[Parser][NFC] Split parser into multiple compilation units #6653
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
Because the parser has five stages, it requires instantiating all of the templates in parsers.h with up to five different contexts. Instantiating all those templates in a single compilation unit takes a long time. On my machine, a release build of wat-parser.cpp.o took 32 seconds. To reduce the time of incremental rebuilds on machines with many cores, split the code across several compilation units so that the templates need to be instantiated for just a single context in each unit. On my machine the longest compilation time after this splitting is 17 seconds. The time for a full release build also drops from 42 seconds to 33 seconds. On machines with fewer cores, the benefit may be smaller or even negative, though.
Closed
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Outdated suggestions cannot be applied.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.
Because the parser has five stages, it requires instantiating all of the templates in parsers.h with up to five different contexts. Instantiating all those templates in a single compilation unit takes a long time. On my machine, a release build of wat-parser.cpp.o took 32 seconds. To reduce the time of incremental rebuilds on machines with many cores, split the code across several compilation units so that the templates need to be instantiated for just a single context in each unit. On my machine the longest compilation time after this splitting is 17 seconds. The time for a full release build also drops from 42 seconds to 33 seconds. On machines with fewer cores, the benefit may be smaller or even negative, though.