Commit Graph

392 Commits

Author SHA1 Message Date
Tue Ly
484319f497 [libc] Make expm1f correctly rounded when the targets have no FMA instructions.
Add another exceptional value and fix the case when |x| is small.

Performance tests with CORE-MATH project scripts:
With FMA instructions on Ryzen 1700:
```
$ ./perf.sh expm1f
LIBC-location: /home/lnt/experiment/llvm/llvm-project/build/projects/libc/lib/libllvmlibc.a
CORE-MATH reciprocal throughput   : 15.362
System LIBC reciprocal throughput : 53.194
LIBC reciprocal throughput        : 14.595
$ ./perf.sh expm1f --latency
LIBC-location: /home/lnt/experiment/llvm/llvm-project/build/projects/libc/lib/libllvmlibc.a
CORE-MATH latency   : 57.755
System LIBC latency : 147.020
LIBC latency        : 60.269
```
Without FMA instructions:
```
$ ./perf.sh expm1f
LIBC-location: /home/lnt/experiment/llvm/llvm-project/build/projects/libc/lib/libllvmlibc.a
CORE-MATH reciprocal throughput   : 15.362
System LIBC reciprocal throughput : 53.300
LIBC reciprocal throughput        : 18.020
$ ./perf.sh expm1f --latency
LIBC-location: /home/lnt/experiment/llvm/llvm-project/build/projects/libc/lib/libllvmlibc.a
CORE-MATH latency   : 57.758
System LIBC latency : 147.025
LIBC latency        : 70.304
```

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D123440
2022-06-03 15:57:48 -04:00
Tue Ly
614567a7bf [libc] Automatically add -mfma flag for architectures supporting FMA.
Detect if the architecture supports FMA instructions and if
the targets depend on fma.

Reviewed By: gchatelet

Differential Revision: https://reviews.llvm.org/D123615
2022-06-03 01:21:20 -04:00
Siva Chandra Reddy
70c8d12b79 [libc] Add pthread_create and pthread_join functions.
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
2022-06-02 01:47:24 +00:00
Guillaume Chatelet
4cbfd2e7eb [libc][mem*] Address facility + test enum support
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
2022-06-01 09:09:43 +00:00
Tue Ly
800051487f [libc] Implement FLAGS option for generating all combinations for targets.
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
2022-06-01 00:54:07 -04:00
Michael Jones
ba7e1cddda [libc] add fprintf and file_writer
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
2022-05-31 13:59:19 -07:00
Siva Chandra Reddy
9b8ca3c1f1 [libc] Add global stdout and stderr objects.
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
2022-05-27 05:43:49 +00:00
Siva Chandra Reddy
2a5d5078d5 [libc] Add the pthread_mutex_t type.
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
2022-05-24 22:48:14 +00:00
Alex Brachet
b1183305f8 [libc] Add strlcat
Differential Revision: https://reviews.llvm.org/D125978
2022-05-19 21:48:39 +00:00
Michael Jones
72f6dfb378 [libc][windows] fix strlcpy tests
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
2022-05-18 14:11:53 -07:00
Alex Brachet
fc2c8b2371 [libc] Add strlcpy
Differential Revision: https://reviews.llvm.org/D125806
2022-05-18 17:45:05 +00:00
Michael Jones
9f1d905f39 [libc] add snprintf
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
2022-05-17 13:32:59 -07:00
Michael Jones
ff6fe39eca [libc] add sprintf
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
2022-05-17 11:32:20 -07:00
Michael Jones
6a22b185d6 [libc] add printf converter
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
2022-05-12 13:10:05 -07:00
Michael Jones
1170951c73 [libc] add uint128 implementation
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
2022-05-12 11:16:53 -07:00
Tue Ly
13f358376a [libc] Add LINK_LIBRARIES option to add_fp_unittest and add_libc_unittest.
This is needed to prepare for adding FLAGS option.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D125055
2022-05-08 17:33:45 +00:00
Michael Jones
945fa672c6 [libc][NFC] add index mode to printf parser
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
2022-05-06 12:06:08 -07:00
Michael Jones
e072a123d3 [libc] add printf writer
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
2022-05-03 10:15:04 -07:00
Michael Jones
5d1dbe1119 [libc] fix strtold tests on 32 bit systems
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
2022-05-03 10:07:21 -07:00
Siva Chandra Reddy
9db0037bf1 [libc] Add implementations of feof, ferror and clearerr.
The corresponding _unlocked functions have also been added.

Reviewed By: lntue, michaelrj

Differential Revision: https://reviews.llvm.org/D124311
2022-04-29 23:04:35 +00:00
Dominic Chen
ce6bfd102a [libc] Support 32-bit ARM platform tests
Set LONG_DOUBLE_IS_DOUBLE, add ifdefs for 128-bit integer types

Differential Revision: https://reviews.llvm.org/D124204
2022-04-28 12:00:28 -07:00
Dominic Chen
de94cf5286 [libc] Minor test signedness fixes
Resolve compiler warnings about signed conversion

Differential Revision: https://reviews.llvm.org/D124468
2022-04-26 17:10:33 -07:00
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