add ASO prefix to E8 call opcode #46
Merged
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
RyanGlScott
approved these changes
Jun 8, 2023
There was a problem hiding this comment.
I think this is fine, assuming that it doesn't introduce any ambiguities described in this Note. (My reading of the Note has led me to conclude that this patch shouldn't introduce any additional complications.) I am also aligned with making the disassembler more permissive to handle binaries in the wild, as this is something that we have already done in the past. (See the commit history for opcode.xml for examples of this.)
My only suggestion would be to include a comment explaining why this (peculiar) prefix is allowed here, perhaps citing the example from https://reviews.llvm.org/D120592#3348274 as a place where this prefix can arise in practice.
While the specification seems to imply that this is reserved and unspecified, there is a compiler out there producing binaries where `67 e8` is used, supposedly as a means to alignment, as the prefix ought to have no effect on this instruction.
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Outdated suggestions cannot be applied.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.
While the specification seems to imply that this is reserved and unspecified, there is a compiler out there producing binaries where
67 e8is used, supposedly as a means to alignment, as the prefix ought to have no effect on this instruction.Kind of want to open this to discussion: do we want flexdis86 to be somewhat lax with the specification, recognizing binaries that compilers produce even when they use somewhat under-specified corners of the ISA semantics, or do we want to be stringent and reject such binaries?