gh-130480: Move LOAD_SMALL_INT optimization from codegen to CFG
#130481
+131
−113
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
WolframAlph
requested review from
markshannon and
iritkatriel
as code owners
WolframAlph
commented
Feb 23, 2025
| if (maybe_instr_make_load_smallint(inst, constant, consts, const_cache)) { | ||
| assert(inst->i_opcode == LOAD_SMALL_INT); | ||
| } | ||
| Py_DECREF(constant); |
There was a problem hiding this comment.
For small ints this is effectively no-op as they are immortal, but it helps readability because get_const_value returns new reference.
tomasr8
reviewed
Feb 23, 2025
| if (inst->i_opcode == LOAD_CONST) { | ||
| PyObject *constant = get_const_value(inst->i_opcode, inst->i_oparg, consts); | ||
| if (maybe_instr_make_load_smallint(inst, constant, consts, const_cache)) { | ||
| assert(inst->i_opcode == LOAD_SMALL_INT); |
There was a problem hiding this comment.
Is the assert needed? If so, maybe you can assert inside maybe_instr_make_load_smallint (then we could also get rid of the if)?
There was a problem hiding this comment.
It helps readability IMO, and performance-wise (if this is your concern), asserts are stripped out on non-debug builds so compiler should eliminate this branch.
sobolevn
reviewed
Feb 23, 2025
| @@ -1992,6 +2006,13 @@ basicblock_optimize_load_const(PyObject *const_cache, basicblock *bb, PyObject * | |||
| int oparg = 0; | |||
| for (int i = 0; i < bb->b_iused; i++) { | |||
| cfg_instr *inst = &bb->b_instr[i]; | |||
| if (inst->i_opcode == LOAD_CONST) { | |||
| PyObject *constant = get_const_value(inst->i_opcode, inst->i_oparg, consts); | |||
| if (maybe_instr_make_load_smallint(inst, constant, consts, const_cache)) { | |||
There was a problem hiding this comment.
I agree that having an if with just one assert feels a bit weird.
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.
LOAD_SMALL_INToptimization from codegen to CFG #130480cc @Eclips4 @tomasr8