Clean up the Spiller.h interface.

The earliestStart argument is entirely specific to linear scan allocation, and
can be easily calculated by RegAllocLinearScan.

Replace std::vector with SmallVector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111055 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/InlineSpiller.cpp

@@ -45,7 +45,7 @@ class InlineSpiller : public Spiller {
 
   // Variables that are valid during spill(), but used by multiple methods.
   LiveInterval *li_;
-  std::vector<LiveInterval*> *newIntervals_;
+  SmallVectorImpl<LiveInterval*> *newIntervals_;
   const TargetRegisterClass *rc_;
   int stackSlot_;
   const SmallVectorImpl<LiveInterval*> *spillIs_;
@@ -75,9 +75,8 @@ public:
       splitAnalysis_(mf, lis_, loops_) {}
 
   void spill(LiveInterval *li,
-             std::vector<LiveInterval*> &newIntervals,
-             SmallVectorImpl<LiveInterval*> &spillIs,
-             SlotIndex *earliestIndex);
+             SmallVectorImpl<LiveInterval*> &newIntervals,
+             SmallVectorImpl<LiveInterval*> &spillIs);
 
 private:
   bool split();
@@ -388,9 +387,8 @@ void InlineSpiller::insertSpill(LiveInterval &NewLI,
 }
 
 void InlineSpiller::spill(LiveInterval *li,
-                          std::vector<LiveInterval*> &newIntervals,
-                          SmallVectorImpl<LiveInterval*> &spillIs,
-                          SlotIndex *earliestIndex) {
+                          SmallVectorImpl<LiveInterval*> &newIntervals,
+                          SmallVectorImpl<LiveInterval*> &spillIs) {
   DEBUG(dbgs() << "Inline spilling " << *li << "\n");
   assert(li->isSpillable() && "Attempting to spill already spilled value.");
   assert(!li->isStackSlot() && "Trying to spill a stack slot.");

lib/CodeGen/RegAllocLinearScan.cpp

@@ -1202,8 +1202,7 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur) {
   // linearscan.
   if (cur->weight != HUGE_VALF && cur->weight <= minWeight) {
     DEBUG(dbgs() << "\t\t\tspilling(c): " << *cur << '\n');
-    SmallVector<LiveInterval*, 8> spillIs;
-    std::vector<LiveInterval*> added;
+    SmallVector<LiveInterval*, 8> spillIs, added;
     spiller_->spill(cur, added, spillIs);
 
     std::sort(added.begin(), added.end(), LISorter());
@@ -1268,25 +1267,31 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur) {
   // in handled we need to roll back
   assert(!spillIs.empty() && "No spill intervals?"); 
   SlotIndex earliestStart = spillIs[0]->beginIndex();
-  
+
   // Spill live intervals of virtual regs mapped to the physical register we
   // want to clear (and its aliases).  We only spill those that overlap with the
   // current interval as the rest do not affect its allocation. we also keep
   // track of the earliest start of all spilled live intervals since this will
   // mark our rollback point.
-  std::vector<LiveInterval*> added;
+  SmallVector<LiveInterval*, 8> added;
   while (!spillIs.empty()) {
     LiveInterval *sli = spillIs.back();
     spillIs.pop_back();
     DEBUG(dbgs() << "\t\t\tspilling(a): " << *sli << '\n');
     if (sli->beginIndex() < earliestStart)
       earliestStart = sli->beginIndex();
-       
-    spiller_->spill(sli, added, spillIs, &earliestStart);
+    spiller_->spill(sli, added, spillIs);
     addStackInterval(sli, ls_, li_, mri_, *vrm_);
     spilled.insert(sli->reg);
   }
 
+  // Include any added intervals in earliestStart.
+  for (unsigned i = 0, e = added.size(); i != e; ++i) {
+    SlotIndex SI = added[i]->beginIndex();
+    if (SI < earliestStart)
+      earliestStart = SI;
+  }
+
   DEBUG(dbgs() << "\t\trolling back to: " << earliestStart << '\n');
 
   // Scan handled in reverse order up to the earliest start of a

lib/CodeGen/Spiller.cpp

@@ -74,7 +74,7 @@ protected:
   /// immediately before each use, and stores after each def. No folding or
   /// remat is attempted.
   void trivialSpillEverywhere(LiveInterval *li,
-                              std::vector<LiveInterval*> &newIntervals) {
+                              SmallVectorImpl<LiveInterval*> &newIntervals) {
     DEBUG(dbgs() << "Spilling everywhere " << *li << "\n");
 
     assert(li->weight != HUGE_VALF &&
@@ -181,9 +181,8 @@ public:
     : SpillerBase(pass, mf, vrm) {}
 
   void spill(LiveInterval *li,
-             std::vector<LiveInterval*> &newIntervals,
-             SmallVectorImpl<LiveInterval*> &,
-             SlotIndex*) {
+             SmallVectorImpl<LiveInterval*> &newIntervals,
+             SmallVectorImpl<LiveInterval*> &) {
     // Ignore spillIs - we don't use it.
     trivialSpillEverywhere(li, newIntervals);
   }
@@ -208,9 +207,8 @@ public:
 
   /// Falls back on LiveIntervals::addIntervalsForSpills.
   void spill(LiveInterval *li,
-             std::vector<LiveInterval*> &newIntervals,
-             SmallVectorImpl<LiveInterval*> &spillIs,
-             SlotIndex*) {
+             SmallVectorImpl<LiveInterval*> &newIntervals,
+             SmallVectorImpl<LiveInterval*> &spillIs) {
     std::vector<LiveInterval*> added =
       lis->addIntervalsForSpills(*li, spillIs, loopInfo, *vrm);
     newIntervals.insert(newIntervals.end(), added.begin(), added.end());
@@ -236,13 +234,12 @@ public:
   }
 
   void spill(LiveInterval *li,
-             std::vector<LiveInterval*> &newIntervals,
-             SmallVectorImpl<LiveInterval*> &spillIs,
-             SlotIndex *earliestStart) {
+             SmallVectorImpl<LiveInterval*> &newIntervals,
+             SmallVectorImpl<LiveInterval*> &spillIs) {
     if (worthTryingToSplit(li))
-      tryVNISplit(li, earliestStart);
+      tryVNISplit(li);
     else
-      StandardSpiller::spill(li, newIntervals, spillIs, earliestStart);
+      StandardSpiller::spill(li, newIntervals, spillIs);
   }
 
 private:
@@ -257,8 +254,7 @@ private:
   }
 
   /// Try to break a LiveInterval into its component values.
-  std::vector<LiveInterval*> tryVNISplit(LiveInterval *li,
-                                         SlotIndex *earliestStart) {
+  std::vector<LiveInterval*> tryVNISplit(LiveInterval *li) {
 
     DEBUG(dbgs() << "Trying VNI split of %reg" << *li << "\n");
 
@@ -282,10 +278,6 @@ private:
         DEBUG(dbgs() << *splitInterval << "\n");
         added.push_back(splitInterval);
         alreadySplit.insert(splitInterval);
-        if (earliestStart != 0) {
-          if (splitInterval->beginIndex() < *earliestStart)
-            *earliestStart = splitInterval->beginIndex();
-        }
       } else {
         DEBUG(dbgs() << "0\n");
       }
@@ -298,10 +290,6 @@ private:
     if (!li->empty()) {
       added.push_back(li);
       alreadySplit.insert(li);
-      if (earliestStart != 0) {
-        if (li->beginIndex() < *earliestStart)
-          *earliestStart = li->beginIndex();
-      }
     }
 
     return added;

lib/CodeGen/Spiller.h

@@ -11,7 +11,6 @@
 #define LLVM_CODEGEN_SPILLER_H
 
 #include "llvm/ADT/SmallVector.h"
-#include <vector>
 
 namespace llvm {
 
@@ -36,12 +35,9 @@ namespace llvm {
     /// @param spillIs       A list of intervals that are about to be spilled,
     ///                      and so cannot be used for remat etc.
     /// @param newIntervals  The newly created intervals will be appended here.
-    /// @param earliestIndex The earliest point for splitting. (OK, it's another
-    ///                      pointer to the allocator guts).
     virtual void spill(LiveInterval *li,
-                       std::vector<LiveInterval*> &newIntervals,
-                       SmallVectorImpl<LiveInterval*> &spillIs,
-                       SlotIndex *earliestIndex = 0) = 0;
+                       SmallVectorImpl<LiveInterval*> &newIntervals,
+                       SmallVectorImpl<LiveInterval*> &spillIs) = 0;
 
   };
 

lib/CodeGen/SplitKit.cpp

@@ -342,7 +342,7 @@ bool SplitAnalysis::getMultiUseBlocks(BlockPtrSet &Blocks) {
 
 /// Create a new SplitEditor for editing the LiveInterval analyzed by SA.
 SplitEditor::SplitEditor(SplitAnalysis &sa, LiveIntervals &lis, VirtRegMap &vrm,
-                         std::vector<LiveInterval*> &intervals)
+                         SmallVectorImpl<LiveInterval*> &intervals)
   : sa_(sa), lis_(lis), vrm_(vrm),
     mri_(vrm.getMachineFunction().getRegInfo()),
     tii_(*vrm.getMachineFunction().getTarget().getInstrInfo()),

lib/CodeGen/SplitKit.h

@@ -183,7 +183,7 @@ class SplitEditor {
   bool liveThrough_;
 
   /// All the new intervals created for this split are added to intervals_.
-  std::vector<LiveInterval*> &intervals_;
+  SmallVectorImpl<LiveInterval*> &intervals_;
 
   /// The index into intervals_ of the first interval we added. There may be
   /// others from before we got it.
@@ -199,7 +199,7 @@ public:
   /// Create a new SplitEditor for editing the LiveInterval analyzed by SA.
   /// Newly created intervals will be appended to newIntervals.
   SplitEditor(SplitAnalysis &SA, LiveIntervals&, VirtRegMap&,
-              std::vector<LiveInterval*> &newIntervals);
+              SmallVectorImpl<LiveInterval*> &newIntervals);
 
   /// getAnalysis - Get the corresponding analysis.
   SplitAnalysis &getAnalysis() { return sa_; }