Const-correct and prevent a copy of a SmallPtrSet.

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

diff --git a/lib/Transforms/Utils/SimplifyInstructions.cpp b/lib/Transforms/Utils/SimplifyInstructions.cpp
index 8241b07eeb2acc74fc3a68216c92cb3fde159f2f..33b36378027d01715456f9b9382e62225e142eac 100644 (file)
--- a/lib/Transforms/Utils/SimplifyInstructions.cpp
+++ b/lib/Transforms/Utils/SimplifyInstructions.cpp
@@ -48,9 +48,9 @@ namespace {
     bool runOnFunction(Function &F) override {
       const DominatorTreeWrapperPass *DTWP =
           getAnalysisIfAvailable<DominatorTreeWrapperPass>();
-      const DominatorTree *DT = DTWP ? &DTWP->getDomTree() : 0;
+      const DominatorTree *DT = DTWP ? &DTWP->getDomTree() : nullptr;
       DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-      const DataLayout *DL = DLP ? &DLP->getDataLayout() : 0;
+      const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
       const TargetLibraryInfo *TLI = &getAnalysis<TargetLibraryInfo>();
       SmallPtrSet<const Instruction*, 8> S1, S2, *ToSimplify = &S1, *Next = &S2;
       bool Changed = false;
@@ -76,7 +76,15 @@ namespace {
                 ++NumSimplified;
                 Changed = true;
               }
-            Changed |= RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
+            bool res = RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
+            if (res)  {
+              // RecursivelyDeleteTriviallyDeadInstruction can remove
+              // more than one instruction, so simply incrementing the
+              // iterator does not work. When instructions get deleted
+              // re-iterate instead.
+              BI = BB->begin(); BE = BB->end();
+              Changed |= res;
+            }
           }
 
         // Place the list of instructions to simplify on the next loop iteration