[llvm] [SCEVExpander] Clear flags when reusing GEP (PR #109293)

[Nikita Popov via llvm-commits]

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@@ -370,11 +375,15 @@ Value *SCEVExpander::expandAddToGEP(const SCEV *Offset, Value *V) {
       // generated code.
       if (isa<DbgInfoIntrinsic>(IP))
         ScanLimit++;
-      if (IP->getOpcode() == Instruction::GetElementPtr &&
-          IP->getOperand(0) == V && IP->getOperand(1) == Idx &&
-          cast<GEPOperator>(&*IP)->getSourceElementType() ==
-              Builder.getInt8Ty())
-        return &*IP;
+      if (auto *GEP = dyn_cast<GetElementPtrInst>(IP)) {
+        if (GEP->getPointerOperand() == V &&
+            GEP->getSourceElementType() == Builder.getInt8Ty() &&
+            GEP->getOperand(1) == Idx) {
+          rememberFlags(GEP);
+          GEP->setNoWrapFlags(GEPNoWrapFlags::none());
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nikic wrote:

In https://github.com/llvm/llvm-project/pull/102133 this will become an intersect with SCEV nuw flag instead.

https://github.com/llvm/llvm-project/pull/109293