[PATCH] D87163: [DSE] Switch to MemorySSA-backed DSE by default.

[Alina Sbirlea via Phabricator via cfe-commits]

asbirlea added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp:312
     switch (II->getIntrinsicID()) {
     default: llvm_unreachable("doesn't pass 'hasAnalyzableMemoryWrite' predicate");
     case Intrinsic::lifetime_end:
----------------
The crash is hitting this unreachable for the intrinsic "llvm.memcpy.inline".
Simple repro: opt -dse test1.ll
```
define void @test(i8* noalias nocapture %0, i8* noalias nocapture readonly %1) {
  tail call void @llvm.memcpy.inline(i8* align 1 %0, i8* align 1 %1, i64 3, i1 false)
  ret void
}

declare void @llvm.memcpy.inline(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i64 immarg, i1 immarg)
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87163/new/

https://reviews.llvm.org/D87163