+0x00] ref
// | | /--* lclVar ref V02 tmp0 u:3 $280
// | +--* putarg_reg ref
// | | /--* const int 8 $4a
// | +--* putarg_reg int
// \--* call help void HELPER.CORINFO_HELP_ARRADDR_ST $205
//
// (editor brace matching compensation: }}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}})
}
//------------------------------------------------------------------------
// DecomposeStoreLclVar: Decompose GT_STORE_LCL_VAR.
//
// Arguments:
// ppTree - the tree to decompose
// data - tree walk context
//
// Return Value:
// None.
//
void DecomposeLongs::DecomposeStoreLclVar(GenTree** ppTree, Compiler::fgWalkData* data)
{
assert(ppTree != nullptr);
assert(*ppTree != nullptr);
assert(data != nullptr);
assert((*ppTree)->OperGet() == GT_STORE_LCL_VAR);
assert(m_compiler->compCurStmt != nullptr);
GenTreeStmt* curStmt = m_compiler->compCurStmt->AsStmt();
GenTree* tree = *ppTree;
GenTree* nextTree = tree->gtNext;
GenTree* rhs = tree->gtGetOp1();
if ((rhs->OperGet() == GT_PHI) || (rhs->OperGet() == GT_CALL))
{
// GT_CALLs are not decomposed, so will not be converted to GT_LONG
// GT_STORE_LCL_VAR = GT_CALL are handled in genMultiRegCallStoreToLocal
return;
}
noway_assert(rhs->OperGet() == GT_LONG);
unsigned varNum = tree->AsLclVarCommon()->gtLclNum;
LclVarDsc* varDsc = m_compiler->lvaTable + varNum;
m_compiler->lvaDecRefCnts(tree);
GenTree* loRhs = rhs->gtGetOp1();
GenTree* hiRhs = rhs->gtGetOp2();
GenTree* hiStore = m_compiler->gtNewLclLNode(varNum, TYP_INT);
if (varDsc->lvPromoted)
{
assert(varDsc->lvFieldCnt == 2);
unsigned loVarNum = varDsc->lvFieldLclStart;
unsigned hiVarNum = loVarNum + 1;
tree->AsLclVarCommon()->SetLclNum(loVarNum);
hiStore->SetOper(GT_STORE_LCL_VAR);
hiStore->AsLclVarCommon()->SetLclNum(hiVarNum);
}
else
{
noway_assert(varDsc->lvLRACandidate == false);
tree->SetOper(GT_STORE_LCL_FLD);
tree->AsLclFld()->gtLclOffs = 0;
tree->AsLclFld()->gtFieldSeq = FieldSeqStore::NotAField();
hiStore->SetOper(GT_STORE_LCL_FLD);
hiStore->AsLclFld()->gtLclOffs = 4;
hiStore->AsLclFld()->gtFieldSeq = FieldSeqStore::NotAField();
}
tree->gtOp.gtOp1 = loRhs;
tree->gtType = TYP_INT;
loRhs->gtNext = tree;
tree->gtPrev = loRhs;
hiStore->gtOp.gtOp1 = hiRhs;
hiStore->CopyCosts(tree);
hiStore->gtFlags |= GTF_VAR_DEF;
m_compiler->lvaIncRefCnts(tree);
m_compiler->lvaIncRefCnts(hiStore);
tree->gtNext = hiRhs;
hiRhs->gtPrev = tree;
hiRhs->gtNext = hiStore;
hiStore->gtPrev = hiRhs;
hiStore->gtNext = nextTree;
if (nextTree != nullptr)
{
nextTree->gtPrev = hiStore;
}
nextTree = hiRhs;
bool isEmbeddedStmt = !curStmt->gtStmtIsTopLevel();
if (!isEmbeddedStmt)
{
tree->gtNext = nullptr;
hiRhs->gtPrev = nullptr;
}
InsertNodeAsStmt(hiStore);
}
//------------------------------------------------------------------------
// DecomposeArith: Decompose GT_ADD, GT_SUB, GT_OR, GT_XOR, GT_AND.
//
// Arguments:
// use - the LIR::Use object for the def that needs to be decomposed.
//
// Return Value:
// The next node to process.
//
GenTree* DecomposeLongs::DecomposeArith(LIR::Use& use)
{
assert(use.IsInitialized());
GenTree* tree = use.Def();
genTreeOps oper = tree->OperGet();
assert((oper == GT_ADD) || (oper == GT_SUB) || (oper == GT_OR) || (oper == GT_XOR) || (oper == GT_AND));
GenTree* op1 = tree->gtGetOp1();
GenTree* op2 = tree->gtGetOp2();
// Both operands must have already been decomposed into GT_LONG operators.
noway_assert((op1->OperGet() == GT_LONG) && (op2->OperGet() == GT_LONG));
// Capture the lo and hi halves of op1 and op2.
GenTree* loOp1 = op1->gtGetOp1();
GenTree* hiOp1 = op1->gtGetOp2();
GenTree* loOp2 = op2->gtGetOp1();
GenTree* hiOp2 = op2->gtGetOp2();
// We don't have support to decompose a TYP_LONG node that already has a child that has
// been decomposed into parts, where the high part depends on the value generated by the
// low part (via the flags register). For example, if we have:
// +(gt_long(+(lo3, lo4), +Hi(hi3, hi4)), gt_long(lo2, hi2))
// We would decompose it here to:
// gt_long(+(+(lo3, lo4), lo2), +Hi(+Hi(hi3, hi4), hi2))
// But this would generate incorrect code, because the "+Hi(hi3, hi4)" code generation
// needs to immediately follow the "+(lo3, lo4)" part. Also, if this node is one that
// requires a unique high operator, and the child nodes are not simple locals (e.g.,
// they are decomposed nodes), then we also can't decompose the node, as we aren't
// guaranteed the high and low parts will be executed immediately after each other.
NYI_IF(hiOp1->OperIsHigh() || hiOp2->OperIsHigh() ||
(GenTree::OperIsHigh(GetHiOper(oper)) &&
(!loOp1->OperIsLeaf() || !hiOp1->OperIsLeaf() || !loOp1->OperIsLeaf() || !hiOp2->OperIsLeaf())),
"Can't decompose expression tree TYP_LONG node");
// Now, remove op1 and op2 from the node list.
BlockRange().Remove(op1);
BlockRange().Remove(op2);
// We will reuse "tree" for the loResult, which will now be of TYP_INT, and its operands
// will be the lo halves of op1 from above.
GenTree* loResult = tree;
loResult->SetOper(GetLoOper(loResult->OperGet()));
loResult->gtType = TYP_INT;
loResult->gtOp.gtOp1 = loOp1;
loResult->gtOp.gtOp2 = loOp2;
GenTree* hiResult = new (m_compiler, oper) GenTreeOp(GetHiOper(oper), TYP_INT, hiOp1, hiOp2);
hiResult->CopyCosts(loResult);
BlockRange().InsertAfter(loResult, hiResult);
if ((oper == GT_ADD) || (oper == GT_SUB))
{
if (loResult->gtOverflow())
{
hiResult->gtFlags |= GTF_OVERFLOW;
loResult->gtFlags &= ~GTF_OVERFLOW;
}
if (loResult->gtFlags & GTF_UNSIGNED)
{
hiResult->gtFlags |= GTF_UNSIGNED;
}
}
return FinalizeDecomposition(use, loResult, hiResult);
}
//------------------------------------------------------------------------
// DecomposeStoreLclVar: Decompose GT_STORE_LCL_VAR.
//
// Arguments:
// use - the LIR::Use object for the def that needs to be decomposed.
//
// Return Value:
// The next node to process.
//
GenTree* DecomposeLongs::DecomposeStoreLclVar(LIR::Use& use)
{
assert(use.IsInitialized());
assert(use.Def()->OperGet() == GT_STORE_LCL_VAR);
GenTree* tree = use.Def();
GenTree* rhs = tree->gtGetOp1();
if ((rhs->OperGet() == GT_PHI) || (rhs->OperGet() == GT_CALL))
{
// GT_CALLs are not decomposed, so will not be converted to GT_LONG
// GT_STORE_LCL_VAR = GT_CALL are handled in genMultiRegCallStoreToLocal
return tree->gtNext;
}
noway_assert(rhs->OperGet() == GT_LONG);
unsigned varNum = tree->AsLclVarCommon()->gtLclNum;
LclVarDsc* varDsc = m_compiler->lvaTable + varNum;
m_compiler->lvaDecRefCnts(tree);
GenTree* loRhs = rhs->gtGetOp1();
GenTree* hiRhs = rhs->gtGetOp2();
GenTree* hiStore = m_compiler->gtNewLclLNode(varNum, TYP_INT);
if (varDsc->lvPromoted)
{
assert(varDsc->lvFieldCnt == 2);
unsigned loVarNum = varDsc->lvFieldLclStart;
unsigned hiVarNum = loVarNum + 1;
tree->AsLclVarCommon()->SetLclNum(loVarNum);
hiStore->SetOper(GT_STORE_LCL_VAR);
hiStore->AsLclVarCommon()->SetLclNum(hiVarNum);
}
else
{
noway_assert(varDsc->lvLRACandidate == false);
tree->SetOper(GT_STORE_LCL_FLD);
tree->AsLclFld()->gtLclOffs = 0;
tree->AsLclFld()->gtFieldSeq = FieldSeqStore::NotAField();
hiStore->SetOper(GT_STORE_LCL_FLD);
hiStore->AsLclFld()->gtLclOffs = 4;
hiStore->AsLclFld()->gtFieldSeq = FieldSeqStore::NotAField();
}
// 'tree' is going to steal the loRhs node for itself, so we need to remove the
// GT_LONG node from the threading.
BlockRange().Remove(rhs);
tree->gtOp.gtOp1 = loRhs;
tree->gtType = TYP_INT;
hiStore->gtOp.gtOp1 = hiRhs;
hiStore->gtFlags |= GTF_VAR_DEF;
m_compiler->lvaIncRefCnts(tree);
m_compiler->lvaIncRefCnts(hiStore);
hiStore->CopyCosts(tree);
BlockRange().InsertAfter(tree, hiStore);
return hiStore->gtNext;
}