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Rust: Fix bad joins#19250

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hvitved merged 2 commits intogithub:mainfrom
hvitved:rust/fix-bad-joins
Apr 9, 2025
Merged

Rust: Fix bad joins#19250
hvitved merged 2 commits intogithub:mainfrom
hvitved:rust/fix-bad-joins

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@hvitved hvitved commented Apr 8, 2025

Fixes two bad joins, reported by DCA's Join-order badness report. DCA shows an average 3% analysis time speedup.

hvitved added 2 commits April 8, 2025 13:10
Before
```
Pipeline standard for PathResolution::unqualifiedPathLookup/2#6b171b76#reorder_2_0_1@822d53wq was evaluated in 61 iterations totaling 118ms (delta sizes total: 131072).
          606491   ~0%    {4} r1 = SCAN `PathResolution::getASuccessor/3#febac7bd#prev_delta` OUTPUT In.1, In.2, In.0, In.3
          106457   ~1%    {3}    | JOIN WITH `PathResolution::unqualifiedPathLookup/4#e32cdfce_1230#join_rhs` ON FIRST 3 OUTPUT Lhs.3, Rhs.3, Lhs.1

          606491   ~2%    {4} r2 = SCAN `PathResolution::getASuccessor/3#febac7bd#prev_delta` OUTPUT In.0, In.2, In.3, In.1

           19261   ~0%    {4} r3 = JOIN r2 WITH `PathResolution::ModuleLikeNode.isRoot/0#dispred#21662e64` ON FIRST 1 OUTPUT Lhs.3, Lhs.0, Lhs.1, Lhs.2

        42776643   ~1%    {4} r4 = JOIN r2 WITH `doublyBoundedFastTC@PathResolution::hasChild/2#6b318d51#2@PathResolution::isRoot/1#a01ce5c3#1@PathResolution::hasCratePath/1#73ea688d#1` ON FIRST 1 OUTPUT Lhs.3, Rhs.1, Lhs.1, Lhs.2

        42795904   ~1%    {4} r5 = r3 UNION r4
           24921   ~6%    {3}    | JOIN WITH `PathResolution::RelevantPath.isCratePath/2#e595e892_120#join_rhs` ON FIRST 2 OUTPUT Lhs.3, Rhs.2, Lhs.2

          131378   ~2%    {3} r6 = r1 UNION r5
          131072   ~2%    {3}    | AND NOT `PathResolution::unqualifiedPathLookup/2#6b171b76#reorder_2_0_1#prev`(FIRST 3)
                          return r6
```

After
```
Pipeline standard for PathResolution::unqualifiedPathLookup/2#6b171b76#reorder_2_0_1@0553a4wi was evaluated in 66 iterations totaling 10ms (delta sizes total: 131072).
        610251  ~0%    {4} r1 = SCAN `PathResolution::getASuccessor/3#febac7bd#prev_delta` OUTPUT In.1, In.2, In.0, In.3
        131378  ~0%    {3}    | JOIN WITH `PathResolution::unqualifiedPathLookup1/4#781de0cd_1230#join_rhs` ON FIRST 3 OUTPUT Lhs.3, Rhs.3, Lhs.1
        131072  ~0%    {3}    | AND NOT `PathResolution::unqualifiedPathLookup/2#6b171b76#reorder_2_0_1#prev`(FIRST 3)
                       return r1
```
Before
```
Pipeline standard for PathResolution::getAPrivateVisibleModule/1#3829a5ee@822d5hwq was evaluated in 24 iterations totaling 16ms (delta sizes total: 4843).
         105047   ~63652%    {2} r1 = SCAN `PathResolution::resolvePathPrivate/3#56db2cdf#reorder_1_2_0_3#prev_delta` OUTPUT In.0, In.0

             69       ~0%    {2} r2 = JOIN `#PathResolution::ItemNode.getImmediateParentModule/0#dispred#57c4c6d5Plus#bf#reorder_1_0#prev_delta` WITH `PathResolution::resolvePathPrivate/3#56db2cdf#reorder_1_2_0_3#prev` ON FIRST 1 OUTPUT Lhs.0, Lhs.1

        5766690  ~148309%    {2} r3 = JOIN `PathResolution::resolvePathPrivate/3#56db2cdf#reorder_1_2_0_3#prev_delta` WITH `#PathResolution::ItemNode.getImmediateParentModule/0#dispred#57c4c6d5Plus#bf#reorder_1_0#prev` ON FIRST 1 OUTPUT Lhs.0, Rhs.1

        5871806  ~143984%    {2} r4 = r1 UNION r2 UNION r3
           6859     ~148%    {2}    | AND NOT `PathResolution::getAPrivateVisibleModule/1#3829a5ee#prev`(FIRST 2)
                             return r4
```

After
```
Pipeline standard for PathResolution::getAPrivateVisibleModule/1#3829a5ee@5edefhwp was evaluated in 12 iterations totaling 0ms (delta sizes total: 3515).
         339   ~1%    {2} r1 = SCAN `PathResolution::isItemParent/1#d5e587d6#prev_delta` OUTPUT In.0, In.0

        3130   ~0%    {2} r2 = JOIN `PathResolution::isItemParent/1#d5e587d6#prev_delta` WITH `#PathResolution::ItemNode.getImmediateParentModule/0#dispred#57c4c6d5Plus#bf#reorder_1_0#prev` ON FIRST 1 OUTPUT Lhs.0, Rhs.1

          46   ~0%    {2} r3 = JOIN `#PathResolution::ItemNode.getImmediateParentModule/0#dispred#57c4c6d5Plus#bf#reorder_1_0#prev_delta` WITH `PathResolution::isItemParent/1#d5e587d6#prev` ON FIRST 1 OUTPUT Lhs.0, Lhs.1

        3515   ~2%    {2} r4 = r1 UNION r2 UNION r3
        3515   ~2%    {2}    | AND NOT `PathResolution::getAPrivateVisibleModule/1#3829a5ee#prev`(FIRST 2)
                      return r4
```
@github-actions github-actions Bot added the Rust Pull requests that update Rust code label Apr 8, 2025
@hvitved hvitved marked this pull request as ready for review April 9, 2025 06:45
Copilot AI review requested due to automatic review settings April 9, 2025 06:45
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Copilot wasn't able to review any files in this pull request.

Files not reviewed (1)
  • rust/ql/lib/codeql/rust/internal/PathResolution.qll: Language not supported

@hvitved hvitved requested a review from paldepind April 9, 2025 07:53
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Nice!

@hvitved hvitved merged commit 9323f1a into github:main Apr 9, 2025
16 checks passed
@hvitved hvitved deleted the rust/fix-bad-joins branch April 9, 2025 11:36
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