IR: Properly return nullptr when getAggregateElement is out-of-bounds

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

diff --git a/lib/CodeGen/LiveRangeCalc.h b/lib/CodeGen/LiveRangeCalc.h
index 913d09edbdd0ddd1791819c9712af20a9df993f7..1b9099b5fc7e7a05b127ab39e8ae38ccc51d4a15 100644 (file)
--- a/lib/CodeGen/LiveRangeCalc.h
+++ b/lib/CodeGen/LiveRangeCalc.h
@@ -47,14 +47,14 @@ class LiveRangeCalc {
   /// LiveOutMap - Map basic blocks to the value leaving the block.
   typedef IndexedMap<LiveOutPair, MBB2NumberFunctor> LiveOutMap;
 
-  /// Seen - Bit vector of active entries in LiveOut, also used as a visited
-  /// set by findReachingDefs.  One entry per basic block, indexed by block
-  /// number.  This is kept as a separate bit vector because it can be cleared
-  /// quickly when switching live ranges.
+  /// Bit vector of active entries in LiveOut, also used as a visited set by
+  /// findReachingDefs.  One entry per basic block, indexed by block number.
+  /// This is kept as a separate bit vector because it can be cleared quickly
+  /// when switching live ranges.
   BitVector Seen;
 
-  /// LiveOut - Map each basic block where a live range is live out to the
-  /// live-out value and its defining block.
+  /// Map each basic block where a live range is live out to the live-out value
+  /// and its defining block.
   ///
   /// For every basic block, MBB, one of these conditions shall be true:
   ///
@@ -129,7 +129,10 @@ class LiveRangeCalc {
   ///
   /// All uses must be jointly dominated by existing liveness.  PHI-defs are
   /// inserted as needed to preserve SSA form.
-  void extendToUses(LiveRange &LR, unsigned Reg, unsigned LaneMask = ~0u);
+  void extendToUses(LiveRange &LR, unsigned Reg, unsigned LaneMask);
+
+  /// Reset Map and Seen fields.
+  void resetLiveOutMap();
 
 public:
   LiveRangeCalc() : MF(nullptr), MRI(nullptr), Indexes(nullptr),
@@ -169,9 +172,18 @@ public:
   /// PhysReg, when set, is used to verify live-in lists on basic blocks.
   void extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg = 0);
 
-  /// Calculates liveness for the uses/defs of a given registers.  The results
-  /// are written to @p LR.
-  void calculate(LiveRange &LR, unsigned Reg, bool IgnoreUses);
+  /// createDeadDefs - Create a dead def in LI for every def operand of Reg.
+  /// Each instruction defining Reg gets a new VNInfo with a corresponding
+  /// minimal live range.
+  void createDeadDefs(LiveRange &LR, unsigned Reg);
+
+  /// Extend the live range of @p LR to reach all uses of Reg.
+  ///
+  /// All uses must be jointly dominated by existing liveness.  PHI-defs are
+  /// inserted as needed to preserve SSA form.
+  void extendToUses(LiveRange &LR, unsigned PhysReg) {
+    extendToUses(LR, PhysReg, ~0u);
+  }
 
   /// Calculates liveness for the register specified in live interval @p LI.
   /// Creates subregister live ranges as needed if subreg liveness tracking is