[PATCH] D29641: [SLP] Fix for PR31847: Assertion failed: (isLoopInvariant(Operands[i], L) && "SCEVAddRecExpr operand is not loop-invariant!")

[Gerolf Hoflehner via Phabricator via llvm-commits]

Gerolf added a comment.

Hi,

I would like to understand this better. Could somebody explain what assumptions SCEV makes about its clients? Which assumption(s) is broken by SLP? It seems to me that this issue potentially touches fundamental design decisions/questions and I don't see any verifiers in place.

Thanks
Gerolf



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Comment at: test/Transforms/SLPVectorizer/X86/crash-SCEV.ll:1
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -slp-vectorizer -S -o - -mtriple=i386 -mcpu=haswell < %s | FileCheck %s
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What is this supposed to test? I'm wondering if there can be a smaller test for what this one is supposed to do. As is at the least it looks hard to maintain.


https://reviews.llvm.org/D29641