Commit Graph

370 Commits

Author SHA1 Message Date
Siva Chandra e161d36cea [libc][Obvious] Add deps of fopencookie_test only if it is enabled. 2022-04-26 00:10:29 -07:00
Michael Jones ff1374785f [libc] Add Printf FormatSection Matcher
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
2022-04-22 14:21:39 -07:00
Siva Chandra Reddy 19a6dd33ee [libc] Add the implementation of the GNU extension function fopencookie.
Reviewed By: lntue, michaelrj

Differential Revision: https://reviews.llvm.org/D124141
2022-04-22 08:02:25 +00:00
Siva Chandra Reddy 22f9dca113 [libc] Add the implementation of the fflush function.
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
2022-04-20 19:43:39 +00:00
Siva Chandra Reddy 945e0220fd [libc] Add GNU extention functions fread_unlocked and fwrite_unlocked.
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
2022-04-20 15:39:27 +00:00
Michael Jones f14334ffa1 [libc][docs] Add doc for libc string functions
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
2022-04-14 13:03:01 -07:00
Siva Chandra Reddy 0258f56646 [libc] Add a definition of pthread_attr_t and its getters and setters.
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
2022-04-11 16:08:49 +00:00
Michael Jones 4f4752ee6f [libc][NFC] implement printf parser
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
2022-04-08 14:21:13 -07:00
Michael Jones 5561ab3495 [libc] Add holder class for va_lists
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
2022-04-05 11:39:57 -07:00
Siva Chandra Reddy 83f153ce34 [libc] Add pthread_mutexattr_t type and its setters and getters.
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
2022-04-04 18:11:12 +00:00
Tue Ly a5466f0436 [libc] Improve the performance of expm1f.
Improve the performance of expm1f:
- Rearrange the selection logic for different cases to improve the overall
throughput.
- Use the same degree-4 polynomial for large inputs as `expf`
(https://reviews.llvm.org/D122418), reduced from a degree-7 polynomial.

Performance benchmark using perf tool from CORE-MATH project
(https://gitlab.inria.fr/core-math/core-math/-/tree/master):
Before this patch:
```
$ ./perf.sh expm1f

CORE-MATH reciprocal throughput   : 15.362
System LIBC reciprocal throughput : 53.288
LIBC reciprocal throughput        : 54.572

$ ./perf.sh expm1f --latency

CORE-MATH latency   : 57.759
System LIBC latency : 147.146
LIBC latency        : 118.057
```

After this patch:
```
$ ./perf.sh expm1f

CORE-MATH reciprocal throughput   : 15.359
System LIBC reciprocal throughput : 53.188
LIBC reciprocal throughput        : 14.600

$ ./perf.sh expm1f --latency

CORE-MATH latency   : 57.774
System LIBC latency : 147.119
LIBC latency        : 60.280

```

Reviewed By: michaelrj, santoshn, zimmermann6

Differential Revision: https://reviews.llvm.org/D122538
2022-03-30 19:23:25 -04:00
Tue Ly 6168b42225 [libc] Improve the performance of expf.
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
2022-03-25 12:20:20 -04:00
Tue Ly b9d87d7466 [libc] Improve the performance of exp2f.
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
2022-03-24 18:06:37 -04:00
Michael Jones 6d8ce42825 [libc][obvious] only test FILE on working platforms
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
2022-03-24 10:19:34 -07:00
Siva Chandra Reddy 107ce71849 [libc] Use real objects and archives in integration tests.
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.
2022-03-24 07:02:33 +00:00
Siva Chandra Reddy 441606f5ff [libc] Add implementations of fopen, flose, fread, fwrite and fseek.
A follow up patch will add feof and ferror.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D122327
2022-03-24 04:20:12 +00:00
Michael Jones 6d0f5d95ad [libc][obvious] add aligned_alloc as entrypoint
This patch adds aligned_alloc as an entrypoint. Previously it was being
included implicitly.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D122362
2022-03-23 16:44:15 -07:00
Siva Chandra Reddy 316f9fd638 [libc] Link the SCUDO integration tests to a special entrypoint collection.
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
2022-03-23 23:27:23 +00:00
Michael Jones 805899e68a [libc] Change FEnv to use MXCSR as source of truth
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
2022-03-23 16:08:00 -07:00
Siva Chandra Reddy 7fdb50c813 [libc] Add a new rule add_integration_test.
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
2022-03-23 20:57:29 +00:00
Siva Chandra Reddy 3bfbb68e1e [libc] Rename libc-integration-test to libc-api-test.
Reviewed By: jeffbailey, michaelrj

Differential Revision: https://reviews.llvm.org/D122272
2022-03-23 20:25:34 +00:00
Siva Chandra Reddy a0f6d12cd4 [libc][File] Fix a bug under fseek(..., SEEK_CUR).
Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D122284
2022-03-23 16:24:15 +00:00
Siva Chandra Reddy df4814d45d [libc] Add a linux file implementation.
Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D121976
2022-03-21 07:07:22 +00:00
Siva Chandra Reddy 9527a2f58f [libc][NFC] Keep the mutex with the base File data structure.
This is now possible because we have a platform independent abstraction
for mutexes.

Reviewed By: lntue, michaelrj

Differential Revision: https://reviews.llvm.org/D121773
2022-03-16 19:05:23 +00:00
Tue Ly 4c9bfec67c [libc] Let exhaustive tests indicate each interval PASSED/FAILED.
Let exhaustive tests indicate each interval PASSED/FAILED.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D121564
2022-03-16 09:56:03 -04:00
Siva Chandra Reddy 827575a7f8 [libc] Add implementation of POSIX lseek function.
Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D121676
2022-03-15 16:24:48 +00:00
Alex Brachet ae4b59f179 [libc] Fix exit not calling new handlers registered from a call to atexit in atexit handler 2022-03-15 15:18:41 +00:00
Alex Brachet d7c920e1a0 [libc][BlockStore] Add back, pop_back and empty methods
Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D121656
2022-03-15 15:11:57 +00:00
Tue Ly 64af346b18 [libc] Implement expm1f function that is correctly rounded for all rounding modes.
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
2022-03-15 10:24:56 -04:00
Tue Ly 64721a3312 [libc] Implement exp2f function that is correctly rounded for all rounding modes.
Implement exp2f function that is correctly rounded for all rounding modes.

Reviewed By: sivachandra, zimmermann6

Differential Revision: https://reviews.llvm.org/D121463
2022-03-14 09:42:37 -04:00
Tue Ly 38cadd90b7 [libc] Implement expf function that is correctly rounded for all rounding modes.
Implement expf function that is correctly rounded for all rounding modes.

Reviewed By: sivachandra, zimmermann6

Differential Revision: https://reviews.llvm.org/D121440
2022-03-11 07:16:47 -05:00
Siva Chandra Reddy 1f45a1071d [libc][Obvious] Destroy the block store var in block store test. 2022-03-10 21:36:46 +00:00
Siva Chandra Reddy 19c6098097 [libc] Add a resizable container with constexpr constructor and destructor.
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
2022-03-10 21:28:23 +00:00
Tue Ly 0f031daea8 [libc] Initial support for darwin-aarch64.
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
2022-03-10 09:26:09 -05:00
Tue Ly ffb410d3f9 [libc] Add testing macros for errno and floating point exceptions.
Add testing macros for errno and floating point exceptions.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D121235
2022-03-08 15:49:43 -05:00
Michael Jones e1dcda966e [libc][NFC] remove completed TODOs
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
2022-03-08 11:58:14 -08:00
Michael Jones bf0ded805a [libc][NFC] split standalone_cpp into single headers
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
2022-03-08 11:56:08 -08:00
Siva Chandra Reddy fe2cc14ad4 [libc] Align the stack pointer in the start function.
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
2022-03-07 19:45:53 +00:00
Stella Laurenzo 38151a08c2 Reapply "[cmake] Prefix gtest and gtest_main with "llvm_"."
This reverts commit 7cdda6b8ce.

Differential Revision: https://reviews.llvm.org/D121020
2022-03-04 13:45:43 -08:00
Tue Ly db46c7770f [libc] Fix small bugs in aarch64/FEnvImpl.h and simplify feclearexcept_test.
Fix small bugs in aarch64/EFnvImpl.h and simplify feclearexcept_test.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D120997
2022-03-04 15:18:03 -05:00
Tue Ly 76ec69a911 [libc] Remove the redundant header FPUtil/FEnvUtils.h
Remove the redundant header FPUtil/FEnvUtils.h, use FPUtil/FEnvImpl.h header instead.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D120965
2022-03-04 14:09:47 -05:00
Siva Chandra Reddy dd33f9cdef [libc] Make the errno macro resolve to the thread local variable directly.
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
2022-03-04 17:29:49 +00:00
Stella Laurenzo 7cdda6b8ce Revert "[cmake] Prefix gtest and gtest_main with "llvm_"."
lldb buildbot failure. will investigate and roll forward.

This reverts commit 9f37775472.
2022-03-02 11:13:46 -08:00
Stella Laurenzo 9f37775472 [cmake] Prefix gtest and gtest_main with "llvm_".
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
2022-03-02 10:53:32 -08:00
Siva Chandra Reddy 75747c7394 [libc] Remove the remaining uses of stdatomic.h.
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
2022-03-01 17:12:39 +00:00
Siva Chandra Reddy 1137255585 [libc] Add a class "Atomic" as a simple equivalent of std::atomic.
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
2022-02-28 23:51:44 +00:00
Alex Brachet d66983861a [libc] Add exit and atexit
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
2022-02-17 17:21:55 +00:00
Tue Ly f1ec99f973 [libc] Improve hypotf performance with different algorithm correctly rounded to all rounding modes.
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
2022-02-16 09:48:51 -05:00
Siva Chandra Reddy 4ef02da094 [libc] Add a platform independent buffered file IO data structure.
Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D119458
2022-02-15 05:34:29 +00:00
Raman Tenneti 31eccf99ec [libc] [Obvious] Fix.
Disable getenv_test.

Reviewed By: rtenneti

Differential Revision: https://reviews.llvm.org/D119758
2022-02-14 11:56:01 -08:00