[llvm] [LoopVectorize] Check for vector-to-scalar casts in legalizer (PR #106244)

[Ramkumar Ramachandra via llvm-commits]

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+; RUN: opt --force-widen-divrem-via-safe-divisor=false -passes=loop-vectorize -S --debug-only=loop-vectorize < %s 2>&1 | FileCheck %s
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artagnon wrote:

Actually, instead of checking debug strings, you can simply check the output (and it will be evident that the example is not vectorized), which can be generated using update_test_checks.py, and add a comment saying that the test was triggering an assertion earlier. That way, we don't have to rely on assertion builds (hence, no need for REQUIRES: asserts).

https://github.com/llvm/llvm-project/pull/106244