It appears that sys_epoll_pwait2 isn't always available, so we need to
add some sort of condition to enable it. This patch disables it until
that happens.
The epoll_wait functions are syscall wrappers that were requested by
upstream users. This patch adds them, as well as their header and types.
The tests are currently incomplete since they require epoll_create to
properly test epoll_wait. That will be added in a followup patch since
this one is already very large.
The epoll_wait functions are syscall wrappers that were requested by
upstream users. This patch adds them, as well as their header and types.
The tests are currently incomplete since they require epoll_create to
properly test epoll_wait. That will be added in a followup patch since
this one is already very large.
This header first appeared in 4.4BSD and is provided by a number of C
libraries including Newlib. Several of our embedded projects use this
header and so to make LLVM libc a drop-in replacement, we need to
provide it as well.
For the initial commit, we only implement singly linked variants (SLIST
and STAILQ). The doubly linked variants (LIST, TAILQ and CIRCLEQ) can be
implemented in the future as needed.
In particular, we have internal customers that would like to use nanf
and
scalbnf.
The differences between various entrypoint files can be checked via:
$ comm -3 <(grep libc\.src path/to/entrypoints.txt | sort) \
<(grep libc\.src path/to/other/entrypoints.txt | sort)
* separate initialization routines into _start and do_start for all
architectures.
* lift do_start as a separate object library to avoid code duplication.
* (addtionally) address the problem of building hermetic libc with
-fstack-pointer-*
The `crt1.o` is now a merged result of three components:
```
___
|___ x86_64
| |_______ start.cpp.o <- _start (loads process initial stack and aligns stack pointer)
| |_______ tls.cpp.o <- init_tls, cleanup_tls, set_thread_pointer (TLS related routines)
|___ do_start.cpp.o <- do_start (sets up global variables and invokes the main function)
```
__stack_chk_fail should be provided by libc.a, not startup files.
Add __stack_chk_fail to existing linux and arm entrypoints. On Windows
(when
not targeting MinGW), it seems that the corresponding function
identifier is
__security_check_cookie, so no entrypoint is added for Windows.
Baremetal
targets also ought to be compileable with `-fstack-protector*`
There is no common header for this prototype, since calls to
__stack_chk_fail
are meant to be inserted by the compiler upon function return when
compiled
`-fstack-protector*`.
This patch lifts aux vector related definitions to app.h. Because
startup's refactoring is in progress, this patch still contains
duplicated changes. This problem will be addressed very soon in an
incoming patch.
Implement `prctl` as specified in
https://man7.org/linux/man-pages/man2/prctl.2.html.
This patch also includes test cases covering two simple use cases:
1. `PR_GET_NAME/PR_SET_NAME`: where userspace data is passed via arg2.
2. `PR_GET_THP_DISABLE`: where return value is passed via syscal retval.
The test cases of mincore require getting correct page size from OS. As
`sysconf` is not functioning correctly, these patches are implemented in
a somewhat confusing way. We revert such patches and will reintroduce
mincore after we correct sysconf.
This reverts 54878b8, 985c0d1 and 418a3a4.
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.
Implements the `nexttoward`, `nexttowardf` and `nexttowardl` functions.
Also, raise excepts required by the standard in `nextafter` functions.
cc: @lntue
Currently the only way to add or remove entrypoints is to modify the
entrypoints.txt file for the current target. This isn't ideal since
a user would have to carry a diff for this file when updating their
checkout. This patch adds a basic mechanism to allow the user to remove
entrypoints without modifying the repository.
We compute `pow(x, y)` using the formula
```
pow(x, y) = x^y = 2^(y * log2(x))
```
We follow similar steps as in `log2f(x)` and `exp2f(x)`, by breaking
down into `hi + mid + lo` parts, in which `hi` parts are computed using
the exponent field directly, `mid` parts will use look-up tables, and
`lo` parts are approximated by polynomials.
We add some speedup for common use-cases:
```
pow(2, y) = exp2(y)
pow(10, y) = exp10(y)
pow(x, 2) = x * x
pow(x, 1/2) = sqrt(x)
pow(x, -1/2) = rsqrt(x) - to be added
```
Implementing expm1 function for double precision based on exp function
algorithm:
- Reduced x = log2(e) * (hi + mid1 + mid2) + lo, where:
* hi is an integer
* mid1 * 2^-6 is an integer
* mid2 * 2^-12 is an integer
* |lo| < 2^-13 + 2^-30
- Then exp(x) - 1 = 2^hi * 2^mid1 * 2^mid2 * exp(lo) - 1 ~ 2^hi *
(2^mid1 * 2^mid2 * (1 + lo * P(lo)) - 2^(-hi) )
- We evaluate fast pass with P(lo) is a degree-3 Taylor polynomial of
(e^lo - 1) / lo in double precision
- If the Ziv accuracy test fails, we use degree-6 Taylor polynomial of
(e^lo - 1) / lo in double double precision
- If the Ziv accuracy test still fails, we re-evaluate everything in
128-bit precision.
This patch enables the compilation of libc for rv32 by unifying the
current rv64 and rv32 implementation into a single rv implementation.
We updated the cmake file to match the new riscv32 arch and force
LIBC_TARGET_ARCHITECTURE to be "riscv" whenever we find "riscv32" or
"riscv64". This is required as LIBC_TARGET_ARCHITECTURE is used in the
path for several platform specific implementations.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D148797
In a previous patch, the printf writer was rewritten to use a single
writer class with a buffer and a callback hook. This patch refactors
scanf's reader to match conceptually.
This patch changes the default types of argc/argv so it's no longer a
uint64_t in all systems, instead, it's now a uintptr_t, which fixes
crashes in 32-bit systems that expect 32-bit types. This patch also adds
two uintptr_t types (EnvironType and AuxEntryType) for the same reason.
The patch also adds a PgrHdrTableType type behind an ifdef that's
Elf64_Phdr in 64-bit systems and Elf32_Phdr in 32-bit systems.
Implement double precision exp2 function correctly rounded for all
rounding modes. Using the same algorithm as double precision exp function in
https://reviews.llvm.org/D158551.
Reviewed By: zimmermann6
Differential Revision: https://reviews.llvm.org/D158812
Implement double precision exp function correctly rounded for all
rounding modes. Using 4 stages:
- Range reduction: reduce to `exp(x) = 2^hi * 2^mid1 * 2^mid2 * exp(lo)`.
- Use 64 + 64 LUT for 2^mid1 and 2^mid2, and use cubic Taylor polynomial to
approximate `(exp(lo) - 1) / lo` in double precision. Relative error in this
step is bounded by 1.5 * 2^-63.
- If the rounding test fails, use degree-6 Taylor polynomial to approximate
`exp(lo)` in double-double precision. Relative error in this step is bounded by
2^-99.
- If the rounding test still fails, use degree-7 Taylor polynomial to compute
`exp(lo)` in ~128-bit precision.
Reviewed By: zimmermann6
Differential Revision: https://reviews.llvm.org/D158551
limits.h currently interferes with Clang's limits.h. include_next
emits a warning because it is a GNU extension. Will re add this once
we figure out a good solution.
This reverts commits 13bbca8d694b4ef2ad03ec1805f07da8640c1a31,
002cba03298a7e8f0c1cadcb7996379e9ea5feff, and
0fb3066873fdfbe28dbb6409c58a8bff7cf208c6.
This header contains implementation specific constants.
The compiler already provides its own limits.h with numerical limits
conforming to freestanding ISO C. But it is missing extensions like
POSIX, and does for example not include <linux/limits.h> which is
expected on a Linux system, therefore, an LLVM libc implementation of
limits.h is needed for hosted (__STDC_HOSTED__) environments.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D156961
The v variants of the printf functions take their variadic arguments as
a va_list instead of as individual arguments. They are otherwise
identical to the corresponding printf variants. This patch adds them
(vprintf, vfprintf, vsprintf, and vsnprintf) as well as tests.
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D157138
