From 3adf3b0ac0927ee95d59e3c98599254072fb26f5 Mon Sep 17 00:00:00 2001 From: Anshuman Dasgupta Date: Fri, 7 Sep 2012 21:35:43 +0000 Subject: Refactored DFA generator. Merged transition class into state class. Patch by Ivan Llopard! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163424 91177308-0d34-0410-b5e6-96231b3b80d8 --- utils/TableGen/DFAPacketizerEmitter.cpp | 168 ++++++++++---------------------- 1 file changed, 51 insertions(+), 117 deletions(-) (limited to 'utils') diff --git a/utils/TableGen/DFAPacketizerEmitter.cpp b/utils/TableGen/DFAPacketizerEmitter.cpp index 8bfecead6d..0ad25a5428 100644 --- a/utils/TableGen/DFAPacketizerEmitter.cpp +++ b/utils/TableGen/DFAPacketizerEmitter.cpp @@ -17,6 +17,7 @@ #include "CodeGenTarget.h" #include "llvm/ADT/DenseSet.h" +#include "llvm/ADT/STLExtras.h" #include "llvm/TableGen/Record.h" #include "llvm/TableGen/TableGenBackend.h" #include @@ -74,6 +75,8 @@ public: // Another way of thinking about this transition is we are mapping a NDFA with // two states [0x01] and [0x10] into a DFA with a single state [0x01, 0x10]. // +// A State instance also contains a collection of transitions from that state: +// a map from inputs to new states. // namespace { class State { @@ -82,10 +85,16 @@ class State { int stateNum; bool isInitial; std::set stateInfo; + typedef std::map TransitionMap; + TransitionMap Transitions; State(); State(const State &S); + bool operator<(const State &s) const { + return stateNum < s.stateNum; + } + // // canAddInsnClass - Returns true if an instruction of type InsnClass is a // valid transition from this state, i.e., can an instruction of type InsnClass @@ -100,38 +109,18 @@ class State { // which are possible from this state (PossibleStates). // void AddInsnClass(unsigned InsnClass, std::set &PossibleStates); + // + // addTransition - Add a transition from this state given the input InsnClass + // + void addTransition(unsigned InsnClass, State *To); + // + // hasTransition - Returns true if there is a transition from this state + // given the input InsnClass + // + bool hasTransition(unsigned InsnClass); }; } // End anonymous namespace. - -namespace { -struct Transition { - public: - static int currentTransitionNum; - int transitionNum; - State *from; - unsigned input; - State *to; - - Transition(State *from_, unsigned input_, State *to_); -}; -} // End anonymous namespace. - - -// -// Comparators to keep set of states sorted. -// -namespace { -struct ltState { - bool operator()(const State *s1, const State *s2) const; -}; - -struct ltTransition { - bool operator()(const Transition *s1, const Transition *s2) const; -}; -} // End anonymous namespace. - - // // class DFA: deterministic finite automaton for processor resource tracking. // @@ -139,36 +128,19 @@ namespace { class DFA { public: DFA(); + ~DFA(); // Set of states. Need to keep this sorted to emit the transition table. - std::set states; + typedef std::set > StateSet; + StateSet states; - // Map from a state to the list of transitions with that state as source. - std::map, ltState> - stateTransitions; State *currentState; - // Highest valued Input seen. - unsigned LargestInput; - // // Modify the DFA. // void initialize(); void addState(State *); - void addTransition(Transition *); - - // - // getTransition - Return the state when a transition is made from - // State From with Input I. If a transition is not found, return NULL. - // - State *getTransition(State *, unsigned); - - // - // isValidTransition: Predicate that checks if there is a valid transition - // from state From on input InsnClass. - // - bool isValidTransition(State *From, unsigned InsnClass); // // writeTable: Print out a table representing the DFA. @@ -179,7 +151,7 @@ public: // -// Constructors for State, Transition, and DFA +// Constructors and destructors for State and DFA // State::State() : stateNum(currentStateNum++), isInitial(false) {} @@ -189,22 +161,27 @@ State::State(const State &S) : stateNum(currentStateNum++), isInitial(S.isInitial), stateInfo(S.stateInfo) {} +DFA::DFA(): currentState(NULL) {} -Transition::Transition(State *from_, unsigned input_, State *to_) : - transitionNum(currentTransitionNum++), from(from_), input(input_), - to(to_) {} - - -DFA::DFA() : - LargestInput(0) {} - +DFA::~DFA() { + DeleteContainerPointers(states); +} -bool ltState::operator()(const State *s1, const State *s2) const { - return (s1->stateNum < s2->stateNum); +// +// addTransition - Add a transition from this state given the input InsnClass +// +void State::addTransition(unsigned InsnClass, State *To) { + assert(!Transitions.count(InsnClass) && + "Cannot have multiple transitions for the same input"); + Transitions[InsnClass] = To; } -bool ltTransition::operator()(const Transition *s1, const Transition *s2) const { - return (s1->input < s2->input); +// +// hasTransition - Returns true if there is a transition from this state +// given the input InsnClass +// +bool State::hasTransition(unsigned InsnClass) { + return Transitions.count(InsnClass) > 0; } // @@ -272,6 +249,7 @@ bool State::canAddInsnClass(unsigned InsnClass) const { void DFA::initialize() { + assert(currentState && "Missing current state"); currentState->isInitial = true; } @@ -282,47 +260,7 @@ void DFA::addState(State *S) { } -void DFA::addTransition(Transition *T) { - // Update LargestInput. - if (T->input > LargestInput) - LargestInput = T->input; - - // Add the new transition. - bool Added = stateTransitions[T->from].insert(T).second; - assert(Added && "Cannot have multiple states for the same input"); - (void)Added; -} - - -// -// getTransition - Return the state when a transition is made from -// State From with Input I. If a transition is not found, return NULL. -// -State *DFA::getTransition(State *From, unsigned I) { - // Do we have a transition from state From? - if (!stateTransitions.count(From)) - return NULL; - - // Do we have a transition from state From with Input I? - Transition TVal(NULL, I, NULL); - // Do not count this temporal instance - Transition::currentTransitionNum--; - std::set::iterator T = - stateTransitions[From].find(&TVal); - if (T != stateTransitions[From].end()) - return (*T)->to; - - return NULL; -} - - -bool DFA::isValidTransition(State *From, unsigned InsnClass) { - return (getTransition(From, InsnClass) != NULL); -} - - int State::currentStateNum = 0; -int Transition::currentTransitionNum = 0; DFAPacketizerEmitter::DFAPacketizerEmitter(RecordKeeper &R): TargetName(CodeGenTarget(R).getName()), @@ -341,7 +279,7 @@ DFAPacketizerEmitter::DFAPacketizerEmitter(RecordKeeper &R): // // void DFA::writeTableAndAPI(raw_ostream &OS, const std::string &TargetName) { - std::set::iterator SI = states.begin(); + DFA::StateSet::iterator SI = states.begin(); // This table provides a map to the beginning of the transitions for State s // in DFAStateInputTable. std::vector StateEntry(states.size()); @@ -353,18 +291,16 @@ void DFA::writeTableAndAPI(raw_ostream &OS, const std::string &TargetName) { // 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"); StateEntry[i] = ValidTransitions; - for (unsigned j = 0; j <= LargestInput; ++j) { - assert (((*SI)->stateNum == (int) i) && "Mismatch in state numbers"); - State *To = getTransition(*SI, j); - if (To == NULL) - continue; - - OS << "{" << j << ", " - << To->stateNum + for (State::TransitionMap::iterator + II = (*SI)->Transitions.begin(), IE = (*SI)->Transitions.end(); + II != IE; ++II) { + OS << "{" << II->first << ", " + << II->second->stateNum << "}, "; - ++ValidTransitions; } + ValidTransitions += (*SI)->Transitions.size(); // If there are no valid transitions from this stage, we need a sentinel // transition. @@ -539,7 +475,7 @@ void DFAPacketizerEmitter::run(raw_ostream &OS) { // If we haven't already created a transition for this input // and the state can accommodate this InsnClass, create a transition. // - if (!D.getTransition(current, InsnClass) && + if (!current->hasTransition(InsnClass) && current->canAddInsnClass(InsnClass)) { State *NewState = NULL; current->AddInsnClass(InsnClass, NewStateResources); @@ -559,10 +495,8 @@ void DFAPacketizerEmitter::run(raw_ostream &OS) { Visited[NewStateResources] = NewState; WorkList.push_back(NewState); } - - Transition *NewTransition = new Transition(current, InsnClass, - NewState); - D.addTransition(NewTransition); + + current->addTransition(InsnClass, NewState); } } } -- cgit v1.2.3