#define DEBUG_TYPE "strongphielim"
#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/BreakCriticalMachineEdge.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
std::set<unsigned>& PHIUnion,
std::vector<StrongPHIElimination::DomForestNode*>& DF,
std::vector<std::pair<unsigned, unsigned> >& locals);
- void breakCriticalEdges(MachineFunction &Fn);
};
}
}
-/// breakCriticalEdges - Break critical edges coming into blocks with PHI
-/// nodes, preserving dominator and livevariable info.
-void StrongPHIElimination::breakCriticalEdges(MachineFunction &Fn) {
- typedef std::pair<MachineBasicBlock*, MachineBasicBlock*> MBB_pair;
-
- MachineDominatorTree& MDT = getAnalysis<MachineDominatorTree>();
- LiveVariables& LV = getAnalysis<LiveVariables>();
-
- // Find critical edges
- std::vector<MBB_pair> criticals;
- for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
- if (!I->empty() &&
- I->begin()->getOpcode() == TargetInstrInfo::PHI &&
- I->pred_size() > 1)
- for (MachineBasicBlock::pred_iterator PI = I->pred_begin(),
- PE = I->pred_end(); PI != PE; ++PI)
- if ((*PI)->succ_size() > 1)
- criticals.push_back(std::make_pair(*PI, I));
-
- for (std::vector<MBB_pair>::iterator I = criticals.begin(),
- E = criticals.end(); I != E; ++I) {
- // Split the edge
- MachineBasicBlock* new_bb = SplitCriticalMachineEdge(I->first, I->second);
-
- // Update dominators
- MDT.splitBlock(I->first);
-
- // Update livevariables
- for (unsigned var = 1024; var < Fn.getSSARegMap()->getLastVirtReg(); ++var)
- if (isLiveOut(LV.getVarInfo(var), I->first))
- LV.getVarInfo(var).AliveBlocks.set(new_bb->getNumber());
- }
-}
-
bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
- breakCriticalEdges(Fn);
computeDFS(Fn);
for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)