[AArch64] Lower ptrauth.sign of constant as PtrAuthGlobalAddress. #133788
+300
−0
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This lets us guarantee the emission of one of our hardened constant signed pointer materialization sequences, rather than emitting the sign intrinsic as a naked sign, and exposing the raw pointer. Do that in the builder to help guarantee that through the backend. At the IR level, there aren't great ways to enforce that the constant operand to the intrinsic stays there, but we might be able to do that by generalizing immarg to be applicable to callsites rather than just Intrinsic definitions. That's all theoretical either way, and there's rarely a good reason to hoist a constant op from an intrinsic anyway. This is pretty tolerant of weird discriminators, which should cover the interesting cases.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This lets us guarantee the emission of one of our hardened constant signed pointer materialization sequences, rather than emitting the sign intrinsic as a naked sign, and exposing the raw pointer.
Do that in the builder to help guarantee that through the backend.
At the IR level, there aren't great ways to enforce that the constant operand to the intrinsic stays there, but we might be able to do that by generalizing immarg to be applicable to callsites rather than just Intrinsic definitions. That's all theoretical either way, and there's rarely a good reason to hoist a constant op from an intrinsic anyway.
This is pretty tolerant of weird discriminators, which should cover the interesting cases.