Invalidations caused by FixedPointNumbers

kimikage · October 10, 2026, 12:25am

@ufechner7

SymbolicUtils.jl v4.50.0 has been released, incorporating:

github.com/JuliaSymbolics/SymbolicUtils.jl

Don't infer `//` on an abstract `Rational` in `^` (#1127)

master ← pankgeorg:pow-rational-inference

merged 02:45PM - 02 Oct 26 UTC

pankgeorg

+2 -2

Follow-up to the type-stability note in https://github.com/JuliaSymbolics/Symbol…icUtils.jl/issues/1101#issuecomment-5884776264. The `sqrt`/`cbrt` branches of `^` computed `b::Rational // 2` (and `// 3`). In the `^(::BasicSymbolic, ::Number)` specialization, that makes inference go through `//(::Rational, ::Int64)` with an abstract `Rational`. That call has a backedge to `checked_mul(::Integer, ::Any)` (JuliaLang/julia#63455), and FixedPointNumbers 0.9 adds a `checked_mul` method, so loading it invalidated `^` and everything inferred through it. `b // 2` behaves the same at runtime, since it dispatches on the concrete `Rational`, but inference no longer specializes `//` on the abstract type: SymbolicUtils compiles with `max_methods=1`, and `(Number, Int)` matches three `//` methods, so the call is left dynamic. **Measured** with SnoopCompileCore and FixedPointNumbers 0.9.1 against current master (v4.49.0): distinct SymbolicUtils method instances invalidated by `using FixedPointNumbers` after a small `^` workload. | Julia | master | this PR | |---|---|---| | 1.12.7 | 83 (70 of them in the `checked_mul` tree, all entering at `^(::BasicSymbolic, ::Number)` → `//(::Rational, ::Int64)`) | 13 | | 1.13.1 | 1163 | 1163 | On 1.13.1 the `checked_mul` tree is gone too, but a separate tree rooted at FixedPointNumbers' `length(::StepRange{X, X})` invalidates 1159 method instances through `Dict{…, StepRange}` operations, `^` included. This PR doesn't address that one. **Tests:** none added, because behaviour is unchanged (the `sqrt`/`cbrt` folds give identical results before and after). There's no automated invalidation test either, since the counts depend on the Julia version and on what has been compiled. On the merged branch I ran `basics`, `methods` and `rulesets` on Julia 1.10.12 and 1.12.7; before the merge, `polyform` (both versions) and `fuzz` (1.12.7) passed too. I did not run the full suite. 🤖 Generated with [Claude Code](https://claude.com/claude-code)

How does it work when combined with FixedPointNumbers.jl v0.9.2?

Topic		Replies	Views
Case Study: Method Invalidations caused by Pkg.jl with Julia 1.11 Internals & Design method-invalidation	13	1775	January 23, 2024
A couple questions on compiler latency and method invalidation Internals & Design method-invalidation	8	1197	October 15, 2020
Invalidations findings (from a GMT case) General Usage performance	64	2883	January 12, 2023
Finding and fixing invalidations: now, everyone can help reduce time-to-first-plot Community package , ttfp	9	2760	August 31, 2020
Static.jl vs StaticNumbers.jl Tooling	24	1682	September 14, 2022

Invalidations caused by FixedPointNumbers

Related topics