[llvm] dffc503 - Revert "[SimplifyLibCalls] Erase replaced instructions"

[Benjamin Kramer via llvm-commits]

Author: Benjamin Kramer
Date: 2020-04-02T17:30:47+02:00
New Revision: dffc5031874edff22d4462ce665acd309ecb9cdc

URL: https://github.com/llvm/llvm-project/commit/dffc5031874edff22d4462ce665acd309ecb9cdc
DIFF: https://github.com/llvm/llvm-project/commit/dffc5031874edff22d4462ce665acd309ecb9cdc.diff

LOG: Revert "[SimplifyLibCalls] Erase replaced instructions"

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

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 10eb1212a591..77fe6c1cb12a 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -832,7 +832,6 @@ Value *LibCallSimplifier::optimizeStrStr(CallInst *CI, IRBuilderBase &B) {
           B.CreateICmp(Old->getPredicate(), StrNCmp,
                        ConstantInt::getNullValue(StrNCmp->getType()), "cmp");
       replaceAllUsesWith(Old, Cmp);
-      eraseFromParent(Old);
     }
     return CI;
   }
@@ -2171,10 +2170,8 @@ Value *LibCallSimplifier::optimizeSinCosPi(CallInst *CI, IRBuilderBase &B) {
 
   auto replaceTrigInsts = [this](SmallVectorImpl<CallInst *> &Calls,
                                  Value *Res) {
-    for (CallInst *C : Calls) {
+    for (CallInst *C : Calls)
       replaceAllUsesWith(C, Res);
-      eraseFromParent(C);
-    }
   };
 
   replaceTrigInsts(SinCalls, Sin);