//
//===----------------------------------------------------------------------===//
//
-// This file describes the structures used for instruction itineraries and
-// stages. This is used by schedulers to determine instruction stages and
-// latencies.
+// This file describes the structures used for instruction
+// itineraries, stages, and operand reads/writes. This is used by
+// schedulers to determine instruction stages and latencies.
//
//===----------------------------------------------------------------------===//
/// indicate that the instruction requires multiple stages at the
/// same time.
///
+/// FU reservation can be of two different kinds:
+/// - FUs which instruction actually requires
+/// - FUs which instruction just reserves. Reserved unit is not available for
+/// execution of other instruction. However, several instructions can reserve
+/// the same unit several times.
+/// Such two types of units reservation is used to model instruction domain
+/// change stalls, FUs using the same resource (e.g. same register file), etc.
+
struct InstrStage {
+ enum ReservationKinds {
+ Required = 0,
+ Reserved = 1
+ };
+
unsigned Cycles_; ///< Length of stage in machine cycles
unsigned Units_; ///< Choice of functional units
- int NextCycles_; ///< Number of machine cycles to next stage
+ int NextCycles_; ///< Number of machine cycles to next stage
+ ReservationKinds Kind_; ///< Kind of the FU reservation
/// getCycles - returns the number of cycles the stage is occupied
unsigned getCycles() const {
return Units_;
}
+ ReservationKinds getReservationKind() const {
+ return Kind_;
+ }
+
/// getNextCycles - returns the number of cycles from the start of
/// this stage to the start of the next stage in the itinerary
unsigned getNextCycles() const {
//===----------------------------------------------------------------------===//
-/// Instruction itinerary - An itinerary represents a sequential series of steps
-/// required to complete an instruction. Itineraries are represented as
-/// sequences of instruction stages.
+/// Instruction itinerary - An itinerary represents the scheduling
+/// information for an instruction. This includes a set of stages
+/// occupies by the instruction, and the pipeline cycle in which
+/// operands are read and written.
///
struct InstrItinerary {
- unsigned First; ///< Index of first stage in itinerary
- unsigned Last; ///< Index of last + 1 stage in itinerary
+ unsigned FirstStage; ///< Index of first stage in itinerary
+ unsigned LastStage; ///< Index of last + 1 stage in itinerary
+ unsigned FirstOperandCycle; ///< Index of first operand rd/wr
+ unsigned LastOperandCycle; ///< Index of last + 1 operand rd/wr
};
-
//===----------------------------------------------------------------------===//
/// Instruction itinerary Data - Itinerary data supplied by a subtarget to be
/// used by a target.
///
-struct InstrItineraryData {
+class InstrItineraryData {
+public:
const InstrStage *Stages; ///< Array of stages selected
+ const unsigned *OperandCycles; ///< Array of operand cycles selected
const InstrItinerary *Itineratries; ///< Array of itineraries selected
/// Ctors.
///
- InstrItineraryData() : Stages(0), Itineratries(0) {}
- InstrItineraryData(const InstrStage *S, const InstrItinerary *I)
- : Stages(S), Itineratries(I) {}
+ InstrItineraryData() : Stages(0), OperandCycles(0), Itineratries(0) {}
+ InstrItineraryData(const InstrStage *S, const unsigned *OS,
+ const InstrItinerary *I)
+ : Stages(S), OperandCycles(OS), Itineratries(I) {}
/// isEmpty - Returns true if there are no itineraries.
///
bool isEmpty() const { return Itineratries == 0; }
-
- /// begin - Return the first stage of the itinerary.
+
+ /// isEndMarker - Returns true if the index is for the end marker
+ /// itinerary.
+ ///
+ bool isEndMarker(unsigned ItinClassIndx) const {
+ return ((Itineratries[ItinClassIndx].FirstStage == ~0U) &&
+ (Itineratries[ItinClassIndx].LastStage == ~0U));
+ }
+
+ /// beginStage - Return the first stage of the itinerary.
///
- const InstrStage *begin(unsigned ItinClassIndx) const {
- unsigned StageIdx = Itineratries[ItinClassIndx].First;
+ const InstrStage *beginStage(unsigned ItinClassIndx) const {
+ unsigned StageIdx = Itineratries[ItinClassIndx].FirstStage;
return Stages + StageIdx;
}
- /// end - Return the last+1 stage of the itinerary.
+ /// endStage - Return the last+1 stage of the itinerary.
///
- const InstrStage *end(unsigned ItinClassIndx) const {
- unsigned StageIdx = Itineratries[ItinClassIndx].Last;
+ const InstrStage *endStage(unsigned ItinClassIndx) const {
+ unsigned StageIdx = Itineratries[ItinClassIndx].LastStage;
return Stages + StageIdx;
}
- /// getLatency - Return the scheduling latency of the given class. A
- /// simple latency value for an instruction is an over-simplification
- /// for some architectures, but it's a reasonable first approximation.
+ /// getStageLatency - Return the total stage latency of the given
+ /// class. The latency is the maximum completion time for any stage
+ /// in the itinerary.
///
- unsigned getLatency(unsigned ItinClassIndx) const {
- // If the target doesn't provide latency information, use a simple
- // non-zero default value for all instructions.
+ unsigned getStageLatency(unsigned ItinClassIndx) const {
+ // If the target doesn't provide itinerary information, use a
+ // simple non-zero default value for all instructions.
if (isEmpty())
return 1;
- // Caclulate the maximum completion time for any stage. The
- // assumption is that all inputs are consumed at the start of the
- // first stage and that all outputs are produced at the end of the
- // latest completing last stage.
+ // Calculate the maximum completion time for any stage.
unsigned Latency = 0, StartCycle = 0;
- for (const InstrStage *IS = begin(ItinClassIndx), *E = end(ItinClassIndx);
- IS != E; ++IS) {
+ for (const InstrStage *IS = beginStage(ItinClassIndx),
+ *E = endStage(ItinClassIndx); IS != E; ++IS) {
Latency = std::max(Latency, StartCycle + IS->getCycles());
StartCycle += IS->getNextCycles();
}
return Latency;
}
+
+ /// getOperandCycle - Return the cycle for the given class and
+ /// operand. Return -1 if no cycle is specified for the operand.
+ ///
+ int getOperandCycle(unsigned ItinClassIndx, unsigned OperandIdx) const {
+ if (isEmpty())
+ return -1;
+
+ unsigned FirstIdx = Itineratries[ItinClassIndx].FirstOperandCycle;
+ unsigned LastIdx = Itineratries[ItinClassIndx].LastOperandCycle;
+ if ((FirstIdx + OperandIdx) >= LastIdx)
+ return -1;
+
+ return (int)OperandCycles[FirstIdx + OperandIdx];
+ }
};