void TR_ReachingDefinitions::initializeGenAndKillSetInfo()
{
// For each block in the CFG build the gen and kill set for this analysis.
// Go in treetop order, which guarantees that we see the correct (i.e. first)
// evaluation point for each node.
//
TR::Block *block;
int32_t blockNum = 0;
bool seenException = false;
TR_BitVector defsKilled(getNumberOfBits(), trMemory()->currentStackRegion());
comp()->incVisitCount();
for (TR::TreeTop *treeTop = comp()->getStartTree(); treeTop; treeTop = treeTop->getNextTreeTop())
{
TR::Node *node = treeTop->getNode();
if (node->getOpCodeValue() == TR::BBStart)
{
block = node->getBlock();
blockNum = block->getNumber();
seenException = false;
if (traceRD())
traceMsg(comp(), "\nNow generating gen and kill information for block_%d\n", blockNum);
continue;
}
#if DEBUG
if (node->getOpCodeValue() == TR::BBEnd && traceRD())
{
traceMsg(comp(), " Block %d:\n", blockNum);
traceMsg(comp(), " Gen set ");
if (_regularGenSetInfo[blockNum])
_regularGenSetInfo[blockNum]->print(comp());
else
traceMsg(comp(), "{}");
traceMsg(comp(), "\n Kill set ");
if (_regularKillSetInfo[blockNum])
_regularKillSetInfo[blockNum]->print(comp());
else
traceMsg(comp(), "{}");
traceMsg(comp(), "\n Exception Gen set ");
if (_exceptionGenSetInfo[blockNum])
_exceptionGenSetInfo[blockNum]->print(comp());
else
traceMsg(comp(), "{}");
traceMsg(comp(), "\n Exception Kill set ");
if (_exceptionKillSetInfo[blockNum])
_exceptionKillSetInfo[blockNum]->print(comp());
else
traceMsg(comp(), "{}");
continue;
}
#endif
initializeGenAndKillSetInfoForNode(node, defsKilled, seenException, blockNum, NULL);
if (!seenException && treeHasChecks(treeTop))
seenException = true;
}
}
void TR_ReachingDefinitions::initializeGenAndKillSetInfoForNode(TR::Node *node, TR_UseDefInfo::BitVector &defsKilled, bool seenException, int32_t blockNum, TR::Node *parent)
{
// Update gen and kill info for nodes in this subtree
//
int32_t i;
if (node->getVisitCount() == comp()->getVisitCount())
return;
node->setVisitCount(comp()->getVisitCount());
// Process the children first
//
for (i = node->getNumChildren()-1; i >= 0; --i)
{
initializeGenAndKillSetInfoForNode(node->getChild(i), defsKilled, seenException, blockNum, node);
}
bool irrelevantStore = false;
scount_t nodeIndex = node->getLocalIndex();
if (nodeIndex <= 0)
{
if (node->getOpCode().isStore() &&
node->getSymbol()->isAutoOrParm() &&
node->storedValueIsIrrelevant())
{
irrelevantStore = true;
}
else
return;
}
bool foundDefsToKill = false;
int32_t numDefNodes = 0;
defsKilled.Clear();
TR::ILOpCode &opCode = node->getOpCode();
TR::SymbolReference *symRef;
TR::Symbol *sym;
uint16_t symIndex;
uint32_t num_aliases;
if (_useDefInfo->_useDefForRegs &&
(opCode.isLoadReg() ||
opCode.isStoreReg()))
{
sym = NULL;
symRef = NULL;
symIndex = _useDefInfo->getNumSymbols() + node->getGlobalRegisterNumber();
num_aliases = 1;
}
else
{
symRef = node->getSymbolReference();
sym = symRef->getSymbol();
symIndex = symRef->getSymbol()->getLocalIndex();
num_aliases = _useDefInfo->getNumAliases(symRef, _aux);
}
if (symIndex == NULL_USEDEF_SYMBOL_INDEX || node->getOpCode().isCall() || node->getOpCode().isFence() ||
(parent && parent->getOpCode().isResolveCheck() && num_aliases > 1))
{
// A call or unresolved reference is a definition of all
// symbols it is aliased with
//
numDefNodes = num_aliases;
//for all symbols that are a mustdef of a call, kill defs of those symbols
if (node->getOpCode().isCall())
foundDefsToKill = false;
}
else if (irrelevantStore || _useDefInfo->isExpandedDefIndex(nodeIndex))
{
// DefOnly node defines all symbols it is aliased with
// UseDef node(load) defines only the symbol itself
//
if (!irrelevantStore)
{
numDefNodes = num_aliases;
numDefNodes = _useDefInfo->isExpandedUseDefIndex(nodeIndex) ? 1 : numDefNodes;
if (!_useDefInfo->getDefsForSymbolIsZero(symIndex, _aux) &&
(!sym ||
(!sym->isShadow() &&
!sym->isMethod())))
{
foundDefsToKill = true;
// defsKilled ORed with defsForSymbol(symIndex);
_useDefInfo->getDefsForSymbol(defsKilled, symIndex, _aux);
}
if (node->getOpCode().isStoreIndirect())
{
int32_t memSymIndex = _useDefInfo->getMemorySymbolIndex(node);
if (memSymIndex != -1 &&
!_useDefInfo->getDefsForSymbolIsZero(memSymIndex, _aux))
{
foundDefsToKill = true;
// defsKilled ORed with defsForSymbol(symIndex);
_useDefInfo->getDefsForSymbol(defsKilled, memSymIndex, _aux);
}
}
}
else if (!_useDefInfo->getDefsForSymbolIsZero(symIndex, _aux))
{
numDefNodes = 1;
foundDefsToKill = true;
// defsKilled ORed with defsForSymbol(symIndex);
_useDefInfo->getDefsForSymbol(defsKilled, symIndex, _aux);
}
}
else
{
numDefNodes = 0;
}
if (foundDefsToKill)
{
if (_regularKillSetInfo[blockNum] == NULL)
allocateContainer(&_regularKillSetInfo[blockNum]);
*_regularKillSetInfo[blockNum] |= defsKilled;
if (!seenException)
{
if (_exceptionKillSetInfo[blockNum] == NULL)
allocateContainer(&_exceptionKillSetInfo[blockNum]);
*_exceptionKillSetInfo[blockNum] |= defsKilled;
}
}
if (_regularGenSetInfo[blockNum] == NULL)
allocateContainer(&_regularGenSetInfo[blockNum]);
else if (foundDefsToKill)
*_regularGenSetInfo[blockNum] -= defsKilled;
if (_exceptionGenSetInfo[blockNum] == NULL)
allocateContainer(&_exceptionGenSetInfo[blockNum]);
else if (foundDefsToKill && !seenException)
*_exceptionGenSetInfo[blockNum] -= defsKilled;
if (!irrelevantStore)
{
for (i = 0; i < numDefNodes; ++i)
{
_regularGenSetInfo[blockNum]->set(nodeIndex+i);
_exceptionGenSetInfo[blockNum]->set(nodeIndex+i);
}
}
else // fake up the method entry def as the def index to "gen" to avoid a use without a def completely
{
_regularGenSetInfo[blockNum]->set(sym->getLocalIndex());
_exceptionGenSetInfo[blockNum]->set(sym->getLocalIndex());
}
}
