X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FCodeGen%2FLiveIntervalAnalysis.h;h=9673f80e0856678b2f14d9ab4bdcf8ed351614d9;hb=1f7a90d7936a9a6278365ea8b0521c7ff17432c3;hp=f6c5a3c0b2c3271217d00348ab246ce6d56cd635;hpb=4402447964e1678fedb5e916f1e8d3e5ce807bd3;p=oota-llvm.git

diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index f6c5a3c0b2c..9673f80e085 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -27,12 +27,15 @@
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/Support/Allocator.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include <cmath>
 #include <iterator>
 
 namespace llvm {
 
+extern cl::opt<bool> UseSegmentSetForPhysRegs;
+
   class AliasAnalysis;
   class BitVector;
   class BlockFrequency;
@@ -97,7 +100,7 @@ namespace llvm {
   public:
     static char ID; // Pass identification, replacement for typeid
     LiveIntervals();
-    virtual ~LiveIntervals();
+    ~LiveIntervals() override;
 
     // Calculate the spill weight to assign to a single instruction.
     static float getSpillWeight(bool isDef, bool isUse,
@@ -154,6 +157,12 @@ namespace llvm {
     bool shrinkToUses(LiveInterval *li,
                       SmallVectorImpl<MachineInstr*> *dead = nullptr);
 
+    /// Specialized version of
+    /// shrinkToUses(LiveInterval *li, SmallVectorImpl<MachineInstr*> *dead)
+    /// that works on a subregister live range and only looks at uses matching
+    /// the lane mask of the subregister range.
+    void shrinkToUses(LiveInterval::SubRange &SR, unsigned Reg);
+
     /// extendToIndices - Extend the live range of LI to reach all points in
     /// Indices. The points in the Indices array must be jointly dominated by
     /// existing defs in LI. PHI-defs are added as needed to maintain SSA form.
@@ -164,14 +173,15 @@ namespace llvm {
     /// See also LiveRangeCalc::extend().
     void extendToIndices(LiveRange &LR, ArrayRef<SlotIndex> Indices);
 
-    /// pruneValue - If an LI value is live at Kill, prune its live range by
-    /// removing any liveness reachable from Kill. Add live range end points to
+
+    /// If @p LR has a live value at @p Kill, prune its live range by removing
+    /// any liveness reachable from Kill. Add live range end points to
     /// EndPoints such that extendToIndices(LI, EndPoints) will reconstruct the
     /// value's live range.
     ///
     /// Calling pruneValue() and extendToIndices() can be used to reconstruct
     /// SSA form after adding defs to a virtual register.
-    void pruneValue(LiveInterval *LI, SlotIndex Kill,
+    void pruneValue(LiveRange &LR, SlotIndex Kill,
                     SmallVectorImpl<SlotIndex> *EndPoints);
 
     SlotIndexes *getSlotIndexes() const {
@@ -370,7 +380,8 @@ namespace llvm {
       LiveRange *LR = RegUnitRanges[Unit];
       if (!LR) {
         // Compute missing ranges on demand.
-        RegUnitRanges[Unit] = LR = new LiveRange();
+        // Use segment set to speed-up initial computation of the live range.
+        RegUnitRanges[Unit] = LR = new LiveRange(UseSegmentSetForPhysRegs);
         computeRegUnitRange(*LR, Unit);
       }
       return *LR;
@@ -386,6 +397,15 @@ namespace llvm {
       return RegUnitRanges[Unit];
     }
 
+    /// Remove value numbers and related live segments starting at position
+    /// @p Pos that are part of any liverange of physical register @p Reg or one
+    /// of its subregisters.
+    void removePhysRegDefAt(unsigned Reg, SlotIndex Pos);
+
+    /// Remove value number and related live segments of @p LI and its subranges
+    /// that start at position @p Pos.
+    void removeVRegDefAt(LiveInterval &LI, SlotIndex Pos);
+
   private:
     /// Compute live intervals for all virtual registers.
     void computeVirtRegs();
@@ -393,17 +413,15 @@ namespace llvm {
     /// Compute RegMaskSlots and RegMaskBits.
     void computeRegMasks();
 
-    /// \brief Walk the values in the @p LR live range and compute which ones
-    /// are dead in live range @p Segments.  Dead values are not deleted,
-    /// however:
+    /// Walk the values in @p LI and check for dead values:
     /// - Dead PHIDef values are marked as unused.
-    /// - if @p dead != nullptr then dead operands are marked as such and
-    ///   completely dead machine instructions are added to the @p dead vector.
-    /// - CanSeparate is set to true if the interval may have been separated
-    ///   into multiple connected components.
-    void computeDeadValues(LiveRange &Segments, LiveRange &LR,
-                           bool *CanSeparate = nullptr, unsigned Reg = 0,
-                           SmallVectorImpl<MachineInstr*> *dead = nullptr);
+    /// - Dead operands are marked as such.
+    /// - Completely dead machine instructions are added to the @p dead vector
+    ///   if it is not nullptr.
+    /// Returns true if any PHI value numbers have been removed which may
+    /// have separated the interval into multiple connected components.
+    bool computeDeadValues(LiveInterval &LI,
+                           SmallVectorImpl<MachineInstr*> *dead);
 
     static LiveInterval* createInterval(unsigned Reg);
 
@@ -414,11 +432,6 @@ namespace llvm {
     void computeRegUnitRange(LiveRange&, unsigned Unit);
     void computeVirtRegInterval(LiveInterval&);
 
-    /// Specialized version of
-    /// shrinkToUses(LiveInterval *li, SmallVectorImpl<MachineInstr*> *dead)
-    /// that works on a subregister live range and only looks at uses matching
-    /// the lane mask of the subregister range.
-    bool shrinkToUses(LiveInterval::SubRange &SR, unsigned Reg);
 
     /// Helper function for repairIntervalsInRange(), walks backwards and
     /// creates/modifies live segments in @p LR to match the operands found.