[llvm] r206807 - Store State objects by value in TableGen's DFAPacketizerEmitter
David Blaikie
dblaikie at gmail.com
Mon Apr 21 15:35:11 PDT 2014
Author: dblaikie
Date: Mon Apr 21 17:35:11 2014
New Revision: 206807
URL: http://llvm.org/viewvc/llvm-project?rev=206807&view=rev
Log:
Store State objects by value in TableGen's DFAPacketizerEmitter
Removes some extra manual dynamic memory allocation/management. It does
get a bit quirky having to make State's members mutable and
pointers/references to const rather than non-const, but that's a
necessary workaround to dealing with the std::set elements.
Modified:
llvm/trunk/utils/TableGen/DFAPacketizerEmitter.cpp
Modified: llvm/trunk/utils/TableGen/DFAPacketizerEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/DFAPacketizerEmitter.cpp?rev=206807&r1=206806&r2=206807&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/DFAPacketizerEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/DFAPacketizerEmitter.cpp Mon Apr 21 17:35:11 2014
@@ -82,11 +82,13 @@ namespace {
class State {
public:
static int currentStateNum;
- int stateNum;
- bool isInitial;
- std::set<unsigned> stateInfo;
- typedef std::map<unsigned, State *> TransitionMap;
- TransitionMap Transitions;
+ // stateNum is the only member used for equality/ordering, all other members
+ // can be mutated even in const State objects.
+ const int stateNum;
+ mutable bool isInitial;
+ mutable std::set<unsigned> stateInfo;
+ typedef std::map<unsigned, const State *> TransitionMap;
+ mutable TransitionMap Transitions;
State();
State(const State &S);
@@ -108,16 +110,16 @@ class State {
// AddInsnClass - Return all combinations of resource reservation
// which are possible from this state (PossibleStates).
//
- void AddInsnClass(unsigned InsnClass, std::set<unsigned> &PossibleStates);
+ void AddInsnClass(unsigned InsnClass, std::set<unsigned> &PossibleStates) const;
//
// addTransition - Add a transition from this state given the input InsnClass
//
- void addTransition(unsigned InsnClass, State *To);
+ void addTransition(unsigned InsnClass, const State *To) const;
//
// hasTransition - Returns true if there is a transition from this state
// given the input InsnClass
//
- bool hasTransition(unsigned InsnClass);
+ bool hasTransition(unsigned InsnClass) const;
};
} // End anonymous namespace.
@@ -128,10 +130,9 @@ namespace {
class DFA {
public:
DFA();
- ~DFA();
// Set of states. Need to keep this sorted to emit the transition table.
- typedef std::set<State *, less_ptr<State> > StateSet;
+ typedef std::set<State> StateSet;
StateSet states;
State *currentState;
@@ -139,7 +140,7 @@ public:
//
// Modify the DFA.
//
- void addState(State *);
+ const State &newState();
//
// writeTable: Print out a table representing the DFA.
@@ -162,14 +163,10 @@ State::State(const State &S) :
DFA::DFA(): currentState(nullptr) {}
-DFA::~DFA() {
- DeleteContainerPointers(states);
-}
-
//
// addTransition - Add a transition from this state given the input InsnClass
//
-void State::addTransition(unsigned InsnClass, State *To) {
+void State::addTransition(unsigned InsnClass, const State *To) const {
assert(!Transitions.count(InsnClass) &&
"Cannot have multiple transitions for the same input");
Transitions[InsnClass] = To;
@@ -179,7 +176,7 @@ void State::addTransition(unsigned InsnC
// hasTransition - Returns true if there is a transition from this state
// given the input InsnClass
//
-bool State::hasTransition(unsigned InsnClass) {
+bool State::hasTransition(unsigned InsnClass) const {
return Transitions.count(InsnClass) > 0;
}
@@ -188,7 +185,7 @@ bool State::hasTransition(unsigned InsnC
// which are possible from this state (PossibleStates).
//
void State::AddInsnClass(unsigned InsnClass,
- std::set<unsigned> &PossibleStates) {
+ std::set<unsigned> &PossibleStates) const {
//
// Iterate over all resource states in currentState.
//
@@ -247,9 +244,10 @@ bool State::canAddInsnClass(unsigned Ins
}
-void DFA::addState(State *S) {
- assert(!states.count(S) && "State already exists");
- states.insert(S);
+const State &DFA::newState() {
+ auto IterPair = states.emplace();
+ assert(IterPair.second && "State already exists");
+ return *IterPair.first;
}
@@ -285,16 +283,16 @@ void DFA::writeTableAndAPI(raw_ostream &
// to construct the StateEntry table.
int ValidTransitions = 0;
for (unsigned i = 0; i < states.size(); ++i, ++SI) {
- assert (((*SI)->stateNum == (int) i) && "Mismatch in state numbers");
+ assert ((SI->stateNum == (int) i) && "Mismatch in state numbers");
StateEntry[i] = ValidTransitions;
for (State::TransitionMap::iterator
- II = (*SI)->Transitions.begin(), IE = (*SI)->Transitions.end();
+ II = SI->Transitions.begin(), IE = SI->Transitions.end();
II != IE; ++II) {
OS << "{" << II->first << ", "
<< II->second->stateNum
<< "}, ";
}
- ValidTransitions += (*SI)->Transitions.size();
+ ValidTransitions += SI->Transitions.size();
// If there are no valid transitions from this stage, we need a sentinel
// transition.
@@ -440,12 +438,11 @@ void DFAPacketizerEmitter::run(raw_ostre
// Run a worklist algorithm to generate the DFA.
//
DFA D;
- State *Initial = new State;
+ const State *Initial = &D.newState();
Initial->isInitial = true;
Initial->stateInfo.insert(0x0);
- D.addState(Initial);
- SmallVector<State*, 32> WorkList;
- std::map<std::set<unsigned>, State*> Visited;
+ SmallVector<const State*, 32> WorkList;
+ std::map<std::set<unsigned>, const State*> Visited;
WorkList.push_back(Initial);
@@ -467,7 +464,7 @@ void DFAPacketizerEmitter::run(raw_ostre
// Add S' to Visited
//
while (!WorkList.empty()) {
- State *current = WorkList.pop_back_val();
+ const State *current = WorkList.pop_back_val();
for (DenseSet<unsigned>::iterator CI = allInsnClasses.begin(),
CE = allInsnClasses.end(); CI != CE; ++CI) {
unsigned InsnClass = *CI;
@@ -479,7 +476,7 @@ void DFAPacketizerEmitter::run(raw_ostre
//
if (!current->hasTransition(InsnClass) &&
current->canAddInsnClass(InsnClass)) {
- State *NewState = nullptr;
+ const State *NewState;
current->AddInsnClass(InsnClass, NewStateResources);
assert(NewStateResources.size() && "New states must be generated");
@@ -487,13 +484,12 @@ void DFAPacketizerEmitter::run(raw_ostre
// If we have seen this state before, then do not create a new state.
//
//
- std::map<std::set<unsigned>, State*>::iterator VI;
- if ((VI = Visited.find(NewStateResources)) != Visited.end())
+ auto VI = Visited.find(NewStateResources);
+ if (VI != Visited.end())
NewState = VI->second;
else {
- NewState = new State;
+ NewState = &D.newState();
NewState->stateInfo = NewStateResources;
- D.addState(NewState);
Visited[NewStateResources] = NewState;
WorkList.push_back(NewState);
}
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