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llvm-project/llvm/utils/TableGen/DFAPacketizerEmitter.cpp

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//===- DFAPacketizerEmitter.cpp - Packetization DFA for a VLIW machine ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This class parses the Schedule.td file and produces an API that can be used
// to reason about whether an instruction can be added to a packet on a VLIW
// architecture. The class internally generates a deterministic finite
// automaton (DFA) that models all possible mappings of machine instructions
// to functional units as instructions are added to a packet.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "dfa-emitter"
#include "CodeGenTarget.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <cstdint>
#include <map>
#include <set>
#include <string>
#include <unordered_map>
#include <vector>
using namespace llvm;
// --------------------------------------------------------------------
// Definitions shared between DFAPacketizer.cpp and DFAPacketizerEmitter.cpp
// DFA_MAX_RESTERMS * DFA_MAX_RESOURCES must fit within sizeof DFAInput.
// This is verified in DFAPacketizer.cpp:DFAPacketizer::DFAPacketizer.
//
// e.g. terms x resource bit combinations that fit in uint32_t:
// 4 terms x 8 bits = 32 bits
// 3 terms x 10 bits = 30 bits
// 2 terms x 16 bits = 32 bits
//
// e.g. terms x resource bit combinations that fit in uint64_t:
// 8 terms x 8 bits = 64 bits
// 7 terms x 9 bits = 63 bits
// 6 terms x 10 bits = 60 bits
// 5 terms x 12 bits = 60 bits
// 4 terms x 16 bits = 64 bits <--- current
// 3 terms x 21 bits = 63 bits
// 2 terms x 32 bits = 64 bits
//
#define DFA_MAX_RESTERMS 4 // The max # of AND'ed resource terms.
#define DFA_MAX_RESOURCES 16 // The max # of resource bits in one term.
typedef uint64_t DFAInput;
typedef int64_t DFAStateInput;
#define DFA_TBLTYPE "int64_t" // For generating DFAStateInputTable.
namespace {
DFAInput addDFAFuncUnits(DFAInput Inp, unsigned FuncUnits) {
return (Inp << DFA_MAX_RESOURCES) | FuncUnits;
}
/// Return the DFAInput for an instruction class input vector.
/// This function is used in both DFAPacketizer.cpp and in
/// DFAPacketizerEmitter.cpp.
DFAInput getDFAInsnInput(const std::vector<unsigned> &InsnClass) {
DFAInput InsnInput = 0;
assert((InsnClass.size() <= DFA_MAX_RESTERMS) &&
"Exceeded maximum number of DFA terms");
for (auto U : InsnClass)
InsnInput = addDFAFuncUnits(InsnInput, U);
return InsnInput;
}
} // end anonymous namespace
// --------------------------------------------------------------------
#ifndef NDEBUG
// To enable debugging, run llvm-tblgen with: "-debug-only dfa-emitter".
//
// dbgsInsnClass - When debugging, print instruction class stages.
//
void dbgsInsnClass(const std::vector<unsigned> &InsnClass);
//
// dbgsStateInfo - When debugging, print the set of state info.
//
void dbgsStateInfo(const std::set<unsigned> &stateInfo);
//
// dbgsIndent - When debugging, indent by the specified amount.
//
void dbgsIndent(unsigned indent);
#endif
//
// class DFAPacketizerEmitter: class that generates and prints out the DFA
// for resource tracking.
//
namespace {
class DFAPacketizerEmitter {
private:
std::string TargetName;
//
// allInsnClasses is the set of all possible resources consumed by an
// InstrStage.
//
std::vector<std::vector<unsigned>> allInsnClasses;
RecordKeeper &Records;
public:
DFAPacketizerEmitter(RecordKeeper &R);
//
// collectAllFuncUnits - Construct a map of function unit names to bits.
//
int collectAllFuncUnits(std::vector<Record*> &ProcItinList,
std::map<std::string, unsigned> &FUNameToBitsMap,
int &maxResources,
raw_ostream &OS);
//
// collectAllComboFuncs - Construct a map from a combo function unit bit to
// the bits of all included functional units.
//
int collectAllComboFuncs(std::vector<Record*> &ComboFuncList,
std::map<std::string, unsigned> &FUNameToBitsMap,
std::map<unsigned, unsigned> &ComboBitToBitsMap,
raw_ostream &OS);
//
// collectOneInsnClass - Populate allInsnClasses with one instruction class.
//
int collectOneInsnClass(const std::string &ProcName,
std::vector<Record*> &ProcItinList,
std::map<std::string, unsigned> &FUNameToBitsMap,
Record *ItinData,
raw_ostream &OS);
//
// collectAllInsnClasses - Populate allInsnClasses which is a set of units
// used in each stage.
//
int collectAllInsnClasses(const std::string &ProcName,
std::vector<Record*> &ProcItinList,
std::map<std::string, unsigned> &FUNameToBitsMap,
std::vector<Record*> &ItinDataList,
int &maxStages,
raw_ostream &OS);
// Emit code for a subset of itineraries.
void emitForItineraries(raw_ostream &OS,
std::vector<Record *> &ProcItinList,
std::string DFAName);
void run(raw_ostream &OS);
};
//
// State represents the usage of machine resources if the packet contains
// a set of instruction classes.
//
// Specifically, currentState is a set of bit-masks.
// The nth bit in a bit-mask indicates whether the nth resource is being used
// by this state. The set of bit-masks in a state represent the different
// possible outcomes of transitioning to this state.
// For example: consider a two resource architecture: resource L and resource M
// with three instruction classes: L, M, and L_or_M.
// From the initial state (currentState = 0x00), if we add instruction class
// L_or_M we will transition to a state with currentState = [0x01, 0x10]. This
// represents the possible resource states that can result from adding a L_or_M
// instruction
//
// 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.
//
class State {
public:
static int currentStateNum;
// 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;
struct TransitionInfo {
// Maps from a resource bitmask in this state to the equivalent resource
// bitmap in the transitioned-to state. This is a 1-to-N mapping.
std::vector<std::pair<unsigned, unsigned>> ResourceTransitions;
const State *S;
};
using TransitionMap = std::map<std::vector<unsigned>, TransitionInfo>;
mutable TransitionMap Transitions;
State();
bool operator<(const State &s) const {
return stateNum < s.stateNum;
}
//
// canMaybeAddInsnClass - Quickly verifies if an instruction of type InsnClass
// may be a valid transition from this state i.e., can an instruction of type
// InsnClass be added to the packet represented by this state.
//
// Note that for multiple stages, this quick check does not take into account
// any possible resource competition between the stages themselves. That is
// enforced in AddInsnClassStages which checks the cross product of all
// stages for resource availability (which is a more involved check).
//
bool canMaybeAddInsnClass(std::vector<unsigned> &InsnClass,
std::map<unsigned, unsigned> &ComboBitToBitsMap) const;
//
// AddInsnClass - Return all combinations of resource reservation
// which are possible from this state (PossibleStates).
//
// PossibleStates is the set of valid resource states that ensue from valid
// transitions.
//
// TransitionInfo maps from a resource bitmask B in this state to a resource
// bitmask B' in PossibleStates. This is a one-to-many (or none) mapping.
//
void AddInsnClass(
std::vector<unsigned> &InsnClass,
std::map<unsigned, unsigned> &ComboBitToBitsMap,
std::set<unsigned> &PossibleStates,
std::vector<std::pair<unsigned, unsigned>> &TransitionInfo) const;
//
// AddInsnClassStages - Return all combinations of resource reservation
// resulting from the cross product of all stages for this InsnClass
// which are possible from this state (PossibleStates).
//
void AddInsnClassStages(std::vector<unsigned> &InsnClass,
std::map<unsigned, unsigned> &ComboBitToBitsMap,
unsigned chkstage, unsigned numstages,
unsigned prevState, unsigned origState,
DenseSet<unsigned> &VisitedResourceStates) const;
//
// addTransition - Add a transition from this state given the input InsnClass.
//
void addTransition(
std::vector<unsigned> InsnClass, const State *To,
const std::vector<std::pair<unsigned, unsigned>> &TransitionInfo) const;
//
// hasTransition - Returns true if there is a transition from this state
// given the input InsnClass
//
bool hasTransition(std::vector<unsigned> InsnClass) const;
};
//
// class DFA: deterministic finite automaton for processor resource tracking.
//
class DFA {
public:
DFA() = default;
// Set of states. Need to keep this sorted to emit the transition table.
typedef std::set<State> StateSet;
StateSet states;
State *currentState = nullptr;
//
// Modify the DFA.
//
const State &newState();
//
// writeTable: Print out a table representing the DFA.
//
void writeTableAndAPI(raw_ostream &OS, const std::string &ClassName,
int numInsnClasses = 0,
int maxResources = 0, int numCombos = 0, int maxStages = 0);
};
} // end anonymous namespace
#ifndef NDEBUG
// To enable debugging, run llvm-tblgen with: "-debug-only dfa-emitter".
//
// dbgsInsnClass - When debugging, print instruction class stages.
//
void dbgsInsnClass(const std::vector<unsigned> &InsnClass) {
LLVM_DEBUG(dbgs() << "InsnClass: ");
for (unsigned i = 0; i < InsnClass.size(); ++i) {
if (i > 0) {
LLVM_DEBUG(dbgs() << ", ");
}
LLVM_DEBUG(dbgs() << "0x" << Twine::utohexstr(InsnClass[i]));
}
DFAInput InsnInput = getDFAInsnInput(InsnClass);
LLVM_DEBUG(dbgs() << " (input: 0x" << Twine::utohexstr(InsnInput) << ")");
}
//
// dbgsStateInfo - When debugging, print the set of state info.
//
void dbgsStateInfo(const std::set<unsigned> &stateInfo) {
LLVM_DEBUG(dbgs() << "StateInfo: ");
unsigned i = 0;
for (std::set<unsigned>::iterator SI = stateInfo.begin();
SI != stateInfo.end(); ++SI, ++i) {
unsigned thisState = *SI;
if (i > 0) {
LLVM_DEBUG(dbgs() << ", ");
}
LLVM_DEBUG(dbgs() << "0x" << Twine::utohexstr(thisState));
}
}
//
// dbgsIndent - When debugging, indent by the specified amount.
//
void dbgsIndent(unsigned indent) {
for (unsigned i = 0; i < indent; ++i) {
LLVM_DEBUG(dbgs() << " ");
}
}
#endif // NDEBUG
//
// Constructors and destructors for State and DFA
//
State::State() :
stateNum(currentStateNum++), isInitial(false) {}
//
// addTransition - Add a transition from this state given the input InsnClass
//
void State::addTransition(
std::vector<unsigned> InsnClass, const State *To,
const std::vector<std::pair<unsigned, unsigned>> &TransitionInfo) const {
assert(!Transitions.count(InsnClass) &&
"Cannot have multiple transitions for the same input");
Transitions[InsnClass] = {TransitionInfo, To};
}
//
// hasTransition - Returns true if there is a transition from this state
// given the input InsnClass
//
bool State::hasTransition(std::vector<unsigned> InsnClass) const {
return Transitions.count(InsnClass) > 0;
}
//
// AddInsnClass - Return all combinations of resource reservation
// which are possible from this state (PossibleStates).
//
// PossibleStates is the set of valid resource states that ensue from valid
// transitions.
//
void State::AddInsnClass(
std::vector<unsigned> &InsnClass,
std::map<unsigned, unsigned> &ComboBitToBitsMap,
std::set<unsigned> &PossibleStates,
std::vector<std::pair<unsigned, unsigned>> &TransitionInfo) const {
//
// Iterate over all resource states in currentState.
//
unsigned numstages = InsnClass.size();
assert((numstages > 0) && "InsnClass has no stages");
for (std::set<unsigned>::iterator SI = stateInfo.begin();
SI != stateInfo.end(); ++SI) {
unsigned ThisState = *SI;
DenseSet<unsigned> VisitedResourceStates;
LLVM_DEBUG(dbgs() << " thisState: 0x" << Twine::utohexstr(ThisState)
<< "\n");
AddInsnClassStages(InsnClass, ComboBitToBitsMap, numstages - 1, numstages,
ThisState, ThisState, VisitedResourceStates);
for (unsigned NewState : VisitedResourceStates) {
PossibleStates.insert(NewState);
TransitionInfo.emplace_back(ThisState, NewState);
}
}
}
void State::AddInsnClassStages(
std::vector<unsigned> &InsnClass,
std::map<unsigned, unsigned> &ComboBitToBitsMap, unsigned chkstage,
unsigned numstages, unsigned prevState, unsigned origState,
DenseSet<unsigned> &VisitedResourceStates) const {
assert((chkstage < numstages) && "AddInsnClassStages: stage out of range");
unsigned thisStage = InsnClass[chkstage];
LLVM_DEBUG({
dbgsIndent((1 + numstages - chkstage) << 1);
dbgs() << "AddInsnClassStages " << chkstage << " (0x"
<< Twine::utohexstr(thisStage) << ") from ";
dbgsInsnClass(InsnClass);
dbgs() << "\n";
});
//
// Iterate over all possible resources used in thisStage.
// For ex: for thisStage = 0x11, all resources = {0x01, 0x10}.
//
for (unsigned int j = 0; j < DFA_MAX_RESOURCES; ++j) {
unsigned resourceMask = (0x1 << j);
if (resourceMask & thisStage) {
unsigned combo = ComboBitToBitsMap[resourceMask];
if (combo && ((~prevState & combo) != combo)) {
LLVM_DEBUG(dbgs() << "\tSkipped Add 0x" << Twine::utohexstr(prevState)
<< " - combo op 0x" << Twine::utohexstr(resourceMask)
<< " (0x" << Twine::utohexstr(combo)
<< ") cannot be scheduled\n");
continue;
}
//
// For each possible resource used in thisStage, generate the
// resource state if that resource was used.
//
unsigned ResultingResourceState = prevState | resourceMask | combo;
LLVM_DEBUG({
dbgsIndent((2 + numstages - chkstage) << 1);
dbgs() << "0x" << Twine::utohexstr(prevState) << " | 0x"
<< Twine::utohexstr(resourceMask);
if (combo)
dbgs() << " | 0x" << Twine::utohexstr(combo);
dbgs() << " = 0x" << Twine::utohexstr(ResultingResourceState) << " ";
});
//
// If this is the final stage for this class
//
if (chkstage == 0) {
//
// Check if the resulting resource state can be accommodated in this
// packet.
// We compute resource OR prevState (originally started as origState).
// If the result of the OR is different than origState, it implies
// that there is at least one resource that can be used to schedule
// thisStage in the current packet.
// Insert ResultingResourceState into PossibleStates only if we haven't
// processed ResultingResourceState before.
//
if (ResultingResourceState != prevState) {
if (VisitedResourceStates.count(ResultingResourceState) == 0) {
VisitedResourceStates.insert(ResultingResourceState);
LLVM_DEBUG(dbgs()
<< "\tResultingResourceState: 0x"
<< Twine::utohexstr(ResultingResourceState) << "\n");
} else {
LLVM_DEBUG(dbgs() << "\tSkipped Add - state already seen\n");
}
} else {
LLVM_DEBUG(dbgs()
<< "\tSkipped Add - no final resources available\n");
}
} else {
//
// If the current resource can be accommodated, check the next
// stage in InsnClass for available resources.
//
if (ResultingResourceState != prevState) {
LLVM_DEBUG(dbgs() << "\n");
AddInsnClassStages(InsnClass, ComboBitToBitsMap, chkstage - 1,
numstages, ResultingResourceState, origState,
VisitedResourceStates);
} else {
LLVM_DEBUG(dbgs() << "\tSkipped Add - no resources available\n");
}
}
}
}
}
//
// canMaybeAddInsnClass - Quickly verifies if an instruction of type InsnClass
// may be a valid transition from this state i.e., can an instruction of type
// InsnClass be added to the packet represented by this state.
//
// Note that this routine is performing conservative checks that can be
// quickly executed acting as a filter before calling AddInsnClassStages.
// Any cases allowed through here will be caught later in AddInsnClassStages
// which performs the more expensive exact check.
//
bool State::canMaybeAddInsnClass(std::vector<unsigned> &InsnClass,
std::map<unsigned, unsigned> &ComboBitToBitsMap) const {
for (std::set<unsigned>::const_iterator SI = stateInfo.begin();
SI != stateInfo.end(); ++SI) {
// Check to see if all required resources are available.
bool available = true;
// Inspect each stage independently.
// note: This is a conservative check as we aren't checking for
// possible resource competition between the stages themselves
// The full cross product is examined later in AddInsnClass.
for (unsigned i = 0; i < InsnClass.size(); ++i) {
unsigned resources = *SI;
if ((~resources & InsnClass[i]) == 0) {
available = false;
break;
}
// Make sure _all_ resources for a combo function are available.
// note: This is a quick conservative check as it won't catch an
// unscheduleable combo if this stage is an OR expression
// containing a combo.
// These cases are caught later in AddInsnClass.
unsigned combo = ComboBitToBitsMap[InsnClass[i]];
if (combo && ((~resources & combo) != combo)) {
LLVM_DEBUG(dbgs() << "\tSkipped canMaybeAdd 0x"
<< Twine::utohexstr(resources) << " - combo op 0x"
<< Twine::utohexstr(InsnClass[i]) << " (0x"
<< Twine::utohexstr(combo)
<< ") cannot be scheduled\n");
available = false;
break;
}
}
if (available) {
return true;
}
}
return false;
}
const State &DFA::newState() {
auto IterPair = states.insert(State());
assert(IterPair.second && "State already exists");
return *IterPair.first;
}
int State::currentStateNum = 0;
DFAPacketizerEmitter::DFAPacketizerEmitter(RecordKeeper &R):
TargetName(CodeGenTarget(R).getName()), Records(R) {}
//
// writeTableAndAPI - Print out a table representing the DFA and the
// associated API to create a DFA packetizer.
//
// Format:
// DFAStateInputTable[][2] = pairs of <Input, Transition> for all valid
// transitions.
// DFAStateEntryTable[i] = Index of the first entry in DFAStateInputTable for
// the ith state.
//
//
void DFA::writeTableAndAPI(raw_ostream &OS, const std::string &TargetName,
int numInsnClasses,
int maxResources, int numCombos, int maxStages) {
unsigned numStates = states.size();
LLVM_DEBUG(dbgs() << "-------------------------------------------------------"
"----------------------\n");
LLVM_DEBUG(dbgs() << "writeTableAndAPI\n");
LLVM_DEBUG(dbgs() << "Total states: " << numStates << "\n");
OS << "\n// " << TargetName << "DFAStateInputTable[][2] = "
<< "pairs of <Input, NextState> for all valid\n";
OS << "// transitions.\n";
OS << "// " << numStates << "\tstates\n";
OS << "// " << numInsnClasses << "\tinstruction classes\n";
OS << "// " << maxResources << "\tresources max\n";
OS << "// " << numCombos << "\tcombo resources\n";
OS << "// " << maxStages << "\tstages max\n";
OS << "const " << DFA_TBLTYPE << " "
<< TargetName << "DFAStateInputTable[][2] = {\n";
// This table provides a map to the beginning of the transitions for State s
// in DFAStateInputTable.
std::vector<int> StateEntry(numStates+1);
static const std::string SentinelEntry = "{-1, -1}";
// Tracks the total valid transitions encountered so far. It is used
// to construct the StateEntry table.
int ValidTransitions = 0;
DFA::StateSet::iterator SI = states.begin();
for (unsigned i = 0; i < numStates; ++i, ++SI) {
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 != IE; ++II) {
OS << "{0x" << Twine::utohexstr(getDFAInsnInput(II->first)) << ", "
<< II->second.S->stateNum << "},\t";
}
ValidTransitions += SI->Transitions.size();
OS << " // state " << i << ": " << StateEntry[i];
if (StateEntry[i] != (ValidTransitions-1)) { // More than one transition.
OS << "-" << (ValidTransitions-1);
}
OS << "\n";
}
// Print out a sentinel entry at the end of the StateInputTable. This is
// needed to iterate over StateInputTable in DFAPacketizer::ReadTable()
OS << SentinelEntry << "\t";
OS << " // state " << numStates << ": " << ValidTransitions;
OS << "\n";
OS << "};\n\n";
OS << "// " << TargetName << "DFAStateEntryTable[i] = "
<< "Index of the first entry in DFAStateInputTable for\n";
OS << "// "
<< "the ith state.\n";
OS << "// " << numStates << " states\n";
OS << "const unsigned int " << TargetName << "DFAStateEntryTable[] = {\n";
unsigned lastState = 0;
for (unsigned i = 0; i < numStates; ++i) {
if (i && ((i % 10) == 0)) {
lastState = i-1;
OS << " // states " << (i-10) << ":" << lastState << "\n";
}
OS << StateEntry[i] << ", ";
}
// Print out the index to the sentinel entry in StateInputTable
OS << ValidTransitions << ", ";
OS << " // states " << (lastState+1) << ":" << numStates << "\n";
OS << "};\n";
// Generate the resource transition table.
OS << "const unsigned " << TargetName
<< "DFAResourceTransitionTable[][2] = { \n";
int N = 0;
StateEntry.clear();
for (const State &S : states) {
for (auto &KV : S.Transitions) {
StateEntry.push_back(N);
for (std::pair<unsigned, unsigned> &T : KV.second.ResourceTransitions) {
OS << "{0x" << utohexstr(T.first) << ", 0x" << utohexstr(T.second)
<< "}, ";
++N;
}
}
OS << "\n ";
}
// Add a sentinel entry to terminate the search.
StateEntry.push_back(N);
OS << "\n {~0U,~0U}\n};\n\n";
OS << "// " << TargetName << "DFAResourceTransitionEntryTable[i] = "
<< "Index of the first entry in DFAResourceTransitionTable for\n";
OS << "// the ith transition.\n";
OS << "const unsigned int " << TargetName
<< "DFAResourceTransitionEntryTable[] = { \n";
N = 0;
for (int S : StateEntry) {
OS << S << ",";
if (N++ % 10 == 0)
OS << "\n ";
}
OS << "\n ~0U\n};\n";
}
//
// collectAllFuncUnits - Construct a map of function unit names to bits.
//
int DFAPacketizerEmitter::collectAllFuncUnits(
std::vector<Record*> &ProcItinList,
std::map<std::string, unsigned> &FUNameToBitsMap,
int &maxFUs,
raw_ostream &OS) {
LLVM_DEBUG(dbgs() << "-------------------------------------------------------"
"----------------------\n");
LLVM_DEBUG(dbgs() << "collectAllFuncUnits");
LLVM_DEBUG(dbgs() << " (" << ProcItinList.size() << " itineraries)\n");
int totalFUs = 0;
// Parse functional units for all the itineraries.
for (unsigned i = 0, N = ProcItinList.size(); i < N; ++i) {
Record *Proc = ProcItinList[i];
std::vector<Record*> FUs = Proc->getValueAsListOfDefs("FU");
LLVM_DEBUG(dbgs() << " FU:" << i << " (" << FUs.size() << " FUs) "
<< Proc->getName());
// Convert macros to bits for each stage.
unsigned numFUs = FUs.size();
for (unsigned j = 0; j < numFUs; ++j) {
assert ((j < DFA_MAX_RESOURCES) &&
"Exceeded maximum number of representable resources");
unsigned FuncResources = (unsigned) (1U << j);
FUNameToBitsMap[FUs[j]->getName()] = FuncResources;
LLVM_DEBUG(dbgs() << " " << FUs[j]->getName() << ":0x"
<< Twine::utohexstr(FuncResources));
}
if (((int) numFUs) > maxFUs) {
maxFUs = numFUs;
}
totalFUs += numFUs;
LLVM_DEBUG(dbgs() << "\n");
}
return totalFUs;
}
//
// collectAllComboFuncs - Construct a map from a combo function unit bit to
// the bits of all included functional units.
//
int DFAPacketizerEmitter::collectAllComboFuncs(
std::vector<Record*> &ComboFuncList,
std::map<std::string, unsigned> &FUNameToBitsMap,
std::map<unsigned, unsigned> &ComboBitToBitsMap,
raw_ostream &OS) {
LLVM_DEBUG(dbgs() << "-------------------------------------------------------"
"----------------------\n");
LLVM_DEBUG(dbgs() << "collectAllComboFuncs");
LLVM_DEBUG(dbgs() << " (" << ComboFuncList.size() << " sets)\n");
int numCombos = 0;
for (unsigned i = 0, N = ComboFuncList.size(); i < N; ++i) {
Record *Func = ComboFuncList[i];
std::vector<Record*> FUs = Func->getValueAsListOfDefs("CFD");
LLVM_DEBUG(dbgs() << " CFD:" << i << " (" << FUs.size() << " combo FUs) "
<< Func->getName() << "\n");
// Convert macros to bits for each stage.
for (unsigned j = 0, N = FUs.size(); j < N; ++j) {
assert ((j < DFA_MAX_RESOURCES) &&
"Exceeded maximum number of DFA resources");
Record *FuncData = FUs[j];
Record *ComboFunc = FuncData->getValueAsDef("TheComboFunc");
const std::vector<Record*> &FuncList =
FuncData->getValueAsListOfDefs("FuncList");
const std::string &ComboFuncName = ComboFunc->getName();
unsigned ComboBit = FUNameToBitsMap[ComboFuncName];
unsigned ComboResources = ComboBit;
LLVM_DEBUG(dbgs() << " combo: " << ComboFuncName << ":0x"
<< Twine::utohexstr(ComboResources) << "\n");
for (unsigned k = 0, M = FuncList.size(); k < M; ++k) {
std::string FuncName = FuncList[k]->getName();
unsigned FuncResources = FUNameToBitsMap[FuncName];
LLVM_DEBUG(dbgs() << " " << FuncName << ":0x"
<< Twine::utohexstr(FuncResources) << "\n");
ComboResources |= FuncResources;
}
ComboBitToBitsMap[ComboBit] = ComboResources;
numCombos++;
LLVM_DEBUG(dbgs() << " => combo bits: " << ComboFuncName << ":0x"
<< Twine::utohexstr(ComboBit) << " = 0x"
<< Twine::utohexstr(ComboResources) << "\n");
}
}
return numCombos;
}
//
// collectOneInsnClass - Populate allInsnClasses with one instruction class
//
int DFAPacketizerEmitter::collectOneInsnClass(const std::string &ProcName,
std::vector<Record*> &ProcItinList,
std::map<std::string, unsigned> &FUNameToBitsMap,
Record *ItinData,
raw_ostream &OS) {
const std::vector<Record*> &StageList =
ItinData->getValueAsListOfDefs("Stages");
// The number of stages.
unsigned NStages = StageList.size();
LLVM_DEBUG(dbgs() << " " << ItinData->getValueAsDef("TheClass")->getName()
<< "\n");
std::vector<unsigned> UnitBits;
// Compute the bitwise or of each unit used in this stage.
for (unsigned i = 0; i < NStages; ++i) {
const Record *Stage = StageList[i];
// Get unit list.
const std::vector<Record*> &UnitList =
Stage->getValueAsListOfDefs("Units");
LLVM_DEBUG(dbgs() << " stage:" << i << " [" << UnitList.size()
<< " units]:");
unsigned dbglen = 26; // cursor after stage dbgs
// Compute the bitwise or of each unit used in this stage.
unsigned UnitBitValue = 0;
for (unsigned j = 0, M = UnitList.size(); j < M; ++j) {
// Conduct bitwise or.
std::string UnitName = UnitList[j]->getName();
LLVM_DEBUG(dbgs() << " " << j << ":" << UnitName);
dbglen += 3 + UnitName.length();
assert(FUNameToBitsMap.count(UnitName));
UnitBitValue |= FUNameToBitsMap[UnitName];
}
if (UnitBitValue != 0)
UnitBits.push_back(UnitBitValue);
while (dbglen <= 64) { // line up bits dbgs
dbglen += 8;
LLVM_DEBUG(dbgs() << "\t");
}
LLVM_DEBUG(dbgs() << " (bits: 0x" << Twine::utohexstr(UnitBitValue)
<< ")\n");
}
if (!UnitBits.empty())
allInsnClasses.push_back(UnitBits);
LLVM_DEBUG({
dbgs() << " ";
dbgsInsnClass(UnitBits);
dbgs() << "\n";
});
return NStages;
}
//
// collectAllInsnClasses - Populate allInsnClasses which is a set of units
// used in each stage.
//
int DFAPacketizerEmitter::collectAllInsnClasses(const std::string &ProcName,
std::vector<Record*> &ProcItinList,
std::map<std::string, unsigned> &FUNameToBitsMap,
std::vector<Record*> &ItinDataList,
int &maxStages,
raw_ostream &OS) {
// Collect all instruction classes.
unsigned M = ItinDataList.size();
int numInsnClasses = 0;
LLVM_DEBUG(dbgs() << "-------------------------------------------------------"
"----------------------\n"
<< "collectAllInsnClasses " << ProcName << " (" << M
<< " classes)\n");
// Collect stages for each instruction class for all itinerary data
for (unsigned j = 0; j < M; j++) {
Record *ItinData = ItinDataList[j];
int NStages = collectOneInsnClass(ProcName, ProcItinList,
FUNameToBitsMap, ItinData, OS);
if (NStages > maxStages) {
maxStages = NStages;
}
numInsnClasses++;
}
return numInsnClasses;
}
//
// Run the worklist algorithm to generate the DFA.
//
void DFAPacketizerEmitter::run(raw_ostream &OS) {
OS << "\n"
<< "#include \"llvm/CodeGen/DFAPacketizer.h\"\n";
OS << "namespace llvm {\n";
OS << "\n// Input format:\n";
OS << "#define DFA_MAX_RESTERMS " << DFA_MAX_RESTERMS
<< "\t// maximum AND'ed resource terms\n";
OS << "#define DFA_MAX_RESOURCES " << DFA_MAX_RESOURCES
<< "\t// maximum resource bits in one term\n";
// Collect processor iteraries.
std::vector<Record*> ProcItinList =
Records.getAllDerivedDefinitions("ProcessorItineraries");
std::unordered_map<std::string, std::vector<Record*>> ItinsByNamespace;
for (Record *R : ProcItinList)
ItinsByNamespace[R->getValueAsString("PacketizerNamespace")].push_back(R);
for (auto &KV : ItinsByNamespace)
emitForItineraries(OS, KV.second, KV.first);
OS << "} // end namespace llvm\n";
}
void DFAPacketizerEmitter::emitForItineraries(
raw_ostream &OS, std::vector<Record *> &ProcItinList,
std::string DFAName) {
//
// Collect the Functional units.
//
std::map<std::string, unsigned> FUNameToBitsMap;
int maxResources = 0;
collectAllFuncUnits(ProcItinList,
FUNameToBitsMap, maxResources, OS);
//
// Collect the Combo Functional units.
//
std::map<unsigned, unsigned> ComboBitToBitsMap;
std::vector<Record*> ComboFuncList =
Records.getAllDerivedDefinitions("ComboFuncUnits");
int numCombos = collectAllComboFuncs(ComboFuncList,
FUNameToBitsMap, ComboBitToBitsMap, OS);
//
// Collect the itineraries.
//
int maxStages = 0;
int numInsnClasses = 0;
for (unsigned i = 0, N = ProcItinList.size(); i < N; i++) {
Record *Proc = ProcItinList[i];
// Get processor itinerary name.
const std::string &ProcName = Proc->getName();
// Skip default.
if (ProcName == "NoItineraries")
continue;
// Sanity check for at least one instruction itinerary class.
unsigned NItinClasses =
Records.getAllDerivedDefinitions("InstrItinClass").size();
if (NItinClasses == 0)
return;
// Get itinerary data list.
std::vector<Record*> ItinDataList = Proc->getValueAsListOfDefs("IID");
// Collect all instruction classes
numInsnClasses += collectAllInsnClasses(ProcName, ProcItinList,
FUNameToBitsMap, ItinDataList, maxStages, OS);
}
//
// Run a worklist algorithm to generate the DFA.
//
DFA D;
const State *Initial = &D.newState();
Initial->isInitial = true;
Initial->stateInfo.insert(0x0);
SmallVector<const State*, 32> WorkList;
std::map<std::set<unsigned>, const State*> Visited;
WorkList.push_back(Initial);
//
// Worklist algorithm to create a DFA for processor resource tracking.
// C = {set of InsnClasses}
// Begin with initial node in worklist. Initial node does not have
// any consumed resources,
// ResourceState = 0x0
// Visited = {}
// While worklist != empty
// S = first element of worklist
// For every instruction class C
// if we can accommodate C in S:
// S' = state with resource states = {S Union C}
// Add a new transition: S x C -> S'
// If S' is not in Visited:
// Add S' to worklist
// Add S' to Visited
//
while (!WorkList.empty()) {
const State *current = WorkList.pop_back_val();
LLVM_DEBUG({
dbgs() << "---------------------\n";
dbgs() << "Processing state: " << current->stateNum << " - ";
dbgsStateInfo(current->stateInfo);
dbgs() << "\n";
});
for (unsigned i = 0; i < allInsnClasses.size(); i++) {
std::vector<unsigned> InsnClass = allInsnClasses[i];
LLVM_DEBUG({
dbgs() << i << " ";
dbgsInsnClass(InsnClass);
dbgs() << "\n";
});
std::set<unsigned> NewStateResources;
//
// If we haven't already created a transition for this input
// and the state can accommodate this InsnClass, create a transition.
//
if (!current->hasTransition(InsnClass) &&
current->canMaybeAddInsnClass(InsnClass, ComboBitToBitsMap)) {
const State *NewState = nullptr;
std::vector<std::pair<unsigned, unsigned>> TransitionInfo;
current->AddInsnClass(InsnClass, ComboBitToBitsMap, NewStateResources,
TransitionInfo);
if (NewStateResources.empty()) {
LLVM_DEBUG(dbgs() << " Skipped - no new states generated\n");
continue;
}
LLVM_DEBUG({
dbgs() << "\t";
dbgsStateInfo(NewStateResources);
dbgs() << "\n";
});
//
// If we have seen this state before, then do not create a new state.
//
auto VI = Visited.find(NewStateResources);
if (VI != Visited.end()) {
NewState = VI->second;
LLVM_DEBUG({
dbgs() << "\tFound existing state: " << NewState->stateNum
<< " - ";
dbgsStateInfo(NewState->stateInfo);
dbgs() << "\n";
});
} else {
NewState = &D.newState();
NewState->stateInfo = NewStateResources;
Visited[NewStateResources] = NewState;
WorkList.push_back(NewState);
LLVM_DEBUG({
dbgs() << "\tAccepted new state: " << NewState->stateNum << " - ";
dbgsStateInfo(NewState->stateInfo);
dbgs() << "\n";
});
}
current->addTransition(InsnClass, NewState, TransitionInfo);
}
}
}
// Print out the table.
D.writeTableAndAPI(OS, TargetName + DFAName, numInsnClasses, maxResources,
numCombos, maxStages);
OS << "} // end namespace llvm\n";
std::string SubTargetClassName = TargetName + "GenSubtargetInfo";
OS << "namespace llvm {\n";
OS << "DFAPacketizer *" << SubTargetClassName << "::"
<< "create" << DFAName
<< "DFAPacketizer(const InstrItineraryData *IID) const {\n"
<< " return new DFAPacketizer(IID, " << TargetName << DFAName
<< "DFAStateInputTable, " << TargetName << DFAName
<< "DFAStateEntryTable, " << TargetName << DFAName
<< "DFAResourceTransitionTable, " << TargetName << DFAName
<< "DFAResourceTransitionEntryTable"
<< ");\n}\n\n";
}
namespace llvm {
void EmitDFAPacketizer(RecordKeeper &RK, raw_ostream &OS) {
emitSourceFileHeader("Target DFA Packetizer Tables", OS);
DFAPacketizerEmitter(RK).run(OS);
}
} // end namespace llvm
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