Revert r70645 for now; it's causing a variety of regressions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70661 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
index 93764b6..076f89e 100644
--- a/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -78,8 +78,9 @@
/// DeleteDeadPHIs - Examine each PHI in the given block and delete it if it
/// is dead. Also recursively delete any operands that become dead as
/// a result. This includes tracing the def-use list from the PHI to see if
-/// it is ultimately unused or if it reaches an unused cycle.
-void llvm::DeleteDeadPHIs(BasicBlock *BB) {
+/// it is ultimately unused or if it reaches an unused cycle. If a
+/// ValueDeletionListener is specified, it is notified of the deletions.
+void llvm::DeleteDeadPHIs(BasicBlock *BB, ValueDeletionListener *VDL) {
// Recursively deleting a PHI may cause multiple PHIs to be deleted
// or RAUW'd undef, so use an array of WeakVH for the PHIs to delete.
SmallVector<WeakVH, 8> PHIs;
@@ -89,7 +90,7 @@
for (unsigned i = 0, e = PHIs.size(); i != e; ++i)
if (PHINode *PN = dyn_cast_or_null<PHINode>(PHIs[i].operator Value*()))
- RecursivelyDeleteDeadPHINode(PN);
+ RecursivelyDeleteDeadPHINode(PN, VDL);
}
/// MergeBlockIntoPredecessor - Attempts to merge a block into its predecessor,
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index fea739c..3b36362 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -178,10 +178,18 @@
return false;
}
+/// ~ValueDeletionListener - A trivial dtor, defined out of line to give the
+/// class a home.
+llvm::ValueDeletionListener::~ValueDeletionListener() {}
+
/// RecursivelyDeleteTriviallyDeadInstructions - If the specified value is a
/// trivially dead instruction, delete it. If that makes any of its operands
/// trivially dead, delete them too, recursively.
-void llvm::RecursivelyDeleteTriviallyDeadInstructions(Value *V) {
+///
+/// If a ValueDeletionListener is specified, it is notified of instructions that
+/// are actually deleted (before they are actually deleted).
+void llvm::RecursivelyDeleteTriviallyDeadInstructions(Value *V,
+ ValueDeletionListener *VDL) {
Instruction *I = dyn_cast<Instruction>(V);
if (!I || !I->use_empty() || !isInstructionTriviallyDead(I))
return;
@@ -193,6 +201,10 @@
I = DeadInsts.back();
DeadInsts.pop_back();
+ // If the client wanted to know, tell it about deleted instructions.
+ if (VDL)
+ VDL->ValueWillBeDeleted(I);
+
// Null out all of the instruction's operands to see if any operand becomes
// dead as we go.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
@@ -218,8 +230,11 @@
/// either forms a cycle or is terminated by a trivially dead instruction,
/// delete it. If that makes any of its operands trivially dead, delete them
/// too, recursively.
+///
+/// If a ValueDeletionListener is specified, it is notified of instructions that
+/// are actually deleted (before they are actually deleted).
void
-llvm::RecursivelyDeleteDeadPHINode(PHINode *PN) {
+llvm::RecursivelyDeleteDeadPHINode(PHINode *PN, ValueDeletionListener *VDL) {
// We can remove a PHI if it is on a cycle in the def-use graph
// where each node in the cycle has degree one, i.e. only one use,
@@ -238,7 +253,7 @@
if (!PHIs.insert(cast<PHINode>(JP))) {
// Break the cycle and delete the PHI and its operands.
JP->replaceAllUsesWith(UndefValue::get(JP->getType()));
- RecursivelyDeleteTriviallyDeadInstructions(JP);
+ RecursivelyDeleteTriviallyDeadInstructions(JP, VDL);
break;
}
}