tree 3e3ba342a0e5dfde9705be933c4409f8870d7fd0
parent bc4cc11c8d84a5b5c5d4f885868fe9428cfa196b
author Philip Reames <listmail@philipreames.com> 1638478569 -0800
committer Copybara-Service <copybara-worker@google.com> 1638479376 -0800

[funcattrs] Infer writeonly argument attribute

This change extends the current logic for inferring readonly and readnone argument attributes to also infer writeonly.

This change is deliberately minimal; there's a couple of areas for follow up.
* I left out all call handling and thus any benefit from the SCC walk. When examining the test changes, I realized the existing code is imprecise, and am going to fix that in it's own revision before adding in the writeonly handling. (Mostly because updating the tests is hard when I, the human, can't figure out whether the result is correct.)
* I left out handling for storing a value (as opposed to storing to a pointer). This should benefit readonly/readnone as well, and applies to a bunch of other instructions. Seemed worth having as a separate review.

Differential Revision: https://reviews.llvm.org/D114963

GitOrigin-RevId: 740057d185ea0e8b5a4f8b7c78fdf38ae7a66f76