This patch adds the entrypoint for printf. With this, building a
"hello world" program with just LLVM-libc is possible.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D126831
Add return values to converter functions to allow for better error
handling when writing files. Also move the file writing code around to
be easier to read.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D127773
Tests for pthread_detach and thrd_detach have not been added. Instead, a
test for the underlying implementation has been added as it makes use of
an internal wait method to synchronize with detached threads.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D127479
Implement double precision FMA (Fused Multiply-Add) for targets without
FMA instructions using __uint128_t to store the intermediate results.
Reviewed By: michaelrj, sivachandra
Differential Revision: https://reviews.llvm.org/D124495
A previous patch added the constant EXP_MANT_MASK to the FloatProperties
for other types of long double. This patch adds it to the special 80-bit
x87 long double.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D127550
Previously all FILE objects were fully buffered, this patch adds line
buffering and unbuffered output, as well as applying them to stdout and
stderr.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D126829
A small refactoring of builtin functions in preparation to adding fmod/fmodf function.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D127088
Previously printf_main was a header library, but header library
dependencies don't work properly so it's been moved to an object
library. Additionally, the writers have been marked inline.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D126830
This patch adds support for d, i, and u conversions in printf, as well
as comprehensive unit tests.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D125929
The compile options now match that of thrd_create. Two compile options
are of importance:
1. -O3 - This is required so that stack is not used between the clone
syscall and the start function in the child thread.
2. -fno-omit-frame-pointer - This is required so that we can sniff out
the thread start args from the child thread's stack memory.
Without these two options, pthread_create will exhibit flaky behavior.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D127381
previously the printf converter tests reused the same string_writer,
which meant that each test depended on the tests before it to succeed.
This makes a new string_writer for each test to simplify and clarify the
tests.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D127341
Rewrite the introduction of the page to state clearly the goals of
LLVM's libc project.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D127174
list(POP_FRONT) is only added to cmake in 3.15, while our base line
version is 3.13
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D127129
Detect if the architecture supports FMA instructions and if
the targets depend on fma.
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D123615
They do not yet support all the feature/attributes in pthread_attr_t.
Future changes will add such support.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D126718
The state is now stored on the thread's stack memory. This enables
implementing pthread API like pthread_detach which takes the pthread_t
structure argument by value.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D126716
Note, this is a re-submission of D125894 with `features = ["-header_modules"]`
added to the main BUILD.bazel file.
Some functions like `stpncpy` are implemented in terms of `memset` but are not
currently using `-fno-builtin-memset`. This is somewhat hidden by the fact that
we use `-ffreestanding` globally and that `-ffreestanding` implies
`-fno-builtin` for Clang.
This patch also removes `-mllvm -combiner-global-alias-analysis` that is Clang
specific and that does not bring substantial gains on modern processors.
Also we keep `-mllvm --tail-merge-threshold=0` for aarch64 in CMakeLists.txt
but we omit it in the Bazel config. This is because Bazel consumes the source
files directly and so it can use PGO to take optimal decisions locally.
Differential Revision: https://reviews.llvm.org/D126773
This patch is a subpart of D125768 intented to make the review easier.
The `Address` struct represents a pointer but also adds compile time knowledge
like alignment or temporal/non-temporal that helps with downstream instruction
selection.
Differential Revision: https://reviews.llvm.org/D125966
Add FLAGS option for add_header_library, add_object_library,
add_entrypoint_object, and add_libc_unittest.
In general, a flag is a string provided for supported functions under the
multi-valued option `FLAGS`. It should be one of the following forms:
FLAG_NAME
FLAG_NAME__NO
FLAG_NAME__ONLY
A target will inherit all the flags of its upstream dependency.
When we create a target `TARGET_NAME` with a flag using (add_header_library,
add_object_library, ...), its behavior will depend on the flag form as follow:
- FLAG_NAME: The following 2 targets will be generated:
`TARGET_NAME` that has `FLAG_NAME` in its `FLAGS` property.
`TARGET_NAME.__NO_FLAG_NAME` that depends on `DEP.__NO_FLAG_NAME` if
`TARGET_NAME` depends on `DEP` and `DEP` has `FLAG_NAME` in its `FLAGS`
property.
- FLAG_NAME__ONLY: Only generate 1 target `TARGET_NAME` that has `FLAG_NAME`
in its `FLAGS` property.
- FLAG_NAME__NO: Only generate 1 target `TARGET_NAME.__NO_FLAG_NAME` that
depends on `DEP.__NO_FLAG_NAME` if `DEP` is in its DEPENDS list and `DEP`
has `FLAG_NAME` in its `FLAGS` property.
To show all the targets generated, pass SHOW_INTERMEDIATE_OBJECTS=ON to cmake.
To show all the targets' dependency and flags, pass
`SHOW_INTERMEDIATE_OBJECTS=DEPS` to cmake.
To completely disable a flag FLAG_NAME expansion, set the variable
`SKIP_FLAG_EXPANSION_FLAG_NAME=TRUE`.
Reviewed By: michaelrj, sivachandra
Differential Revision: https://reviews.llvm.org/D125174
This patch adds the file_writer header, which just provides a wrapper
for File->write, as well as fprintf to use it. There are no unit tests
for file_writer since it's too simple to need them, but fprintf does
have a simple test of writing to a file.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D125939
They are added as entrypoint object targets. The header-gen
infrastructure has been extended to enable handling standard required
global objects. The libc-api-test has also been extended to verify the
global object declarations.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D126329
Simple implementations of the functions pthread_mutex_init,
pthread_mutex_destroy, pthread_mutex_lock and pthread_mutex_unlock have
have also been added. Future patches will extend these functions to add
features required by the POSIX specification.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D126235
Some functions like `stpncpy` are implemented in terms of `memset` but are not
currently using `-fno-builtin-memset`. This is somewhat hidden by the fact that
we use `-ffreestanding` globally and that `-ffreestanding` implies
`-fno-builtin` for Clang.
This patch also removes `-mllvm -combiner-global-alias-analysis` that is Clang
specific and that does not bring substantial gains on modern processors.
Also we keep `-mllvm --tail-merge-threshold=0` for aarch64 in CMakeLists.txt
but we omit it in the Bazel config. This is because Bazel consumes the source
files directly and so it can use PGO to take optimal decisions locally.
Differential Revision: https://reviews.llvm.org/D125894
Generally, size_t is an alias for unsigned long long. In the strlcpy
tests, the return value of strlcpy (a size_t) is compared to an unsigned
long. On Linux unsigned long and unsigned long long are both 64 bits,
but on windows unsigned long is 32 bits. Since the macros require
identical types for both sides, this caused a build failure on windows.
This patch changes the constants to be explicit size_t values.
Differential Revision: https://reviews.llvm.org/D125917
After adding sprintf, snprintf is simple. The functions are very
similar. The tests only cover the behavior of the max length since the
sprintf tests should cover the other behavior.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D125826
This adds the sprintf entrypoint, as well as unit tests. Currently
sprintf only supports %%, %s, and %c, but the other conversions are on
the way.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D125573
This adds the main pieces of the last piece of printf, the converter.
This takes the completed format section from the parser and then
converts it to a string for the writer, which is why it was the last
piece to be written. So far it supports chars and strings, but more
pieces are coming. Additionally, it supports replacing all of the
conversion functions with user supplied versions at compile time to
allow for additional functionality.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D125327
This patch adds a document describing the status of the string functions
in LLVM-libc.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D123823
This patch fixes the includes for the new UInt class so that the api
test now passes, additionally it fixes the bazel files to account for
the new dependencies.
Differential Revision: https://reviews.llvm.org/D125490
Some platforms don't support proper 128 bit integers, but some
algorithms use them, such as any that use long doubles. This patch
modifies the existing UInt class to support the necessary operators.
This does not put this new class into use, that will be in followup
patches.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D124959
This patch is a followup to the previous patch which implemented the
main printf parsing logic as well as sequential mode. This patch adds
index mode.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D123424
The entrypoint list for windows hasn't been updated in a while, this
adds all of the entrypoints that are working for windows now.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D125058
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
Guillaume Chatelet