Introduce `strxfrm` and unit tests. The current implementation is
introduced without locale support.
The simplified function performs a `memcpy` if the `n` value is large
enough to store the source len + '\0', otherwise `dest` is unmodified.
Ticket: https://fxbug.dev/124217
Differential Revision: https://reviews.llvm.org/D147478
The stdio test failures were due to headers potentially not being built
in the correct order. This should set up the dependencies correctly.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D146551
This patch implements setjmp and longjmp in riscv using inline asm. The
following changes were required:
* Omit frame pointer: otherwise gcc won't allow us to use s0
* Use __attribute__((naked)): otherwise both gcc and clang will generate
function prologue and epilogue in both functions. This doesn't happen
in x86_64, so we guard it to only riscv
Furthermore, using __attribute__((naked)) causes two problems: we
can't use `return 0` (both gcc and clang) and the function arguments in
the function body (clang only), so we had to use a0 and a1 directly.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D145584
The printf and fprintf implementations use our internal implementation
to improve performance when it's available, but this patch enables using
the public FILE API for overlay mode.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D146001
This patch adds the wchar header, as well as the functions to convert to
and from wide chars. The header also sets up the definitions for wint
and wchar.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D145995
This patch enables the remaining calls from unistd.
The test cases had to be updated to:
1. Use SYS_symlinkat if SYS_symlink is not available
2. Use SYS_readlinkat if SYS_readlink is not available
3. Use SYS_unlinkat if SYS_unlink is not available
4. Use SYS_openat if SYS_open is not available
We also abort compilation if neither of the syscalls mentioned above are
available.
Differential Revision: https://reviews.llvm.org/D146161
In this patch we add support for the spawn lib in riscv.
Only small changes were required, the biggest one was to use of dup3
instead of dup2, if the latter is not available. This follows our
implementation of dup2.
Differential Revision: https://reviews.llvm.org/D146145
This patch removes some duplicated libs added to entrypoints.txt, adds
new libs supported to entrypoints.txt and updates header.txt
Differential Revision: https://reviews.llvm.org/D146065
Also, added riscv64 startup code for static linking which is used
by the integration tests. Functions from the C standard threads
library have been enabled.
Reviewed By: mikhail.ramalho
Differential Revision: https://reviews.llvm.org/D145670
Memory functions get the basic implementation. They can be tuned
as a follow up.
Reviewed By: michaelrj, lntue
Differential Revision: https://reviews.llvm.org/D145433
The entrypoint has been added to the various entrypoint lists. The libc
code style doc has been updated with information on how errno should be
set from the libc runtime code.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D145179
Implement double precision log10 function correctly rounded for all
rounding modes. This implementation currently needs FMA instructions for
correctness.
Use 2 passes:
Fast pass:
- 1 step range reduction with a lookup table of `2^7 = 128` elements to reduce the ranges to `[-2^-7, 2^-7]`.
- Use a degree-7 minimax polynomial generated by Sollya, evaluated using a mixed of double-double and double precisions.
- Apply Ziv's test for accuracy.
Accurate pass:
- Apply 5 more range reduction steps to reduce the ranges further to [-2^-27, 2^-27].
- Use a degree-4 minimax polynomial generated by Sollya, evaluated using 192-bit precisions.
- By the result of Lefevre (add quote), this is more than enough for correct rounding to all rounding modes.
In progress: Adding detail documentations about the algorithm.
Depend on: https://reviews.llvm.org/D136799
Reviewed By: zimmermann6
Differential Revision: https://reviews.llvm.org/D139846
To improve code generation for C++ code that directly includes our
headers, the external function definitions will now be marked noexcept.
This may not be necessary for the internal definitions since we build
with the -fno-exceptions flag.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D141095
The config currently includes ctype, math, stdlib, inttypes and string
functions.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D140378
We do not list macro definitions in api.td files anymore. Not all macros
definitions have been moved out. This change moves the definition of the
NULL macro out.
Reviewed By: lntue, jhuber6
Differential Revision: https://reviews.llvm.org/D140376
This patch contains the initial support for building LLVM's libc as a
target for the GPU. Currently this only supports a handful of very basic
functions that can be implemented without an operating system. The GPU
code is build using the existing OpenMP toolchain. This allows us to
minimally change the existing codebase and get a functioning static
library. This patch allows users to create a static library called
`libcgpu.a` that contains fat binaries containing device IR.
Current limitations are the lack of test support and the fact that only
one target OS can be built at a time. That is, the user cannot get a
`libc` for Linux and one for the GPU simultaneously.
This introduces two new CMake variables to control the behavior
`LLVM_LIBC_TARET_OS` is exported so the user can now specify it to equal
`"gpu"`. `LLVM_LIBC_GPU_ARCHITECTURES` is also used to configure how
many targets to build for at once.
Depends on D138607
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D138608
This patch adds scanf, sscanf, and fscanf entrypoints. It also adds unit
tests for sscanf and a basic test to fscanf. The scanf function is
basically impossible to test in an automated fashion due to it recieving
user input.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D138076
The `assert.h` and `ctype.h` headers are never built despite their
entrypoints being present in the generated library. This patch adds a
dependency on these headers so that they will be built properly.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D138142
The assert functions were disabled while the signal functions were being
fixed. This patch re-enables them.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D138056
Implement gettimeofday per
.../onlinepubs/9699919799/functions/gettimeofday.html.
This call clock_gettime to implement gettimeofday function.
Tested:
Limited unit test: This makes a call and checks that no error was
returned. Used nanosleep for 100 microseconds and verfified it
returns a value that elapses more than 100 microseconds and less
than 300 microseconds.
Co-authored-by: Jeff Bailey <jeffbailey@google.com>
Differential Revision: https://reviews.llvm.org/D137881
A bug in the file read logic has also been fixed along the way. Parts
of the ungetc tests will fail without that bug fixed.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D137286
The strcoll function is intended to compare strings based on their
ordering in the current locale. Since the locale facilities have not yet
been added, a simple implementation that is the same as strcmp has been
added as a placeholder.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D136802
The difftime function computes the difference between two calendar
times: time1 - time0 as per as per 7.27.2.2 section in
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2478.pdf.
double difftime(time_t time1, time_t time0);
Tested:
Unit tests
Co-authored-by: Jeff Bailey <jeffbailey@google.com>
Reviewed By: jeffbailey
Differential Revision: https://reviews.llvm.org/D136631
The implementation currently ignores all spawn attributes. Support for
them will be added in future changes.
A simple allocator for integration tests has been added so that the
integration test for posix_spawn can use the
posix_spawn_file_actions_add* functions.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D135752
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
Some headers hadn't been added, this fixes that and improves the
ordering.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D135629
The isatty function uses the side effects of an ioctl call to determine
if a specific file descriptor is a terminal. I chose TIOCGETD (get line
discipline of terminal) because it didn't require any new structs.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D135618
The sysconf function has many options, this patch adds the basic funtion
and the pagesize option. More options will be added in future patches.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D135409
The logic for strsignal and strerror is very similar, so I've moved them
both to use a shared utility (MessageMapper) for the basic
functionality.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D135322
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
Without this fix, the declaration in sched.h will not have the "__" prefix and
will cause a compile failure.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D135286
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
This provides the reference implementation of rand and srand. In future
this will likely be upgraded to something that supports full ints.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D135187
A very simple and minimal implementation of fork is added. Future
changes will add more functionality to satisfy POSIX and Linux
requirements.
An implementation of wait and a few support macros in sys/wait.h
have also been added to help with testing the fork function.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D135131
Add the syscall wrapper function and tests. It's implemented using a
macro to guarantee the minimum number of arguments.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D134919
They were disabled because we were including linux/signal.h from our
signal.h. Linux's signal.h is not designed to be included from user
programs as it causes a lot of non-standard name pollution. Also, it is
not self-contained. This change defines types and macros relevant for
signal related syscalls within libc's headers and removes inclusion of
Linux headers.
This patch enables the funtions only for x86_64. They will be enabled
for aarch64 also in a follow up patch after testing.
Reviewed By: abrachet, lntue
Differential Revision: https://reviews.llvm.org/D134567
The existing thrd_once function has been refactored so that the
implementation can be shared between thrd_once and pthread_once
functions.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D134716
Tested:
Limited unit test: This makes a call and checks that no error was
returned, but we currently don't have the ability to ensure that
time has elapsed as expected.
Co-authored-by: Jeff Bailey <jeffbailey@google.com>
Reviewed By: sivachandra, jeffbailey
Differential Revision: https://reviews.llvm.org/D134095
Previously the mman macros were in api.td, but platform differences are
easier to handle with preprocessor macros so they have been moved to
include. Also I completed the list of macros (at least for what I need
soon) and fixed some previously incorrect values.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D134491
Strerror maps error numbers to strings. Additionally, a utility for
mapping errors to strings was added so that it could be reused for
perror and similar.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D134074
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
Implement acosf function correctly rounded for all rounding modes.
We perform range reduction as follows:
- When `|x| < 2^(-10)`, we use cubic Taylor polynomial:
```
acos(x) = pi/2 - asin(x) ~ pi/2 - x - x^3 / 6.
```
- When `2^(-10) <= |x| <= 0.5`, we use the same approximation that is used for `asinf(x)` when `|x| <= 0.5`:
```
acos(x) = pi/2 - asin(x) ~ pi/2 - x - x^3 * P(x^2).
```
- When `0.5 < x <= 1`, we use the double angle formula: `cos(2y) = 1 - 2 * sin^2 (y)` to reduce to:
```
acos(x) = 2 * asin( sqrt( (1 - x)/2 ) )
```
- When `-1 <= x < -0.5`, we reduce to the positive case above using the formula:
```
acos(x) = pi - acos(-x)
```
Performance benchmark using perf tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh acosf
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH reciprocal throughput : 28.613
System LIBC reciprocal throughput : 29.204
LIBC reciprocal throughput : 24.271
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh asinf --latency
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH latency : 55.554
System LIBC latency : 76.879
LIBC latency : 62.118
```
Reviewed By: orex, zimmermann6
Differential Revision: https://reviews.llvm.org/D133550
The implementation currently supports only non-thumb mode. As a test for
the implementation, mmap and munmap functions have been enabled.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D132825
Performance by core-math (core-math/glibc 2.31/current llvm-14):
10.845/43.174/13.467
The review is done on top of D132809.
Differential Revision: https://reviews.llvm.org/D132811
To use the FILE data structure, LLVM-libc must be in fullbuild mode
since it expects its own implementation. This means that (f)printf can't
be used without fullbuild, but s(n)printf only uses strings. This patch
adjusts the CMake to allow for this.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D131913
Implement tanf function correctly rounded for all rounding modes.
We use the range reduction that is shared with `sinf`, `cosf`, and `sincosf`:
```
k = round(x * 32/pi) and y = x * (32/pi) - k.
```
Then we use the tangent of sum formula:
```
tan(x) = tan((k + y)* pi/32) = tan((k mod 32) * pi / 32 + y * pi/32)
= (tan((k mod 32) * pi/32) + tan(y * pi/32)) / (1 - tan((k mod 32) * pi/32) * tan(y * pi/32))
```
We need to make a further reduction when `k mod 32 >= 16` due to the pole at `pi/2` of `tan(x)` function:
```
if (k mod 32 >= 16): k = k - 31, y = y - 1.0
```
And to compute the final result, we store `tan(k * pi/32)` for `k = -15..15` in a table of 32 double values,
and evaluate `tan(y * pi/32)` with a degree-11 minimax odd polynomial generated by Sollya with:
```
> P = fpminimax(tan(y * pi/32)/y, [|0, 2, 4, 6, 8, 10|], [|D...|], [0, 1.5]);
```
Performance benchmark using `perf` tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh tanf
CORE-MATH reciprocal throughput : 18.586
System LIBC reciprocal throughput : 50.068
LIBC reciprocal throughput : 33.823
LIBC reciprocal throughput : 25.161 (with `-msse4.2` flag)
LIBC reciprocal throughput : 19.157 (with `-mfma` flag)
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh tanf --latency
GNU libc version: 2.31
GNU libc release: stable
CORE-MATH latency : 55.630
System LIBC latency : 106.264
LIBC latency : 96.060
LIBC latency : 90.727 (with `-msse4.2` flag)
LIBC latency : 82.361 (with `-mfma` flag)
```
Reviewed By: orex
Differential Revision: https://reviews.llvm.org/D131715
Specifically, POSIX functions pthread_key_create, pthread_key_delete,
pthread_setspecific and pthread_getspecific have been added. The C
standard equivalents tss_create, tss_delete, tss_set and tss_get have
also been added.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D131647
