[PATCH] D86798: [EarlyCSE] fold commutable intrinsics

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

> As noted in https://llvm.org/PR46897 , there is a commutative property specifier for intrinsics, but no corresponding function attribute, and so apparently no uses of that bit. I can remove that here or independently if this is an adequate or better solution.

I think the basic approach here is fine. Dropping the confusing intrinsic property once this lands sounds good.

The only suggestion I would make is to make the primary `Instruction::isCommutative()` method actually forward to `IntrinsicInst::isCommutative()` for intrinsics. Having `I->isCommutative()` and `cast<IntrinsicInst>(I)->isCommutative()` report different things is confusing. I think if you do this, then we will also get commutation support in GVN for free.


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https://reviews.llvm.org/D86798