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[Demangler] Further optimizations for the remangler. #72884

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Merged
merged 2 commits into from
Apr 8, 2024
Merged

[Demangler] Further optimizations for the remangler. #72884

merged 2 commits into from
Apr 8, 2024

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@al45tair
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@al45tair al45tair commented Apr 5, 2024

Replace use of snprintf() with some custom code (this is around 10x faster on my machine).

Move a few of the Node member functions to the header so they're inlined.

Optimize the deepEquals() function by adding an isSimilarTo() method on Node; the checks that were happening in the deepEquals() function could be implemented more efficiently by making use of details of the internal representation of Node.

rdar://125739630

@al45tair
[Demangler] Further optimizations for the remangler.
3bd8337 
Replace use of `snprintf()` with some custom code (this is around 10x
faster on my machine).

Move a few of the `Node` member functions to the header so they're
inlined.

Optimize the `deepEquals()` function by adding an `isSimilarTo()`
method on `Node`; the checks that were happening in the `deepEquals()`
function could be implemented more efficiently by making use of
details of the internal representation of `Node`.

rdar://125739630
@al45tair al45tair requested a review from mikeash April 5, 2024 21:27
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al45tair commented Apr 5, 2024

@swift-ci Please smoke test

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al45tair commented Apr 5, 2024

This is a further 23% reduction in cost for the mangling I'm presently testing, over and above what I've already managed.

@al45tair
[Tests] Make recursion limit test more robust.
3800e63 
Ignore the line and column number in the output.

rdar://125989715
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al45tair commented Apr 8, 2024

@swift-ci Please smoke test

mikeash
mikeash reviewed Apr 8, 2024
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test/Demangle/Inputs/bigtype-objcrt.txt
@@ -1 +1 @@
Error: (3:74) unable to re-mangle $sBf32__t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_tN
Error: (pos) unable to re-mangle $sBf32__t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_t_tN
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@mikeash mikeash Apr 8, 2024

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Is the loss of positional info expected or is "pos" some sort of WIP placeholder?

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@al45tair al45tair Apr 8, 2024

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It's a placeholder.

mikeash
mikeash approved these changes Apr 8, 2024
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I'm informed that pos is expected because the exact line/column changes when you change the remangler code which is a real pain to deal with and not useful to test.

@al45tair al45tair merged commit bdb32c9 into swiftlang:main Apr 8, 2024
@al45tair al45tair mentioned this pull request Apr 8, 2024
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tbkka commented Apr 8, 2024

Do these need to be cherry-picked to 6.0?

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al45tair commented Apr 8, 2024

Do these need to be cherry-picked to 6.0?

Yes. #72902 is the cherry pick for that.

@kastiglione kastiglione mentioned this pull request Jul 2, 2025
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kastiglione added a commit that referenced this pull request Jul 4, 2025
@kastiglione
[utils] Update Demangle::Node data formatter
4749121 
Updates the lldb data formatter for `Demangle::Node` to reflect the current `PayloadKind` enum values (which were changed in #72884)
kastiglione added a commit that referenced this pull request Jul 5, 2025
@kastiglione
[utils] Update Demangle::Node data formatter (#82739)
3ac427f 
Updates the lldb data formatter for `Demangle::Node` to reflect the
current `PayloadKind` enum values (which were changed in
#72884).
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@al45tair @tbkka @mikeash