Fix a silly mistake (which trips over an assertion) in r132099. rdar://9515076

llvm-svn: 132194

1 files changed, 6 insertions, 9 deletions

diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index d42d4ff837b..935cd5d1ee4 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -372,7 +372,11 @@ bool LICM::canSinkOrHoistInst(Instruction &I) {
     return !pointerInvalidatedByLoop(LI->getOperand(0), Size,
                                      LI->getMetadata(LLVMContext::MD_tbaa));
   } else if (CallInst *CI = dyn_cast<CallInst>(&I)) {
-    // Handle obvious cases efficiently.
+    // Don't sink or hoist dbg info; it's legal, but not useful.
+    if (isa<DbgInfoIntrinsic>(I))
+      return false;
+
+    // Handle simple cases by querying alias analysis.
     AliasAnalysis::ModRefBehavior Behavior = AA->getModRefBehavior(CI);
     if (Behavior == AliasAnalysis::DoesNotAccessMemory)
       return true;
@@ -522,14 +526,7 @@ void LICM::sink(Instruction &I) {
       SSA.AddAvailableValue(ExitBlock, New);
   }
   
-  // If the instruction doesn't dominate any exit blocks, it must be dead.
-  if (NumInserted == 0) {
-    CurAST->deleteValue(&I);
-    if (!I.use_empty())
-      I.replaceAllUsesWith(UndefValue::get(I.getType()));
-    I.eraseFromParent();
-    return;
-  }
+  assert(NumInserted && "We shouldn't see dead instructions here!");
   
   // Next, rewrite uses of the instruction, inserting PHI nodes as needed.
   for (Value::use_iterator UI = I.use_begin(), UE = I.use_end(); UI != UE; ) {