Currently, Zig semantically loads an array as a temporary when indexing
it. This means it cannot be guaranteed that only the requested element
is loaded; in particular, our self-hosted backends do not elide the load
of the full array, so this test case was crashing on self-hosted.
Representing this with a `GenZir` field is incredibly bug-prone.
Instead, just pass this data directly to the relevant expression in the
very few places which actually provide a name strategy.
Resolves: #22798
For instance, the file 'cases/compile_errors/undeclared_identifier.zig'
now corresponds to test name 'compile_errors.undeclared_identifier'.
This is useful because you can now filter based on the case dirname
using `-Dtest-filter`.
`castTruncatedData` was a poorly worded error (all shrinking casts
"truncate bits", it's just that we assume those bits to be zext/sext of
the other bits!), and `negativeToUnsigned` was a pointless distinction
which forced the compiler to emit worse code (since two separate safety
checks were required for casting e.g. 'i32' to 'u16') and wasn't even
implemented correctly. This commit combines those safety panics into one
function, `integerOutOfBounds`. The name maybe isn't perfect, but that's
not hugely important; what matters is the new default message, which is
clearer than the old ones: "integer does not fit in destination type".
Runtime `@shuffle` has two cases which backends generally want to handle
differently for efficiency:
* One runtime vector operand; some result elements may be comptime-known
* Two runtime vector operands; some result elements may be undefined
The latter case happens if both vectors given to `@shuffle` are
runtime-known and they are both used (i.e. the mask refers to them).
Otherwise, if the result is not entirely comptime-known, we are in the
former case. `Sema` now diffentiates these two cases in the AIR so that
backends can easily handle them however they want to. Note that this
*doesn't* really involve Sema doing any more work than it would
otherwise need to, so there's not really a negative here!
Most existing backends have their lowerings for `@shuffle` migrated in
this commit. The LLVM backend uses new lowerings suggested by Jacob as
ones which it will handle effectively. The x86_64 backend has not yet
been migrated; for now there's a panic in there. Jacob will implement
that before this is merged anywhere.
std tests are temporarily disabled for arm-freebsd-eabihf due to #23949.
I omitted x86-freebsd-none and powerpc-freebsd-none because these will be
dropped in FreeBSD 15.0 anyway, so there's no point in us spending resources on
those now.
There's not really any point in targeting *-windows-(gnu,msvc) when not linking
libc, so add entries for *-windows-(gnu,msvc) that actually link libc, and
change the old non-libc entries to *-windows-none.
Also add missing aarch64-windows-(none,msvc) and thumb-windows-(none,msvc)
entries. thumb-windows-gnu is disabled for now due to #24016.
Pointers to thread-local variables do not have their addresses known
until runtime, so it is nonsensical for them to be comptime-known. There
was logic in the compiler which was essentially attempting to treat them
as not being comptime-known despite the pointer being an interned value.
This was a bit of a mess, the check was frequent enough to actually show
up in compiler profiles, and it was very awkward for backends to deal
with, because they had to grapple with the fact that a "constant" they
were lowering might actually require runtime operations.
So, instead, do not consider these pointers to be comptime-known in
*any* way. Never intern such a pointer; instead, when the address of a
threadlocal is taken, emit an AIR instruction which computes the pointer
at runtime. This avoids lots of special handling for TLVs across
basically all codegen backends; of all somewhat-functional backends, the
only one which wasn't improved by this change was the LLVM backend,
because LLVM pretends this complexity around threadlocals doesn't exist.
This change simplifies Sema and codegen, avoids a potential source of
bugs, and potentially improves Sema performance very slightly by
avoiding a non-trivial check on a hot path.
