This commit modifies the representation of the AIR `switch_br`
instruction to represent ranges in cases. Previously, Sema emitted
different AIR in the case of a range, where the `else` branch of the
`switch_br` contained a simple `cond_br` for each such case which did a
simple range check (`x > a and x < b`). Not only does this add
complexity to Sema, which we would like to minimize, but it also gets in
the way of the implementation of #8220. That proposal turns certain
`switch` statements into a looping construct, and for optimization
purposes, we want to lower this to AIR fairly directly (i.e. without
involving a `loop` instruction). That means we would ideally like a
single instruction to represent the entire `switch` statement, so that
we can dispatch back to it with a different operand as in #8220. This is
not really possible to do correctly under the status quo system.
This commit implements lowering of this new `switch_br` usage in the
LLVM and C backends. The C backend just turns any case containing ranges
entirely into conditionals, as before. The LLVM backend is a little
smarter, and puts scalar items into the `switch` instruction, only using
conditionals for the range cases (which direct to the same bb). All
remaining self-hosted backends are temporarily regressed in the presence
of switch range cases. This functionality will be restored for at least
the x86_64 backend before merge.
Very simply add the format specifier to the print statement.
Since debug.print is hard coded I couldn't come up with a reasonalble
way to add a test, and since this function is simple enough I doubt it's
useful.
fixes one part of #21094
Both glibc and musl use time64 as the base ABI for riscv32. This fixes the
`sleep` test in `std.time` hanging forever due to the libc functions reading
bogus values.
The kernel does define the struct, it just doesn't use it. Yet both glibc and
musl expose it directly as their public stat struct, and std.c takes it from
std.os.linux. So just define it after all.
Passing it by value means that bringup on new architectures is harder for no
real benefit. Passing it by pointer allows to get the compiler running without
needing to figure out the C calling convention details first. This manifested in
practice on LoongArch, for example.
Most of the required renames here are net wins for readaibility, I'd
say. The ones in `arch` are a little more verbose, but I think better. I
didn't bother renaming the non-conflicting functions in
`arch/arm/bits.zig` and `arch/aarch64/bits.zig`, since these backends
are pretty bit-rotted anyway AIUI.
These names aren't matching any formal specification; they're mostly
just ripped from LLVM code. Therefore, we should definitely follow Zig
naming conventions here.
Most of these changes seem like improvements. The PDB thing had a TODO
saying it used to crash; I anticipate it works now, we'll see what CI
does.
The `std.os.uefi` field renames are a notable breaking change.
because it marks the linker section, preventing garbage collection.
Also, name the members because that is required by this intrinsic.
Also, enable the StackDepth option in the sancov pass as a workaround
for https://github.com/llvm/llvm-project/pull/106464, otherwise, LLVM
enables TracePCGuard even though we explicitly disable it.
This matches what LLVM's sancov pass does and is required so that
optimization passes do not delete the instrumentation.
However, this is currently triggering an error: "members of
llvm.compiler.used must be named" so the next commit will add names to
those globals.
It's useful to have TraceCmp based on the results of LLVM optimizations,
while the code coverage bits were emitted by Zig manually, allowing more
careful correlation to points of interest in the source code.
This re-enables the sancov pass in `-ffuzz` mode, but only TraceCmp.
Notably, IndirectCalls is off, which needs to be implemented manually in
the LLVM backend, and StackDepth remains off, because it is not used by
libfuzzer or AFL either.
If stack depth is re-introduced, it can be done with better performance
characteristics by being function call graph aware, and only lowered in
call graph cycles, where its heuristic properties come in useful.
Fixes the fuzzing regression.
