Handle an empty dupli.

[oota-llvm.git] / lib / CodeGen / LiveVariables.cpp

diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index ca8ecff8e61d65b7ec376bc0b2fe2eed0d255ddd..1d935b207396ccf9d43ffb072561a00d4881697e 100644 (file)
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -42,7 +42,8 @@
 using namespace llvm;
 
 char LiveVariables::ID = 0;
-static RegisterPass<LiveVariables> X("livevars", "Live Variable Analysis");
+INITIALIZE_PASS(LiveVariables, "livevars",
+                "Live Variable Analysis", false, false);
 
 
 void LiveVariables::getAnalysisUsage(AnalysisUsage &AU) const {
@@ -286,7 +287,7 @@ MachineInstr *LiveVariables::FindLastRefOrPartRef(unsigned Reg) {
   MachineInstr *LastDef = PhysRegDef[Reg];
   MachineInstr *LastUse = PhysRegUse[Reg];
   if (!LastDef && !LastUse)
-    return false;
+    return 0;
 
   MachineInstr *LastRefOrPartRef = LastUse ? LastUse : LastDef;
   unsigned LastRefOrPartRefDist = DistanceMap[LastRefOrPartRef];
@@ -531,7 +532,7 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
 
     // Mark live-in registers as live-in.
     SmallVector<unsigned, 4> Defs;
-    for (MachineBasicBlock::const_livein_iterator II = MBB->livein_begin(),
+    for (MachineBasicBlock::livein_iterator II = MBB->livein_begin(),
            EE = MBB->livein_end(); II != EE; ++II) {
       assert(TargetRegisterInfo::isPhysicalRegister(*II) &&
              "Cannot have a live-in virtual register!");
@@ -609,7 +610,12 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
 
     // Finally, if the last instruction in the block is a return, make sure to
     // mark it as using all of the live-out values in the function.
-    if (!MBB->empty() && MBB->back().getDesc().isReturn()) {
+    // Things marked both call and return are tail calls; do not do this for
+    // them.  The tail callee need not take the same registers as input
+    // that it produces as output, and there are dependencies for its input
+    // registers elsewhere.
+    if (!MBB->empty() && MBB->back().getDesc().isReturn()
+        && !MBB->back().getDesc().isCall()) {
       MachineInstr *Ret = &MBB->back();
 
       for (MachineRegisterInfo::liveout_iterator