- Worker programs run strip-mined typed-array loops in blocks of 128
iterations when the program's code is compiled for x86-64-v3 or above,
or with --cpu-dispatch. At that level the vectorized loop over bytes
takes 128 iterations a step, so in blocks of 64 its vector code never
ran.
- In --cpu-dispatch builds, the LLVM helper gives an x86-64-v3 copy the
optimized code of its baseline copy when the v3 code has vectors of at
most 128 bits, none wider, and no rounding or bit-count intrinsic in a
loop. Its direct calls go to the callees' x86-64-v3 copies. The text
partitioner places each x86-64-v3 copy with its baseline copy, so the
two are optimized in one partition.
A partial record assertion's literal now keeps the asserted type's
optional fields it omits, in their absent state, as an ordinary record
of that type does: a read yields undefined, in answers false and a write
adds the property, with no guard. Only an omitted required field is
missing from the view, and only its writes are guarded, so a write to an
absent optional field of an ordinary record of the same type no longer
throws. The receiver of a guarded write is saved whenever its value is,
so a right side that reassigns the receiver's variable no longer
redirects the check and the store.
A call rewritten for a getter-only name records the classes it tests. When a later wave reaches another class with the same getter, the fallback call is rewritten again for that class, instead of being skipped, so its instances also read the getter before the arguments. Before, `target.step(arg)` on such an instance threw "target.step is not a function".
A write completion callback that a JavaScript module returned reaches
the stream lowering as an untyped value. Since the error-argument form
of write callbacks, the lowering refused it with SC2020, so
tests/corpus/8532-stream-saved-callback-receiver failed to compile.
Such a callback is now converted to a function of the error argument.
The stream calls it unbound with null after a successful write or with
the write's error, and ignores what it returns, as Node does.
With SCRIPTC_INFER_JS=1, shape inference writes its overlay for the program's own JavaScript files, with or without npm-static packages, and leaves package files as they are. The analysis and overlay keep a value untyped where an inferred type would be narrower than what the program holds: awaited values of for await, iterable object literals with computed keys, matchAll and other builtin results, fields an instance may lack, overridden methods and getters, class instances reached by reflection, constructor parameters stored into wider fields, and results the analysis cannot type. A computed member name no longer folds a read that runs before its binding is initialized. In every build, a JavaScript binding written with a value that may be a string, or with a union, keeps the dynamic representation.
The event loop slept to its next timer with nanosleep. macOS applies the
timer slack of the thread's QoS class to nanosleep: a 5 ms sleep takes
about 38 ms at utility QoS and 180 ms at background QoS, where launchd
services such as CI jobs run. Timers then fired out of order against
Node, whose libuv loop waits with a kevent timeout that keeps its
deadline at every QoS. On macOS the loop now sleeps with a kevent timeout
on a kqueue with no events, shared by every thread's loop.
Intervals also re-arm from the time their callback started, as Node's
listOnTimeout does, instead of from the clock after the callback: a
callback that takes 30 ms of a 50 ms interval keeps the ticks 50 ms
apart, and one slower than the interval makes the next tick due on the
next turn. interval-slow-callback.ts checks both against Node.
Node sets SIGPIPE and SIGXFSZ to SIG_IGN at startup, so a write to a
closed pipe or past RLIMIT_FSIZE fails with EPIPE or EFBIG, and libuv's
spawns start children with every signal at its default action. The
runtime instead blocked both signals in the writing thread. On Linux the
signal a write raises goes to that thread, but on macOS it goes to the
process, so a write to a closed pipe from the fs pool's threads ended the
program with SIGPIPE.
- scr_init ignores SIGPIPE and SIGXFSZ. A process.on listener replaces the
disposition while it is registered, as before.
- scr_fs_write_once writes directly in executables, and the fs pool's
threads no longer block the two signals. Library builds keep the
per-thread blocking, since their host owns the dispositions.
- scr_spawn_command starts children with SIGPIPE and SIGXFSZ at their
default actions (POSIX_SPAWN_SETSIGDEF), for spawnSync, execFileSync
and spawn alike.
write-signals-ignored.ts and write-signals-listener.mjs check the ignored
signals, a listener, and each spawn path's child against Node.
A JavaScript object pattern over an untyped source (the result of an untyped function, a parameter, a property of an untyped object) now checks the source first when V8 can spell it, as the `any` path in TypeScript files does: a null or undefined source throws "Cannot destructure property 'size' of 'lookup(...)' as it is null." instead of "Cannot read properties of null (reading 'size')". When the first element has a default and a static key (`{ size = 0 }`), the source is not checked first and the read throws, as in V8; this also applies to `any` sources in TypeScript files and to nullable union sources.
The musl lane links zig's libc, whose memset, memcmp, bcmp and strlen are
byte loops, and whose memcpy and memmove copy without string
instructions. An x86_64 musl executable now defines these six routines
(scr_musl_mem.h): SSE2 for short and medium lengths, and rep stosb or rep
movsb from 2 KiB for memset, memcpy and forward memmove. zig's
definitions are weak, so these replace them. Library artifacts keep the
routines of the program they link into.
Adds a test that checks every length up to 600 and longer ones, every
alignment in a 32-byte window, overlapping moves in both directions,
memcmp's sign at each position, and strlen up to the end of a readable
page, optimized and under ASan and UBSan.
A call through a function-valued private static field (this.#fn(...))
completed its arguments against the field's fixed parameter list, so a
rest-parameter function lost the arguments for its rest parameter, and a
function that reads arguments was refused. The call now takes the
ordinary call-through-value lanes (typed rests, runtime-arity closures,
checked-dynamic values) and binds this to the checked receiver.
Chris Tate