Commit Graph

44 Commits

Author SHA1 Message Date
Tue Ly 131dda9acc [libc] Implement sincosf function correctly rounded to all rounding modes.
Refactor common range reductions and evaluations for sinf, cosf, and
sincosf.  Added exhaustive tests for sincosf.

Performance before the patch:
```
System LIBC reciprocal throughput : 30.205
LIBC reciprocal throughput        : 30.533

System LIBC latency : 67.961
LIBC latency        : 61.564
```
Performance after the patch:
```
System LIBC reciprocal throughput : 30.409
LIBC reciprocal throughput        : 20.273

System LIBC latency : 67.527
LIBC latency        : 61.959
```

Reviewed By: orex

Differential Revision: https://reviews.llvm.org/D130901
2022-08-05 09:58:01 -04:00
Jeff Bailey 3b631e47fe [libc] Trivial implementation of std::optional
This class has only the minimum functionality in it to provide what the
TZ variable parsing needs.  In particular, the standard makes guarantees
about how trivial the destructors are, throws an expception if it's used
incorrectly, etc.  There are also missing features.

Tested:
Trivial testsuite added, and use in development.

Reviewed By: gchatelet

Differential Revision: https://reviews.llvm.org/D129920
2022-08-05 02:51:44 +00:00
Guillaume Chatelet 49eb58063f [libc][NFC] Use STL case for utility
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.

Differential Revision: https://reviews.llvm.org/D130771
2022-08-01 09:27:37 +00:00
Guillaume Chatelet 91eb0b6584 [libc][NFC] Use STL case for limits
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.

Differential Revision: https://reviews.llvm.org/D130762
2022-08-01 09:18:25 +00:00
Guillaume Chatelet 3f3bbd7370 [libc][NFC] Use STL case for functional
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.

Differential Revision: https://reviews.llvm.org/D130760
2022-08-01 09:10:59 +00:00
Guillaume Chatelet d3d498fbf6 Reland [libc][NFC] Use STL case for array
This is a reland of https://reviews.llvm.org/D130773
2022-08-01 08:47:27 +00:00
Guillaume Chatelet de00bd573e Revert "[libc][NFC] Use STL case for array"
This reverts commit 7add0e5fdc.
2022-08-01 08:44:52 +00:00
Guillaume Chatelet 7add0e5fdc [libc][NFC] Use STL case for array
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion.

Differential Revision: https://reviews.llvm.org/D130773
2022-08-01 08:43:05 +00:00
Tue Ly 2ff187fbc9 [libc] Implement cosf function that is correctly rounded to all rounding modes.
Implement cosf function that is correctly rounded to all rounding
modes.

Performance benchmark using perf tool from CORE-MATH project

(https://gitlab.inria.fr/core-math/core-math/-/tree/master) on Ryzen 1700:
Before this patch (not correctly rounded):
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh cosf
CORE-MATH reciprocal throughput   : 19.043
System LIBC reciprocal throughput : 26.328
LIBC reciprocal throughput        : 30.955

$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh cosf --latency
GNU libc version: 2.31
GNU libc release: stable
CORE-MATH latency   : 49.995
System LIBC latency : 59.286
LIBC latency        : 60.174

```
After this patch (correctly rounded):
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh cosf
GNU libc version: 2.31
GNU libc release: stable
CORE-MATH reciprocal throughput   : 19.072
System LIBC reciprocal throughput : 26.286
LIBC reciprocal throughput        : 13.631

$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh cosf --latency
GNU libc version: 2.31
GNU libc release: stable
CORE-MATH latency   : 49.872
System LIBC latency : 59.468
LIBC latency        : 56.119
```

Reviewed By: orex, zimmermann6

Differential Revision: https://reviews.llvm.org/D130644
2022-07-29 21:08:31 -04:00
Guillaume Chatelet f72261508a [libc][NFC] Use STL case for type_traits
Migrating all private STL code to the standard STL case but keeping it under the CPP namespace to avoid confusion. Starting with the type_traits header.

Differential Revision: https://reviews.llvm.org/D130727
2022-07-29 09:57:03 +00:00
Tue Ly 15b9380dfd [libc] Change sinf range reduction to mod pi/16 to be shared with cosf.
Change `sinf` range reduction to mod pi/16 to be shared with `cosf`.

Previously, `sinf` used range reduction `mod pi`, but this cannot be used to implement `cosf` since the minimax algorithm for `cosf` does not converge due to critical points at `pi/2`.  In order to be able to share the same range reduction functions for both `sinf` and `cosf`, we change the range reduction to `mod pi/16` for the following reasons:
- The table size is sufficiently small: 32 entries for `sin(k * pi/16)` with `k = 0..31`.  It could be reduced to 16 entries if we treat the final sign separately, with an extra multiplication at the end.
- The polynomials' degrees are reduced to 7/8 from 15, with extra computations to combine `sin` and `cos` with trig sum equality.
- The number of exceptional cases reduced to 2 (with FMA) and 3 (without FMA).
- The latency is reduced while maintaining similar throughput as before.

Reviewed By: zimmermann6

Differential Revision: https://reviews.llvm.org/D130629
2022-07-27 12:23:36 -04:00
Benjamin Kramer 9484ddbfa1 [bazel] Port 628fbbef81 2022-07-26 15:36:15 +02:00
Tue Ly d883a4ad02 [libc] Implement sinf function that is correctly rounded to all rounding modes.
Implement sinf function that is correctly rounded to all rounding modes.

- We use a simple range reduction for `pi/16 < |x|` :
    Let `k = round(x / pi)` and `y = (x/pi) - k`.
    So `k` is an integer and `-0.5 <= y <= 0.5`.
Then
```
sin(x) = sin(y*pi + k*pi)
          = (-1)^(k & 1) * sin(y*pi)
          ~ (-1)^(k & 1) * y * P(y^2)
```
    where `y*P(y^2)` is a degree-15 minimax polynomial generated by Sollya with:
```
> P = fpminimax(sin(x*pi)/x, [|0, 2, 4, 6, 8, 10, 12, 14|], [|D...|], [0, 0.5]);
```

- Performance benchmark using perf tool from CORE-MATH project
(https://gitlab.inria.fr/core-math/core-math/-/tree/master) on Ryzen 1700:
Before this patch (not correctly rounded):
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh sinf
CORE-MATH reciprocal throughput   : 17.892
System LIBC reciprocal throughput : 25.559
LIBC reciprocal throughput        : 29.381
```
After this patch (correctly rounded):
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh sinf
CORE-MATH reciprocal throughput   : 17.896
System LIBC reciprocal throughput : 25.740

LIBC reciprocal throughput        : 27.872
LIBC reciprocal throughput        : 20.012     (with `-msse4.2` flag)
LIBC reciprocal throughput        : 14.244     (with `-mfma` flag)
```

Reviewed By: zimmermann6

Differential Revision: https://reviews.llvm.org/D123154
2022-07-22 10:07:31 -04:00
Tue Ly 0f782b84cb [libc] Add nearest integer instructions to fputil.
Add round to nearest integer instructions to fputil.  This will be
used in sinf implementation https://reviews.llvm.org/D123154

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D129776
2022-07-14 13:20:35 -04:00
Siva Chandra Reddy 300f8da8e8 [libc] Add Uint128 type as a fallback when __uint128_t is not available.
Also, the unused specializations of __int128_t have been removed.

Differential Revision: https://reviews.llvm.org/D128304
2022-06-24 16:03:35 +00:00
Guillaume Chatelet aeccc16497 Re-land [libc] Apply no-builtin everywhere, remove unnecessary flags
This is a reland of D126773 / b2a9ea4420.

The removal of `-mllvm -combiner-global-alias-analysis` has landed separately
in D128051 / 7b73f53790.

And the removal of `-mllvm --tail-merge-threshold=0` is scheduled for
removal in a subsequent patch.
2022-06-22 12:30:20 +00:00
Guillaume Chatelet 7b73f53790 [libc] Rely on __builtin_memcpy_inline for memcpy implementation
This patch removes usage of `-mllvm -combiner-global-alias-analysis`
and relies on compiler builtin to implement `memcpy`.

Note that `-mllvm -combiner-global-alias-analysis` is actually only useful for
functions where buffers can alias (namely `memcpy` and `memmove`). The other
memory functions where not benefiting from the flag anyways.

The upside is that the memory functions can now be compiled from source with
thinlto (thinlto would not be able to carry on the flag when doing inlining).

The downside is that for compilers other than clang (i.e. not providing
`__builtin_memcpy_inline`) the codegen may be worse.

Differential Revision: https://reviews.llvm.org/D128051
2022-06-17 14:22:26 +00:00
Guillaume Chatelet c26366979b [libc][bazel] Remove memcpy dependency in memmove 2022-06-17 09:07:24 +00:00
Guillaume Chatelet 4a6929f811 Revert "[libc] Apply no-builtin everywhere, remove unnecessary flags"
This reverts commit b2a9ea4420.
2022-06-16 09:28:17 +00:00
Adrian Kuegel 61132005a9 Fix bazel BUILD. 2022-06-10 08:26:00 +02:00
Tue Ly 63aa853389 [libc] Add expm1f function to bazel's build overlay.
Add expm1f function to bazel's build overlay.

Reviewed By: gchatelet

Differential Revision: https://reviews.llvm.org/D127298
2022-06-08 09:49:47 -04:00
Guillaume Chatelet ffa479a452 [libc] fix typo in BUILD.bazel feature 2022-06-01 13:53:36 +00:00
Guillaume Chatelet b2a9ea4420 [libc] Apply no-builtin everywhere, remove unnecessary flags
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
2022-06-01 13:34:36 +00:00
Fangrui Song da9d41cb87 [Bazel] Fix typo: startlark=>starlark 2022-05-31 14:12:41 -07:00
Guillaume Chatelet 0443bfabe7 Revert "[libc] Apply no-builtin everywhere, remove unnecessary flags"
This reverts commit 94d6dd9057.
2022-05-20 14:37:17 +00:00
Alex Brachet c3856cb739 [bazel][libc] Fix bazel build
Differential revision: https://reviews.llvm.org/D126028
2022-05-19 22:58:50 +00:00
Guillaume Chatelet 94d6dd9057 [libc] Apply no-builtin everywhere, remove unnecessary flags
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
2022-05-19 09:08:42 +00:00
Michael Jones dd7f30464b [libc] fix uint includes and libc bazel
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
2022-05-12 11:40:52 -07:00
Jorge Gorbe Moya ac1235dda6 Fix bazel rule for __support_fputil_fma when using header modules.
Putting __support/FPUtil/x86_64/FMA.h in `hdrs` will trigger a
compilation action for that header, and it will always `#error` out for
non-FMA targets. Move these platform-specific headers that are
conditionally included to `textual_hdrs` instead.
2022-04-08 16:28:31 -07:00
Tue Ly c5f8a0a1e9 [libc] Add support for x86-64 targets that do not have FMA instructions.
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
2022-04-08 14:12:24 -04:00
Sterling Augustine 07998f6d75 Correct and complete dependency sets after 74b411d38c
Prior to this change the __support_cpp_array_ref target's only dependency was libc_root.
but it #includes "TypeTraits.h" and Array.h for that matter.

These dependencies matter when building in distributed build systems and the relevant
files must be know for the distributed build to ship them to the executor.

Differential Revision: https://reviews.llvm.org/D121974
2022-03-17 19:52:49 -07:00
Michael Jones 74b411d38c [libc][bazel] split support_standalone_cpp target
previously the support_standalone_cpp target contained all of the files
in the __support/cpp folder. This change splits these out so that only
what is needed is included. In addition, this change adds the new
support files that previously didn't have targets.

Reviewed By: lntue, gchatelet

Differential Revision: https://reviews.llvm.org/D121314
2022-03-15 16:40:43 -07:00
Benjamin Kramer 317e6a8077 [bazel] Port 76ec69a911 2022-03-04 20:18:00 +01:00
Alina Sbirlea 21aaa1fb22 [bazel] Add libc dependency. 2022-02-16 17:15:45 -08:00
Guillaume Chatelet 7e7ecef980 [libc] Replace type punning with bit_cast
Although type punning is defined for union in C, it is UB in C++.
This patch introduces a bit_cast function to convert between types in a safe way.

This is necessary to get llvm-libc compile with GCC.
This patch is extracted from D119002.

Differential Revision: https://reviews.llvm.org/D119145
2022-02-08 20:45:59 +00:00
Siva Chandra Reddy e07100002e [libc][bazel overlay] Add a target for strncpy. 2022-02-02 20:19:32 +00:00
Jordan Rupprecht 282c83c323 [libc] Add missing sqrt deps for layering checks 2022-01-28 12:11:27 -08:00
Tue Ly ad4ee2d778 [libc] Refactor sqrt implementations and add tests for generic sqrt implementations.
Re-apply https://reviews.llvm.org/D118173 with fix for aarch64.

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D118433
2022-01-28 13:39:03 -05:00
Siva Chandra Reddy 4beba3a32a [libc] Revert "Refactor sqrt implementations and add tests for generic sqrt implementations."
This reverts commit 21c4c82c20.
2022-01-27 21:06:14 +00:00
Tue Ly 21c4c82c20 [libc] Refactor sqrt implementations and add tests for generic sqrt implementations.
Refactor sqrt implementations:
- Move architecture specific instructions from `src/math/<arch>` to `src/__support/FPUtil/<arch>` folder.
- Move generic implementation of `sqrt` to `src/__support/FPUtil/generic` folder and add it as a header library.
- Use `src/__support/FPUtil/sqrt.h` for architecture/generic selections.
- Add unit tests for generic implementation of `sqrt`.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D118173
2022-01-27 11:54:54 -05:00
Clint Caywood 57eb5033cd [libc] Add bazel definition for hypot/hypotf.
Patch by Clint Caywood.

Differential Revision: https://reviews.llvm.org/D118053
2022-01-24 09:54:23 -08:00
Guillaume Chatelet 0dc339c870 [libc][NFC][bazel] remove unneeded bzl_library 2021-12-15 17:50:32 +00:00
Guillaume Chatelet 354e5cf776
Embed licence into package 2021-12-15 15:17:24 +01:00
Guillaume Chatelet 8ed70d0189 [libc] Bazel overlay for libc
This patch provides a draft overlay to support compilation of llvm libc with Bazel.

Tested on linux x86-64 with
```
cd git/llvm-project/utils/bazel
bazelisk-linux-amd64 build --sandbox_base=/dev/shm --config=generic_clang @llvm-project//libc:all
```

Differential Revision: https://reviews.llvm.org/D114712
2021-12-13 19:14:22 +00:00