From: Johannes Doerfert <jdoerfert@anl.gov>
Date: Mon, 19 Aug 2019 19:14:10 +0000 (+0000)
Subject: Re-apply fixed "[Attributor] Fix: Make sure we set the changed flag"
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=cda1c6dac6cc057afddb7ffb29a58c6a4d92bc89;p=llvm

Re-apply fixed "[Attributor] Fix: Make sure we set the changed flag"

This reverts commit cedd0d9a6e4b433e1cd6585d1d4d152eb5e60b11.

Re-apply the original commit but make sure the variables are initialized
(even if they are not used) so UBSan is not complaining.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369294 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/IPO/Attributor.cpp b/lib/Transforms/IPO/Attributor.cpp
index 4339a65f5e6..34fe5552a40 100644
--- a/lib/Transforms/IPO/Attributor.cpp
+++ b/lib/Transforms/IPO/Attributor.cpp
@@ -878,7 +878,7 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
     // The map in which we collect return values -> return instrs.
     decltype(ReturnedValues) &RetValsMap;
     // The flag to indicate a change.
-    bool Changed;
+    bool &Changed;
     // The return instrs we come from.
     SmallPtrSet<ReturnInst *, 2> RetInsts;
   };
@@ -906,9 +906,8 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
   // Callback for all "return intructions" live in the associated function.
   auto CheckReturnInst = [this, &VisitReturnedValue, &Changed](Instruction &I) {
     ReturnInst &Ret = cast<ReturnInst>(I);
-    RVState RVS({ReturnedValues, false, {}});
+    RVState RVS({ReturnedValues, Changed, {}});
     RVS.RetInsts.insert(&Ret);
-    Changed |= RVS.Changed;
     return VisitReturnedValue(*Ret.getReturnValue(), RVS);
   };
 
@@ -955,7 +954,8 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
       if (Argument *Arg = dyn_cast<Argument>(RetVal)) {
         // Arguments are mapped to call site operands and we begin the traversal
         // again.
-        RVState RVS({NewRVsMap, false, RetValAAIt.second});
+        bool Unused = false;
+        RVState RVS({NewRVsMap, Unused, RetValAAIt.second});
         VisitReturnedValue(*CB->getArgOperand(Arg->getArgNo()), RVS);
         continue;
       } else if (isa<CallBase>(RetVal)) {