Scheduler / Regalloc: use unique_ptr[] instead of std::vector

vector.resize() is significantly slower than memset in many STLs
and the cost of initializing these vectors is significant on targets
with many registers. Since we don't need the overhead of a vector,
use a simple unique_ptr instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254526 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index cbfd8a37eaa6bca2ffdbbbc6cdfc9170350efdbd..0a1f6200632752cb198df7f50150dec1c7e4aff3 100644 (file)
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -73,7 +73,7 @@ private:
 
   /// PhysRegUseDefLists - This is an array of the head of the use/def list for
   /// physical registers.
-  std::vector<MachineOperand *> PhysRegUseDefLists;
+  std::unique_ptr<MachineOperand *[]> PhysRegUseDefLists;
 
   /// getRegUseDefListHead - Return the head pointer for the register use/def
   /// list for the specified virtual or physical register.

diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index abf9b4d676960e56bf23071528d53961468f67e6..03c82f46da63a6e5da16dde5df7724c8ace2e877 100644 (file)
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -27,12 +27,11 @@ void MachineRegisterInfo::Delegate::anchor() {}
 MachineRegisterInfo::MachineRegisterInfo(const MachineFunction *MF)
   : MF(MF), TheDelegate(nullptr), IsSSA(true), TracksLiveness(true),
     TracksSubRegLiveness(false) {
+  unsigned NumRegs = getTargetRegisterInfo()->getNumRegs();
   VRegInfo.reserve(256);
   RegAllocHints.reserve(256);
-  UsedPhysRegMask.resize(getTargetRegisterInfo()->getNumRegs());
-
-  // Create the physreg use/def lists.
-  PhysRegUseDefLists.resize(getTargetRegisterInfo()->getNumRegs(), nullptr);
+  UsedPhysRegMask.resize(NumRegs);
+  PhysRegUseDefLists.reset(new MachineOperand*[NumRegs]());
 }
 
 /// setRegClass - Set the register class of the specified virtual register.

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index e9bd52034ffdac6401d960524eec7062f1921d7c..cb573f2effde28595957d06951962a7ecac28fbd 100644 (file)
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -141,8 +141,8 @@ private:
   /// that are "live". These nodes must be scheduled before any other nodes that
   /// modifies the registers can be scheduled.
   unsigned NumLiveRegs;
-  std::vector<SUnit*> LiveRegDefs;
-  std::vector<SUnit*> LiveRegGens;
+  std::unique_ptr<SUnit*[]> LiveRegDefs;
+  std::unique_ptr<SUnit*[]> LiveRegGens;
 
   // Collect interferences between physical register use/defs.
   // Each interference is an SUnit and set of physical registers.
@@ -328,8 +328,8 @@ void ScheduleDAGRRList::Schedule() {
   NumLiveRegs = 0;
   // Allocate slots for each physical register, plus one for a special register
   // to track the virtual resource of a calling sequence.
-  LiveRegDefs.resize(TRI->getNumRegs() + 1, nullptr);
-  LiveRegGens.resize(TRI->getNumRegs() + 1, nullptr);
+  LiveRegDefs.reset(new SUnit*[TRI->getNumRegs() + 1]());
+  LiveRegGens.reset(new SUnit*[TRI->getNumRegs() + 1]());
   CallSeqEndForStart.clear();
   assert(Interferences.empty() && LRegsMap.empty() && "stale Interferences");
 
@@ -1218,7 +1218,7 @@ static MVT getPhysicalRegisterVT(SDNode *N, unsigned Reg,
 /// CheckForLiveRegDef - Return true and update live register vector if the
 /// specified register def of the specified SUnit clobbers any "live" registers.
 static void CheckForLiveRegDef(SUnit *SU, unsigned Reg,
-                               std::vector<SUnit*> &LiveRegDefs,
+                               SUnit **LiveRegDefs,
                                SmallSet<unsigned, 4> &RegAdded,
                                SmallVectorImpl<unsigned> &LRegs,
                                const TargetRegisterInfo *TRI) {
@@ -1240,11 +1240,11 @@ static void CheckForLiveRegDef(SUnit *SU, unsigned Reg,
 /// CheckForLiveRegDefMasked - Check for any live physregs that are clobbered
 /// by RegMask, and add them to LRegs.
 static void CheckForLiveRegDefMasked(SUnit *SU, const uint32_t *RegMask,
-                                     std::vector<SUnit*> &LiveRegDefs,
+                                     ArrayRef<SUnit*> LiveRegDefs,
                                      SmallSet<unsigned, 4> &RegAdded,
                                      SmallVectorImpl<unsigned> &LRegs) {
   // Look at all live registers. Skip Reg0 and the special CallResource.
-  for (unsigned i = 1, e = LiveRegDefs.size()-1; i != e; ++i) {
+  for (unsigned i = 1, e = LiveRegDefs.size(); i != e; ++i) {
     if (!LiveRegDefs[i]) continue;
     if (LiveRegDefs[i] == SU) continue;
     if (!MachineOperand::clobbersPhysReg(RegMask, i)) continue;
@@ -1278,7 +1278,7 @@ DelayForLiveRegsBottomUp(SUnit *SU, SmallVectorImpl<unsigned> &LRegs) {
   for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
        I != E; ++I) {
     if (I->isAssignedRegDep() && LiveRegDefs[I->getReg()] != SU)
-      CheckForLiveRegDef(I->getSUnit(), I->getReg(), LiveRegDefs,
+      CheckForLiveRegDef(I->getSUnit(), I->getReg(), LiveRegDefs.get(),
                          RegAdded, LRegs, TRI);
   }
 
@@ -1302,7 +1302,7 @@ DelayForLiveRegsBottomUp(SUnit *SU, SmallVectorImpl<unsigned> &LRegs) {
           for (; NumVals; --NumVals, ++i) {
             unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
             if (TargetRegisterInfo::isPhysicalRegister(Reg))
-              CheckForLiveRegDef(SU, Reg, LiveRegDefs, RegAdded, LRegs, TRI);
+              CheckForLiveRegDef(SU, Reg, LiveRegDefs.get(), RegAdded, LRegs, TRI);
           }
         } else
           i += NumVals;
@@ -1328,13 +1328,15 @@ DelayForLiveRegsBottomUp(SUnit *SU, SmallVectorImpl<unsigned> &LRegs) {
       }
     }
     if (const uint32_t *RegMask = getNodeRegMask(Node))
-      CheckForLiveRegDefMasked(SU, RegMask, LiveRegDefs, RegAdded, LRegs);
+      CheckForLiveRegDefMasked(SU, RegMask,
+                               makeArrayRef(LiveRegDefs.get(), TRI->getNumRegs()),
+                               RegAdded, LRegs);
 
     const MCInstrDesc &MCID = TII->get(Node->getMachineOpcode());
     if (!MCID.ImplicitDefs)
       continue;
     for (const uint16_t *Reg = MCID.getImplicitDefs(); *Reg; ++Reg)
-      CheckForLiveRegDef(SU, *Reg, LiveRegDefs, RegAdded, LRegs, TRI);
+      CheckForLiveRegDef(SU, *Reg, LiveRegDefs.get(), RegAdded, LRegs, TRI);
   }
 
   return !LRegs.empty();