//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE ::llvm::ScoreboardHazardRecognizer::DebugType
#include "llvm/CodeGen/ScoreboardHazardRecognizer.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/MC/MCInstrItineraries.h"
using namespace llvm;
+#define DEBUG_TYPE ::llvm::ScoreboardHazardRecognizer::DebugType
+
#ifndef NDEBUG
const char *ScoreboardHazardRecognizer::DebugType = "";
#endif
DebugType = ParentDebugType;
#endif
- // Determine the maximum depth of any itinerary. This determines the
- // depth of the scoreboard. We always make the scoreboard at least 1
- // cycle deep to avoid dealing with the boundary condition.
+ // Determine the maximum depth of any itinerary. This determines the depth of
+ // the scoreboard. We always make the scoreboard at least 1 cycle deep to
+ // avoid dealing with the boundary condition.
unsigned ScoreboardDepth = 1;
if (ItinData && !ItinData->isEmpty()) {
- IssueWidth = ItinData->IssueWidth;
-
for (unsigned idx = 0; ; ++idx) {
if (ItinData->isEndMarker(idx))
break;
// Find the next power-of-2 >= ItinDepth
while (ItinDepth > ScoreboardDepth) {
ScoreboardDepth *= 2;
+ // Don't set MaxLookAhead until we find at least one nonzero stage.
+ // This way, an itinerary with no stages has MaxLookAhead==0, which
+ // completely bypasses the scoreboard hazard logic.
+ MaxLookAhead = ScoreboardDepth;
}
}
- MaxLookAhead = ScoreboardDepth;
}
ReservedScoreboard.reset(ScoreboardDepth);
RequiredScoreboard.reset(ScoreboardDepth);
- DEBUG(dbgs() << "Using scoreboard hazard recognizer: Depth = "
- << ScoreboardDepth << '\n');
+ // If MaxLookAhead is not set above, then we are not enabled.
+ if (!isEnabled())
+ DEBUG(dbgs() << "Disabled scoreboard hazard recognizer\n");
+ else {
+ // A nonempty itinerary must have a SchedModel.
+ IssueWidth = ItinData->SchedModel.IssueWidth;
+ DEBUG(dbgs() << "Using scoreboard hazard recognizer: Depth = "
+ << ScoreboardDepth << '\n');
+ }
}
void ScoreboardHazardRecognizer::Reset() {
ReservedScoreboard.reset();
}
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void ScoreboardHazardRecognizer::Scoreboard::dump() const {
dbgs() << "Scoreboard:\n";
dbgs() << '\n';
}
}
+#endif
bool ScoreboardHazardRecognizer::atIssueLimit() const {
if (IssueWidth == 0)
// free FU's in the scoreboard at the appropriate future cycles.
const MCInstrDesc *MCID = DAG->getInstrDesc(SU);
- if (MCID == NULL) {
+ if (!MCID) {
// Don't check hazards for non-machineinstr Nodes.
return NoHazard;
}
}
if (!freeUnits) {
- DEBUG(dbgs() << "*** Hazard in cycle " << (cycle + i) << ", ");
+ DEBUG(dbgs() << "*** Hazard in cycle +" << StageCycle << ", ");
DEBUG(dbgs() << "SU(" << SU->NodeNum << "): ");
DEBUG(DAG->dumpNode(SU));
return Hazard;