commit dffc5031874edff22d4462ce665acd309ecb9cdc
author Benjamin Kramer <benny.kra@googlemail.com> Thu Apr 02 17:30:47 2020 +0200
committer Benjamin Kramer <benny.kra@googlemail.com> Thu Apr 02 17:30:47 2020 +0200
tree 53cbc7f6ace02d3aec7cf583961768929146c7f2
parent bacade1ddf06b1807aea76a4b30d0faba3106177

Revert "[SimplifyLibCalls] Erase replaced instructions"

This reverts commit 2a77544ad5911a38f81c0300385033fced1cc66d. This
introduces a use-after-free in Transforms/InstCombine/sincospi.ll.
Found by asan.

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 10eb121..77fe6c1 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -832,7 +832,6 @@
           B.CreateICmp(Old->getPredicate(), StrNCmp,
                        ConstantInt::getNullValue(StrNCmp->getType()), "cmp");
       replaceAllUsesWith(Old, Cmp);
-      eraseFromParent(Old);
     }
     return CI;
   }
@@ -2171,10 +2170,8 @@
 
   auto replaceTrigInsts = [this](SmallVectorImpl<CallInst *> &Calls,
                                  Value *Res) {
-    for (CallInst *C : Calls) {
+    for (CallInst *C : Calls)
       replaceAllUsesWith(C, Res);
-      eraseFromParent(C);
-    }
   };
 
   replaceTrigInsts(SinCalls, Sin);