gh-106529: Implement POP_JUMP_IF_XXX uops #106551
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
This adds:
- Hand-written uops JUMP_IF_{TRUE,FALSE,NONE,NOT_NONE}.
These peek at the top of the stack.
The jump target (in superblock space) is absolute.
- Hand-written translation for POP_JUMP_IF_TRUE,
assuming the jump is unlikely.
This can serve as an example for the rest.
(Probably adding the others will cause a little refactoring.)
Once we implement jump-likelihood profiling,
we can implement the jump-unlikely case.
Note that the stubs are placed at the end of the trace array.
There is a gap between the main superblock and the stubs.
We could close the gap, we'd just have to patch up the JUMP uops.
11 tasks
Also include them in the returned trace length.
|
Since we discussed this extensively off-line, I'm going to just merge this once all tests pass. |
This required improving len(ex) and ex[i] a bit. There is now a sentinel opcode (0) at the end, *unless* the trace array is full.
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Outdated suggestions cannot be applied.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.
This adds:
Hand-written uops
_POP_JUMP_IF_{TRUE,FALSE}. These pop the top of the stack. The jump target (in superblock space) is absolute.Hand-written translation for
POP_JUMP_IF_{TRUE,FALSE}, assuming the jump is unlikely. Once we implement jump-likelihood profiling, we can implement the jump-unlikely case.Note that the stubs are placed at the end of the trace array (and not counted in the return value of translate_bytecode_to_trace(), which is a bid dodgy). There is a gap between the main superblock and the stubs. We could close the gap, we'd just have to patch up the JUMP uops.
TODO in this PR:
TODO in a follow-up PR: