The printf implmentation is made up of three main pieces, the parser,
the converter, and the writer. This patch adds the implementation for
the writer, as well as the function for writing to a string, along with
tests.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D124421
This patch fixes the string to long double tests for systems that use
long double is double, and don't support uint128.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D124803
The PrintfMatcher depends on printf which is in stdio. Stdio is
currently fullbuild only, but the matcher wasn't, causing failing builds
when fullbuild was off. This patch adds the fullbuild condition to the
PrintfMatcher cmake.
Differential Revision: https://reviews.llvm.org/D124304
This patch changes the printf parser tests to use a more robust matcher.
This allows for better debugging of parsing issues. This does not affect
the actual printf code at all, only the tests.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D124130
Note that the underlying flush implementation does not yet fully implement
the POSIX standard. It is complete with respect to the C standard
however. A future change will add the POSIX behavior. It should not affect
the implementation of the fflush function however as the POSIX behavior
will be added in a lower layer.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D124073
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
A section briefly mentioning the planned future enhancements has also
been included.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D123761
This patch adds a document describing the status of the string functions
in LLVM-libc.
Reviewed By: sivachandra, jeffbailey
Differential Revision: https://reviews.llvm.org/D123645
Not all attributes have been added to phtread_attr_t in this patch. They
will be added gradually in future patches.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D123423
This patch adds the sequential mode implementation of the printf parser,
as well as unit tests for it. In addition it adjusts the surrounding
files to accomodate changes in the design found in the implementation
process.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D123339
Make FMA flag checks more accurate for x86-64 targets, and refactor
polyeval to use multiply and add instead when FMA instructions are not
available.
Reviewed By: michaelrj, sivachandra
Differential Revision: https://reviews.llvm.org/D123335
This change is essentially a mechanical change which moves the thread
creation and join implementations from src/threads/linux to
src/__support/threads/linux/thread.h. The idea being that, in future, a
pthread implementation can reuse the common thread implementations in
src/__support/threads.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D123287
This class is intended to be used in cases where a class is being used
on a va_list. It provides destruction and copy semantics with small
overhead. This is intended to be used in printf.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D123061
A simple implementation of the getters and setters has been added. More
logic can be added to them in future as required.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D122969
Instead, memory is allocated and deallocated using mmap and munmap
syscalls directly.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D122876
This patch adds the headers for printf. It contains minimal actual code,
and is more intended to be used for design review. The code is not built
yet, and may have minor errors.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D122773
In the previous patch adding -mfma to functions that need it for windows
builds I missed log2f.
Differential Revision: https://reviews.llvm.org/D122693
On Windows the functions that use fma don't properly include the fma
intrinsics unless -mfma is added to the compile options. This patch adds
the compile option to all of the functions that need it.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D122689
Previously, the "fsqrt" instruction was used on all x86_64 platforms
for finding the square root of long doubles. On long double is double
platforms (e.g. windows) this created errors. This patch changes square
root function for long doubles to be the same as the one for doubles if
long doubles are doubles.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D122688
The clang driver to picks up compiler runtime files using full paths.
Without this, at least for aarch64, the driver tries to pick up the
compiler runtime files from the working directory.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D122617
Reduce the polynomial's degree from 7 down to 4.
Currently we use a degree-7 minimax polynomial on an interval of length 2^-7
around 0 to compute `expf`. Based on the suggestion of @santoshn and the RLIBM
project (https://github.com/rutgers-apl/rlibm-all/blob/main/source/float/exp.c)
and the improvement we made with `exp2f` in https://reviews.llvm.org/D122346,
it is possible to have a good polynomial of degree-4 on a subinterval of length
2^(-7) to approximate e^x.
We did try to either reduce the degree of the polynomial down to 3 or increase
the interval size to 2^(-6), but in both cases the number of exceptional values
exploded. So we settle with using a degree-4 polynomial of the interval of
size 2^(-7) around 0.
Reviewed By: sivachandra, zimmermann6, santoshn
Differential Revision: https://reviews.llvm.org/D122418
Reduce the range-reduction table size from 128 entries down to 64 entries, and
reduce the polynomial's degree from 6 down to 4.
Currently we use a degree-6 minimax polynomial on an interval of length 2^-7
around 0 to compute exp2f. Based on the suggestion of @santoshn and the RLIBM
project (https://github.com/rutgers-apl/rlibm-prog/blob/main/libm/float/exp2.c)
it is possible to have a good polynomial of degree-4 on a subinterval of length
2^(-6) to approximate 2^x.
We did try to either reduce the degree of the polynomial down to 3 or increase
the interval size to 2^(-5), but in both cases the number of exceptional values
exploded. So we settle with using a degree-4 polynomial of the interval of
size 2^(-6) around 0.
Reviewed By: michaelrj, sivachandra, zimmermann6, santoshn
Differential Revision: https://reviews.llvm.org/D122346
The main code for the FILE struct is only enabled on platforms that it
works on, but before this patch the tests were included unconditionally.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D122363
Previously, we used empty, non-ELF crti.o, crtn.o, libm.a and libc++.a
files. Instead, we now still use dummies but they are real ELF object
files and archives.
This patch adds aligned_alloc as an entrypoint. Previously it was being
included implicitly.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D122362
We were previously linking to libllvmlibc.a. But, with libllvmlibc.a now
including functions which depend on the loader, we will have to use the
LLVM libc loader as well. To avoid this, we will link to a special
library which is just a collection of SCUDO allocator entrypoints.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D122360
This patch primarily fixes the fenv implementation on Windows, since
Windows uses the MXCSR in place of the x87 status registers for storing
information about the floating point environment. This allows FEnv to
work correctly on Windows, and successfully build.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D121839
All existing loader tests are switched to an integration test added with
the new rule. Also, the getenv test is now enabled as an integration test.
All loader tests have been moved to test/integration. Also, the simple
checker library for the previous loader tests has been moved to a
separate directory of its own.
A follow up change will perform more cleanup of the loader CMake rules
to eliminate now redundent options.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D122266
An unnecessary dep of the getenv function is removed. From the x86_64
loader, a call to __llvm_libc::memcpy is replaced with call to
__llvm_libc::inline_memcpy.
The platform independent file implementation is not an entrypoint so it
cannot be excluded via the entrypoints.txt file. Hence, we need a
special treatment to exclude it from the build.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D121947
Having a separate flag helps in setting up proper flags when
implementing, say the Linux specialization of File.
Along the way, a signature for a function which is to be used to open
files has been added. The implementation of the function is to be
included in platform specializations.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D121889
This is now possible because we have a platform independent abstraction
for mutexes.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D121773
Implement expm1f function that is correctly rounded for all rounding modes. This is based on expf implementation.
From exhaustive testings, using expf implementation, and subtract 1.0 before rounding the final result to single precision
gives correctly rounded results for all |x| > 2^-4 with 1 exception. When |x| < 2^-25, we use x + x^2 (implemented with a
single fma). And for 2^-25 <= |x| <= 2^-4, we use a single degree-8 minimax polynomial generated by Sollya.
Reviewed By: sivachandra, zimmermann6
Differential Revision: https://reviews.llvm.org/D121574
Implement exp2f function that is correctly rounded for all rounding modes.
Reviewed By: sivachandra, zimmermann6
Differential Revision: https://reviews.llvm.org/D121463
Implement expf function that is correctly rounded for all rounding modes.
Reviewed By: sivachandra, zimmermann6
Differential Revision: https://reviews.llvm.org/D121440
The new container is used to store atexit callbacks. This way, we avoid
the possibility of the destructor of the container itself getting added
as an at exit callback.
Reviewed By: abrachet
Differential Revision: https://reviews.llvm.org/D121350
Add initial support for darwin-aarch64 (macOS M1).
Some differences compared to linux-aarch64:
- `math.h` defined `math_errhandling` by the compiler builtin `__math_errhandling()` but Apple Clang 13.0.0 on M1 does not support `__math_errhandling()` builtin as a macro function or a constexpr function.
- `math.h` defines `UNDERFLOW` and `OVERFLOW` macros.
- Besides 5 usual floating point exceptions: `FE_INEXACT`, `FE_UNDERFLOW`, `FE_OVERFLOW`, `FE_DIVBYZERO`, and `FE_INVALID`, `fenv.h` also has another floating point exception: `FE_FLUSHTOZERO`. The corresponding trap for `FE_FLUSHTOZERO` in the control register is at the different location compared to the status register.
- `FE_FLUSHTOZERO` exception flag cannot be raised with the default CPU floating point operation mode.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D120914
There were some "TODO" messages that were for things that I have already
completed. This patch removes those.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D121232
Previously, the entire support/CPP folder was in one header library,
which meant that a lot of headers were included where they shouldn't be.
This patch splits each header into its own target, as well as adjusting
each place they were included to only include what is used.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D121237
The loader TLS test for x86_64, which now passes, has been enabled.
A future change should enable the test for aarch64 as well.
Reviewed By: jeffbailey
Differential Revision: https://reviews.llvm.org/D121091
The idea is that, other parts of the libc which require thread/lock
support will be able to use this platform independent setup.
With this change, only the linux implementation of a mutex type has been
moved to the new library. Because of this, there is some duplication
between the new library and src/threads/linux. A follow up change will
move all of src/threads/linux to the new library. The duplication should
be eliminated with that move.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120795
With modern architectures having a thread pointer and language supporting
thread locals, there is no reason to use a function intermediary to access
the thread local errno value.
The entrypoint corresponding to errno has been replaced with an object
library as there is no formal entrypoint for errno anymore.
Reviewed By: jeffbailey, michaelrj
Differential Revision: https://reviews.llvm.org/D120920
The upstream project ships CMake rules for building vanilla gtest/gmock which conflict with the names chosen by LLVM. Since LLVM's build rules here are quite specific to LLVM, prefixing them to avoid collision is the right thing (i.e. there does not appear to be a path to letting someone *replace* LLVM's googletest with one they bring, so co-existence should be the goal).
This allows LLVM to be included with testing enabled within projects that themselves have a dependency on an official gtest release.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D120789
New methods to the Atomic class have been added as required. Futex
related types have been consolidated at a common place.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120705
Add LLVM_LIBC_CLANG_TIDY option and allow LLVM_LIBC_ENABLE_LINTING without full build.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119180
Only the methods currently required by the libc have been added.
Most of the existing uses of atomic operations have been switched over
to this new class. A future change will clean up the rest of uses.
This change now allows building mutex and condition variable code with a
C++ compiler which does not have stdatomic.h, for example g++.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120642
__builtin_clz requires just a single instruction on x86 and arm, so this is a performance improvement.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120579
The benchmark framework synthesizes fake "aggregate" Samples representing mean, median and cv.
We're only interested in "iteration" samples.
Differential Revision: https://reviews.llvm.org/D120062
Often atexit is implemented using __cxa_atexit. I have not implemented __cxa_atexit here because it potentially requires more discussion. It is unique for llvm-libc (I think) that it is an exported symbol that wouldn’t be defined in any spec file because it doesn’t have a header. Implementing it will be trivial given what is here already, but I figured it would be more contentious so it can be implemented later.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D119512
Algorithm for hypotf: compute (a*a + b*b) in double precision, then use Dekker's algorithm to find the rounding error, and then correcting it after taking its square-root.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D118157
The prior page was the proposal doc, this one is now
more about what the project intends to do, written in the
present tense.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119379
This implements a basic arm64 loader for Linux, and all the currently
enabled linker tests pass. TLS is not implemented, and functions
using it will have undefined behaviour. Notably, the TLS test is
currently disabled on x86_64.
Much of the structure is copied from x86_64 to allow for a refactoring
of the start code between architectures.
Tested:
ninja libc_loader_tests on aarch64-linux.
Co-authored-by: Raman Tenneti <rtenneti@google.com>
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119641
Previously, building LLVM-libc with GWP ASAN was conditioned on the flag
COMPILER_RT_BUILD_GWP_ASAN, which caused issues do to the default value
of the flag being set in the compiler-rt cmake, which is seperate. Now
GWP ASAN is included based on if it exists as a target, which is more
consistent.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119789
Simplify the logic when the exponent difference is at least MantissaLength + 2, while still maintaining correct rounding for all rounding modes.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119843
Michael Jones