//------------------------------------------------------------------------
// DecomposeCall: Decompose GT_CALL.
//
// Arguments:
// ppTree - the tree to decompose
// data - tree walk context
//
// Return Value:
// None.
//
void DecomposeLongs::DecomposeCall(GenTree** ppTree, Compiler::fgWalkData* data)
{
assert(ppTree != nullptr);
assert(*ppTree != nullptr);
assert(data != nullptr);
assert((*ppTree)->OperGet() == GT_CALL);
GenTree* parent = data->parent;
// We only need to force var = call() if the call is not a top-level node.
if (parent == nullptr)
return;
if (parent->gtOper == GT_STORE_LCL_VAR)
{
// If parent is already a STORE_LCL_VAR, we can skip it if
// it is already marked as lvIsMultiRegRet.
unsigned varNum = parent->AsLclVarCommon()->gtLclNum;
if (m_compiler->lvaTable[varNum].lvIsMultiRegRet)
{
return;
}
else if (!m_compiler->lvaTable[varNum].lvPromoted)
{
// If var wasn't promoted, we can just set lvIsMultiRegRet.
m_compiler->lvaTable[varNum].lvIsMultiRegRet = true;
return;
}
}
// Otherwise, we need to force var = call()
GenTree* tree = *ppTree;
GenTree** treePtr = nullptr;
parent = tree->gtGetParent(&treePtr);
assert(treePtr != nullptr);
GenTreeStmt* asgStmt = m_compiler->fgInsertEmbeddedFormTemp(treePtr);
GenTree* stLclVar = asgStmt->gtStmtExpr;
assert(stLclVar->OperIsLocalStore());
unsigned varNum = stLclVar->AsLclVarCommon()->gtLclNum;
m_compiler->lvaTable[varNum].lvIsMultiRegRet = true;
m_compiler->fgFixupIfCallArg(data->parentStack, tree, *treePtr);
// Decompose new node
DecomposeNode(treePtr, data);
}
