Remove unused but set variable flagged by GCC.

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

diff --git a/lib/CodeGen/LiveRangeCalc.cpp b/lib/CodeGen/LiveRangeCalc.cpp
index 3e5d7f6c295a71fdaa603b06d106bacbf717f4ed..c3ff4f1b6d2eb6708cdd5c0f3ca31da28b7f402c 100644 (file)
--- a/lib/CodeGen/LiveRangeCalc.cpp
+++ b/lib/CodeGen/LiveRangeCalc.cpp
@@ -54,8 +54,7 @@ void LiveRangeCalc::createDeadDefs(LiveInterval *LI, unsigned Reg) {
         .getRegSlot(I.getOperand().isEarlyClobber());
 
     // Create the def in LI. This may find an existing def.
-    VNInfo *VNI = LI->createDeadDef(Idx, *Alloc);
-    VNI->setIsPHIDef(MI->isPHI());
+    LI->createDeadDef(Idx, *Alloc);
   }
 }
 
@@ -66,7 +65,11 @@ void LiveRangeCalc::extendToUses(LiveInterval *LI, unsigned Reg) {
   // Visit all operands that read Reg. This may include partial defs.
   for (MachineRegisterInfo::reg_nodbg_iterator I = MRI->reg_nodbg_begin(Reg),
        E = MRI->reg_nodbg_end(); I != E; ++I) {
-    const MachineOperand &MO = I.getOperand();
+    MachineOperand &MO = I.getOperand();
+    // Clear all kill flags. They will be reinserted after register allocation
+    // by LiveIntervalAnalysis::addKillFlags().
+    if (MO.isUse())
+      MO.setIsKill(false);
     if (!MO.readsReg())
       continue;
     // MI is reading Reg. We may have visited MI before if it happens to be
@@ -95,7 +98,7 @@ void LiveRangeCalc::extendToUses(LiveInterval *LI, unsigned Reg) {
           Idx = Idx.getRegSlot(true);
       }
     }
-    extend(LI, Idx);
+    extend(LI, Idx, Reg);
   }
 }
 
@@ -129,7 +132,8 @@ void LiveRangeCalc::updateLiveIns(VNInfo *OverrideVNI) {
 
 
 void LiveRangeCalc::extend(LiveInterval *LI,
-                           SlotIndex Kill) {
+                           SlotIndex Kill,
+                           unsigned PhysReg) {
   assert(LI && "Missing live range");
   assert(Kill.isValid() && "Invalid SlotIndex");
   assert(Indexes && "Missing SlotIndexes");
@@ -146,7 +150,7 @@ void LiveRangeCalc::extend(LiveInterval *LI,
   // multiple values, and we may need to create even more phi-defs to preserve
   // VNInfo SSA form.  Perform a search for all predecessor blocks where we
   // know the dominating VNInfo.
-  VNInfo *VNI = findReachingDefs(LI, KillMBB, Kill);
+  VNInfo *VNI = findReachingDefs(LI, KillMBB, Kill, PhysReg);
 
   // When there were multiple different values, we may need new PHIs.
   if (!VNI)
@@ -169,7 +173,8 @@ void LiveRangeCalc::calculateValues() {
 
 VNInfo *LiveRangeCalc::findReachingDefs(LiveInterval *LI,
                                         MachineBasicBlock *KillMBB,
-                                        SlotIndex Kill) {
+                                        SlotIndex Kill,
+                                        unsigned PhysReg) {
   // Blocks where LI should be live-in.
   SmallVector<MachineBasicBlock*, 16> WorkList(1, KillMBB);
 
@@ -180,7 +185,22 @@ VNInfo *LiveRangeCalc::findReachingDefs(LiveInterval *LI,
   // Using Seen as a visited set, perform a BFS for all reaching defs.
   for (unsigned i = 0; i != WorkList.size(); ++i) {
     MachineBasicBlock *MBB = WorkList[i];
-    assert(!MBB->pred_empty() && "Value live-in to entry block?");
+
+#ifndef NDEBUG
+    if (MBB->pred_empty()) {
+      MBB->getParent()->verify();
+      llvm_unreachable("Use not jointly dominated by defs.");
+    }
+
+    if (TargetRegisterInfo::isPhysicalRegister(PhysReg) &&
+        !MBB->isLiveIn(PhysReg)) {
+      MBB->getParent()->verify();
+      errs() << "The register needs to be live in to BB#" << MBB->getNumber()
+             << ", but is missing from the live-in list.\n";
+      llvm_unreachable("Invalid global physical register");
+    }
+#endif
+
     for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
            PE = MBB->pred_end(); PI != PE; ++PI) {
        MachineBasicBlock *Pred = *PI;
@@ -303,7 +323,6 @@ void LiveRangeCalc::updateSSA() {
         SlotIndex Start, End;
         tie(Start, End) = Indexes->getMBBRange(MBB);
         VNInfo *VNI = I->LI->getNextValue(Start, *Alloc);
-        VNI->setIsPHIDef(true);
         I->Value = VNI;
         // This block is done, we know the final value.
         I->DomNode = 0;