[MEMTAGABIELF64] Rewrite LDG as a logical operation - #412
Open
smithp35 wants to merge 1 commit into
Open
Conversation
The `LDG(pointer)` operation is defined in terms of the runtime environment using the `ldg` instruction. In most cases using the ldg instruction will work on allocation tagged memory and untagged memory. However if the untagged memory cannot be read, such as when that memory is execute-only then `ldg` cannot be used. Rewrite `LDG(pointer) in terms of the underlying requirement which is that after the operation, `pointer` has the same logical tag as the allocation tag for *pointer. With memory that is not allocation tagged having a tag of 0000. fixes: ARM-software#411
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
The
LDG(pointer)operation is defined in terms of the runtime environment using theldginstruction. In most cases using the ldg instruction will work on allocation tagged memory and untagged memory. However if the untagged memory cannot be read, such as when that memory is execute-only thenldgcannot be used.Rewrite
LDG(pointer) in terms of the underlying requirement which is that after the operation,pointer` has the same logical tag as the allocation tag for *pointer. With memory that is not allocation tagged having a tag of 0000.fixes: #411