Use names instead of numbers for some of the magic

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

diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp
index 7d4f3a343e6253e6cd247c6a51863da31353e8d0..48e6a17a0661f8b69912337fccbe6713fc3378f3 100644 (file)
--- a/lib/Transforms/Utils/LCSSA.cpp
+++ b/lib/Transforms/Utils/LCSSA.cpp
@@ -33,6 +33,7 @@
 #include "llvm/Pass.h"
 #include "llvm/Function.h"
 #include "llvm/Instructions.h"
+#include "llvm/LLVMContext.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/Dominators.h"
@@ -57,6 +58,7 @@ namespace {
     DominatorTree *DT;
     std::vector<BasicBlock*> LoopBlocks;
     PredIteratorCache PredCache;
+    Loop *L;
     
     virtual bool runOnLoop(Loop *L, LPPassManager &LPM);
 
@@ -71,9 +73,9 @@ namespace {
       AU.setPreservesCFG();
       AU.addRequiredID(LoopSimplifyID);
       AU.addPreservedID(LoopSimplifyID);
-      AU.addRequired<LoopInfo>();
+      AU.addRequiredTransitive<LoopInfo>();
       AU.addPreserved<LoopInfo>();
-      AU.addRequired<DominatorTree>();
+      AU.addRequiredTransitive<DominatorTree>();
       AU.addPreserved<ScalarEvolution>();
       AU.addPreserved<DominatorTree>();
 
@@ -85,6 +87,13 @@ namespace {
       AU.addPreserved<DominanceFrontier>();
     }
   private:
+
+    /// verifyAnalysis() - Verify loop nest.
+    virtual void verifyAnalysis() const {
+      // Check the special guarantees that LCSSA makes.
+      assert(L->isLCSSAForm() && "LCSSA form not preserved!");
+    }
+
     void getLoopValuesUsedOutsideLoop(Loop *L,
                                       SetVector<Instruction*> &AffectedValues,
                                  const SmallVector<BasicBlock*, 8>& exitBlocks);
@@ -106,7 +115,8 @@ Pass *llvm::createLCSSAPass() { return new LCSSA(); }
 const PassInfo *const llvm::LCSSAID = &X;
 
 /// runOnFunction - Process all loops in the function, inner-most out.
-bool LCSSA::runOnLoop(Loop *L, LPPassManager &LPM) {
+bool LCSSA::runOnLoop(Loop *l, LPPassManager &LPM) {
+  L = l;
   PredCache.clear();
   
   LI = &LPM.getAnalysis<LoopInfo>();
@@ -149,7 +159,16 @@ void LCSSA::ProcessInstruction(Instruction *Instr,
   // Keep track of the blocks that have the value available already.
   DenseMap<DomTreeNode*, Value*> Phis;
 
-  DomTreeNode *InstrNode = DT->getNode(Instr->getParent());
+  BasicBlock *DomBB = Instr->getParent();
+
+  // Invoke instructions are special in that their result value is not available
+  // along their unwind edge. The code below tests to see whether DomBB dominates
+  // the value, so adjust DomBB to the normal destination block, which is
+  // effectively where the value is first usable.
+  if (InvokeInst *Inv = dyn_cast<InvokeInst>(Instr))
+    DomBB = Inv->getNormalDest();
+
+  DomTreeNode *DomNode = DT->getNode(DomBB);
 
   // Insert the LCSSA phi's into the exit blocks (dominated by the value), and
   // add them to the Phi's map.
@@ -158,7 +177,7 @@ void LCSSA::ProcessInstruction(Instruction *Instr,
     BasicBlock *BB = *BBI;
     DomTreeNode *ExitBBNode = DT->getNode(BB);
     Value *&Phi = Phis[ExitBBNode];
-    if (!Phi && DT->dominates(InstrNode, ExitBBNode)) {
+    if (!Phi && DT->dominates(DomNode, ExitBBNode)) {
       PHINode *PN = PHINode::Create(Instr->getType(), Instr->getName()+".lcssa",
                                     BB->begin());
       PN->reserveOperandSpace(PredCache.GetNumPreds(BB));