[PATCH] D99719: [SLP] Better estimate cost of no-op extracts on target vectors.

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added inline comments.


================
Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3476
+    // Reached the start of a new vector registers.
+    if (Idx % EltsPerVector == 0) {
+      AllConsecutive = true;
----------------
I have seen a case where 

```
VecTy->getNumElements() == 2
NumOfParts == 4
EltsPerVector == 0
Idx == 0
```

So divide-by-zero SIGFPE. Trying to reduce to a test case, but how should I paper over the problem quickly?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D99719/new/

https://reviews.llvm.org/D99719