[Diffusion] rG13ec913bdf50: [InstCombine] Recognize `((x * y) s/ x) !=/== y` as an signed multiplication…

[Roman Lebedev via Phabricator via llvm-commits]

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In rG13ec913bdf500e2354cc55bf29e2f5d99e0c709e#990753 <https://reviews.llvm.org/rG13ec913bdf500e2354cc55bf29e2f5d99e0c709e#990753>, @rnk wrote:

> I reverted this because it introduces new references to libclang_rt.builtins*, which typically doesn't appear on the link line on Windows. This is a longstanding issue, tracked at least here:
> https://bugs.llvm.org/show_bug.cgi?id=25305#c7

There is any number of these folds.
Are you planning on disabling them all, regressing other targets?
For example, isn't the unsigned version also problematic?

> I think we can improve the situation with some autolinking magic, but for now, the optimizer needs to worry about this limitation.

Define "for now"?


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https://reviews.llvm.org/rG13ec913bdf50