System/Path/Windows: Make GetSystemLibraryPaths more generic.

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

diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index 519990e04a2c540f4377528cc71461406658a465..66f8e237da68c9f1f7813a6fa3a064f2ae18f00d 100644 (file)
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -42,7 +42,11 @@
 using namespace llvm;
 
 char LiveVariables::ID = 0;
-static RegisterPass<LiveVariables> X("livevars", "Live Variable Analysis");
+INITIALIZE_PASS_BEGIN(LiveVariables, "livevars",
+                "Live Variable Analysis", false, false)
+INITIALIZE_PASS_DEPENDENCY(UnreachableMachineBlockElim)
+INITIALIZE_PASS_END(LiveVariables, "livevars",
+                "Live Variable Analysis", false, false)
 
 
 void LiveVariables::getAnalysisUsage(AnalysisUsage &AU) const {
@@ -286,7 +290,7 @@ 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];
@@ -482,21 +486,6 @@ void LiveVariables::UpdatePhysRegDefs(MachineInstr *MI,
   }
 }
 
-namespace {
-  struct RegSorter {
-    const TargetRegisterInfo *TRI;
-
-    RegSorter(const TargetRegisterInfo *tri) : TRI(tri) { }
-    bool operator()(unsigned A, unsigned B) {
-      if (TRI->isSubRegister(A, B))
-        return true;
-      else if (TRI->isSubRegister(B, A))
-        return false;
-      return A < B;
-    }
-  };
-}
-
 bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
   MF = &mf;
   MRI = &mf.getRegInfo();
@@ -531,7 +520,7 @@ 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!");
@@ -556,17 +545,21 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
       if (MI->isPHI())
         NumOperandsToProcess = 1;
 
+      // Clear kill and dead markers. LV will recompute them.
       SmallVector<unsigned, 4> UseRegs;
       SmallVector<unsigned, 4> DefRegs;
       for (unsigned i = 0; i != NumOperandsToProcess; ++i) {
-        const MachineOperand &MO = MI->getOperand(i);
+        MachineOperand &MO = MI->getOperand(i);
         if (!MO.isReg() || MO.getReg() == 0)
           continue;
         unsigned MOReg = MO.getReg();
-        if (MO.isUse())
+        if (MO.isUse()) {
+          MO.setIsKill(false);
           UseRegs.push_back(MOReg);
-        if (MO.isDef())
+        } else /*MO.isDef()*/ {
+          MO.setIsDead(false);
           DefRegs.push_back(MOReg);
+        }
       }
 
       // Process all uses.
@@ -605,7 +598,12 @@ 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