source2il: implement alignment support #112
Open
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
The `size` procedure also returns a `SizeUnit` (currently an alias of `int`) now, making it clear what domain the result value is part of.
Aggregate types now respect the alignment requirement of their constituent types. The IL type of aggregate types also uses the correct alignment now, instead of always being 8.
* make the allocator alignment aware (`alloc` and `realloc` take an additional alignment parameter) * update all calls to `alloc` and `realloc` * update the payload size computation to take alignment into account
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Outdated suggestions cannot be applied.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.
Summary
Implement internal support for locations with an alignment requirement
greater than 1 byte. This is a preparation for the source language
gaining type alignment requirements.
Details
The alignment for numeric types (int and float) is equal to their size,
while for aggregate types (other than
seq) it's that of their mostaligned constituent type.
The size of aggregate types is padded to be a multiple of their
alignment. This is so that their size matches the space they would take
up within an array, while still allowing copying
sizebytes from apointer to a location of said type to be valid, regardless of where the
location is located. Record fields are placed such that their relative
offset is a multiple of their alignment requirement.
The allocator procedures
allocandrealloctake an additionalparameter specifying the allocation's required alignment.
growandpreparedAddalso take an additional parameter, which specifies thealignment of the dynamic array's element type. The callsites of all
four procedures are updated accordingly.
Finally, the value rendering in
vmexecis updated to take the newobject layout into account.
Notes For Reviewers
asm.jstranslation pass, asasm.jsdoesn't have native support for misaligned memory access