maintain LiveIn when splitting blocks (register scavenging needs it)
llvm-svn: 35226
diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
index d6bedb8..1f5d675 100644
--- a/llvm/lib/CodeGen/BranchFolding.cpp
+++ b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -21,8 +21,10 @@
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/MRegisterInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/Statistic.h"
@@ -49,7 +51,9 @@
MachineBasicBlock *NewDest);
MachineBasicBlock *SplitMBBAt(MachineBasicBlock &CurMBB,
MachineBasicBlock::iterator BBI1);
-
+
+ const MRegisterInfo *RegInfo;
+ RegScavenger *RS;
// Branch optzn.
bool OptimizeBranches(MachineFunction &MF);
void OptimizeBlock(MachineBasicBlock *MBB);
@@ -95,6 +99,9 @@
TII = MF.getTarget().getInstrInfo();
if (!TII) return false;
+ RegInfo = MF.getTarget().getRegisterInfo();
+ RS = RegInfo->requiresRegisterScavenging(MF) ? new RegScavenger() : NULL;
+
MMI = getAnalysisToUpdate<MachineModuleInfo>();
bool EverMadeChange = false;
@@ -153,6 +160,7 @@
}
}
+ delete RS;
return EverMadeChange;
}
@@ -280,6 +288,19 @@
// Splice the code over.
NewMBB->splice(NewMBB->end(), &CurMBB, BBI1, CurMBB.end());
+
+ // For targets that use the register scavenger, we must maintain LiveIns.
+ if (RS) {
+ RS->enterBasicBlock(&CurMBB);
+ if (!CurMBB.empty())
+ RS->forward(prior(CurMBB.end()));
+ BitVector RegsLiveAtExit(RegInfo->getNumRegs());
+ RS->getRegsUsed(RegsLiveAtExit, false);
+ for (unsigned int i=0, e=RegInfo->getNumRegs(); i!=e; i++)
+ if (RegsLiveAtExit[i])
+ NewMBB->addLiveIn(i);
+ }
+
return NewMBB;
}