[llvm-commits] [llvm] r44063 - /llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp
Owen Anderson
resistor at mac.com
Tue Nov 13 12:04:45 PST 2007
Author: resistor
Date: Tue Nov 13 14:04:45 2007
New Revision: 44063
URL: http://llvm.org/viewvc/llvm-project?rev=44063&view=rev
Log:
Preserve LiveVariables when doing critical edge splitting.
Modified:
llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp
Modified: llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp?rev=44063&r1=44062&r2=44063&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp Tue Nov 13 14:04:45 2007
@@ -26,6 +26,7 @@
#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"
@@ -296,12 +297,15 @@
}
}
+/// 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() &&
@@ -314,9 +318,16 @@
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());
}
}
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