[clang] [llvm] [InstCombine] remove dead loads, such as memcpy from undef (PR #143958)

[Nikita Popov via llvm-commits]

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@@ -0,0 +1,63 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes='instcombine<max-iterations=5>' -S | FileCheck %s
+
+; This is a fuzzer-generated test that would assert because
+; we'd get into foldAndOfICmps() without running InstSimplify
+; on an 'and' that should have been killed. It's not obvious
+; why, but removing anything hides the bug, hence the long test.
+
+define void @simplify_before_foldAndOfICmps(ptr %p, ptr %A8) {
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nikic wrote:

```suggestion
define void @simplify_before_foldAndOfICmps(ptr %p, ptr %A8) "instcombine-no-verify-fixpoint" {
```
Use the attribute instead. Then you can also leave the test where it was.

https://github.com/llvm/llvm-project/pull/143958