This patch implements `hcreate(_r)/hsearch(_r)/hdestroy(_r)` as
specified in https://man7.org/linux/man-pages/man3/hsearch.3.html.
Notice that `neon/asimd` extension is not yet added in this patch.
- The implementation is largely simplified from rust's
[`hashbrown`](https://github.com/rust-lang/hashbrown/blob/master/src/raw/mod.rs)
as we only consider fix-sized insertion-only hashtables. Technical
details are provided in code comments.
- This patch also contains a portable string hash function, which is
derived from [`aHash`](https://github.com/tkaitchuck/aHash)'s fallback
routine. Not using any SIMD acceleration, it has a good enough quality
(passing all SMHasher tests) and is not too bad in speed.
- Some general functionalities are added, such as `memory_size`,
`offset_to`(alignment), `next_power_of_two`, `is_power_of_two`.
`ctz/clz` are extended to support shorter integers.
Summary:
This was disabled on the GPU because it conflicted with the definition
in `glibc`. According to information online and in the `glibc`
implementation, the first argument should be a `const void *`. Fixing
this resolves the problem when exporting this to offloading languages.
This patch adds the reentrent qsort entrypoint, qsort_r. This is done by
extending the qsort functionality and moving it to a shared utility
header. For this reason the qsort_r tests focus mostly on the places
where it differs from qsort, since they share the same sorting code.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D152467
Implements: https://linux.die.net/man/2/sched_yield
Possibly we don't need the return value check / errno as according to
both the manpage (and current linux source) `sched_yield` cannot fail.
Reviewed By: sivachandra, michaelrj
Differential Revision: https://reviews.llvm.org/D147985
Introduce the `memmem` libc string function.
`memmem_implementation` performs shared logic for `strstr`,
`strcasestr`, and `memmem`; essentially reconfiguring what was the
`strstr_implementation` to support length parameters.
Differential Revision: https://reviews.llvm.org/D147822
These headers are uncommonly used, and from extensions, but some basic
support is needed. Macros have been added where available.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D135731
I've implemente the gnu variant of strerror_r since that seems to be the
one more relevant to what we're trying to do.
Differential Revision: https://reviews.llvm.org/D135227
Add the macro CPU_COUNT as well as a backing function to implement the
functionality.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D135179
Implement exp10f function correctly rounded to all rounding modes.
Algorithm: perform range reduction to reduce
```
10^x = 2^(hi + mid) * 10^lo
```
where:
```
hi is an integer,
0 <= mid * 2^5 < 2^5
-log10(2) / 2^6 <= lo <= log10(2) / 2^6
```
Then `2^mid` is stored in a table of 32 entries and the product `2^hi * 2^mid` is
performed by adding `hi` into the exponent field of `2^mid`.
`10^lo` is then approximated by a degree-5 minimax polynomials generated by Sollya with:
```
> P = fpminimax((10^x - 1)/x, 4, [|D...|], [-log10(2)/64. log10(2)/64]);
```
Performance benchmark using perf tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp10f
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH reciprocal throughput : 10.215
System LIBC reciprocal throughput : 7.944
LIBC reciprocal throughput : 38.538
LIBC reciprocal throughput : 12.175 (with `-msse4.2` flag)
LIBC reciprocal throughput : 9.862 (with `-mfma` flag)
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp10f --latency
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH latency : 40.744
System LIBC latency : 37.546
BEFORE
LIBC latency : 48.989
LIBC latency : 44.486 (with `-msse4.2` flag)
LIBC latency : 40.221 (with `-mfma` flag)
```
This patch relies on https://reviews.llvm.org/D134002
Reviewed By: orex, zimmermann6
Differential Revision: https://reviews.llvm.org/D134104
POSIX locking and unlocking functions flockfile and funlockfile have
also been added. The locking is not recursive yet. A future patch will
make the underlying lock a recursive lock.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D123986
