Rip out live range splitting support from the inline spiller.

The spiller should only spill. The register allocator will drive live range
splitting, it has the needed information about register pressure and
interferences.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121590 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 56 deletions

diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp
index 7e4fbadea4..f18c8ddef5 100644
--- a/lib/CodeGen/InlineSpiller.cpp
+++ b/lib/CodeGen/InlineSpiller.cpp
@@ -15,15 +15,12 @@
 #define DEBUG_TYPE "regalloc"
 #include "Spiller.h"
 #include "LiveRangeEdit.h"
-#include "SplitKit.h"
 #include "VirtRegMap.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
 #include "llvm/CodeGen/LiveStackAnalysis.h"
-#include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetInstrInfo.h"
@@ -36,18 +33,12 @@ using namespace llvm;
 static cl::opt<bool>
 VerifySpills("verify-spills", cl::desc("Verify after each spill/split"));
 
-static cl::opt<bool>
-ExtraSpillerSplits("extra-spiller-splits",
-                   cl::desc("Enable additional splitting during splitting"));
-
 namespace {
 class InlineSpiller : public Spiller {
   MachineFunctionPass &pass_;
   MachineFunction &mf_;
   LiveIntervals &lis_;
   LiveStacks &lss_;
-  MachineDominatorTree &mdt_;
-  MachineLoopInfo &loops_;
   AliasAnalysis *aa_;
   VirtRegMap &vrm_;
   MachineFrameInfo &mfi_;
@@ -56,8 +47,6 @@ class InlineSpiller : public Spiller {
   const TargetRegisterInfo &tri_;
   const BitVector reserved_;
 
-  SplitAnalysis splitAnalysis_;
-
   // Variables that are valid during spill(), but used by multiple methods.
   LiveRangeEdit *edit_;
   const TargetRegisterClass *rc_;
@@ -76,16 +65,13 @@ public:
       mf_(mf),
       lis_(pass.getAnalysis<LiveIntervals>()),
       lss_(pass.getAnalysis<LiveStacks>()),
-      mdt_(pass.getAnalysis<MachineDominatorTree>()),
-      loops_(pass.getAnalysis<MachineLoopInfo>()),
       aa_(&pass.getAnalysis<AliasAnalysis>()),
       vrm_(vrm),
       mfi_(*mf.getFrameInfo()),
       mri_(mf.getRegInfo()),
       tii_(*mf.getTarget().getInstrInfo()),
       tri_(*mf.getTarget().getRegisterInfo()),
-      reserved_(tri_.getReservedRegs(mf_)),
-      splitAnalysis_(mf, lis_, loops_) {}
+      reserved_(tri_.getReservedRegs(mf_)) {}
 
   void spill(LiveInterval *li,
              SmallVectorImpl<LiveInterval*> &newIntervals,
@@ -94,8 +80,6 @@ public:
   void spill(LiveRangeEdit &);
 
 private:
-  bool split();
-
   bool reMaterializeFor(MachineBasicBlock::iterator MI);
   void reMaterializeAll();
 
@@ -117,42 +101,6 @@ Spiller *createInlineSpiller(MachineFunctionPass &pass,
 }
 }
 
-/// split - try splitting the current interval into pieces that may allocate
-/// separately. Return true if successful.
-bool InlineSpiller::split() {
-  splitAnalysis_.analyze(&edit_->getParent());
-
-  // Try splitting around loops.
-  if (ExtraSpillerSplits) {
-    const MachineLoop *loop = splitAnalysis_.getBestSplitLoop();
-    if (loop) {
-      SplitEditor(splitAnalysis_, lis_, vrm_, mdt_, *edit_)
-        .splitAroundLoop(loop);
-      return true;
-    }
-  }
-
-  // Try splitting into single block intervals.
-  SplitAnalysis::BlockPtrSet blocks;
-  if (splitAnalysis_.getMultiUseBlocks(blocks)) {
-    SplitEditor(splitAnalysis_, lis_, vrm_, mdt_, *edit_)
-      .splitSingleBlocks(blocks);
-    return true;
-  }
-
-  // Try splitting inside a basic block.
-  if (ExtraSpillerSplits) {
-    const MachineBasicBlock *MBB = splitAnalysis_.getBlockForInsideSplit();
-    if (MBB){
-      SplitEditor(splitAnalysis_, lis_, vrm_, mdt_, *edit_)
-        .splitInsideBlock(MBB);
-      return true;
-    }
-  }
-
-  return false;
-}
-
 /// reMaterializeFor - Attempt to rematerialize edit_->getReg() before MI instead of
 /// reloading it.
 bool InlineSpiller::reMaterializeFor(MachineBasicBlock::iterator MI) {
@@ -377,9 +325,6 @@ void InlineSpiller::spill(LiveRangeEdit &edit) {
   assert(edit.getParent().isSpillable() &&
          "Attempting to spill already spilled value.");
 
-  if (split())
-    return;
-
   reMaterializeAll();
 
   // Remat may handle everything.