Teach if-converter to be more careful with predicating instructions that would

take multiple cycles to decode.
For the current if-converter clients (actually only ARM), the instructions that
are predicated on false are not nops. They would still take machine cycles to
decode. Micro-coded instructions such as LDM / STM can potentially take multiple
cycles to decode. If-converter should take treat them as non-micro-coded
simple instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113570 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 45 insertions, 41 deletions

diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp
index 0ea30d7..d73cd53 100644
--- a/lib/CodeGen/IfConversion.cpp
+++ b/lib/CodeGen/IfConversion.cpp
@@ -18,6 +18,7 @@
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetInstrItineraries.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
@@ -150,6 +151,7 @@ namespace {
     const TargetLowering *TLI;
     const TargetInstrInfo *TII;
     const TargetRegisterInfo *TRI;
+    const InstrItineraryData *InstrItins;
     bool MadeChange;
     int FnNum;
   public:
@@ -238,6 +240,7 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
   TLI = MF.getTarget().getTargetLowering();
   TII = MF.getTarget().getInstrInfo();
   TRI = MF.getTarget().getRegisterInfo();
+  InstrItins = MF.getTarget().getInstrItineraryData();
   if (!TII) return false;
 
   // Tail merge tend to expose more if-conversion opportunities.
@@ -641,9 +644,10 @@ void IfConverter::ScanInstructions(BBInfo &BBI) {
     bool isCondBr = BBI.IsBrAnalyzable && TID.isConditionalBranch();
 
     if (!isCondBr) {
-      if (!isPredicated)
-        BBI.NonPredSize++;
-      else if (!AlreadyPredicated) {
+      if (!isPredicated) {
+        unsigned NumOps = TII->getNumMicroOps(&*I, InstrItins);
+        BBI.NonPredSize += NumOps;
+      } else if (!AlreadyPredicated) {
         // FIXME: This instruction is already predicated before the
         // if-conversion pass. It's probably something like a conditional move.
         // Mark this block unpredicable for now.
@@ -1364,7 +1368,8 @@ void IfConverter::CopyAndPredicateBlock(BBInfo &ToBBI, BBInfo &FromBBI,
 
     MachineInstr *MI = MF.CloneMachineInstr(I);
     ToBBI.BB->insert(ToBBI.BB->end(), MI);
-    ToBBI.NonPredSize++;
+    unsigned NumOps = TII->getNumMicroOps(MI, InstrItins);
+    ToBBI.NonPredSize += NumOps;
 
     if (!TII->isPredicated(I) && !MI->isDebugValue()) {
       if (!TII->PredicateInstruction(MI, Cond)) {
diff --git a/lib/CodeGen/PostRAHazardRecognizer.cpp b/lib/CodeGen/PostRAHazardRecognizer.cpp
index cbde2b0..2e39196 100644
--- a/lib/CodeGen/PostRAHazardRecognizer.cpp
+++ b/lib/CodeGen/PostRAHazardRecognizer.cpp
@@ -23,19 +23,19 @@
 using namespace llvm;
 
 PostRAHazardRecognizer::
-PostRAHazardRecognizer(const InstrItineraryData &LItinData) :
+PostRAHazardRecognizer(const InstrItineraryData *LItinData) :
   ScheduleHazardRecognizer(), ItinData(LItinData) {
   // 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.isEmpty()) {
+  if (ItinData && !ItinData->isEmpty()) {
     for (unsigned idx = 0; ; ++idx) {
-      if (ItinData.isEndMarker(idx))
+      if (ItinData->isEndMarker(idx))
         break;
 
-      const InstrStage *IS = ItinData.beginStage(idx);
-      const InstrStage *E = ItinData.endStage(idx);
+      const InstrStage *IS = ItinData->beginStage(idx);
+      const InstrStage *E = ItinData->endStage(idx);
       unsigned ItinDepth = 0;
       for (; IS != E; ++IS)
         ItinDepth += IS->getCycles();
@@ -74,7 +74,7 @@ void PostRAHazardRecognizer::ScoreBoard::dump() const {
 
 ScheduleHazardRecognizer::HazardType
 PostRAHazardRecognizer::getHazardType(SUnit *SU) {
-  if (ItinData.isEmpty())
+  if (!ItinData || ItinData->isEmpty())
     return NoHazard;
 
   unsigned cycle = 0;
@@ -82,8 +82,8 @@ PostRAHazardRecognizer::getHazardType(SUnit *SU) {
   // Use the itinerary for the underlying instruction to check for
   // free FU's in the scoreboard at the appropriate future cycles.
   unsigned idx = SU->getInstr()->getDesc().getSchedClass();
-  for (const InstrStage *IS = ItinData.beginStage(idx),
-         *E = ItinData.endStage(idx); IS != E; ++IS) {
+  for (const InstrStage *IS = ItinData->beginStage(idx),
+         *E = ItinData->endStage(idx); IS != E; ++IS) {
     // We must find one of the stage's units free for every cycle the
     // stage is occupied. FIXME it would be more accurate to find the
     // same unit free in all the cycles.
@@ -121,7 +121,7 @@ PostRAHazardRecognizer::getHazardType(SUnit *SU) {
 }
 
 void PostRAHazardRecognizer::EmitInstruction(SUnit *SU) {
-  if (ItinData.isEmpty())
+  if (!ItinData || ItinData->isEmpty())
     return;
 
   unsigned cycle = 0;
@@ -129,8 +129,8 @@ void PostRAHazardRecognizer::EmitInstruction(SUnit *SU) {
   // Use the itinerary for the underlying instruction to reserve FU's
   // in the scoreboard at the appropriate future cycles.
   unsigned idx = SU->getInstr()->getDesc().getSchedClass();
-  for (const InstrStage *IS = ItinData.beginStage(idx),
-         *E = ItinData.endStage(idx); IS != E; ++IS) {
+  for (const InstrStage *IS = ItinData->beginStage(idx),
+         *E = ItinData->endStage(idx); IS != E; ++IS) {
     // We must reserve one of the stage's units for every cycle the
     // stage is occupied. FIXME it would be more accurate to reserve
     // the same unit free in all the cycles.
diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index f0bd6d1..bd5b2b8 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -213,7 +213,7 @@ bool PostRAScheduler::runOnMachineFunction(MachineFunction &Fn) {
   const MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
   const MachineDominatorTree &MDT = getAnalysis<MachineDominatorTree>();
   const TargetMachine &TM = Fn.getTarget();
-  const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
+  const InstrItineraryData *InstrItins = TM.getInstrItineraryData();
   ScheduleHazardRecognizer *HR =
     TM.getInstrInfo()->CreateTargetPostRAHazardRecognizer(InstrItins);
   AntiDepBreaker *ADB =
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index ea93dd5..da0b056 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -32,9 +32,9 @@ using namespace llvm;
 ScheduleDAGInstrs::ScheduleDAGInstrs(MachineFunction &mf,
                                      const MachineLoopInfo &mli,
                                      const MachineDominatorTree &mdt)
-  : ScheduleDAG(mf), MLI(mli), MDT(mdt), Defs(TRI->getNumRegs()),
-    Uses(TRI->getNumRegs()), LoopRegs(MLI, MDT) {
-  MFI = mf.getFrameInfo();
+  : ScheduleDAG(mf), MLI(mli), MDT(mdt), MFI(mf.getFrameInfo()),
+    InstrItins(mf.getTarget().getInstrItineraryData()),
+    Defs(TRI->getNumRegs()), Uses(TRI->getNumRegs()), LoopRegs(MLI, MDT) {
   DbgValueVec.clear();
 }
 
@@ -498,23 +498,22 @@ void ScheduleDAGInstrs::FinishBlock() {
 }
 
 void ScheduleDAGInstrs::ComputeLatency(SUnit *SU) {
-  const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
-
   // Compute the latency for the node.
-  SU->Latency =
-    InstrItins.getStageLatency(SU->getInstr()->getDesc().getSchedClass());
+  if (!InstrItins || InstrItins->isEmpty()) {
+    SU->Latency = 1;
 
-  // Simplistic target-independent heuristic: assume that loads take
-  // extra time.
-  if (InstrItins.isEmpty())
+    // Simplistic target-independent heuristic: assume that loads take
+    // extra time.
     if (SU->getInstr()->getDesc().mayLoad())
       SU->Latency += 2;
+  } else
+    SU->Latency =
+      InstrItins->getStageLatency(SU->getInstr()->getDesc().getSchedClass());
 }
 
 void ScheduleDAGInstrs::ComputeOperandLatency(SUnit *Def, SUnit *Use, 
                                               SDep& dep) const {
-  const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
-  if (InstrItins.isEmpty())
+  if (!InstrItins || InstrItins->isEmpty())
     return;
   
   // For a data dependency with a known register...
@@ -528,8 +527,8 @@ void ScheduleDAGInstrs::ComputeOperandLatency(SUnit *Def, SUnit *Use,
   MachineInstr *DefMI = Def->getInstr();
   int DefIdx = DefMI->findRegisterDefOperandIdx(Reg);
   if (DefIdx != -1) {
-    int DefCycle = InstrItins.getOperandCycle(DefMI->getDesc().getSchedClass(),
-                                              DefIdx);
+    int DefCycle = InstrItins->getOperandCycle(DefMI->getDesc().getSchedClass(),
+                                               DefIdx);
     if (DefCycle >= 0) {
       MachineInstr *UseMI = Use->getInstr();
       const unsigned UseClass = UseMI->getDesc().getSchedClass();
@@ -544,7 +543,7 @@ void ScheduleDAGInstrs::ComputeOperandLatency(SUnit *Def, SUnit *Use,
         if (MOReg != Reg)
           continue;
 
-        int UseCycle = InstrItins.getOperandCycle(UseClass, i);
+        int UseCycle = InstrItins->getOperandCycle(UseClass, i);
         if (UseCycle >= 0)
           Latency = std::max(Latency, DefCycle - UseCycle + 1);
       }
diff --git a/lib/CodeGen/ScheduleDAGInstrs.h b/lib/CodeGen/ScheduleDAGInstrs.h
index c8f543f..bc07d9e 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.h
+++ b/lib/CodeGen/ScheduleDAGInstrs.h
@@ -101,6 +101,7 @@ namespace llvm {
     const MachineLoopInfo &MLI;
     const MachineDominatorTree &MDT;
     const MachineFrameInfo *MFI;
+    const InstrItineraryData *InstrItins;
 
     /// Defs, Uses - Remember where defs and uses of each physical register
     /// are as we iterate upward through the instructions. This is allocated
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index f1bf82a..fbf621d 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -34,8 +34,8 @@ using namespace llvm;
 STATISTIC(LoadsClustered, "Number of loads clustered together");
 
 ScheduleDAGSDNodes::ScheduleDAGSDNodes(MachineFunction &mf)
-  : ScheduleDAG(mf) {
-}
+  : ScheduleDAG(mf),
+    InstrItins(mf.getTarget().getInstrItineraryData()) {}
 
 /// Run - perform scheduling.
 ///
@@ -429,8 +429,7 @@ void ScheduleDAGSDNodes::ComputeLatency(SUnit *SU) {
     return;
   }
 
-  const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
-  if (InstrItins.isEmpty()) {
+  if (!InstrItins || InstrItins->isEmpty()) {
     SU->Latency = 1;
     return;
   }
@@ -440,7 +439,7 @@ void ScheduleDAGSDNodes::ComputeLatency(SUnit *SU) {
   SU->Latency = 0;
   for (SDNode *N = SU->getNode(); N; N = N->getFlaggedNode())
     if (N->isMachineOpcode()) {
-      SU->Latency += InstrItins.
+      SU->Latency += InstrItins->
         getStageLatency(TII->get(N->getMachineOpcode()).getSchedClass());
     }
 }
@@ -451,8 +450,7 @@ void ScheduleDAGSDNodes::ComputeOperandLatency(SDNode *Def, SDNode *Use,
   if (ForceUnitLatencies())
     return;
 
-  const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
-  if (InstrItins.isEmpty())
+  if (!InstrItins || InstrItins->isEmpty())
     return;
   
   if (dep.getKind() != SDep::Data)
@@ -463,13 +461,13 @@ void ScheduleDAGSDNodes::ComputeOperandLatency(SDNode *Def, SDNode *Use,
     const TargetInstrDesc &II = TII->get(Def->getMachineOpcode());
     if (DefIdx >= II.getNumDefs())
       return;
-    int DefCycle = InstrItins.getOperandCycle(II.getSchedClass(), DefIdx);
+    int DefCycle = InstrItins->getOperandCycle(II.getSchedClass(), DefIdx);
     if (DefCycle < 0)
       return;
     int UseCycle = 1;
     if (Use->isMachineOpcode()) {
       const unsigned UseClass = TII->get(Use->getMachineOpcode()).getSchedClass();
-      UseCycle = InstrItins.getOperandCycle(UseClass, OpIdx);
+      UseCycle = InstrItins->getOperandCycle(UseClass, OpIdx);
     }
     if (UseCycle >= 0) {
       int Latency = DefCycle - UseCycle + 1;
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
index 842fc8c..8008ef8 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
@@ -36,6 +36,7 @@ namespace llvm {
   class ScheduleDAGSDNodes : public ScheduleDAG {
   public:
     SelectionDAG *DAG;                    // DAG of the current basic block
+    const InstrItineraryData *InstrItins;
 
     explicit ScheduleDAGSDNodes(MachineFunction &mf);
 
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 6e4a0d8..d106ead 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -416,6 +416,6 @@ bool TargetInstrInfoImpl::isSchedulingBoundary(const MachineInstr *MI,
 
 // Default implementation of CreateTargetPostRAHazardRecognizer.
 ScheduleHazardRecognizer *TargetInstrInfoImpl::
-CreateTargetPostRAHazardRecognizer(const InstrItineraryData &II) const {
+CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II) const {
   return (ScheduleHazardRecognizer *)new PostRAHazardRecognizer(II);
 }