[llvm] 2a77544 - [SimplifyLibCalls] Erase replaced instructions

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2020-04-01T20:00:10+02:00
New Revision: 2a77544ad5911a38f81c0300385033fced1cc66d

URL: https://github.com/llvm/llvm-project/commit/2a77544ad5911a38f81c0300385033fced1cc66d
DIFF: https://github.com/llvm/llvm-project/commit/2a77544ad5911a38f81c0300385033fced1cc66d.diff

LOG: [SimplifyLibCalls] Erase replaced instructions

After RAUWing an instruction, also erase it. This makes sure we
don't perform extra InstCombine iterations to clean up the garbage.

Added: 
    

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

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 77fe6c1cb12a..10eb1212a591 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -832,6 +832,7 @@ Value *LibCallSimplifier::optimizeStrStr(CallInst *CI, IRBuilderBase &B) {
           B.CreateICmp(Old->getPredicate(), StrNCmp,
                        ConstantInt::getNullValue(StrNCmp->getType()), "cmp");
       replaceAllUsesWith(Old, Cmp);
+      eraseFromParent(Old);
     }
     return CI;
   }
@@ -2170,8 +2171,10 @@ 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);