commit 3081b0f5ec95a150a88ae9f80b079c42d686eea3
author Tobias Grosser <grosser@fim.uni-passau.de> Thu May 16 06:40:24 2013 +0000
committer Tobias Grosser <grosser@fim.uni-passau.de> Thu May 16 06:40:24 2013 +0000
tree 88eac20e4bdecb92a81b9dd5a193dfa25e46a47c
parent 5db6ffd76f50e58467530c63feb098d2ec59410e

Update LoopInfo correctly

When the Polly code generation was written we did not correctly update the
LoopInfo data, but still claimed that the loop information is correct. This
does not only lead to missed optimizations, but it can also cause
miscompilations in case passes such as LoopSimplify are run after Polly.

Reported-by: Sergei Larin <slarin@codeaurora.org>
llvm-svn: 181987

polly/lib/CodeGen/CodeGeneration.cpp

diff --git a/polly/lib/CodeGen/CodeGeneration.cpp b/polly/lib/CodeGen/CodeGeneration.cpp
index 06f0fa7..753942f 100644
--- a/polly/lib/CodeGen/CodeGeneration.cpp
+++ b/polly/lib/CodeGen/CodeGeneration.cpp
@@ -924,6 +924,13 @@
   Builder.CreateBr(MergeBB);
   Builder.SetInsertPoint(ThenBB->begin());
 
+  LoopInfo &LI = P->getAnalysis<LoopInfo>();
+  Loop *L = LI.getLoopFor(CondBB);
+  if (L) {
+    L->addBasicBlockToLoop(ThenBB, LI.getBase());
+    L->addBasicBlockToLoop(MergeBB, LI.getBase());
+  }
+
   codegen(g->then);
 
   Builder.SetInsertPoint(MergeBB->begin());
@@ -1030,8 +1037,6 @@
 
     AU.addPreserved<CloogInfo>();
     AU.addPreserved<Dependences>();
-
-    // FIXME: We do not create LoopInfo for the newly generated loops.
     AU.addPreserved<LoopInfo>();
     AU.addPreserved<DominatorTree>();
     AU.addPreserved<ScopDetection>();

polly/lib/CodeGen/IslCodeGeneration.cpp

diff --git a/polly/lib/CodeGen/IslCodeGeneration.cpp b/polly/lib/CodeGen/IslCodeGeneration.cpp
index 136a873..d5c3a9f 100644
--- a/polly/lib/CodeGen/IslCodeGeneration.cpp
+++ b/polly/lib/CodeGen/IslCodeGeneration.cpp
@@ -860,6 +860,13 @@
   DT.addNewBlock(ElseBB, CondBB);
   DT.changeImmediateDominator(MergeBB, CondBB);
 
+  LoopInfo &LI = P->getAnalysis<LoopInfo>();
+  Loop *L = LI.getLoopFor(CondBB);
+  if (L) {
+    L->addBasicBlockToLoop(ThenBB, LI.getBase());
+    L->addBasicBlockToLoop(ElseBB, LI.getBase());
+  }
+
   CondBB->getTerminator()->eraseFromParent();
 
   Builder.SetInsertPoint(CondBB);
@@ -1051,7 +1058,6 @@
 
     AU.addPreserved<Dependences>();
 
-    // FIXME: We do not create LoopInfo for the newly generated loops.
     AU.addPreserved<LoopInfo>();
     AU.addPreserved<DominatorTree>();
     AU.addPreserved<IslAstInfo>();

polly/lib/CodeGen/LoopGenerators.cpp

diff --git a/polly/lib/CodeGen/LoopGenerators.cpp b/polly/lib/CodeGen/LoopGenerators.cpp
index 881a0ac..da0c782 100644
--- a/polly/lib/CodeGen/LoopGenerators.cpp
+++ b/polly/lib/CodeGen/LoopGenerators.cpp
@@ -15,6 +15,7 @@
 #include "polly/ScopDetection.h"
 #include "polly/CodeGen/LoopGenerators.h"
 #include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/LoopInfo.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
@@ -50,6 +51,7 @@
                          ICmpInst::Predicate Predicate) {
 
   DominatorTree &DT = P->getAnalysis<DominatorTree>();
+  LoopInfo &LI = P->getAnalysis<LoopInfo>();
   Function *F = Builder.GetInsertBlock()->getParent();
   LLVMContext &Context = F->getContext();
 
@@ -63,6 +65,23 @@
   BasicBlock *PreHeaderBB =
       BasicBlock::Create(Context, "polly.loop_preheader", F);
 
+  // Update LoopInfo
+  Loop *OuterLoop = LI.getLoopFor(BeforeBB);
+  Loop *NewLoop = new Loop();
+
+  if (OuterLoop) {
+    OuterLoop->addChildLoop(NewLoop);
+  } else {
+    LI.addTopLevelLoop(NewLoop);
+  }
+
+  if (OuterLoop) {
+    OuterLoop->addBasicBlockToLoop(GuardBB, LI.getBase());
+    OuterLoop->addBasicBlockToLoop(PreHeaderBB, LI.getBase());
+  }
+
+  NewLoop->addBasicBlockToLoop(HeaderBB, LI.getBase());
+
   // ExitBB
   ExitBB = SplitBlock(BeforeBB, Builder.GetInsertPoint()++, P);
   ExitBB->setName("polly.loop_exit");