rdrand: Avoid assuming usize is the native word size.
#442
Conversation
This file contains hidden or 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
newpavlov
reviewed
May 31, 2024
newpavlov
approved these changes
May 31, 2024
Member
newpavlov
left a comment
newpavlov
left a comment
There was a problem hiding this comment.
Looks good, but I think we should remove the x32 testing for now.
josephlr
approved these changes
May 31, 2024
Member
josephlr
left a comment
josephlr
left a comment
There was a problem hiding this comment.
Looks good! I don't know if any of the Linux GitHub actions runners support x32. It turns out they don't, I think it's fine to jsut check that x32 builds.
`x86_64-unknown-linux-gnux32` has target_pointer_width = "32", so usize is 32-bits. In this case, we were throwing away half of each RDRAND result and doing twice as many RDRAND invocations as necessary. This wasn't noticed because `as` silently does a lossy conversion.
Contributor
Author
|
I removed the CI changes because we don't have a way of testing this on an x32 target, and the code built and ran correctly (but suboptimally) before and after this change on all these targets |
Merged
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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Outdated suggestions cannot be applied.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.
x86_64-unknown-linux-gnux32has target_pointer_width = "32", so usize is 32-bits. In this case, we were throwing away half of each RDRAND result and doing twice as many RDRAND invocations as necessary. This wasn't noticed becauseassilently does a lossy conversion.Add x86_64-unknown-linux-gnux32 to the test matrix.[Edit: Ubuntu doesn't support x32 by policy; see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1994516/comments/21].