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MachineCopyPropagation: Move variables from function to pass 

This avoids unnecessarily passing them around when calling helper
functions. It may also be slightly faster to call clear() on the
datastructures instead of freshly initializing them for each block.

llvm-svn: 261407
This commit is contained in:
Matthias Braun 2016-02-20 03:56:39 +00:00
parent 273575dcbe
commit bd18d751de
1 changed files with 22 additions and 18 deletions
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40
llvm/lib/CodeGen/MachineCopyPropagation.cpp
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@ -49,9 +49,18 @@ namespace {
typedef SmallVector<unsigned, 4> DestList;
typedef DenseMap<unsigned, DestList> SourceMap;
void SourceNoLongerAvailable(unsigned Reg, SourceMap &SrcMap,
DenseMap<unsigned, MachineInstr*> &AvailCopyMap);
bool CopyPropagateBlock(MachineBasicBlock &MBB);
void SourceNoLongerAvailable(unsigned Reg);
void CopyPropagateBlock(MachineBasicBlock &MBB);
/// Candidates for deletion.
SmallSetVector<MachineInstr*, 8> MaybeDeadCopies;
/// Def -> available copies map.
DenseMap<unsigned, MachineInstr*> AvailCopyMap;
/// Def -> copies map.
DenseMap<unsigned, MachineInstr*> CopyMap;
/// Src -> Def map
SourceMap SrcMap;
bool Changed;
};
}
char MachineCopyPropagation::ID = 0;
@ -60,9 +69,7 @@ char &llvm::MachineCopyPropagationID = MachineCopyPropagation::ID;
INITIALIZE_PASS(MachineCopyPropagation, "machine-cp",
"Machine Copy Propagation Pass", false, false)
void
MachineCopyPropagation::SourceNoLongerAvailable(unsigned Reg, SourceMap &SrcMap,
DenseMap<unsigned, MachineInstr*> &AvailCopyMap) {
void MachineCopyPropagation::SourceNoLongerAvailable(unsigned Reg) {
for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
SourceMap::iterator SI = SrcMap.find(*AI);
if (SI != SrcMap.end()) {
@ -116,15 +123,9 @@ static bool isNopCopy(const MachineInstr *CopyMI, unsigned Def, unsigned Src,
return false;
}
bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
SmallSetVector<MachineInstr*, 8> MaybeDeadCopies; // Candidates for deletion
DenseMap<unsigned, MachineInstr*> AvailCopyMap; // Def -> available copies map
DenseMap<unsigned, MachineInstr*> CopyMap; // Def -> copies map
SourceMap SrcMap; // Src -> Def map
void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
DEBUG(dbgs() << "MCP: CopyPropagateBlock " << MBB.getName() << "\n");
bool Changed = false;
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ) {
MachineInstr *MI = &*I;
++I;
@ -195,7 +196,7 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
// %xmm2<def> = copy %xmm0
// ...
// %xmm2<def> = copy %xmm9
SourceNoLongerAvailable(Def, SrcMap, AvailCopyMap);
SourceNoLongerAvailable(Def);
// Remember Def is defined by the copy.
// ... Make sure to clear the def maps of aliases first.
@ -292,7 +293,7 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
// If 'Reg' is previously source of a copy, it is no longer available for
// copy propagation.
SourceNoLongerAvailable(Reg, SrcMap, AvailCopyMap);
SourceNoLongerAvailable(Reg);
}
}
@ -308,21 +309,24 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
}
}
return Changed;
MaybeDeadCopies.clear();
AvailCopyMap.clear();
CopyMap.clear();
SrcMap.clear();
}
bool MachineCopyPropagation::runOnMachineFunction(MachineFunction &MF) {
if (skipOptnoneFunction(*MF.getFunction()))
return false;
bool Changed = false;
Changed = false;
TRI = MF.getSubtarget().getRegisterInfo();
TII = MF.getSubtarget().getInstrInfo();
MRI = &MF.getRegInfo();
for (MachineBasicBlock &MBB : MF)
Changed |= CopyPropagateBlock(MBB);
CopyPropagateBlock(MBB);
return Changed;
}