MIPS I has load hazards so we need to insert nops in a few places. This is not a
problem for MIPS II and later.
While doing this, I also touched up all the inline asm to use ABI register
aliases and a consistent formatting convention. Also fixed a few places that
didn't properly check if the syscall return value should be negated.
This allows us to rule out support for certain address spaces based on the OS.
This commit is just a refactor, however, and doesn't actually make use of that
opportunity yet.
The Wycheproof test suite is extensive, but takes a long time to
complete on CI.
Keep only the most relevant ones and take it as an opportunity to describe
what they are.
The remaining ones are still available for manual testing when required.
This test called `yield` 80,000 times, which is nothing on a system with
little load, but murder on a CI system. macOS' scheduler in particular
doesn't seem to deal with this very well. The `yield` calls also weren't
even necessarily doing what they were meant to: if the optimizer could
figure out that it doesn't clobber some memory, then it could happily
reorder around the `yield`s anyway!
The test has been simplified and made to work better, and the number of
yields have been reduced. The number of overall iterations has also been
reduced, because with the `yield` calls making races very likely, we
don't really need to run too many iterations to be confident that the
implementation is race-free.
For instance, when running a Zig test using the self-hosted aarch64
backend, this logic was previously expecting `std.zig.Server` to be
used, but the default test runner intentionally does not do this because
the backend is too immature to handle it. On 'master', this is causing
sporadic failures; on this branch, they became consistent failures.
The new `--error-style` option decides how build failures are printed.
The default mode "verbose" prints all context including the step graph
fragment and the failed command (if any). The alternative mode "minimal"
prints only the failed step itself, and does not print the failed
command. There are also "verbose_clear" and "minimal_clear" modes, which
have the distinction that the output is cleared (through ANSI escape
codes) between updates, preventing different updates from being confused
in the output. If `--error-style` is not specified, the environment
variable `ZIG_BUILD_ERROR_STYLE` is checked before falling back to the
default of "verbose"; this means the value can effectively be chosen
system-wide since it is generally a personal preference.
Also introduced is a `--multiline-errors` option which decides how to
print errors which span multiple lines. By default, non-initial lines
are indented to align with the first. Alternatively, a leading newline
can be printed to align everyting on the first column, or no special
treatment can be applied, resulting in misaligned output. Again, there
is an environment variable (`ZIG_BUILD_MULTILINE_ERRORS`) to specify a
preferred default if the option is not explicitly provided.
Resolves: #23472
