Add an assert to MDNode::deleteTemporary check that the node being deleted

[oota-llvm.git] / lib / VMCore / Instruction.cpp

diff --git a/lib/VMCore/Instruction.cpp b/lib/VMCore/Instruction.cpp
index e8d2814c44fe540f75c2f78461acb8d988aec2e2..05bed4c64316fa77e406ec96153c6ccd0c700bd0 100644 (file)
--- a/lib/VMCore/Instruction.cpp
+++ b/lib/VMCore/Instruction.cpp
@@ -49,8 +49,8 @@ Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
 // Out of line virtual method, so the vtable, etc has a home.
 Instruction::~Instruction() {
   assert(Parent == 0 && "Instruction still linked in the program!");
-  if (hasMetadata())
-    removeAllMetadata();
+  if (hasMetadataHashEntry())
+    clearMetadataHashEntries();
 }
 
 
@@ -286,9 +286,10 @@ bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
   for (const_use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
     // PHI nodes uses values in the corresponding predecessor block.  For other
     // instructions, just check to see whether the parent of the use matches up.
-    const PHINode *PN = dyn_cast<PHINode>(*UI);
+    const User *U = *UI;
+    const PHINode *PN = dyn_cast<PHINode>(U);
     if (PN == 0) {
-      if (cast<Instruction>(*UI)->getParent() != BB)
+      if (cast<Instruction>(U)->getParent() != BB)
         return true;
       continue;
     }
@@ -401,12 +402,20 @@ bool Instruction::isSafeToSpeculativelyExecute() const {
       return false;
     // Note that it is not safe to speculate into a malloc'd region because
     // malloc may return null.
-    if (isa<AllocaInst>(getOperand(0)))
+    // It's also not safe to follow a bitcast, for example:
+    //   bitcast i8* (alloca i8) to i32*
+    // would result in a 4-byte load from a 1-byte alloca.
+    Value *Op0 = getOperand(0);
+    if (GEPOperator *GEP = dyn_cast<GEPOperator>(Op0)) {
+      // TODO: it's safe to do this for any GEP with constant indices that
+      // compute inside the allocated type, but not for any inbounds gep.
+      if (GEP->hasAllZeroIndices())
+        Op0 = GEP->getPointerOperand();
+    }
+    if (isa<AllocaInst>(Op0))
       return true;
     if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
       return !GV->hasExternalWeakLinkage();
-    // FIXME: Handle cases involving GEPs.  We have to be careful because
-    // a load of a out-of-bounds GEP has undefined behavior.
     return false;
   }
   case Call: