Skip to content

gh-93223: More aggressive Jump-To-Jump elimination #93229

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
May 27, 2022

Conversation

sweeneyde
Copy link
Member

Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=84, starts_line=8, is_jump_target=False, positions=None),
Instruction(opname='JUMP_FORWARD', opcode=110, arg=14, argval=116, argrepr='to 116', offset=86, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='JUMP_BACKWARD', opcode=140, arg=31, argval=28, argrepr='to 28', offset=88, starts_line=7, is_jump_target=True, positions=None),
Copy link
Member Author

@sweeneyde sweeneyde May 25, 2022

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This instruction gets deleted altogether

@@ -1392,100 +1392,99 @@ def _prepare_test_cases():
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=72, starts_line=7, is_jump_target=True, positions=None),
Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=74, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_OP', opcode=107, arg=4, argval='>', argrepr='>', offset=76, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='POP_JUMP_FORWARD_IF_FALSE', opcode=114, arg=2, argval=88, argrepr='to 88', offset=82, starts_line=None, is_jump_target=False, positions=None),
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This jump-to-jump gets folded together

Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=262, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='CALL', opcode=171, arg=2, argval=2, argrepr='', offset=264, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=274, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='JUMP_FORWARD', opcode=110, arg=11, argval=300, argrepr='to 300', offset=276, starts_line=None, is_jump_target=False, positions=None),
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

A jump-to-jump gets eliminated here

@markshannon
Copy link
Member

My only concern with this PR is that I would like to remove all backwards conditional jumps: faster-cpython/ideas#297 (comment).
Having said that, we'll need to handle conditional backward jumps anyway, so this seems like an improvement even then.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants