What is `sparcel`, you might ask? Good question!
If you take a peek in the SPARC v8 manual, §2.2, it is quite explicit that SPARC
v8 is a big-endian architecture. No little-endian or mixed-endian support to be
found here.
On the other hand, the SPARC v9 manual, in §3.2.1.2, states that it has support
for mixed-endian operation, with big-endian mode being the default.
Ok, so `sparcel` must just be referring to SPARC v9 running in little-endian
mode, surely?
Nope:
* 40b4fd7a3e/llvm/lib/Target/Sparc/SparcTargetMachine.cpp (L226)
* 40b4fd7a3e/llvm/lib/Target/Sparc/SparcTargetMachine.cpp (L104)
So, `sparcel` in LLVM is referring to some sort of fantastical little-endian
SPARC v8 architecture. I've scoured the internet and I can find absolutely no
evidence that such a thing exists or has ever existed. In fact, I can find no
evidence that a little-endian implementation of SPARC v9 ever existed, either.
Or any SPARC version, actually!
The support was added here: https://reviews.llvm.org/D8741
Notably, there is no mention whatsoever of what CPU this might be referring to,
and no justification given for the "but some are little" comment added in the
patch.
My best guess is that this might have been some private exercise in creating a
little-endian version of SPARC that never saw the light of day. Given that SPARC
v8 explicitly doesn't support little-endian operation (let alone little-endian
instruction encoding!), and no CPU is known to be implemented as such, I think
it's very reasonable for us to just remove this support.
* Elaborate on the sub-variants of Variant I.
* Clarify the use of the TCB term.
* Rename a bunch of stuff to be more accurate/descriptive.
* Follow Zig's style around namespacing more.
* Use a structure for the ABI TCB.
No functional change intended.
The code would cause LLVM to emit a jump table for the switch in the loop over
the dynamic tags. That jump table was far enough away that the compiler decided
to go through the GOT, which would of course break at this early stage as we
haven't applied MIPS's local GOT relocations yet, nor can we until we've walked
through the _DYNAMIC array.
The first attempt at rewriting this used code like this:
var sorted_dynv = [_]elf.Addr{0} ** elf.DT_NUM;
But this is also problematic as it results in a memcpy() call. Instead, we
explicitly initialize it to undefined and use a loop of volatile stores to
clear it.
loongarch64 syscalls not updated because it seems like that kernel port hasn't
been working for a year or so:
In file included from arch/loongarch/include/uapi/asm/unistd.h:5:
include/uapi/asm-generic/unistd.h:2:10: fatal error: 'asm/bitsperlong.h' file not found
That file is just missing from the tree. 🤷
This prevents it from trying to access thread local storage before it
has set up thread local storage, particularly when code coverage
instrumentation is enabled.
* common symbols are now public from std.c even if they live in
std.posix
* LOCK is now one of the common symbols since it is the same on 100% of
operating systems.
* flock is now void value on wasi and windows
* std.fs.Dir now uses flock being void as feature detection, avoiding
trying to call it on wasi and windows
It is now composed of these main sections:
* Declarations that are shared among all operating systems.
* Declarations that have the same name, but different type signatures
depending on the operating system. Often multiple operating systems
share the same type signatures however.
* Declarations that are specific to a single operating system.
- These are imported one per line so you can see where they come from,
protected by a comptime block to prevent accessing the wrong one.
Closes#19352 by changing the convention to making types `void` and
functions `{}`, so that it becomes possible to update `@hasDecl` sites
to use `@TypeOf(f) != void` or `T != void`. Happily, this ended up
removing some duplicate logic and update some bitrotted feature
detection checks.
A handful of types have been modified to gain namespacing and type
safety. This is a breaking change.
Oh, and the last usage of `usingnamespace` site is eliminated.
