fix literal-pow to return the right type when the base is -1 #53736
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oscardssmith
added
domain:maths
fingolfin
reviewed
Mar 15, 2024
KlausC
reviewed
Mar 15, 2024
| @inline literal_pow(::typeof(^), x::HWNumber, ::Val{-1}) = inv(x) | ||
| @inline literal_pow(::typeof(^), x::HWNumber, ::Val{-2}) = (i=inv(x); i*i) | ||
| @inline function literal_pow(::typeof(^), x::HWNumber, ::Val{-1}) | ||
| if x == -one(x) |
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This change introduces even more type instability, now depending on the value of the x argument.
Other question: why special-case -1 and not 1?
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the reason to specialize only on -1 is that inv(x) often has a different type than x, but x*x generally is ok. what is a fade where this version is type unstable? unitful?
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I meant depending on the first argument: typeof ((-1)^-1) == Int, while typeof(1^-1) == Float64)
| inv(x) | ||
| end | ||
| @inline function literal_pow(::typeof(^), x::HWNumber, ::Val{-2}) | ||
| if x == -one(x) |
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See previous comment on line 373
| @@ -379,7 +390,9 @@ const HWNumber = Union{HWReal, Complex{<:HWReal}, Rational{<:HWReal}} | |||
| # for other types, define x^-n as inv(x)^n so that negative literal powers can | |||
| # be computed in a type-stable way even for e.g. integers. | |||
| @inline function literal_pow(f::typeof(^), x, ::Val{p}) where {p} | |||
| if p < 0 | |||
| if x == -one(x) | |||
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See previous comment on line 373
Co-authored-by: Max Horn <max@quendi.de>
60 tasks
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Ref #53735 (comment) |
KristofferC
added a commit
that referenced
this pull request
Mar 17, 2024
Backported PRs: - [x] #39071 <!-- Add a lazy `logrange` function and `LogRange` type --> - [x] #51802 <!-- Allow AnnotatedStrings in log messages --> - [x] #53369 <!-- Orthogonalize re-indexing for FastSubArrays --> - [x] #48050 <!-- improve `--heap-size-hint` arg handling --> - [x] #53482 <!-- add IR encoding for EnterNode --> - [x] #53499 <!-- Avoid compiler warning about redefining jl_globalref_t --> - [x] #53507 <!-- update staled `Core.Compiler.Effects` documentation --> - [x] #53408 <!-- task splitting: change additive accumulation to multiplicative --> - [x] #53523 <!-- add back an alias for `check_top_bit` --> - [x] #53377 <!-- add _readdirx for returning more object info gathered during dir scan --> - [x] #53525 <!-- fix InteractiveUtils call in Base.runtests on failure --> - [x] #53540 <!-- use more efficient `_readdirx` for tab completion --> - [x] #53545 <!-- use `_readdirx` for `walkdir` --> - [x] #53551 <!-- revert "Add @create_log_macro for making custom styled logging macros (#52196)" --> - [x] #53554 <!-- Always return a value in 1-d circshift! of abstractarray.jl --> - [x] #53424 <!-- yet more atomics & cache-line fixes on work-stealing queue --> - [x] #53571 <!-- Update Documenter to v1.3 for inventory writing --> - [x] #53403 <!-- Move parallel precompilation to Base --> - [x] #53589 <!-- add back `unsafe_convert` to pointer for arrays --> - [x] #53596 <!-- build: remove extra .a file --> - [x] #53606 <!-- fix error path in `precompilepkgs` --> - [x] #53004 <!-- Unexport with, at_with, and ScopedValue from Base --> - [x] #53629 <!-- typo fix in scoped values docs --> - [x] #53630 <!-- sroa: Fix incorrect scope counting --> - [x] #53598 <!-- Use Base parallel precompilation to build stdlibs --> - [x] #53649 <!-- precompilepkgs: package in boths deps and weakdeps are in fact only weak --> - [x] #53671 <!-- Fix bootstrap Base precompile in cross compile configuration --> - [x] #52125 <!-- Load Pkg if not already to reinstate missing package add prompt --> - [x] #53602 <!-- Handle zero on arrays of unions of number types and missings --> - [x] #53516 <!-- permit NamedTuple{<:Any, Union{}} to be created --> - [x] #53643 <!-- Bump CSL to 1.1.1 to fix libgomp bug --> - [x] #53679 <!-- move precompile workload back from Base --> - [x] #53663 <!-- add isassigned methods for reinterpretarray --> - [x] #53662 <!-- [REPL] fix incorrectly cleared line after completions accepted --> - [x] #53611 <!-- Linalg: matprod_dest for Diagonal and adjvec --> - [x] #53659 <!-- fix #52025, re-allow all implicit pointer casts in cconvert for Array --> - [x] #53631 <!-- LAPACK: validate input parameters to throw informative errors --> - [x] #53628 <!-- Make some improvements to the Scoped Values documentation. --> - [x] #53655 <!-- Change tbaa of ptr_phi to tbaa_value --> - [x] #53391 <!-- Default to the medium code model in x86 linux --> - [x] #53699 <!-- Move `isexecutable, isreadable, iswritable` to `filesystem.jl` --> - [x] #41232 <!-- Fix linear indexing for ReshapedArray if the parent has offset axes --> - [x] #53527 <!-- Enable analyzegc checks for try catch and fix found issues --> - [x] #52092 - [x] #53682 <!-- Increase build precompilation --> - [x] #53720 - [x] #53553 <!-- typeintersect: fix `UnionAll` unaliasing bug caused by innervars. --> Contains multiple commits, manual intervention needed: - [ ] #53305 <!-- Propagate inbounds in isassigned with CartesianIndex indices --> Non-merged PRs with backport label: - [ ] #53736 <!-- fix literal-pow to return the right type when the base is -1 --> - [ ] #53707 <!-- Make ScopedValue public --> - [ ] #53696 <!-- add invokelatest to on_done callback in bracketed paste --> - [ ] #53660 <!-- put Logging back in default sysimage --> - [ ] #53509 <!-- revert moving "creating packages" from Pkg.jl --> - [ ] #53452 <!-- RFC: allow Tuple{Union{}}, returning Union{} --> - [ ] #53402 <!-- Add `jl_getaffinity` and `jl_setaffinity` --> - [ ] #52694 <!-- Reinstate similar for AbstractQ for backward compatibility --> - [ ] #51928 <!-- Styled markdown, with a few tweaks --> - [ ] #51816 <!-- User-themable stacktraces --> - [ ] #51811 <!-- Make banner size depend on terminal size --> - [ ] #51479 <!-- prevent code loading from lookin in the versioned environment when building Julia -->
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I'm not sure this needs to be changed. Looks like the cure might be worse than the disease. |
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it's really unfortunate that there has to be type weirdness somewhere. that said given the choices we made with literal pow, I think the current behavior unfortunately is just what we're stick with. |
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fixes #53735.