[llvm-commits] [llvm] r85939 - in /llvm/trunk: include/llvm/CodeGen/LatencyPriorityQueue.h include/llvm/CodeGen/ScheduleDAG.h lib/CodeGen/AggressiveAntiDepBreaker.cpp lib/CodeGen/AggressiveAntiDepBreaker.h lib/CodeGen/AntiDepBreaker.h lib/CodeGen/CriticalAntiDepBreaker.cpp lib/CodeGen/CriticalAntiDepBreaker.h lib/CodeGen/ExactHazardRecognizer.cpp lib/CodeGen/LatencyPriorityQueue.cpp lib/CodeGen/PostRASchedulerList.cpp lib/CodeGen/ScheduleDAG.cpp
David Goodwin
david_goodwin at apple.com
Tue Nov 3 12:57:51 PST 2009
Author: david_goodwin
Date: Tue Nov 3 14:57:50 2009
New Revision: 85939
URL: http://llvm.org/viewvc/llvm-project?rev=85939&view=rev
Log:
Do a scheduling pass ignoring anti-dependencies to identify candidate registers that should be renamed.
Modified:
llvm/trunk/include/llvm/CodeGen/LatencyPriorityQueue.h
llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h
llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.cpp
llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.h
llvm/trunk/lib/CodeGen/AntiDepBreaker.h
llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.cpp
llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.h
llvm/trunk/lib/CodeGen/ExactHazardRecognizer.cpp
llvm/trunk/lib/CodeGen/LatencyPriorityQueue.cpp
llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp
llvm/trunk/lib/CodeGen/ScheduleDAG.cpp
Modified: llvm/trunk/include/llvm/CodeGen/LatencyPriorityQueue.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LatencyPriorityQueue.h?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/LatencyPriorityQueue.h (original)
+++ llvm/trunk/include/llvm/CodeGen/LatencyPriorityQueue.h Tue Nov 3 14:57:50 2009
@@ -39,12 +39,21 @@
/// predecessor for. This is used as a tie-breaker heuristic for better
/// mobility.
std::vector<unsigned> NumNodesSolelyBlocking;
-
+
+ /// IgnoreAntiDep - Ignore anti-dependencies
+ bool IgnoreAntiDep;
+
+ /// Queue - The queue.
PriorityQueue<SUnit*, std::vector<SUnit*>, latency_sort> Queue;
+
public:
- LatencyPriorityQueue() : Queue(latency_sort(this)) {
+ LatencyPriorityQueue() : IgnoreAntiDep(false), Queue(latency_sort(this)) {
}
-
+
+ void setIgnoreAntiDep(bool ignore) {
+ IgnoreAntiDep = ignore;
+ }
+
void initNodes(std::vector<SUnit> &sunits) {
SUnits = &sunits;
NumNodesSolelyBlocking.resize(SUnits->size(), 0);
@@ -63,7 +72,7 @@
unsigned getLatency(unsigned NodeNum) const {
assert(NodeNum < (*SUnits).size());
- return (*SUnits)[NodeNum].getHeight();
+ return (*SUnits)[NodeNum].getHeight(IgnoreAntiDep);
}
unsigned getNumSolelyBlockNodes(unsigned NodeNum) const {
Modified: llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h (original)
+++ llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h Tue Nov 3 14:57:50 2009
@@ -340,28 +340,34 @@
void removePred(const SDep &D);
/// getDepth - Return the depth of this node, which is the length of the
- /// maximum path up to any node with has no predecessors.
- unsigned getDepth() const {
- if (!isDepthCurrent) const_cast<SUnit *>(this)->ComputeDepth();
+ /// maximum path up to any node with has no predecessors. If IgnoreAntiDep
+ /// is true, ignore anti-dependence edges.
+ unsigned getDepth(bool IgnoreAntiDep=false) const {
+ if (!isDepthCurrent)
+ const_cast<SUnit *>(this)->ComputeDepth(IgnoreAntiDep);
return Depth;
}
/// getHeight - Return the height of this node, which is the length of the
- /// maximum path down to any node with has no successors.
- unsigned getHeight() const {
- if (!isHeightCurrent) const_cast<SUnit *>(this)->ComputeHeight();
+ /// maximum path down to any node with has no successors. If IgnoreAntiDep
+ /// is true, ignore anti-dependence edges.
+ unsigned getHeight(bool IgnoreAntiDep=false) const {
+ if (!isHeightCurrent)
+ const_cast<SUnit *>(this)->ComputeHeight(IgnoreAntiDep);
return Height;
}
- /// setDepthToAtLeast - If NewDepth is greater than this node's depth
- /// value, set it to be the new depth value. This also recursively
- /// marks successor nodes dirty.
- void setDepthToAtLeast(unsigned NewDepth);
-
- /// setDepthToAtLeast - If NewDepth is greater than this node's depth
- /// value, set it to be the new height value. This also recursively
- /// marks predecessor nodes dirty.
- void setHeightToAtLeast(unsigned NewHeight);
+ /// setDepthToAtLeast - If NewDepth is greater than this node's
+ /// depth value, set it to be the new depth value. This also
+ /// recursively marks successor nodes dirty. If IgnoreAntiDep is
+ /// true, ignore anti-dependence edges.
+ void setDepthToAtLeast(unsigned NewDepth, bool IgnoreAntiDep=false);
+
+ /// setDepthToAtLeast - If NewDepth is greater than this node's
+ /// depth value, set it to be the new height value. This also
+ /// recursively marks predecessor nodes dirty. If IgnoreAntiDep is
+ /// true, ignore anti-dependence edges.
+ void setHeightToAtLeast(unsigned NewHeight, bool IgnoreAntiDep=false);
/// setDepthDirty - Set a flag in this node to indicate that its
/// stored Depth value will require recomputation the next time
@@ -394,8 +400,8 @@
void print(raw_ostream &O, const ScheduleDAG *G) const;
private:
- void ComputeDepth();
- void ComputeHeight();
+ void ComputeDepth(bool IgnoreAntiDep);
+ void ComputeHeight(bool IgnoreAntiDep);
};
//===--------------------------------------------------------------------===//
Modified: llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.cpp?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.cpp (original)
+++ llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.cpp Tue Nov 3 14:57:50 2009
@@ -14,7 +14,7 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "aggressive-antidep"
+#define DEBUG_TYPE "post-RA-sched"
#include "AggressiveAntiDepBreaker.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
@@ -31,7 +31,7 @@
static cl::opt<int>
AntiDepTrials("agg-antidep-trials",
cl::desc("Maximum number of anti-dependency breaking passes"),
- cl::init(2), cl::Hidden);
+ cl::init(1), cl::Hidden);
AggressiveAntiDepState::AggressiveAntiDepState(MachineBasicBlock *BB) :
GroupNodes(TargetRegisterInfo::FirstVirtualRegister, 0) {
@@ -265,18 +265,24 @@
}
/// AntiDepPathStep - Return SUnit that SU has an anti-dependence on.
-static void AntiDepPathStep(SUnit *SU, std::vector<SDep*>& Edges) {
- SmallSet<unsigned, 8> Dups;
+static void AntiDepPathStep(SUnit *SU, AntiDepBreaker::AntiDepRegVector& Regs,
+ std::vector<SDep*>& Edges) {
+ AntiDepBreaker::AntiDepRegSet RegSet;
+ for (unsigned i = 0, e = Regs.size(); i < e; ++i)
+ RegSet.insert(Regs[i]);
+
for (SUnit::pred_iterator P = SU->Preds.begin(), PE = SU->Preds.end();
P != PE; ++P) {
if (P->getKind() == SDep::Anti) {
unsigned Reg = P->getReg();
- if (Dups.count(Reg) == 0) {
+ if (RegSet.count(Reg) != 0) {
Edges.push_back(&*P);
- Dups.insert(Reg);
+ RegSet.erase(Reg);
}
}
}
+
+ assert(RegSet.empty() && "Expected all antidep registers to be found");
}
void AggressiveAntiDepBreaker::HandleLastUse(unsigned Reg, unsigned KillIdx,
@@ -593,6 +599,7 @@
///
unsigned AggressiveAntiDepBreaker::BreakAntiDependencies(
std::vector<SUnit>& SUnits,
+ CandidateMap& Candidates,
MachineBasicBlock::iterator& Begin,
MachineBasicBlock::iterator& End,
unsigned InsertPosIndex) {
@@ -601,9 +608,15 @@
std::multimap<unsigned, AggressiveAntiDepState::RegisterReference>&
RegRefs = State->GetRegRefs();
+ // Nothing to do if no candidates.
+ if (Candidates.empty()) {
+ DEBUG(errs() << "\n===== No anti-dependency candidates\n");
+ return 0;
+ }
+
// The code below assumes that there is at least one instruction,
// so just duck out immediately if the block is empty.
- if (SUnits.empty()) return false;
+ if (SUnits.empty()) return 0;
// Manage saved state to enable multiple passes...
if (AntiDepTrials > 1) {
@@ -618,7 +631,8 @@
// ...need a map from MI to SUnit.
std::map<MachineInstr *, SUnit *> MISUnitMap;
- DEBUG(errs() << "Breaking all anti-dependencies\n");
+ DEBUG(errs() << "\n===== Attempting to break " << Candidates.size() <<
+ " anti-dependencies\n");
for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
SUnit *SU = &SUnits[i];
MISUnitMap.insert(std::pair<MachineInstr *, SUnit *>(SU->getInstr(), SU));
@@ -655,8 +669,10 @@
std::vector<SDep*> Edges;
SUnit *PathSU = MISUnitMap[MI];
- if (PathSU)
- AntiDepPathStep(PathSU, Edges);
+ AntiDepBreaker::CandidateMap::iterator
+ citer = Candidates.find(PathSU);
+ if (citer != Candidates.end())
+ AntiDepPathStep(PathSU, citer->second, Edges);
// Ignore KILL instructions (they form a group in ScanInstruction
// but don't cause any anti-dependence breaking themselves)
Modified: llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.h?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.h (original)
+++ llvm/trunk/lib/CodeGen/AggressiveAntiDepBreaker.h Tue Nov 3 14:57:50 2009
@@ -131,6 +131,9 @@
/// dependencies may be exposed, so multiple passes are required.
unsigned GetMaxTrials();
+ /// NeedCandidates - Candidates required.
+ bool NeedCandidates() { return true; }
+
/// Start - Initialize anti-dep breaking for a new basic block.
void StartBlock(MachineBasicBlock *BB);
@@ -138,6 +141,7 @@
/// of the ScheduleDAG and break them by renaming registers.
///
unsigned BreakAntiDependencies(std::vector<SUnit>& SUnits,
+ CandidateMap& Candidates,
MachineBasicBlock::iterator& Begin,
MachineBasicBlock::iterator& End,
unsigned InsertPosIndex);
Modified: llvm/trunk/lib/CodeGen/AntiDepBreaker.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AntiDepBreaker.h?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AntiDepBreaker.h (original)
+++ llvm/trunk/lib/CodeGen/AntiDepBreaker.h Tue Nov 3 14:57:50 2009
@@ -21,6 +21,8 @@
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/SmallVector.h"
namespace llvm {
@@ -29,12 +31,20 @@
/// anti-dependencies.
class AntiDepBreaker {
public:
+ typedef SmallSet<unsigned, 4> AntiDepRegSet;
+ typedef SmallVector<unsigned, 4> AntiDepRegVector;
+ typedef std::map<SUnit *, AntiDepRegVector> CandidateMap;
+
virtual ~AntiDepBreaker();
/// GetMaxTrials - Return the maximum number of anti-dependence
/// breaking attempts that will be made for a block.
virtual unsigned GetMaxTrials() =0;
+ /// NeedCandidates - Return true if the schedule must provide
+ /// candidates with BreakAntiDependencies().
+ virtual bool NeedCandidates() =0;
+
/// Start - Initialize anti-dep breaking for a new basic block.
virtual void StartBlock(MachineBasicBlock *BB) =0;
@@ -43,9 +53,10 @@
/// the number of anti-dependencies broken.
///
virtual unsigned BreakAntiDependencies(std::vector<SUnit>& SUnits,
- MachineBasicBlock::iterator& Begin,
- MachineBasicBlock::iterator& End,
- unsigned InsertPosIndex) =0;
+ CandidateMap& Candidates,
+ MachineBasicBlock::iterator& Begin,
+ MachineBasicBlock::iterator& End,
+ unsigned InsertPosIndex) =0;
/// Observe - Update liveness information to account for the current
/// instruction, which will not be scheduled.
Modified: llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.cpp?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.cpp (original)
+++ llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.cpp Tue Nov 3 14:57:50 2009
@@ -13,7 +13,7 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "critical-antidep"
+#define DEBUG_TYPE "post-RA-sched"
#include "CriticalAntiDepBreaker.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
@@ -316,6 +316,7 @@
unsigned CriticalAntiDepBreaker::
BreakAntiDependencies(std::vector<SUnit>& SUnits,
+ CandidateMap& Candidates,
MachineBasicBlock::iterator& Begin,
MachineBasicBlock::iterator& End,
unsigned InsertPosIndex) {
Modified: llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.h?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.h (original)
+++ llvm/trunk/lib/CodeGen/CriticalAntiDepBreaker.h Tue Nov 3 14:57:50 2009
@@ -68,6 +68,9 @@
/// only a single pass
unsigned GetMaxTrials() { return 1; }
+ /// NeedCandidates - Candidates not needed.
+ bool NeedCandidates() { return false; }
+
/// Start - Initialize anti-dep breaking for a new basic block.
void StartBlock(MachineBasicBlock *BB);
@@ -75,6 +78,7 @@
/// of the ScheduleDAG and break them by renaming registers.
///
unsigned BreakAntiDependencies(std::vector<SUnit>& SUnits,
+ CandidateMap& Candidates,
MachineBasicBlock::iterator& Begin,
MachineBasicBlock::iterator& End,
unsigned InsertPosIndex);
Modified: llvm/trunk/lib/CodeGen/ExactHazardRecognizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ExactHazardRecognizer.cpp?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ExactHazardRecognizer.cpp (original)
+++ llvm/trunk/lib/CodeGen/ExactHazardRecognizer.cpp Tue Nov 3 14:57:50 2009
@@ -12,7 +12,7 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "exact-hazards"
+#define DEBUG_TYPE "post-RA-sched"
#include "ExactHazardRecognizer.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/Support/Debug.h"
Modified: llvm/trunk/lib/CodeGen/LatencyPriorityQueue.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LatencyPriorityQueue.cpp?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LatencyPriorityQueue.cpp (original)
+++ llvm/trunk/lib/CodeGen/LatencyPriorityQueue.cpp Tue Nov 3 14:57:50 2009
@@ -55,6 +55,7 @@
SUnit *OnlyAvailablePred = 0;
for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
I != E; ++I) {
+ if (IgnoreAntiDep && (I->getKind() == SDep::Anti)) continue;
SUnit &Pred = *I->getSUnit();
if (!Pred.isScheduled) {
// We found an available, but not scheduled, predecessor. If it's the
@@ -73,9 +74,11 @@
// this node is the sole unscheduled node for.
unsigned NumNodesBlocking = 0;
for (SUnit::const_succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
- I != E; ++I)
+ I != E; ++I) {
+ if (IgnoreAntiDep && (I->getKind() == SDep::Anti)) continue;
if (getSingleUnscheduledPred(I->getSUnit()) == SU)
++NumNodesBlocking;
+ }
NumNodesSolelyBlocking[SU->NodeNum] = NumNodesBlocking;
Queue.push(SU);
@@ -88,8 +91,10 @@
// the node available.
void LatencyPriorityQueue::ScheduledNode(SUnit *SU) {
for (SUnit::const_succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
- I != E; ++I)
+ I != E; ++I) {
+ if (IgnoreAntiDep && (I->getKind() == SDep::Anti)) continue;
AdjustPriorityOfUnscheduledPreds(I->getSUnit());
+ }
}
/// AdjustPriorityOfUnscheduledPreds - One of the predecessors of SU was just
Modified: llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp (original)
+++ llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp Tue Nov 3 14:57:50 2009
@@ -175,10 +175,11 @@
void FixupKills(MachineBasicBlock *MBB);
private:
- void ReleaseSucc(SUnit *SU, SDep *SuccEdge);
- void ReleaseSuccessors(SUnit *SU);
- void ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle);
- void ListScheduleTopDown();
+ void ReleaseSucc(SUnit *SU, SDep *SuccEdge, bool IgnoreAntiDep);
+ void ReleaseSuccessors(SUnit *SU, bool IgnoreAntiDep);
+ void ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle, bool IgnoreAntiDep);
+ void ListScheduleTopDown(
+ AntiDepBreaker::CandidateMap *AntiDepCandidates);
void StartBlockForKills(MachineBasicBlock *BB);
// ToggleKillFlag - Toggle a register operand kill flag. Other
@@ -320,15 +321,32 @@
BuildSchedGraph(AA);
if (AntiDepBreak != NULL) {
+ AntiDepBreaker::CandidateMap AntiDepCandidates;
+ const bool NeedCandidates = AntiDepBreak->NeedCandidates();
+
for (unsigned i = 0, Trials = AntiDepBreak->GetMaxTrials();
i < Trials; ++i) {
- DEBUG(errs() << "********** Break Anti-Deps, Trial " <<
+ DEBUG(errs() << "\n********** Break Anti-Deps, Trial " <<
i << " **********\n");
+
+ // If candidates are required, then schedule forward ignoring
+ // anti-dependencies to collect the candidate operands for
+ // anti-dependence breaking. The candidates will be the def
+ // operands for the anti-dependencies that if broken would allow
+ // an improved schedule
+ if (NeedCandidates) {
+ DEBUG(for (unsigned su = 0, e = SUnits.size(); su != e; ++su)
+ SUnits[su].dumpAll(this));
+
+ AntiDepCandidates.clear();
+ AvailableQueue.initNodes(SUnits);
+ ListScheduleTopDown(&AntiDepCandidates);
+ AvailableQueue.releaseState();
+ }
+
unsigned Broken =
- AntiDepBreak->BreakAntiDependencies(SUnits, Begin, InsertPos,
- InsertPosIndex);
- if (Broken == 0)
- break;
+ AntiDepBreak->BreakAntiDependencies(SUnits, AntiDepCandidates,
+ Begin, InsertPos, InsertPosIndex);
// We made changes. Update the dependency graph.
// Theoretically we could update the graph in place:
@@ -336,24 +354,26 @@
// the def's anti-dependence *and* output-dependence edges due to
// that register, and add new anti-dependence and output-dependence
// edges based on the next live range of the register.
- SUnits.clear();
- EntrySU = SUnit();
- ExitSU = SUnit();
- BuildSchedGraph(AA);
+ if ((Broken != 0) || NeedCandidates) {
+ SUnits.clear();
+ Sequence.clear();
+ EntrySU = SUnit();
+ ExitSU = SUnit();
+ BuildSchedGraph(AA);
+ }
NumFixedAnti += Broken;
+ if (Broken == 0)
+ break;
}
}
DEBUG(errs() << "********** List Scheduling **********\n");
-
DEBUG(for (unsigned su = 0, e = SUnits.size(); su != e; ++su)
SUnits[su].dumpAll(this));
AvailableQueue.initNodes(SUnits);
-
- ListScheduleTopDown();
-
+ ListScheduleTopDown(NULL);
AvailableQueue.releaseState();
}
@@ -552,7 +572,8 @@
/// ReleaseSucc - Decrement the NumPredsLeft count of a successor. Add it to
/// the PendingQueue if the count reaches zero. Also update its cycle bound.
-void SchedulePostRATDList::ReleaseSucc(SUnit *SU, SDep *SuccEdge) {
+void SchedulePostRATDList::ReleaseSucc(SUnit *SU, SDep *SuccEdge,
+ bool IgnoreAntiDep) {
SUnit *SuccSU = SuccEdge->getSUnit();
#ifndef NDEBUG
@@ -568,7 +589,8 @@
// Compute how many cycles it will be before this actually becomes
// available. This is the max of the start time of all predecessors plus
// their latencies.
- SuccSU->setDepthToAtLeast(SU->getDepth() + SuccEdge->getLatency());
+ SuccSU->setDepthToAtLeast(SU->getDepth(IgnoreAntiDep) +
+ SuccEdge->getLatency(), IgnoreAntiDep);
// If all the node's predecessors are scheduled, this node is ready
// to be scheduled. Ignore the special ExitSU node.
@@ -577,40 +599,73 @@
}
/// ReleaseSuccessors - Call ReleaseSucc on each of SU's successors.
-void SchedulePostRATDList::ReleaseSuccessors(SUnit *SU) {
+void SchedulePostRATDList::ReleaseSuccessors(SUnit *SU, bool IgnoreAntiDep) {
for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
- I != E; ++I)
- ReleaseSucc(SU, &*I);
+ I != E; ++I) {
+ if (IgnoreAntiDep && (I->getKind() == SDep::Anti)) continue;
+ ReleaseSucc(SU, &*I, IgnoreAntiDep);
+ }
}
/// ScheduleNodeTopDown - Add the node to the schedule. Decrement the pending
/// count of its successors. If a successor pending count is zero, add it to
/// the Available queue.
-void SchedulePostRATDList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
+void SchedulePostRATDList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle,
+ bool IgnoreAntiDep) {
DEBUG(errs() << "*** Scheduling [" << CurCycle << "]: ");
DEBUG(SU->dump(this));
Sequence.push_back(SU);
- assert(CurCycle >= SU->getDepth() && "Node scheduled above its depth!");
- SU->setDepthToAtLeast(CurCycle);
+ assert(CurCycle >= SU->getDepth(IgnoreAntiDep) &&
+ "Node scheduled above its depth!");
+ SU->setDepthToAtLeast(CurCycle, IgnoreAntiDep);
- ReleaseSuccessors(SU);
+ ReleaseSuccessors(SU, IgnoreAntiDep);
SU->isScheduled = true;
AvailableQueue.ScheduledNode(SU);
}
/// ListScheduleTopDown - The main loop of list scheduling for top-down
/// schedulers.
-void SchedulePostRATDList::ListScheduleTopDown() {
+void SchedulePostRATDList::ListScheduleTopDown(
+ AntiDepBreaker::CandidateMap *AntiDepCandidates) {
unsigned CurCycle = 0;
+ const bool IgnoreAntiDep = (AntiDepCandidates != NULL);
+
+ // We're scheduling top-down but we're visiting the regions in
+ // bottom-up order, so we don't know the hazards at the start of a
+ // region. So assume no hazards (this should usually be ok as most
+ // blocks are a single region).
+ HazardRec->Reset();
+
+ // If ignoring anti-dependencies, the Schedule DAG still has Anti
+ // dep edges, but we ignore them for scheduling purposes
+ AvailableQueue.setIgnoreAntiDep(IgnoreAntiDep);
// Release any successors of the special Entry node.
- ReleaseSuccessors(&EntrySU);
+ ReleaseSuccessors(&EntrySU, IgnoreAntiDep);
- // All leaves to Available queue.
+ // Add all leaves to Available queue. If ignoring antideps we also
+ // adjust the predecessor count for each node to not include antidep
+ // edges.
for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
// It is available if it has no predecessors.
- if (SUnits[i].Preds.empty()) {
+ bool available = SUnits[i].Preds.empty();
+ // If we are ignoring anti-dependencies then a node that has only
+ // anti-dep predecessors is available.
+ if (!available && IgnoreAntiDep) {
+ available = true;
+ for (SUnit::const_pred_iterator I = SUnits[i].Preds.begin(),
+ E = SUnits[i].Preds.end(); I != E; ++I) {
+ if (I->getKind() != SDep::Anti) {
+ available = false;
+ } else {
+ SUnits[i].NumPredsLeft -= 1;
+ }
+ }
+ }
+
+ if (available) {
AvailableQueue.push(&SUnits[i]);
SUnits[i].isAvailable = true;
}
@@ -629,26 +684,25 @@
// so, add them to the available queue.
unsigned MinDepth = ~0u;
for (unsigned i = 0, e = PendingQueue.size(); i != e; ++i) {
- if (PendingQueue[i]->getDepth() <= CurCycle) {
+ if (PendingQueue[i]->getDepth(IgnoreAntiDep) <= CurCycle) {
AvailableQueue.push(PendingQueue[i]);
PendingQueue[i]->isAvailable = true;
PendingQueue[i] = PendingQueue.back();
PendingQueue.pop_back();
--i; --e;
- } else if (PendingQueue[i]->getDepth() < MinDepth)
- MinDepth = PendingQueue[i]->getDepth();
+ } else if (PendingQueue[i]->getDepth(IgnoreAntiDep) < MinDepth)
+ MinDepth = PendingQueue[i]->getDepth(IgnoreAntiDep);
}
DEBUG(errs() << "\n*** Examining Available\n";
LatencyPriorityQueue q = AvailableQueue;
while (!q.empty()) {
SUnit *su = q.pop();
- errs() << "Height " << su->getHeight() << ": ";
+ errs() << "Height " << su->getHeight(IgnoreAntiDep) << ": ";
su->dump(this);
});
SUnit *FoundSUnit = 0;
-
bool HasNoopHazards = false;
while (!AvailableQueue.empty()) {
SUnit *CurSUnit = AvailableQueue.pop();
@@ -672,9 +726,30 @@
NotReady.clear();
}
- // If we found a node to schedule, do it now.
+ // If we found a node to schedule...
if (FoundSUnit) {
- ScheduleNodeTopDown(FoundSUnit, CurCycle);
+ // If we are ignoring anti-dependencies and the SUnit we are
+ // scheduling has an antidep predecessor that has not been
+ // scheduled, then we will need to break that antidep if we want
+ // to get this schedule when not ignoring anti-dependencies.
+ if (IgnoreAntiDep) {
+ AntiDepBreaker::AntiDepRegVector AntiDepRegs;
+ for (SUnit::const_pred_iterator I = FoundSUnit->Preds.begin(),
+ E = FoundSUnit->Preds.end(); I != E; ++I) {
+ if ((I->getKind() == SDep::Anti) && !I->getSUnit()->isScheduled)
+ AntiDepRegs.push_back(I->getReg());
+ }
+
+ if (AntiDepRegs.size() > 0) {
+ DEBUG(errs() << "*** AntiDep Candidate: ");
+ DEBUG(FoundSUnit->dump(this));
+ AntiDepCandidates->insert(
+ AntiDepBreaker::CandidateMap::value_type(FoundSUnit, AntiDepRegs));
+ }
+ }
+
+ // ... schedule the node...
+ ScheduleNodeTopDown(FoundSUnit, CurCycle, IgnoreAntiDep);
HazardRec->EmitInstruction(FoundSUnit);
CycleHasInsts = true;
Modified: llvm/trunk/lib/CodeGen/ScheduleDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ScheduleDAG.cpp?rev=85939&r1=85938&r2=85939&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ScheduleDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/ScheduleDAG.cpp Tue Nov 3 14:57:50 2009
@@ -183,8 +183,8 @@
/// setDepthToAtLeast - Update this node's successors to reflect the
/// fact that this node's depth just increased.
///
-void SUnit::setDepthToAtLeast(unsigned NewDepth) {
- if (NewDepth <= getDepth())
+void SUnit::setDepthToAtLeast(unsigned NewDepth, bool IgnoreAntiDep) {
+ if (NewDepth <= getDepth(IgnoreAntiDep))
return;
setDepthDirty();
Depth = NewDepth;
@@ -194,8 +194,8 @@
/// setHeightToAtLeast - Update this node's predecessors to reflect the
/// fact that this node's height just increased.
///
-void SUnit::setHeightToAtLeast(unsigned NewHeight) {
- if (NewHeight <= getHeight())
+void SUnit::setHeightToAtLeast(unsigned NewHeight, bool IgnoreAntiDep) {
+ if (NewHeight <= getHeight(IgnoreAntiDep))
return;
setHeightDirty();
Height = NewHeight;
@@ -204,7 +204,7 @@
/// ComputeDepth - Calculate the maximal path from the node to the exit.
///
-void SUnit::ComputeDepth() {
+void SUnit::ComputeDepth(bool IgnoreAntiDep) {
SmallVector<SUnit*, 8> WorkList;
WorkList.push_back(this);
do {
@@ -214,6 +214,7 @@
unsigned MaxPredDepth = 0;
for (SUnit::const_pred_iterator I = Cur->Preds.begin(),
E = Cur->Preds.end(); I != E; ++I) {
+ if (IgnoreAntiDep && (I->getKind() == SDep::Anti)) continue;
SUnit *PredSU = I->getSUnit();
if (PredSU->isDepthCurrent)
MaxPredDepth = std::max(MaxPredDepth,
@@ -237,7 +238,7 @@
/// ComputeHeight - Calculate the maximal path from the node to the entry.
///
-void SUnit::ComputeHeight() {
+void SUnit::ComputeHeight(bool IgnoreAntiDep) {
SmallVector<SUnit*, 8> WorkList;
WorkList.push_back(this);
do {
@@ -247,6 +248,7 @@
unsigned MaxSuccHeight = 0;
for (SUnit::const_succ_iterator I = Cur->Succs.begin(),
E = Cur->Succs.end(); I != E; ++I) {
+ if (IgnoreAntiDep && (I->getKind() == SDep::Anti)) continue;
SUnit *SuccSU = I->getSUnit();
if (SuccSU->isHeightCurrent)
MaxSuccHeight = std::max(MaxSuccHeight,
@@ -346,7 +348,7 @@
AnyNotSched = true;
}
if (SUnits[i].isScheduled &&
- (isBottomUp ? SUnits[i].getHeight() : SUnits[i].getHeight()) >
+ (isBottomUp ? SUnits[i].getHeight() : SUnits[i].getDepth()) >
unsigned(INT_MAX)) {
if (!AnyNotSched)
errs() << "*** Scheduling failed! ***\n";
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