Python: Fix bad scope_entry_points_to join
#7332
Merged
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
From `pritomrajkhowa/LoopBound`:
```
Definitions.ql-7:PointsTo::PointsToInternal::scope_entry_points_to#ffff#antijoin_rhs#2 ........... 55.1s
```
specifically
```
(443s) Tuple counts for PointsTo::PointsToInternal::scope_entry_points_to#ffff#antijoin_rhs#2/3@74a7cart after 55.1s:
184070 ~0% {3} r1 = JOIN PointsTo::PointsToInternal::scope_entry_points_to#ffff#shared#1 WITH Variables::GlobalVariable#class#f ON FIRST 1 OUTPUT Lhs.0 'arg2', Lhs.1 'arg0', Lhs.2 'arg1'
184070 ~0% {3} r2 = STREAM DEDUP r1
919966523 ~2% {4} r3 = JOIN r2 WITH Essa::EssaDefinition::getSourceVariable_dispred#ff_10#join_rhs ON FIRST 1 OUTPUT Rhs.1, Lhs.1 'arg0', Lhs.2 'arg1', Lhs.0 'arg2'
4281779 ~2293% {3} r4 = JOIN r3 WITH Essa::EssaVariable::getScope_dispred#ff ON FIRST 2 OUTPUT Lhs.1 'arg0', Lhs.2 'arg1', Lhs.3 'arg2'
return r4
```
First, this is an `antijoin`, so there's likely some negation involved.
Also, there's mention of `GlobalVariable`, `getScope`, and
`getSourceVariable`, none of which appear in `scope_entry_points_to`, so
it's likely that something got inlined.
Taking a closer look at the predicates mentioned in the body, we spot
`undefined_variable` as a likely culprit.
Evaluating this predicate in isolation reveals that it's not terribly
big, so we could try just marking it with `pragma[noinline]` (I opted
for the slightly more solid `nomagic`) and see how that fares. I also
checked that `builtin_not_in_outer_scope` was similarly small, and
made that one un-inlineable as well.
The result? Well, I can't even show you. Both `scope_entry_points_to`
and `undefined_variable` are so fast that they don't appear in the
clause timing report (so they can at most take 3.5s each to evaluate, as
that is the smallest timing in the list).
tausbn
added
Awaiting evaluation
tausbn
removed
the
Awaiting evaluation
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.
From
pritomrajkhowa/LoopBound:specifically
First, this is an
antijoin, so there's likely some negation involved. Also, there's mention ofGlobalVariable,getScope, andgetSourceVariable, none of which appear inscope_entry_points_to, so it's likely that something got inlined.Taking a closer look at the predicates mentioned in the body, we spot
undefined_variableas a likely culprit.Evaluating this predicate in isolation reveals that it's not terribly big, so we could try just marking it with
pragma[noinline](I opted for the slightly more solidnomagic) and see how that fares. I also checked thatbuiltin_not_in_outer_scopewas similarly small, and made that one un-inlineable as well.The result? Well, I can't even show you. Both
scope_entry_points_toandundefined_variableare so fast that they don't appear in the clause timing report (so they can at most take 3.5s each to evaluate, as that is the smallest timing in the list).