#include "LiveDebugVariables.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/SparseSet.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
SlotIndexes *Indexes;
LiveIntervals *LIS;
VirtRegMap *VRM;
+ SparseSet<unsigned> PhysRegs;
void rewrite();
void addMBBLiveIns();
SmallVector<unsigned, 8> SuperKills;
SmallPtrSet<const MachineInstr *, 4> NoReturnInsts;
+ // Here we have a SparseSet to hold which PhysRegs are actually encountered
+ // in the MF we are about to iterate over so that later when we call
+ // setPhysRegUsed, we are only doing it for physRegs that were actually found
+ // in the program and not for all of the possible physRegs for the given
+ // target architecture. If the target has a lot of physRegs, then for a small
+ // program there will be a significant compile time reduction here.
+ PhysRegs.clear();
+ PhysRegs.setUniverse(TRI->getNumRegs());
+
for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
MBBI != MBBE; ++MBBI) {
DEBUG(MBBI->print(dbgs(), Indexes));
if (MO.isRegMask())
MRI->addPhysRegsUsedFromRegMask(MO.getRegMask());
+ // If we encounter a VirtReg or PhysReg then get at the PhysReg and add
+ // it to the physreg bitset. Later we use only the PhysRegs that were
+ // actually encountered in the MF to populate the MRI's used physregs.
+ if (MO.isReg() && MO.getReg())
+ PhysRegs.insert(
+ TargetRegisterInfo::isVirtualRegister(MO.getReg()) ?
+ VRM->getPhys(MO.getReg()) :
+ MO.getReg());
+
if (!MO.isReg() || !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
continue;
unsigned VirtReg = MO.getReg();
// Tell MRI about physical registers in use.
if (NoReturnInsts.empty()) {
- for (unsigned Reg = 1, RegE = TRI->getNumRegs(); Reg != RegE; ++Reg)
- if (!MRI->reg_nodbg_empty(Reg))
- MRI->setPhysRegUsed(Reg);
+ for (SparseSet<unsigned>::iterator
+ RegI = PhysRegs.begin(), E = PhysRegs.end(); RegI != E; ++RegI)
+ if (!MRI->reg_nodbg_empty(*RegI))
+ MRI->setPhysRegUsed(*RegI);
} else {
- for (unsigned Reg = 1, RegE = TRI->getNumRegs(); Reg != RegE; ++Reg) {
+ for (SparseSet<unsigned>::iterator
+ I = PhysRegs.begin(), E = PhysRegs.end(); I != E; ++I) {
+ unsigned Reg = *I;
if (MRI->reg_nodbg_empty(Reg))
continue;
// Check if this register has a use that will impact the rest of the
}
}
}
+