Commit Graph

428 Commits

Author SHA1 Message Date
Siva Chandra Reddy dba74c6817 [libc] Make ULP error reflect the bit distance more closely.
Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D105334
2021-07-02 16:56:01 +00:00
Caitlyn Cano e4b9fecd39 [libc] Add minimal Windows config
A README file with procedure for building/testing LLVM libc on Windows
has also been added.

Reviewed By: sivachandra, aeubanks

Differential Revision: https://reviews.llvm.org/D105231
2021-07-01 20:45:57 +00:00
Siva Chandra Reddy e7e71e9454 [libc][NFC] Remove few deprecated FPUtil header files and test patterns.
Few tests have been converted to the new test patterns to facilitate
this.
2021-06-30 22:09:23 +00:00
Siva Chandra 578a4cfe19 [libc][NFC] Clear all exceptions in exception_flags_test before raising another.
This is because, raising some exceptions can raise other ones. For
example, raising FE_OVERFLOW can raise FE_INEXACT. So, we need to clear all
exceptions if we want a clean slate.
2021-06-30 13:48:07 -07:00
Siva Chandra Reddy 230df8a419 [libc] Allow reading and writing __FE_DENORM if available on x86_64.
Some libcs define __FE_DENORM on x86_64. This change allows reading the
bits corresponding to that non-standard exception.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D105004
2021-06-30 17:32:24 +00:00
Siva Chandra Reddy 804dc3dcf2 [libc] Clear all exceptions before setting in fesetexceptflag.
Previously, exceptions from the flag were being added. This patch
changes it such that only the exceptions in the flag will be set.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D105085
2021-06-30 17:29:48 +00:00
Siva Chandra Reddy 9474ddc3ac [libc] Fix feclearexcept for x86_64.
Previously, feclearexcept cleared all exceptions irrespective of the
argument. This change brings it in line with the aarch64 flavors wherein
only those exceptions listed in the argument will be cleared.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D105081
2021-06-30 17:28:06 +00:00
Siva Chandra Reddy 58af0d567d [libc] Allow target architecture independent configs
Previously, we required entrypoints.txt for every target architecture
supported by a target OS. With this change, we allow architecture
independent config for a target OS. That is, if an architecture specific
entrypoints.txt is missing, then a generic entrypoints.txt for that
target OS will be used.

Reviewed By: caitlyncano

Differential Revision: https://reviews.llvm.org/D105147
2021-06-29 20:41:28 +00:00
Siva Chandra 487f74a6c4 [libc][Obvious] Fix typo in implementation of aarch64 clearExcept.
Instead of reading and updating the status word, control word was being
updated.
2021-06-28 23:17:37 -07:00
Siva Chandra Reddy 2e9c75daff [libc] Use __builtin_ctzll instead of __builtin_ctzl in elements_x86.h.
__builtin_ctzl takes an unsigned long argument which need not be 64-bit
long on all platforms. Using __builtin_ctzll, which takes an unsigned
long long argument, ensures that 64-bit values will be handled on a
wider range of platforms.

Without this change, the test corresponding to M512 fails in Windows.

Reviewed By: gchatelet

Differential Revision: https://reviews.llvm.org/D104897
2021-06-25 22:58:13 +00:00
Siva Chandra Reddy d5700bb694 [libc] Calculate ulp error after rounding MPFR result to the result type.
Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D104615
2021-06-23 20:29:46 +00:00
Guillaume Chatelet 87065c0d24 [libc] add benchmarks for memcmp and bzero
Differential Revision: https://reviews.llvm.org/D104511
2021-06-23 14:19:40 +00:00
Siva Chandra Reddy 7a1e4f1846 [libc][Obvious] Add the new header file PlatformDefs.h to the fputil target. 2021-06-18 07:37:06 +00:00
Siva Chandra Reddy 37afd67c38 [libc] Add few macro definitions to make it easy to accommodate Windows.
The new macro definitions have been used to add Windows specific
specializations.
2021-06-18 07:17:36 +00:00
Guillaume Chatelet 8d64ed8544 [libc] Generate one benchmark per implementation
We now generate as many benchmarks as there are implementations.

Differential Revision: https://reviews.llvm.org/D102156
2021-06-17 12:14:10 +00:00
Guillaume Chatelet 7fff39d9b0 [libc] Add a set of elementary operations
Resubmission of D100646 now making sure that we handle cases were `__builtin_memcpy_inline` is not available.

Original commit message:
Each of these elementary operations can be assembled to support higher order constructs (Overlapping access, Loop, Aligned Loop).
The patch does not compile yet as it depends on other ones (D100571, D100631) but it allows to get the conversation started.

A self-contained version of this code is available at https://godbolt.org/z/e1x6xdaxM
2021-06-16 12:11:45 +00:00
Guillaume Chatelet c3242238b7 Revert "[libc] Add a set of elementary operations"
This reverts commit 4694321fbe.
2021-06-16 11:22:46 +00:00
Guillaume Chatelet 4694321fbe [libc] Add a set of elementary operations
Resubmission of D100646 now making sure that we handle cases were `__builtin_memcpy_inline` is not available.

Original commit message:
Each of these elementary operations can be assembled to support higher order constructs (Overlapping access, Loop, Aligned Loop).
The patch does not compile yet as it depends on other ones (D100571, D100631) but it allows to get the conversation started.

A self-contained version of this code is available at https://godbolt.org/z/e1x6xdaxM
2021-06-16 11:16:24 +00:00
Siva Chandra Reddy 3af3e7dc57 [libc][NFC] Disable thrd_test as it is exhibiting flaky behavior on the bots. 2021-06-15 20:58:36 +00:00
Guillaume Chatelet 2e286f233e Revert "[libc] Add a set of elementary operations"
This reverts commit 8387187c2f.
2021-06-15 15:00:21 +00:00
Guillaume Chatelet 8387187c2f [libc] Add a set of elementary operations
Resubmission of D100646 now making sure that we handle cases were `__builtin_memcpy_inline` is not available.

Original commit message:
Each of these elementary operations can be assembled to support higher order constructs (Overlapping access, Loop, Aligned Loop).
The patch does not compile yet as it depends on other ones (D100571, D100631) but it allows to get the conversation started.

A self-contained version of this code is available at https://godbolt.org/z/e1x6xdaxM
2021-06-15 14:39:04 +00:00
Guillaume Chatelet c11032ad9a Revert "[libc] Add a set of elementary operations"
This reverts commit 454d92ac3b.
2021-06-15 08:01:59 +00:00
Guillaume Chatelet 454d92ac3b [libc] Add a set of elementary operations
Resubmission of D100646 now making sure that we handle cases were `__builtin_memcpy_inline` is not available.

Original commit message:
Each of these elementary operations can be assembled to support higher order constructs (Overlapping access, Loop, Aligned Loop).
The patch does not compile yet as it depends on other ones (D100571, D100631) but it allows to get the conversation started.

A self-contained version of this code is available at https://godbolt.org/z/e1x6xdaxM
2021-06-15 07:57:13 +00:00
Siva Chandra Reddy a58b2827fe [libc] Add hardware implementations of x86_64 sqrt functions. 2021-06-14 21:25:37 +00:00
Guillaume Chatelet ab45c1f21f Revert "[libc] Add a set of elementary operations"
This reverts commit e63f27a3cf.
2021-06-14 09:34:03 +00:00
Guillaume Chatelet e63f27a3cf [libc] Add a set of elementary operations
Each of these elementary operations can be assembled to support higher order constructs (Overlapping access, Loop, Aligned Loop).
The patch does not compile yet as it depends on other ones (D100571, D100631) but it allows to get the conversation started.

Differential Revision: https://reviews.llvm.org/D100646
2021-06-14 09:01:06 +00:00
Tue Ly 4e5f8b4d8d [libc] Add implementation of expm1f.
Use expm1f(x) = exp(x) - 1 for |x| > ln(2).
For |x| <= ln(2), divide it into 3 subintervals: [-ln2, -1/8], [-1/8, 1/8], [1/8, ln2]
and use a degree-6 polynomial approximation generated by Sollya's fpminmax for each interval.
Errors < 1.5 ULPs when we use fma to evaluate the polynomials.

Differential Revision: https://reviews.llvm.org/D101134
2021-06-10 14:58:34 -04:00
Siva Chandra Reddy b5d6da3587 [libc] Remove libc-fuzzer as a dependency to check-libc. 2021-06-10 05:06:03 +00:00
Siva Chandra Reddy 3d515cb185 [libc][NFC][Obvious] Compare against size_t values in ArrayRef tests.
Different platforms treat size_t differently so we should compare sizes
of ArrayRef objects with size_t values (instead of the current unsigned
long values.)
2021-06-09 00:14:05 +00:00
Siva Chandra Reddy 6344a583ca [libc] Add a macro to include/exclude subprocess tests.
This is useful when bringing up LLVM libc on a new OS on which we do not
yet have the subprocess related helper functions.
2021-06-08 23:30:21 +00:00
Siva Chandra Reddy f4c8fd12d5 [libc][NFC] Use add_library instead of add_llvm_library for a few libraries.
These libraries do not depend on LLVM libraries anymore so they do not
have to be added using add_llvm_library.
2021-06-08 23:15:24 +00:00
Simon Pilgrim c2ab3d2c85 LibcBenchmark.h - add missing implicit cmath header dependency. NFCI.
Noticed while investigating if we can remove an unnecessary MathExtras.h include from SmallVector.h
2021-06-06 10:39:31 +01:00
Siva Chandra Reddy b47539a14d [libc] Enable fmaf and fma on x86_64.
They require clang-11 or above for building and hence had to be disabled
as the bots did not have clang-11 or higher. Bots have now been upgraded
so we can enable these functions now.
2021-05-13 20:51:15 +00:00
Siva Chandra Reddy 7deb5ef44f [libc][NFC] Instead of erroring, skip math targets with missing implementations.
Fixes Aarch64 bot.
2021-05-13 19:22:11 +00:00
Siva Chandra Reddy 861dc75906 [libc] Add x86_64 implementations of double precision cos, sin and tan.
The implementations use the x86_64 FPU instructions. These instructions
are extremely slow compared to a polynomial based software
implementation. Also, their accuracy falls drastically once the input
goes beyond 2PI. To improve both the speed and accuracy, we will be
taking the following approach going forward:
1. As a follow up to this CL, we will implement a range reduction algorithm
which will expand the accuracy to the entire double precision range.
2. After that, we will replace the HW instructions with a polynomial
implementation to improve the run time.

After step 2, the implementations will be accurate, performant and target
architecture independent.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D102384
2021-05-13 19:02:00 +00:00
Guillaume Chatelet 6351993da7 [libc] Simplifies multi implementations
This is a roll forward of D101895 with two additional fixes:

Original Patch description:
> This is a follow up on D101524 which:
>
> - simplifies cpu features detection and usage,
> - flattens target dependent optimizations so it's obvious which implementations are generated,
> - provides an implementation targeting the host (march/mtune=native) for the mem* functions,
> - makes sure all implementations are unittested (provided the host can run them).

Additional fixes:
 - Fix uninitialized ALL_CPU_FEATURES
 - Use non pseudo microarch as it is only supported from Clang 12 on

Differential Revision: https://reviews.llvm.org/D102233
2021-05-12 07:24:53 +00:00
Siva Chandra Reddy 0c64cef894 [libc] Rever "Simplifies multi implementations and benchmarks".
This reverts commit 541f107871 as the bots
are failing with unknown architecture "x86-64-v*". Will let the original
author decide on the right course of action to correct the problem and
reland.
2021-05-10 19:20:27 +00:00
Guillaume Chatelet 541f107871 [libc] Simplifies multi implementations and benchmarks
This is a follow up on D101524 which:
 - simplifies cpu features detection and usage,
 - flattens target dependent optimizations so it's obvious which implementations are generated,
 - provides an implementation targeting the host (march/mtune=native) for the mem* functions,
 - makes sure all implementations are unittested (provided the host can run them),
 - makes sure all implementations are benchmarkable (provided the host can run them).

Differential Revision: https://reviews.llvm.org/D101895
2021-05-10 08:23:30 +00:00
Guillaume Chatelet ed4f4edea2 [libc] Allow target architecture customization
This patch provides a way to specify the default target cpu optimizations to use when compiling llvm-libc.
This ensures we don't rely on current compiler's default and allows compiling and cross compiling for a particular target.

Differential Revision: https://reviews.llvm.org/D101991
2021-05-10 07:53:48 +00:00
Guillaume Chatelet 7c2ece523d [libc] Normalize LIBC_TARGET_MACHINE
Current implementation defines LIBC_TARGET_MACHINE with the use of CMAKE_SYSTEM_PROCESSOR.
Unfortunately CMAKE_SYSTEM_PROCESSOR is OS dependent and can produce different results.
An evidence of this is the various matchers used to detect whether the architecture is x86.

This patch normalizes LIBC_TARGET_MACHINE and renames it LIBC_TARGET_ARCHITECTURE.
I've added many architectures but we may want to limit ourselves to x86 and ARM.

Differential Revision: https://reviews.llvm.org/D101524
2021-05-05 15:52:42 +00:00
Raman Tenneti a72499e475 [libc] Introduce asctime, asctime_r to LLVM libc
[libc] Introduce asctime, asctime_r to LLVM libc

asctime and asctime_r share the same common code. They call asctime_internal
a static inline function.

asctime uses snprintf to return the string representation in a buffer.
It uses the following format (26 characters is the buffer size) as per
7.27.3.1 section in http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2478.pdf.
The buf parameter for asctime_r shall point to a buffer of at least 26 bytes.

snprintf(buf, 26, "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n",...)

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D99686
2021-05-03 17:15:00 -07:00
Guillaume Chatelet 0e97e84a65 [libc] warns about missing linting only in full build mode
Differential Revision: https://reviews.llvm.org/D101609
2021-05-03 08:39:26 +00:00
Siva Chandra Reddy c6aa206b42 [libc] Add differential quality and perf analysis targets for sinf and cosf.
Infrastructure needed for setting up the diff binaries has been added.
 Along the way, an exhaustive test for sinf and cosf have also been added.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D101276
2021-04-26 19:39:33 +00:00
Guillaume Chatelet b5f04d81a2 [libc] Use different alignment for memcpy between ARM and x86.
Aligned copy used to be 'destination aligned' for x86 but this decision was reverted in D93457 where we noticed that it was better for ARM to be 'source aligned'.
More benchmarking confirmed that it can be up to 30% faster to align copy to destination for x86. This Patch offers both implementations and switches x86 back to destination aligned.
It also fixes alignment to 32 byte on x86.

Differential Revision: https://reviews.llvm.org/D101296
2021-04-26 19:30:00 +00:00
Guillaume Chatelet fa404ae43a [libc] Enhance ArrayRef + unittests
This patch mostly adds unittests for `ArrayRef` and `MutableArrayRef`, additionnaly:
 - We mimic the behavior of `std::vector` and disallow CV qualified type (`ArrayRef<const X>` is not allowed).
   This is to make sure that the type traits are always valid (e.g. `value_type`, `pointer`, ...).
 - In the previous implementation `ArrayRef` would define `value_type` as `const T` but this is not correct, it should be `T` for both `MutableArrayRef` and `ArrayRef`.
 - We add the `equals` method to ease testing,
 - We define the constructor taking an `Array` outside of the base implementation to ensure we match `const Array<T>&` and not `Array<const T>&` in the case of `ArrayRef`.

Differential Revision: https://reviews.llvm.org/D100732
2021-04-21 13:25:24 +00:00
Siva Chandra Reddy f76fb7d420 [libc] Add fma to the C standard spec. 2021-04-21 06:00:35 +00:00
Siva Chandra Reddy 653345155a [libc] Disable fma and fmaf for x86_64.
The version of clang installed on the buildbot workers is not able to
compile them. However, the version of gcc installed is able to compile
them fine. So, this change disables them until we can find a way to
compile them using clang on the buildbot workers.
2021-04-21 05:01:15 +00:00
Siva Chandra 95934c3a37 [libc] Add hardware implementations of fma and fmaf for x86_64 and aarch64.
The current generic implementation of the fmaf function has been moved
to the FPUtil directory. This allows one use the fma operation from
implementations of other math functions like the trignometric functions
without depending on/requiring the fma/fmaf/fmal function targets. If
this pattern ends being convenient, we will switch all generic math
implementations to this pattern.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D100811
2021-04-21 04:31:27 +00:00
Siva Chandra bbba69425c [libc][NFC] Use explicit conversion in aarch64 FEnv. 2021-04-16 22:53:12 -07:00
Siva Chandra Reddy 7db1102a10 [libc]NFC] Use explicit conversion on frexpl_test and logbl_test. 2021-04-17 05:50:00 +00:00