<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/121894>121894</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Crash in SLP-Vectorizer
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          Nirhar
      </td>
    </tr>
</table>

<pre>
    The Crash in SLP Vectorizer can be seen here: https://godbolt.org/z/1MMaYrxfx . 

I believe the crash occurs because of Unhandled check for std::nullopt, as reported here: https://github.com/llvm/llvm-project/issues/121489
And the std::nullopt was returned by `getPointersDiff` because of https://github.com/llvm/llvm-project/issues/121796.

For the record, here is the IR:
```
target triple = "x86_64-unknown-linux-gnu"

define ptr addrspace(1) @widget(i32 %arg) {
bb:
  %zext = zext i32 0 to i64
  %zext1 = zext i32 %arg to i64
  br label %bb12

bb2: ; preds = %bb12
  br i1 false, label %bb3, label %bb14

bb3:                                              ; preds = %bb2
 %getelementptr = getelementptr float, ptr addrspace(1) null, i64 %phi
 %load = load float, ptr addrspace(1) %getelementptr, align 4
 %getelementptr4 = getelementptr float, ptr addrspace(1) null, i64 %add13
 %load5 = load float, ptr addrspace(1) %getelementptr4, align 4
  %fadd = fadd float %load, %load5
  store float %fadd, ptr addrspace(1) null, align 4
  br label %bb6

bb6:                                              ; preds = %bb3
  %add = add i64 %phi, 1
  %icmp = icmp ult i64 %phi, %zext1
 %add7 = add i64 0, 0
  %icmp8 = icmp ult i64 0, %zext
  br i1 %icmp, label %bb9, label %bb14

bb9:                                              ; preds = %bb6
  %getelementptr10 = getelementptr float, ptr addrspace(1) null, i64 %add
  %getelementptr11 = getelementptr i32, ptr addrspace(1) null, i64 %add7
  br label %bb12

bb12: ; preds = %bb9, %bb
  %phi = phi i64 [ 0, %bb ], [ %add, %bb9 ]
 %add13 = add i64 %phi, 1
  br label %bb2

bb14: ; preds = %bb6, %bb2
  ret ptr addrspace(1) null
}
```
Crash:
```
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/opt -o /app/output.s -S -passes=slp-vectorizer -slp-threshold=-99999 <source>
1.      Running pass "function(slp-vectorizer)" on module "<source>"
2.      Running pass "slp-vectorizer" on function "widget"
 #0 0x00000000052656f8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x52656f8)
 #1 0x00000000052630fc SignalHandler(int) Signals.cpp:0:0
 #2 0x000074d097e42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x000074d097e969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #4 0x000074d097e42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #5 0x000074d097e287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #6 0x000000000092d5d2 (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x92d5d2)
 #7 0x00000000042b8f1b llvm::slpvectorizer::BoUpSLP::canVectorizeLoads(llvm::ArrayRef<llvm::Value*>, llvm::Value const*, llvm::SmallVectorImpl<unsigned int>&, llvm::SmallVectorImpl<llvm::Value*>&, unsigned int*, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x42b8f1b)
 #8 0x00000000042e164e llvm::slpvectorizer::BoUpSLP::buildTree_rec(llvm::ArrayRef<llvm::Value*>, unsigned int, llvm::slpvectorizer::BoUpSLP::EdgeInfo const&, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x42e164e)
 #9 0x0000000004310069 llvm::SLPVectorizerPass::tryToVectorizeList(llvm::ArrayRef<llvm::Value*>, llvm::slpvectorizer::BoUpSLP&, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4310069)
#10 0x00000000043130c8 llvm::SLPVectorizerPass::tryToVectorize(llvm::Instruction*, llvm::slpvectorizer::BoUpSLP&) (.part.0) SLPVectorizer.cpp:0:0
#11 0x00000000043133fe llvm::SLPVectorizerPass::tryToVectorize(llvm::ArrayRef<llvm::WeakTrackingVH>, llvm::slpvectorizer::BoUpSLP&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x43133fe)
#12 0x0000000004313ad0 llvm::SLPVectorizerPass::vectorizeRootInstruction(llvm::PHINode*, llvm::Instruction*, llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&) (.constprop.0) SLPVectorizer.cpp:0:0
#13 0x0000000004318636 llvm::SLPVectorizerPass::vectorizeChainsInBlock(llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4318636)
#14 0x000000000431ebf6 llvm::SLPVectorizerPass::runImpl(llvm::Function&, llvm::ScalarEvolution*, llvm::TargetTransformInfo*, llvm::TargetLibraryInfo*, llvm::AAResults*, llvm::LoopInfo*, llvm::DominatorTree*, llvm::AssumptionCache*, llvm::DemandedBits*, llvm::OptimizationRemarkEmitter*) (.part.0) SLPVectorizer.cpp:0:0
#15 0x000000000431f72b llvm::SLPVectorizerPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x431f72b)
#16 0x000000000302ca5e llvm::detail::PassModel<llvm::Function, llvm::SLPVectorizerPass, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x302ca5e)
#17 0x0000000005063490 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5063490)
#18 0x0000000000e6b0be llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0xe6b0be)
#19 0x0000000005061dab llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5061dab)
#20 0x0000000000e6a74e llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0xe6a74e)
#21 0x00000000050617b0 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x50617b0)
#22 0x000000000094241a llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::ArrayRef<std::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x94241a)
#23 0x00000000009349b9 optMain (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x9349b9)
#24 0x000074d097e29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#25 0x000074d097e29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#26 0x000000000092c295 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x92c295)
Program terminated with signal: SIGSEGV
Compiler returned: 139
```


</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzcWl9P4zj3_jTmxmrlOGnaXPQiFLqDfrCLgJ2f3ivkxE7rF9eObIeB-fSv7CTkD4Wh0JVWU4HaxvZznvOcE_vYKTGGbyRjSzA7BbOzE1LZrdLLP7neEn2SKfq8vNsyuNLEbCGX8PbyGn5nuVWa_2Qa5kTCjEHDmIRbphkIU7i1tjQgTAFeA7zeKJopYadKbwBe_wR4HVxdkf_op-IJTiFAKUDpBcyY4OyRQbtlMPe2VJ5X2sCM5aQyDKoC_i23RFLBKMy3LH-AhdLQWOoshamshFClBXgFiYGalUpbRt_ixO22yqa52gG8FuKxfZuUWv2X5RbgNTemYsaxxUG0SABKU0k9vbFJ-MMbtJWWjMLsGYIYbZi9Vlxaps0ZLwoQo74jXyIzT-JprdpaaU9Is1xp6jx33kJu_NWLG2cBpSBGzR9KLdEbZqHVvBQMgvAMAoyfFvF9HE0q-SDVDzkRXFZPk42sAMa1HcoKLhksrYaEUm1KkjOAFwHACQQR-sHphlmAFzzEEOAZcYFOIJifApRmWc0Cupaf7Ml6q_6D646gVZDHUb9HMOxSI_b7ZRoKkjHhmrIsaFhmGXaBBuEpLDWjpnGv7eGH8QAWRBjmtOpBhKPvQdRChg7yoNce-948wLMNs0ywHZPWSemah1cKoYhP4L1Ku2xzjTyOHFi55Q2sUIR6NP_hfZAxC3-7CL6RMNpHMvoqS0JpEPZ4zj5LNBoxdR0KQmvH_QeP19pxvVuTvruxSrOujxvxSx_65oY5F7f5ER8jP8LWodYf994LM17BoO3C813p-_gPlbCjju091GhOKJ0PIJHrhPpoi9dwqIfUu3WaAaObJXnz5kmOIU7cch2kQ4COkJn7kYM9yDzEB-DO352lgremqaRRPctaYuWW-2b37uFnpy-xyTIIZmf-y-y0dahtSnzbSwoE4btpNWTaEY3eIBq_2KknVs3sO9KgFMzPRuuQryZeL0_Xl-fp7Tk0VbbjFhKYVZtmJXfT_-dXTUgkhVzmoqL9CiMj-YPVJGduPb21JH-AtNqVNS80BSi51mqjyQ4SvalcLhivCF77QmOdq13JBdMT9lQKpZl21wSRmwkxhmnLlTQTqyv5APA647IeCCfKQZCydN8rW1Z2auDkFk5KN8yA8MyIcvLY1VgT991uNTNbJSgIzyaJe0EQroyqdM5AeA5QGjjGN5WUXG6gw3KLe1HJ3BEBeDFEBTgBGEMl4U7RylUDGA8A_eqP92GOgTxKa8h1aCuCZuELEURPqH3NcDyLiwX0MfN1lHk29YdrzaX1gbjTdRp1nTT5ca-M1YzsAPYZyKWtV4rFFyMC8Cl6amg5WWrSwYh0iIoc3vKNJOKbL0O1K3lqDvVlM81Llz3I_9couEGZRxQlcxbhGUYNZcEzgNdN9dWrulxDPjVqGntifkhHKxwCJnFS5LB02UHo_QMX4jB0P75Dj8Z0o3kMN8a7dyjtaB53wLMhMF7MixCSzN3aB8H6gR1s3A8SSjCdUXysjKjROlvzvq0IZ4siyPpZLMreTeEvnaq_y9vL6_pLTuTLvulSEWoG6Z1qTZ5vWAHCVXfxOxEVAzj1t-MKjhpgrqSxrnnQdrsjQtSWLnalAOGqkn6LR_0d46DiX414g4IfN0CrjWdKCXcbeELHkr9RuNN_MdSfBXHEDtA_q7igd5qxe83yg7Ufer06wO453bALWag2XHtEPNok1qjSaZYMNAsDhOKkH_nL624vf01MMw9b_XynumTljvanc_UdfWot2uw5lga1l7UGbh5HIw1ClC8O1WDg_4U0VlfNspoe5K33cloSbafILxx946Plw3EPxtzDgn2J-97Y_T8jfsV94HLz_duhETxm5Jx_XeTw2HtC0a-9f-F6o5QdxKqnw_W3iz8VZa_i915sT4nh-alQ-cPnwu4ngFKr8mOxD0feL-IwPsD71ZZwaS5kQ3hxND-OFGrnThfqaOQsy4oPOKsr6Vesvnfrl4p3vMzlRBB9_qhEtTe8d_5w7E4TaQqld27OfqPPJc800c97e6TpDTOVsOZVy6VS5d4hZ2rHJbFKu9XpNaAx1a50jFck375uP2M7Iimjp3yPzb9Ky3f8J3HDb9iO6IfzHbfWhSo9fDaajYJUzHH2oSB9LECpJOLZcHNFJNm49FvtGdTUIcfMROdGl4mDkjJEOCez_pRLmSVcNJMIMeZKUSb2Ux1m3ytxPuW7-_v3i9rI1ok6qJ1nKA6jpD-TeyHfI_gba9Wo0Wk1qHMRizOUHSMB_zGNf-PY1OJ3oUlGaRxQ0p8Ar_xJyp1q-TjJU0pKq_R-b-sBB_naDPkHstA58-IqRqMsJPPosCxsfVt9UKBPKPBWEv17ZK1161QNxgk0zz4yD-7T8neRqFGh0wgPz3QiHAWkR1FXPm2ueckEl8Pdza3VXG7c9mZP2r1yti7mrki-9Ti_KvXqSnPcSynxlz_EXXOxB-RLzW-4s3cP5zUR1YbL13Ny1__l2fXLuXC4elScwuHmiBhzWnFBXRx9kb5nplelvbdu614Xmt6L_-OSvtfrO9O84Ey3_eqt_6HvR0u9Ore6zAuHmRdGSZZAVdorwuXRbHrUzuboxBUnNDnwgNgP6QDHJ60JixC8v3dj7o0l2t7vOnc-bIJFPRPjU9ccJzNYgx_v8NWB1ibbpzCWab9RYhT-4HYL62NpEKbw9uKP2_M_vgOUrhqTLz_IcM1BmIyeNAGUntBlSJMwISdsGczDGIczFCcn22WCEWXRIqGUsAUmKAwLmmMyRyxGC5YEJ3yJEZ6hAM3RPAxQMi2SfLaI5mEe5smcxRGIENsRLqbuPpgqvTnxj6KWAQ4WSXTiH7aZ9gc3eukfW2XVxoAICW6s6cZZbgVb9n98M-l2ESeVFssv_ZbEsXlc4v8FAAD__y768k0">