Revision 3711749292ba9c29ad2e3b9eaee90995f8c8290a authored by Keno Fischer on 11 October 2023, 14:41:22 UTC, committed by GitHub on 11 October 2023, 14:41:22 UTC
This should be NFC and is intended to allow the optimizer to delete :enter statements (by replacing them with `nothing`), without leaving dangling `:leave`s around. This is accomplished by having `leave` take (a variable number of) `:enter` tokens (that are already being used by `:pop_exception`). The semantics are that a literal `nothing` or an SSAValue pointing to a `nothing` statement are ignored, and one exception handler is popped for each remaining argument. The actual value of the token is ignored, except that the verifier asserts that it belongs to an `:enter`. Note that we don't need to do the same for :pop_exception, because the token generated by an `:enter` is semantically only in scope for :pop_exception during its catch block. If we determine the `:enter` is dead, then its catch block is guaranteed to not be executed and will be deleted wholesale by cfg liveness. I was considering doing something fancier where :leave is changed back to taking an integer after optimization, but the case where the IR size is bigger after this change (when we are `:leave`ing many handlers) is fairly rare and likely not worth the additional complexity or time cost to do anything special. If it does show up in size benchmarks, I'd rather give `:leave` a special, compact encoding.
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NEWS.md
Julia v1.11 Release Notes
========================
New language features
---------------------
* `public` is a new keyword. Symbols marked with `public` are considered public
API. Symbols marked with `export` are now also treated as public API. The
difference between `public` and `export` is that `public` names do not become
available when `using` a package/module. ([#50105])
* `ScopedValue` implement dynamic scope with inheritance across tasks ([#50958]).
Language changes
----------------
Compiler/Runtime improvements
-----------------------------
* Updated GC heuristics to count allocated pages instead of individual objects ([#50144]).
* A new `LazyLibrary` type is exported from `Libdl` for use in building chained lazy library
loads, primarily to be used within JLLs ([#50074]).
Command-line option changes
---------------------------
* The entry point for Julia has been standardized to `Main.main(ARGS)`. This must be explicitly opted into using the `@main` macro
(see the docstring for futher details). When opted-in, and julia is invoked to run a script or expression
(i.e. using `julia script.jl` or `julia -e expr`), julia will subsequently run the `Main.main` function automatically.
This is intended to unify script and compilation workflows, where code loading may happen
in the compiler and execution of `Main.main` may happen in the resulting executable. For interactive use, there is no semantic
difference between defining a `main` function and executing the code directly at the end of the script. ([50974])
Multi-threading changes
-----------------------
Build system changes
--------------------
New library functions
---------------------
* The new `Libc.mkfifo` function wraps the `mkfifo` C function on Unix platforms ([#34587]).
* `hardlink(src, dst)` can be used to create hard links. ([#41639])
* `diskstat(path=pwd())` can be used to return statistics about the disk. ([#42248])
* `copyuntil(out, io, delim)` and `copyline(out, io)` copy data into an `out::IO` stream ([#48273]).
* `eachrsplit(string, pattern)` iterates split substrings right to left.
New library features
--------------------
* `replace(string, pattern...)` now supports an optional `IO` argument to
write the output to a stream rather than returning a string ([#48625]).
Standard library changes
------------------------
#### Package Manager
#### LinearAlgebra
#### Printf
#### Profile
#### Random
* `rand` now supports sampling over `Tuple` types ([#35856], [#50251]).
* `rand` now supports sampling over `Pair` types ([#28705]).
* When seeding RNGs provided by `Random`, negative integer seeds can now be used ([#51416]).
* Seedable random number generators from `Random` can now be seeded by a string, e.g.
`seed!(rng, "a random seed")` ([#51527]).
#### REPL
* Tab complete hints now show in lighter text while typing in the repl. To disable
set `Base.active_repl.options.hint_tab_completes = false` ([#51229])
#### SuiteSparse
#### SparseArrays
#### Test
#### Dates
#### Statistics
* Statistics is now an upgradeable standard library.([#46501])
#### Distributed
* `pmap` now defaults to using a `CachingPool` ([#33892]).
#### Unicode
#### DelimitedFiles
#### InteractiveUtils
Deprecated or removed
---------------------
External dependencies
---------------------
* `tput` is no longer called to check terminal capabilities, it has been replaced with a pure-Julia terminfo parser.
Tooling Improvements
--------------------
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