[Attributor] Introduce an API to delete stuff
Summary:
During the fixpoint iteration, including the manifest stage, we should
not delete stuff as other abstract attributes might have a reference to
the value. Through the API this can now be done safely at the very end.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66779
llvm-svn: 370014
diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index a6e8e52..a2d470a 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -2641,6 +2641,26 @@
assert(
NumFinalAAs == AllAbstractAttributes.size() &&
"Expected the final number of abstract attributes to remain unchanged!");
+
+ // Delete stuff at the end to avoid invalid references and a nice order.
+ LLVM_DEBUG(dbgs() << "\n[Attributor] Delete " << ToBeDeletedFunctions.size()
+ << " functions and " << ToBeDeletedBlocks.size()
+ << " blocks and " << ToBeDeletedInsts.size()
+ << " instructions\n");
+ for (Instruction *I : ToBeDeletedInsts) {
+ if (I->hasNUsesOrMore(1))
+ I->replaceAllUsesWith(UndefValue::get(I->getType()));
+ I->eraseFromParent();
+ }
+ for (BasicBlock *BB : ToBeDeletedBlocks) {
+ // TODO: Check if we need to replace users (PHIs, indirect branches?)
+ BB->eraseFromParent();
+ }
+ for (Function *Fn : ToBeDeletedFunctions) {
+ Fn->replaceAllUsesWith(UndefValue::get(Fn->getType()));
+ Fn->eraseFromParent();
+ }
+
return ManifestChange;
}