#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/ADT/Statistic.h"
}
}
+/// 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>();
+ 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() &&
for (std::vector<MBB_pair>::iterator I = criticals.begin(),
E = criticals.end(); I != E; ++I) {
- SplitCriticalMachineEdge(I->first, I->second);
+ // 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());
}
}