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
Our syscall implementation depends on a specific macro that's only
defined in our headers. If we're not using our headers, then the test
doesn't work. I've disabled the test in this case because there's no
point in testing the system libc's syscall implementation.
Differential Revision: https://reviews.llvm.org/D134994
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
On windows, including math.h causes macros for "OVERFLOW" and
"UNDERFLOW" to be defined. This patch renames some variables internal to
FEnvImpl.h to avoid colliding with those.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D134775
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
The windows build has fallen behind a little, this patch fixes some
issues that were preventing it from building.
Specifically: Some subfolders weren't being included, leading to missing
targets in the cmake.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D134676
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
Now libc headers can be installed separately from installing the rest of
the libc.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D133960
Reduce the number of subintervals that need lookup table and optimize
the evaluation steps.
Currently, `exp2f` is computed by reducing to `2^hi * 2^mid * 2^lo` where
`-16/32 <= mid <= 15/32` and `-1/64 <= lo <= 1/64`, and `2^lo` is then
approximated by a degree 6 polynomial.
Experiment with Sollya showed that by using a degree 6 polynomial, we
can approximate `2^lo` for a bigger range with reasonable errors:
```
> P = fpminimax((2^x - 1)/x, 5, [|D...|], [-1/64, 1/64]);
> dirtyinfnorm(2^x - 1 - x*P, [-1/64, 1/64]);
0x1.e18a1bc09114def49eb851655e2e5c4dd08075ac2p-63
> P = fpminimax((2^x - 1)/x, 5, [|D...|], [-1/32, 1/32]);
> dirtyinfnorm(2^x - 1 - x*P, [-1/32, 1/32]);
0x1.05627b6ed48ca417fe53e3495f7df4baf84a05e2ap-56
```
So we can optimize the implementation a bit with:
# Reduce the range to `mid = i/16` for `i = 0..15` and `-1/32 <= lo <= 1/32`
# Store the table `2^mid` in bits, and add `hi` directly to its exponent field to compute `2^hi * 2^mid`
# Rearrange the order of evaluating the polynomial approximating `2^lo`.
Performance benchmark using perf tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp2f
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH reciprocal throughput : 9.534
System LIBC reciprocal throughput : 6.229
BEFORE:
LIBC reciprocal throughput : 21.405
LIBC reciprocal throughput : 15.241 (with `-msse4.2` flag)
LIBC reciprocal throughput : 11.111 (with `-mfma` flag)
AFTER:
LIBC reciprocal throughput : 18.617
LIBC reciprocal throughput : 12.852 (with `-msse4.2` flag)
LIBC reciprocal throughput : 9.253 (with `-mfma` flag)
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp2f --latency
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH latency : 40.869
System LIBC latency : 30.580
BEFORE
LIBC latency : 64.888
LIBC latency : 61.027 (with `-msse4.2` flag)
LIBC latency : 48.778 (with `-mfma` flag)
AFTER
LIBC latency : 48.803
LIBC latency : 45.047 (with `-msse4.2` flag)
LIBC latency : 37.487 (with `-mfma` flag)
```
Reviewed By: sivachandra, orex
Differential Revision: https://reviews.llvm.org/D133870
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
This function cannot have any instrumentation because it's
assembly must match exactly what the debugger is expecting.
Previously it was just a list of what sanitizers we expect
libc would be sanitized with but this is untenable.
Update the utility functions for checking exceptional values of math
functions to use cpp::optional return values.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D133134
This adds division and power implementations to UInt. Modulo and
division are handled by the same function. These are necessary for some
higher order mathematics, often involving large floating point numbers.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D132184
builtin_wrappers contains the wrappers for the clz builtins, which do
not depend on anything in fputil. This patch moves the file out of
FPUtil. The location is updated as appropriate.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D133035
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
The libc.src.__support.FPUtil.fputil target encompassed many unrelated
files, and provided a lot of hidden dependencies. This patch splits out
all of these files into component parts and cleans up the cmake files
that used them. It does not touch any source files for simplicity, but
there may be changes made to them in future patches.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D132980
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
1) `double log2_eval(double)` function added with better than float precision is added.
2) Some refactoring done to put all auxiliary functions and corresponding data
to one place to reuse the code.
3) Added tests for new functions.
4) Performance and precision tests of the function shows, that it more precise than exiting log2,
(no exceptional cases), but timing is ~5% higer that on current one.
Differential Revision: https://reviews.llvm.org/D132809
This patch allows for adjusting the size of the array that printf uses
to track the types of arguments in index mode. This is useful for
optimizing the tradeoff between memory usage and performance.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131993
The FormatSection and the writer functions both previously took a char*
and a length to represent a string. Now they use the StringView class to
represent that more succinctly. This change also required fixing
everywhere these were used, so it touches a lot of files.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131994
We held off on this before as `LLVM_LIBDIR_SUFFIX` conflicted with it.
Now we return this.
`LLVM_LIBDIR_SUFFIX` is kept as a deprecated way to set
`CMAKE_INSTALL_LIBDIR`. The other `*_LIBDIR_SUFFIX` are just removed
entirely.
I imagine this is too potentially-breaking to make LLVM 15. That's fine.
I have a more minimal version of this in the disto (NixOS) patches for
LLVM 15 (like previous versions). This more expansive version I will
test harder after the release is cut.
Reviewed By: sebastian-ne, ldionne, #libc, #libc_abi
Differential Revision: https://reviews.llvm.org/D130586
* In the full build mode, `ninja install-libc` will install the headers as
well the static archive named libc.a.
* In the default mode, `ninja install-llvmlibc` will only install the
static archive libllvmlibc.a.
Reviewed By: jeffbailey
Differential Revision: https://reviews.llvm.org/D132015
In the printf_core CMake, the file pieces are defined as object
libraries that depend on the File data structure. If these are added
unconditionally they'll try to evaluate that dependancy even when there
is no File available. This patch adds a guard to prevent that error.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131921
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
To accurately measure the size of sprintf in a finished binary, the
easiest method is to simply build a binary with and without sprintf.
This patch adds an integration test that can be built with and without
sprintf, as well as targets to build it.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131735
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
The convert_alpha_numeric function is intentionally non-templated so
that its code can be reused for different bases in code-size sensitive
cases. Previously it was inside the IntegerToString class which created
a different version for each base.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D131725
Change sinf/cosf range reduction to mod pi/32 to be shared with tanf,
since polynomial approximations for tanf on subintervals of length pi/16 do not
provide enough accuracy.
Reviewed By: orex
Differential Revision: https://reviews.llvm.org/D131652
The functions converting integers into decimal, hexadecimal, and octal,
are all very similar. This patch moves to a combined converter to save
code size.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131302
The default IntegerToString class only supports base 10, this patch adds
a version which supports any base between 2 and 36 inclusive. This will
be used in an upcoming patch.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131301
Previously, the integer_to_string tests used EXPECT_TRUE(.equals)
which doesn't have useful error messages. Now they properly check
equality with the EXPECT_EQ macro, which allows for comparing the
strings more naturally.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131300
This data structure uses a backing cpp::array object and supports a
vector like push_back API. In comparison with a traditional vector
data structure, it is of a fixed capacity and cannot be resized.
Differential Revision: https://reviews.llvm.org/D131377
Add "using" and "status" sections to the sidebar to make getting these
easier.
Fixed mobile formatting not overflow left and right.
Tested:
Chrome on Desktop, using mobile restrictions in devtools.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131369
This design is borrowed from the lldb folks (thank you!) to declutter
the page.
* The version number at the top is removed.
* Links are pushed over to a sidebar
* The sidebar has headings
There are other minor changes:
* The warning about this project not being ready is now an RST "warning"
* Links to the Bug Reports and the Source Code are Added
* Refer to this project as either "The LLVM C LIbrary" or "The libc"
Tested:
Built locally
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D131242
This class has only the minimum functionality in it to provide what the
TZ variable parsing needs. In particular, the standard makes guarantees
about how trivial the destructors are, throws an expception if it's used
incorrectly, etc. There are also missing features.
Tested:
Trivial testsuite added, and use in development.
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D129920
Since this now allows, the init/fini array iteration has been added in
a similar fashion to x86_64 and the corresponding test enabled.
Reviewed By: jeffbailey
Differential Revision: https://reviews.llvm.org/D131133
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.
Differential Revision: https://reviews.llvm.org/D130771
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.
Differential Revision: https://reviews.llvm.org/D130762
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.
Differential Revision: https://reviews.llvm.org/D130760
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.
Differential Revision: https://reviews.llvm.org/D130773
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion. Starting with the type_traits header.
Differential Revision: https://reviews.llvm.org/D130727
New exp2 function algorithm:
1) Improved performance: 8.176 vs 15.270 by core-math perf tool.
2) Improved accuracy. Only two special values left.
3) Lookup table size reduced twice.
Differential Revision: https://reviews.llvm.org/D129005
Change `sinf` range reduction to mod pi/16 to be shared with `cosf`.
Previously, `sinf` used range reduction `mod pi`, but this cannot be used to implement `cosf` since the minimax algorithm for `cosf` does not converge due to critical points at `pi/2`. In order to be able to share the same range reduction functions for both `sinf` and `cosf`, we change the range reduction to `mod pi/16` for the following reasons:
- The table size is sufficiently small: 32 entries for `sin(k * pi/16)` with `k = 0..31`. It could be reduced to 16 entries if we treat the final sign separately, with an extra multiplication at the end.
- The polynomials' degrees are reduced to 7/8 from 15, with extra computations to combine `sin` and `cos` with trig sum equality.
- The number of exceptional cases reduced to 2 (with FMA) and 3 (without FMA).
- The latency is reduced while maintaining similar throughput as before.
Reviewed By: zimmermann6
Differential Revision: https://reviews.llvm.org/D130629
The floating point functions all use the same inf and nan formatting. By
separating this functionality out of the %a conversion I make it
available for reuse by %f/e/g.
Reviewed By: lntue, sivachandra
Differential Revision: https://reviews.llvm.org/D129665
The standard says two equal pointers must compare equal
so there is no need to call the user comparator function
in this case.
Differential Revision: https://reviews.llvm.org/D130310
With correctly rounded implementations, these functions will be tested for all
rounding modes. Since fegetround and fesetround are not implemented for arm32,
these tests will fail in all non-default rounding modes. We will re-enable
these entrypoints and tests once fegetround and fesetround are implemented for
arm32.
Add float type and flag for nearest integer to automatically test with
and without SSE4.2 flag.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D129916
Printf's integer converter has been modified to use the new converter. In
future, it will be used to implement other parts of the libc.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D130227
Currently, there are two string parsers that can be used in a call to
strtofloatingpoint. There is the main parser used by Clinger's fast path
and Eisel-Lemire, and the backup parser used by Simple Decimal
Conversion. There was a bug in the backup parser where if the number had
more than 800 digits (the size of the SDC buffer) before the decimal
point, it would just ignore the digits after the 800th and not count
them into the exponent. This patch fixes that issue and adds regression
tests.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D130032
The API in StringView.h for remove_prefix was incorrect and was returning a
new StringView rather than just altering the view.
As part of this, also removed some of the safety features. The comment
correctly noted that the behaviour is undefined in some cases,
but the code and test cases checked for that.
One caller was relying on the old behaviour, so fixed it and added some
comments.
Tested:
check-libc
llvmlibc
libc-loader-tests
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D129950
This adds functionality for rounding towards negative inf, positive inf,
and zero to the float hex conversion (%a).
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D129702
This patch adds all the string and stdlib entrypoints, as well as a few
math entrypoints to the arm32 build.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D129821
Add support for three more string_view functions
1) starts_with(char)
2) ends_with(char)
3) find_first_of(char, size_t)
Reimplemented trim in terms of the new starts_with and ends_with.
Tested:
New unit tests.
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D129618
The integration tests use the loader which sets up the main thread's
self object. So, all integration tests have to depend on the threads
implementation.
Dominic Chen