[llvm] [SLP] NFC. Refactor getSameOpcode and reduce for loop iterations. (PR #122241)

[Mikael Holmén via llvm-commits]

mikaelholmen wrote:

> > Hi @HanKuanChen and @alexey-bataev ,
> > The following starts crashing with this "NFC" patch:
> > ```
> > opt -passes="slp-vectorizer" bbi-103405.ll -S -o /dev/null -mtriple=thumb7 -mcpu=swift
> > ```
> > 
> > 
> >     
> >       
> >     
> > 
> >       
> >     
> > 
> >     
> >   
> > [bbi-103405.ll.gz](https://github.com/user-attachments/files/18573264/bbi-103405.ll.gz)
> 
> Fixed in [a1ab5b4](https://github.com/llvm/llvm-project/commit/a1ab5b4c87256ce7e99d6fd4bd0c62641e6ce853)

I've verified that the crash goes away with the fix.
Thanks!

https://github.com/llvm/llvm-project/pull/122241