Rewrite part of the SSAUpdater to be more careful about inserting redundant

[oota-llvm.git] / lib / Transforms / Utils / LoopUnroll.cpp

diff --git a/lib/Transforms/Utils/LoopUnroll.cpp b/lib/Transforms/Utils/LoopUnroll.cpp
index 3c58abe37e08d6d0f5f23047d1355a7728dabf96..ac59b4d7b3e8ec18dfcb9ffe7e86049424db5e0d 100644 (file)
--- a/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/lib/Transforms/Utils/LoopUnroll.cpp
@@ -29,7 +29,6 @@
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/Local.h"
-#include <cstdio>
 
 using namespace llvm;
 
@@ -63,7 +62,7 @@ static BasicBlock *FoldBlockIntoPredecessor(BasicBlock *BB, LoopInfo* LI) {
   if (OnlyPred->getTerminator()->getNumSuccessors() != 1)
     return 0;
 
-  DEBUG(errs() << "Merging: " << *BB << "into: " << *OnlyPred);
+  DEBUG(dbgs() << "Merging: " << *BB << "into: " << *OnlyPred);
 
   // Resolve any PHI nodes at the start of the block.  They are all
   // guaranteed to have exactly one entry if they exist, unless there are
@@ -106,17 +105,15 @@ static BasicBlock *FoldBlockIntoPredecessor(BasicBlock *BB, LoopInfo* LI) {
 /// If a LoopPassManager is passed in, and the loop is fully removed, it will be
 /// removed from the LoopPassManager as well. LPM can also be NULL.
 bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM) {
-  assert(L->isLCSSAForm());
-
   BasicBlock *Preheader = L->getLoopPreheader();
   if (!Preheader) {
-    DEBUG(errs() << "  Can't unroll; loop preheader-insertion failed.\n");
+    DEBUG(dbgs() << "  Can't unroll; loop preheader-insertion failed.\n");
     return false;
   }
 
   BasicBlock *LatchBlock = L->getLoopLatch();
   if (!LatchBlock) {
-    DEBUG(errs() << "  Can't unroll; loop exit-block-insertion failed.\n");
+    DEBUG(dbgs() << "  Can't unroll; loop exit-block-insertion failed.\n");
     return false;
   }
 
@@ -125,7 +122,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
   
   if (!BI || BI->isUnconditional()) {
     // The loop-rotate pass can be helpful to avoid this in many cases.
-    DEBUG(errs() <<
+    DEBUG(dbgs() <<
              "  Can't unroll; loop not terminated by a conditional branch.\n");
     return false;
   }
@@ -138,9 +135,9 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
     TripMultiple = L->getSmallConstantTripMultiple();
 
   if (TripCount != 0)
-    DEBUG(errs() << "  Trip Count = " << TripCount << "\n");
+    DEBUG(dbgs() << "  Trip Count = " << TripCount << "\n");
   if (TripMultiple != 1)
-    DEBUG(errs() << "  Trip Multiple = " << TripMultiple << "\n");
+    DEBUG(dbgs() << "  Trip Multiple = " << TripMultiple << "\n");
 
   // Effectively "DCE" unrolled iterations that are beyond the tripcount
   // and will never be executed.
@@ -166,17 +163,17 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
   }
 
   if (CompletelyUnroll) {
-    DEBUG(errs() << "COMPLETELY UNROLLING loop %" << Header->getName()
+    DEBUG(dbgs() << "COMPLETELY UNROLLING loop %" << Header->getName()
           << " with trip count " << TripCount << "!\n");
   } else {
-    DEBUG(errs() << "UNROLLING loop %" << Header->getName()
+    DEBUG(dbgs() << "UNROLLING loop %" << Header->getName()
           << " by " << Count);
     if (TripMultiple == 0 || BreakoutTrip != TripMultiple) {
-      DEBUG(errs() << " with a breakout at trip " << BreakoutTrip);
+      DEBUG(dbgs() << " with a breakout at trip " << BreakoutTrip);
     } else if (TripMultiple != 1) {
-      DEBUG(errs() << " with " << TripMultiple << " trips per branch");
+      DEBUG(dbgs() << " with " << TripMultiple << " trips per branch");
     }
-    DEBUG(errs() << "!\n");
+    DEBUG(dbgs() << "!\n");
   }
 
   std::vector<BasicBlock*> LoopBlocks = L->getBlocks();
@@ -194,7 +191,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
     OrigPHINode.push_back(PN);
     if (Instruction *I = 
                 dyn_cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)))
-      if (L->contains(I->getParent()))
+      if (L->contains(I))
         LastValueMap[I] = I;
   }
 
@@ -204,15 +201,12 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
   Latches.push_back(LatchBlock);
 
   for (unsigned It = 1; It != Count; ++It) {
-    char SuffixBuffer[100];
-    sprintf(SuffixBuffer, ".%d", It);
-    
     std::vector<BasicBlock*> NewBlocks;
     
     for (std::vector<BasicBlock*>::iterator BB = LoopBlocks.begin(),
          E = LoopBlocks.end(); BB != E; ++BB) {
       ValueMapTy ValueMap;
-      BasicBlock *New = CloneBasicBlock(*BB, ValueMap, SuffixBuffer);
+      BasicBlock *New = CloneBasicBlock(*BB, ValueMap, "." + Twine(It));
       Header->getParent()->getBasicBlockList().push_back(New);
 
       // Loop over all of the PHI nodes in the block, changing them to use the
@@ -222,7 +216,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
           PHINode *NewPHI = cast<PHINode>(ValueMap[OrigPHINode[i]]);
           Value *InVal = NewPHI->getIncomingValueForBlock(LatchBlock);
           if (Instruction *InValI = dyn_cast<Instruction>(InVal))
-            if (It > 1 && L->contains(InValI->getParent()))
+            if (It > 1 && L->contains(InValI))
               InVal = LastValueMap[InValI];
           ValueMap[OrigPHINode[i]] = InVal;
           New->getInstList().erase(NewPHI);
@@ -244,7 +238,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
              UI != UE;) {
           Instruction *UseInst = cast<Instruction>(*UI);
           ++UI;
-          if (isa<PHINode>(UseInst) && !L->contains(UseInst->getParent())) {
+          if (isa<PHINode>(UseInst) && !L->contains(UseInst)) {
             PHINode *phi = cast<PHINode>(UseInst);
             Value *Incoming = phi->getIncomingValueForBlock(*BB);
             phi->addIncoming(Incoming, New);
@@ -295,7 +289,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
       // If this value was defined in the loop, take the value defined by the
       // last iteration of the loop.
       if (Instruction *InValI = dyn_cast<Instruction>(InVal)) {
-        if (L->contains(InValI->getParent()))
+        if (L->contains(InValI))
           InVal = LastValueMap[InVal];
       }
       PN->addIncoming(InVal, LastIterationBB);
@@ -362,8 +356,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
 
       if (isInstructionTriviallyDead(Inst))
         (*BB)->getInstList().erase(Inst);
-      else if (Constant *C = ConstantFoldInstruction(Inst, 
-                                                     Header->getContext())) {
+      else if (Constant *C = ConstantFoldInstruction(Inst)) {
         Inst->replaceAllUsesWith(C);
         (*BB)->getInstList().erase(Inst);
       }
@@ -375,9 +368,5 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
   if (CompletelyUnroll && LPM != NULL)
     LPM->deleteLoopFromQueue(L);
 
-  // If we didn't completely unroll the loop, it should still be in LCSSA form.
-  if (!CompletelyUnroll)
-    assert(L->isLCSSAForm());
-
   return true;
 }