[PATCH] D36059: [memops] Add a new pass to inject fast-path code for specific library function calls.

[Mehdi AMINI via Phabricator via llvm-commits]

mehdi_amini added a comment.

In https://reviews.llvm.org/D36059#826963, @chandlerc wrote:

> Just want to point out that we're getting a bit far afield of this patch. Would love any comments on the actually technique...


That's because we like it :)

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> In https://reviews.llvm.org/D36059#826960, @mehdi_amini wrote:
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> I actually view the entire "optimization" phase as somewhat lowering -- we're destroying information and specializing for execution performance on a *particular* target. Many steps here lose significant analysis information in exchange for this.

I actually agree with that, and looking at the code for the new pass manager I see that your `buildModuleOptimizationPipeline` is not matching the legacy `populateModulePassManager` but already implementing separately only the end of the pipeline (I didn't notice before, and I know better the legacy one...).

> Still, all of this is somewhat of a larger more meta discussion...

Yeah but it seems that these only happen when they're triggered by such patch.


https://reviews.llvm.org/D36059