From 721c201bd55ffb73cb2ba8d39e0570fa38c44e15 Mon Sep 17 00:00:00 2001
From: dim <dim@FreeBSD.org>
Date: Wed, 15 Aug 2012 19:34:23 +0000
Subject: Vendor import of llvm trunk r161861:
http://llvm.org/svn/llvm-project/llvm/trunk@161861
---
lib/CodeGen/ScoreboardHazardRecognizer.cpp | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
(limited to 'lib/CodeGen/ScoreboardHazardRecognizer.cpp')
diff --git a/lib/CodeGen/ScoreboardHazardRecognizer.cpp b/lib/CodeGen/ScoreboardHazardRecognizer.cpp
index 3d22035..e675366 100644
--- a/lib/CodeGen/ScoreboardHazardRecognizer.cpp
+++ b/lib/CodeGen/ScoreboardHazardRecognizer.cpp
@@ -39,13 +39,11 @@ ScoreboardHazardRecognizer(const InstrItineraryData *II,
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;
@@ -63,16 +61,26 @@ ScoreboardHazardRecognizer(const InstrItineraryData *II,
// 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() {
@@ -151,7 +159,7 @@ ScoreboardHazardRecognizer::getHazardType(SUnit *SU, int Stalls) {
}
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;
--
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