[llvm-commits] CVS: llvm/lib/Transforms/Scalar/ADCE.cpp

[Chris Lattner]

Changes in directory llvm/lib/Transforms/Scalar:

ADCE.cpp updated: 1.76 -> 1.77

---
Log message:

Do not mark instructions in unreachable sections of the function as live.
This fixes PR332: http://llvm.cs.uiuc.edu/PR332  and ADCE/2004-05-04-UnreachableBlock.llx



---
Diffs of the changes:  (+5 -2)

Index: llvm/lib/Transforms/Scalar/ADCE.cpp
diff -u llvm/lib/Transforms/Scalar/ADCE.cpp:1.76 llvm/lib/Transforms/Scalar/ADCE.cpp:1.77
--- llvm/lib/Transforms/Scalar/ADCE.cpp:1.76	Sat Apr 10 13:06:21 2004
+++ llvm/lib/Transforms/Scalar/ADCE.cpp	Tue May  4 12:00:46 2004
@@ -215,8 +215,10 @@
   // instructions live in basic blocks that are unreachable.  These blocks will
   // be eliminated later, along with the instructions inside.
   //
-  for (df_iterator<Function*> BBI = df_begin(Func), BBE = df_end(Func);
-       BBI != BBE; ++BBI) {
+  std::set<BasicBlock*> ReachableBBs;
+  for (df_ext_iterator<BasicBlock*>
+         BBI = df_ext_begin(&Func->front(), ReachableBBs),
+         BBE = df_ext_end(&Func->front(), ReachableBBs); BBI != BBE; ++BBI) {
     BasicBlock *BB = *BBI;
     for (BasicBlock::iterator II = BB->begin(), EI = BB->end(); II != EI; ) {
       Instruction *I = II++;
@@ -279,6 +281,7 @@
     WorkList.pop_back();
 
     BasicBlock *BB = I->getParent();
+    if (!ReachableBBs.count(BB)) continue;
     if (!AliveBlocks.count(BB)) {     // Basic block not alive yet...
       AliveBlocks.insert(BB);         // Block is now ALIVE!
       markBlockAlive(BB);             // Make it so now!