[llvm] r198121 - Move the PostRA scheduler's fixupKills function for reuse.
Andrew Trick
atrick at apple.com
Sat Dec 28 13:56:55 PST 2013
Author: atrick
Date: Sat Dec 28 15:56:55 2013
New Revision: 198121
URL: http://llvm.org/viewvc/llvm-project?rev=198121&view=rev
Log:
Move the PostRA scheduler's fixupKills function for reuse.
Modified:
llvm/trunk/include/llvm/CodeGen/MachineScheduler.h
llvm/trunk/include/llvm/CodeGen/ScheduleDAGInstrs.h
llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp
llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp
Modified: llvm/trunk/include/llvm/CodeGen/MachineScheduler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineScheduler.h?rev=198121&r1=198120&r2=198121&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineScheduler.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineScheduler.h Sat Dec 28 15:56:55 2013
@@ -246,11 +246,11 @@ protected:
unsigned NumInstrsScheduled;
#endif
public:
- ScheduleDAGMI(MachineSchedContext *C, MachineSchedStrategy *S,
- bool IsPostRA):
- ScheduleDAGInstrs(*C->MF, *C->MLI, *C->MDT, IsPostRA, C->LIS), AA(C->AA),
- SchedImpl(S), Topo(SUnits, &ExitSU), CurrentTop(), CurrentBottom(),
- NextClusterPred(NULL), NextClusterSucc(NULL) {
+ ScheduleDAGMI(MachineSchedContext *C, MachineSchedStrategy *S, bool IsPostRA):
+ ScheduleDAGInstrs(*C->MF, *C->MLI, *C->MDT, IsPostRA,
+ /*RemoveKillFlags=*/IsPostRA, C->LIS),
+ AA(C->AA), SchedImpl(S), Topo(SUnits, &ExitSU), CurrentTop(),
+ CurrentBottom(), NextClusterPred(NULL), NextClusterSucc(NULL) {
#ifndef NDEBUG
NumInstrsScheduled = 0;
#endif
Modified: llvm/trunk/include/llvm/CodeGen/ScheduleDAGInstrs.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/ScheduleDAGInstrs.h?rev=198121&r1=198120&r2=198121&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/ScheduleDAGInstrs.h (original)
+++ llvm/trunk/include/llvm/CodeGen/ScheduleDAGInstrs.h Sat Dec 28 15:56:55 2013
@@ -88,6 +88,10 @@ namespace llvm {
/// isPostRA flag indicates vregs cannot be present.
bool IsPostRA;
+ /// True if the DAG builder should remove kill flags (in preparation for
+ /// rescheduling).
+ bool RemoveKillFlags;
+
/// The standard DAG builder does not normally include terminators as DAG
/// nodes because it does not create the necessary dependencies to prevent
/// reordering. A specialized scheduler can overide
@@ -145,15 +149,21 @@ namespace llvm {
DbgValueVector DbgValues;
MachineInstr *FirstDbgValue;
+ /// Set of live physical registers for updating kill flags.
+ BitVector LiveRegs;
+
public:
explicit ScheduleDAGInstrs(MachineFunction &mf,
const MachineLoopInfo &mli,
const MachineDominatorTree &mdt,
bool IsPostRAFlag,
+ bool RemoveKillFlags = false,
LiveIntervals *LIS = 0);
virtual ~ScheduleDAGInstrs() {}
+ bool isPostRA() const { return IsPostRA; }
+
/// \brief Expose LiveIntervals for use in DAG mutators and such.
LiveIntervals *getLIS() const { return LIS; }
@@ -227,12 +237,23 @@ namespace llvm {
/// Return a label for the region of code covered by the DAG.
virtual std::string getDAGName() const;
+ /// \brief Fix register kill flags that scheduling has made invalid.
+ void fixupKills(MachineBasicBlock *MBB);
protected:
void initSUnits();
void addPhysRegDataDeps(SUnit *SU, unsigned OperIdx);
void addPhysRegDeps(SUnit *SU, unsigned OperIdx);
void addVRegDefDeps(SUnit *SU, unsigned OperIdx);
void addVRegUseDeps(SUnit *SU, unsigned OperIdx);
+
+ /// \brief PostRA helper for rewriting kill flags.
+ void startBlockForKills(MachineBasicBlock *BB);
+
+ /// \brief Toggle a register operand kill flag.
+ ///
+ /// Other adjustments may be made to the instruction if necessary. Return
+ /// true if the operand has been deleted, false if not.
+ bool toggleKillFlag(MachineInstr *MI, MachineOperand &MO);
};
/// newSUnit - Creates a new SUnit and return a ptr to it.
Modified: llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp?rev=198121&r1=198120&r2=198121&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp (original)
+++ llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp Sat Dec 28 15:56:55 2013
@@ -30,7 +30,6 @@
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterClassInfo.h"
@@ -121,9 +120,6 @@ namespace {
/// AA - AliasAnalysis for making memory reference queries.
AliasAnalysis *AA;
- /// LiveRegs - true if the register is live.
- BitVector LiveRegs;
-
/// The schedule. Null SUnit*'s represent noop instructions.
std::vector<SUnit*> Sequence;
@@ -174,11 +170,6 @@ namespace {
///
void finishBlock();
- /// FixupKills - Fix register kill flags that have been made
- /// invalid due to scheduling
- ///
- void FixupKills(MachineBasicBlock *MBB);
-
private:
void ReleaseSucc(SUnit *SU, SDep *SuccEdge);
void ReleaseSuccessors(SUnit *SU);
@@ -186,11 +177,6 @@ namespace {
void ListScheduleTopDown();
void StartBlockForKills(MachineBasicBlock *BB);
- // ToggleKillFlag - Toggle a register operand kill flag. Other
- // adjustments may be made to the instruction if necessary. Return
- // true if the operand has been deleted, false if not.
- bool ToggleKillFlag(MachineInstr *MI, MachineOperand &MO);
-
void dumpSchedule() const;
void emitNoop(unsigned CurCycle);
};
@@ -206,9 +192,8 @@ SchedulePostRATDList::SchedulePostRATDLi
AliasAnalysis *AA, const RegisterClassInfo &RCI,
TargetSubtargetInfo::AntiDepBreakMode AntiDepMode,
SmallVectorImpl<const TargetRegisterClass*> &CriticalPathRCs)
- : ScheduleDAGInstrs(MF, MLI, MDT, /*IsPostRA=*/true), AA(AA),
- LiveRegs(TRI->getNumRegs()), EndIndex(0)
-{
+ : ScheduleDAGInstrs(MF, MLI, MDT, /*IsPostRA=*/true), AA(AA), EndIndex(0) {
+
const TargetMachine &TM = MF.getTarget();
const InstrItineraryData *InstrItins = TM.getInstrItineraryData();
HazardRec =
@@ -353,7 +338,7 @@ bool PostRAScheduler::runOnMachineFuncti
Scheduler.finishBlock();
// Update register kills
- Scheduler.FixupKills(MBB);
+ Scheduler.fixupKills(MBB);
}
return true;
@@ -424,148 +409,6 @@ void SchedulePostRATDList::finishBlock()
ScheduleDAGInstrs::finishBlock();
}
-/// StartBlockForKills - Initialize register live-range state for updating kills
-///
-void SchedulePostRATDList::StartBlockForKills(MachineBasicBlock *BB) {
- // Start with no live registers.
- LiveRegs.reset();
-
- // Examine the live-in regs of all successors.
- for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
- SE = BB->succ_end(); SI != SE; ++SI) {
- for (MachineBasicBlock::livein_iterator I = (*SI)->livein_begin(),
- E = (*SI)->livein_end(); I != E; ++I) {
- unsigned Reg = *I;
- // Repeat, for reg and all subregs.
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.set(*SubRegs);
- }
- }
-}
-
-bool SchedulePostRATDList::ToggleKillFlag(MachineInstr *MI,
- MachineOperand &MO) {
- // Setting kill flag...
- if (!MO.isKill()) {
- MO.setIsKill(true);
- return false;
- }
-
- // If MO itself is live, clear the kill flag...
- if (LiveRegs.test(MO.getReg())) {
- MO.setIsKill(false);
- return false;
- }
-
- // If any subreg of MO is live, then create an imp-def for that
- // subreg and keep MO marked as killed.
- MO.setIsKill(false);
- bool AllDead = true;
- const unsigned SuperReg = MO.getReg();
- MachineInstrBuilder MIB(MF, MI);
- for (MCSubRegIterator SubRegs(SuperReg, TRI); SubRegs.isValid(); ++SubRegs) {
- if (LiveRegs.test(*SubRegs)) {
- MIB.addReg(*SubRegs, RegState::ImplicitDefine);
- AllDead = false;
- }
- }
-
- if(AllDead)
- MO.setIsKill(true);
- return false;
-}
-
-/// FixupKills - Fix the register kill flags, they may have been made
-/// incorrect by instruction reordering.
-///
-void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
- DEBUG(dbgs() << "Fixup kills for BB#" << MBB->getNumber() << '\n');
-
- BitVector killedRegs(TRI->getNumRegs());
-
- StartBlockForKills(MBB);
-
- // Examine block from end to start...
- unsigned Count = MBB->size();
- for (MachineBasicBlock::iterator I = MBB->end(), E = MBB->begin();
- I != E; --Count) {
- MachineInstr *MI = --I;
- if (MI->isDebugValue())
- continue;
-
- // Update liveness. Registers that are defed but not used in this
- // instruction are now dead. Mark register and all subregs as they
- // are completely defined.
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (MO.isRegMask())
- LiveRegs.clearBitsNotInMask(MO.getRegMask());
- if (!MO.isReg()) continue;
- unsigned Reg = MO.getReg();
- if (Reg == 0) continue;
- if (!MO.isDef()) continue;
- // Ignore two-addr defs.
- if (MI->isRegTiedToUseOperand(i)) continue;
-
- // Repeat for reg and all subregs.
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.reset(*SubRegs);
- }
-
- // Examine all used registers and set/clear kill flag. When a
- // register is used multiple times we only set the kill flag on
- // the first use. Don't set kill flags on undef operands.
- killedRegs.reset();
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
- unsigned Reg = MO.getReg();
- if ((Reg == 0) || MRI.isReserved(Reg)) continue;
-
- bool kill = false;
- if (!killedRegs.test(Reg)) {
- kill = true;
- // A register is not killed if any subregs are live...
- for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
- if (LiveRegs.test(*SubRegs)) {
- kill = false;
- break;
- }
- }
-
- // If subreg is not live, then register is killed if it became
- // live in this instruction
- if (kill)
- kill = !LiveRegs.test(Reg);
- }
-
- if (MO.isKill() != kill) {
- DEBUG(dbgs() << "Fixing " << MO << " in ");
- // Warning: ToggleKillFlag may invalidate MO.
- ToggleKillFlag(MI, MO);
- DEBUG(MI->dump());
- }
-
- killedRegs.set(Reg);
- }
-
- // Mark any used register (that is not using undef) and subregs as
- // now live...
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
- unsigned Reg = MO.getReg();
- if ((Reg == 0) || MRI.isReserved(Reg)) continue;
-
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.set(*SubRegs);
- }
- }
-}
-
//===----------------------------------------------------------------------===//
// Top-Down Scheduling
//===----------------------------------------------------------------------===//
Modified: llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp?rev=198121&r1=198120&r2=198121&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp (original)
+++ llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp Sat Dec 28 15:56:55 2013
@@ -21,6 +21,7 @@
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
@@ -48,9 +49,11 @@ ScheduleDAGInstrs::ScheduleDAGInstrs(Mac
const MachineLoopInfo &mli,
const MachineDominatorTree &mdt,
bool IsPostRAFlag,
+ bool RemoveKillFlags,
LiveIntervals *lis)
: ScheduleDAG(mf), MLI(mli), MDT(mdt), MFI(mf.getFrameInfo()), LIS(lis),
- IsPostRA(IsPostRAFlag), CanHandleTerminators(false), FirstDbgValue(0) {
+ IsPostRA(IsPostRAFlag), RemoveKillFlags(RemoveKillFlags),
+ CanHandleTerminators(false), FirstDbgValue(0) {
assert((IsPostRA || LIS) && "PreRA scheduling requires LiveIntervals");
DbgValues.clear();
assert(!(IsPostRA && MRI.getNumVirtRegs()) &&
@@ -284,8 +287,8 @@ void ScheduleDAGInstrs::addPhysRegDataDe
/// this SUnit to following instructions in the same scheduling region that
/// depend the physical register referenced at OperIdx.
void ScheduleDAGInstrs::addPhysRegDeps(SUnit *SU, unsigned OperIdx) {
- const MachineInstr *MI = SU->getInstr();
- const MachineOperand &MO = MI->getOperand(OperIdx);
+ MachineInstr *MI = SU->getInstr();
+ MachineOperand &MO = MI->getOperand(OperIdx);
// Optionally add output and anti dependencies. For anti
// dependencies we use a latency of 0 because for a multi-issue
@@ -323,6 +326,8 @@ void ScheduleDAGInstrs::addPhysRegDeps(S
// retrieve the existing SUnits list for this register's uses.
// Push this SUnit on the use list.
Uses.insert(PhysRegSUOper(SU, OperIdx, MO.getReg()));
+ if (RemoveKillFlags)
+ MO.setIsKill(false);
}
else {
addPhysRegDataDeps(SU, OperIdx);
@@ -1021,6 +1026,145 @@ void ScheduleDAGInstrs::buildSchedGraph(
PendingLoads.clear();
}
+/// \brief Initialize register live-range state for updating kills.
+void ScheduleDAGInstrs::startBlockForKills(MachineBasicBlock *BB) {
+ // Start with no live registers.
+ LiveRegs.reset();
+
+ // Examine the live-in regs of all successors.
+ for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
+ SE = BB->succ_end(); SI != SE; ++SI) {
+ for (MachineBasicBlock::livein_iterator I = (*SI)->livein_begin(),
+ E = (*SI)->livein_end(); I != E; ++I) {
+ unsigned Reg = *I;
+ // Repeat, for reg and all subregs.
+ for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs)
+ LiveRegs.set(*SubRegs);
+ }
+ }
+}
+
+bool ScheduleDAGInstrs::toggleKillFlag(MachineInstr *MI, MachineOperand &MO) {
+ // Setting kill flag...
+ if (!MO.isKill()) {
+ MO.setIsKill(true);
+ return false;
+ }
+
+ // If MO itself is live, clear the kill flag...
+ if (LiveRegs.test(MO.getReg())) {
+ MO.setIsKill(false);
+ return false;
+ }
+
+ // If any subreg of MO is live, then create an imp-def for that
+ // subreg and keep MO marked as killed.
+ MO.setIsKill(false);
+ bool AllDead = true;
+ const unsigned SuperReg = MO.getReg();
+ MachineInstrBuilder MIB(MF, MI);
+ for (MCSubRegIterator SubRegs(SuperReg, TRI); SubRegs.isValid(); ++SubRegs) {
+ if (LiveRegs.test(*SubRegs)) {
+ MIB.addReg(*SubRegs, RegState::ImplicitDefine);
+ AllDead = false;
+ }
+ }
+
+ if(AllDead)
+ MO.setIsKill(true);
+ return false;
+}
+
+// FIXME: Reuse the LivePhysRegs utility for this.
+void ScheduleDAGInstrs::fixupKills(MachineBasicBlock *MBB) {
+ DEBUG(dbgs() << "Fixup kills for BB#" << MBB->getNumber() << '\n');
+
+ LiveRegs.resize(TRI->getNumRegs());
+ BitVector killedRegs(TRI->getNumRegs());
+
+ startBlockForKills(MBB);
+
+ // Examine block from end to start...
+ unsigned Count = MBB->size();
+ for (MachineBasicBlock::iterator I = MBB->end(), E = MBB->begin();
+ I != E; --Count) {
+ MachineInstr *MI = --I;
+ if (MI->isDebugValue())
+ continue;
+
+ // Update liveness. Registers that are defed but not used in this
+ // instruction are now dead. Mark register and all subregs as they
+ // are completely defined.
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isRegMask())
+ LiveRegs.clearBitsNotInMask(MO.getRegMask());
+ if (!MO.isReg()) continue;
+ unsigned Reg = MO.getReg();
+ if (Reg == 0) continue;
+ if (!MO.isDef()) continue;
+ // Ignore two-addr defs.
+ if (MI->isRegTiedToUseOperand(i)) continue;
+
+ // Repeat for reg and all subregs.
+ for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs)
+ LiveRegs.reset(*SubRegs);
+ }
+
+ // Examine all used registers and set/clear kill flag. When a
+ // register is used multiple times we only set the kill flag on
+ // the first use. Don't set kill flags on undef operands.
+ killedRegs.reset();
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
+ unsigned Reg = MO.getReg();
+ if ((Reg == 0) || MRI.isReserved(Reg)) continue;
+
+ bool kill = false;
+ if (!killedRegs.test(Reg)) {
+ kill = true;
+ // A register is not killed if any subregs are live...
+ for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
+ if (LiveRegs.test(*SubRegs)) {
+ kill = false;
+ break;
+ }
+ }
+
+ // If subreg is not live, then register is killed if it became
+ // live in this instruction
+ if (kill)
+ kill = !LiveRegs.test(Reg);
+ }
+
+ if (MO.isKill() != kill) {
+ DEBUG(dbgs() << "Fixing " << MO << " in ");
+ // Warning: toggleKillFlag may invalidate MO.
+ toggleKillFlag(MI, MO);
+ DEBUG(MI->dump());
+ }
+
+ killedRegs.set(Reg);
+ }
+
+ // Mark any used register (that is not using undef) and subregs as
+ // now live...
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
+ unsigned Reg = MO.getReg();
+ if ((Reg == 0) || MRI.isReserved(Reg)) continue;
+
+ for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs)
+ LiveRegs.set(*SubRegs);
+ }
+ }
+}
+
void ScheduleDAGInstrs::dumpNode(const SUnit *SU) const {
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
SU->getInstr()->dump();
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