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
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
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
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
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
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
This patch provides `TYPED_TEST` and `TYPED_TEST_F` (similar in functionnality to gtest).
This is needed to extensively test building blocks for memory functions.
Example for `TYPED_TEST_F`:
```
template <typename T> class LlvmLibcMyTestFixture : public testing::Test {};
using Types = testing::TypeList<char, int, long>;
TYPED_TEST_F(LlvmLibcMyTestFixture, Simple, Types) {
EXPECT_LE(sizeof(ParamType), 8UL);
}
```
Example for `TYPED_TEST`:
```
using Types = testing::TypeList<char, int, long>;
TYPED_TEST(LlvmLibcMyTest, Simple, Types) {
EXPECT_LE(sizeof(ParamType), 8UL);
}
```
`ParamType` is displayed as fully qualified canonical type which can be difficult to read, the user can provide a more readable name by using the `REGISTER_TYPE_NAME` macro.
Differential Revision: https://reviews.llvm.org/D100631
This helps us avoid the uncomfortable reinterpret-casts. Avoiding the
reinterpret casts prevents us from tripping the sanitizers as well.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D100360
This is needed to prevent asan/msan instrumentation to redirect CopyBlock to `__asan_memcpy` (resp. `__msan_memcpy`).
These functions would then differ operation to `memcpy` which leads to reentrancy issues.
With this patch, `memcpy` is fully instrumented and covered by asan/msan.
If this turns out to be too expensive, instrumentation can be selectively or fully disabled through the use of the `__attribute__((no_sanitize(address, memory)))` annotation.
Differential Revision: https://reviews.llvm.org/D99598
This option will build LLVM libc as a full libc by itself. In this mode,
it is not expected that it will be mixed with other libcs. The
non-full-build mode will be the default LLVM libc build mode. In a future
where LLVM libc is complete enough, the full libc build will be made the
default mode.
These functions used inline asm to read FPU state. This change adds
explicit unpoisoning in these functions as the sanitizers don't see the
read operations.
This class is to serve as a replacement for llvm::StringRef as part of
the plans to limit dependency on other parts of LLVM. One use of
llvm::StringRef in MPFRWrapper has been replaced with the new class.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D97330
Namely, implementations of fegetexceptfflag, fesetexceptflag,
fegetenv, fesetenv, feholdexcept and feupdateenv have been added.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D96935
Few math functions manipulate errno. They assumed that LLVM libc's errno
is available. However, that might not be the case when these functions
are used in a libc which does not use LLVM libc's errno. This change
switches such uses of LLVM libc's errno to the normal public errno macro.
This does not affect LLVM libc's build because the include order ensures
we get LLVM libc's errno. Also, the header check rule ensures we are only
including LLVM libc's errno.h.
Fuchsia's zxtest has a slightly different death test definition, and
this macro makes our death test API work on Fuchsia.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D95648
This is useful when cross-compiling libc to another target in which
case we first need to compile libc-hdrgen for host. We rely on the
existing LLVM CMake infrastructure for that.
Differential Revision: https://reviews.llvm.org/D95205
Summary:
Having a consistent prefix makes selecting all of the llvm libc tests
easier on any platform that is also using the gtest framework.
This also modifies the TEST and TEST_F macros to enforce this change
moving forward.
Reviewers: sivachandra
Subscribers:
This change does not try to move the common parts of x86 and aarch64 and
build few abstractions over them. While this is possible, x86 story
needs a bit of cleanup, especially around manipulation of the mxcsr
register. Moreover, on x86 one can raise exceptions without performing
exception raising operations. So, all of this can be done in follow up
patches.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D94947
Standard C allows all standard headers to declare macros for all
their functions. So after possibly including any standard header
like <ctype.h>, it's perfectly normal for any and all of the
functions it declares to be defined as macros. Standard C requires
explicit `#undef` before using that identifier in a way that is not
compatible with function-like macro definitions.
The C standard's rules for this are extended to POSIX as well for
the interfaces it defines, and it's the expected norm for
nonstandard extensions declared by standard C library headers too.
So far the only place this has come up for llvm-libc's code is with
the isascii function in Fuchsia's libc. But other cases can arise
for any standard (or common extension) function names that source
code in llvm-libc is using in nonstandard ways, i.e. as C++
identifiers.
The only correct and robust way to handle the possible inclusion of
standard C library headers when building llvm-libc source code is to
use `#undef` explicitly for each identifier before using it. The
easy and obvious place to do that is in the per-function header.
This requires that all code, such as test code, that might include
any standard C library headers, e.g. via utils/UnitTest/Test.h, make
sure to include those *first* before the per-function header.
This change does that for isascii and its test. But it should be
done uniformly for all the code and documented as a consistent
convention so new implementation files are sure to get this right.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D94642
This moves utils/UnitTest/Test.[h/cpp] to LibcTest.[h/cpp] and adds a
new Test.h that acts as a switcher so that Fuchsia can use the zxtest
backend for running our tests as part of their build.
FuchsiaTest.h is for including fuchsia's zxtest library and anything
else needed to make the tests work under fuchsia (currently just
undefining the isascii macro for the test).
Downstream users, please fix your build instead of reverting.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D94625
A differential fuzzer for these functions has also been added.
Along the way, a small correction has been done to the normal/subnormal
limits of x86 long double values.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D94109
This reverts commit 352cba2441.
"add back math.h #include utils/FPUtil/ManipulationFunctions.h".
Using `<math.h>` correct so downstream setup should be fixed.
This partially reverts cee1e7d14f4628d6174b33640d502bff3b54ae45:
[libc][NFC][Obvious] Remove few unnecessary #include directives in tests.
That commit causes a test failure in our configuration:
[ RUN ] ILogbTest.SpecialNumbers_ilogb
third_party/llvm/llvm-project/libc/test/src/math/ILogbTest.h:28: FAILURE
Expected: FP_ILOGBNAN
Which is: 2147483647
To be equal to: func(__llvm_libc::fputil::FPBits<T>::buildNaN(1))
Which is: -2147483648
Along the way, made a change to run tool unittests when the target
"check-libc" is run by introducing a libc testsuite for tool unittests.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D93142
A new function to MPFRWrapper has been added, which is used to set up
the unit tests.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D93007
Couple of helper functions enableExcept and disableExcept have been
added. In a later round, they will be used to implemented the GNU
extension functions feenableexcept and fedisableexcept.
Differential Revision: https://reviews.llvm.org/D92821
Refactor src/math/hypotf.cpp and test/src/math/hypotf_test.cpp and reuse them for hypot and hypot_test
Differential Revision: https://reviews.llvm.org/D91831
These two cases are fixed:
1. If numerator is not zero and denominator is infinity, then the
numerator is returned as the remainder.
2. If numerator and denominator are equal in magnitude, then quotient
with the right sign is returned.
The differet tests of remquo, remquof and remquol have been unified
into a single file to avoid duplication.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D92353
The rounding behavior of NormalFloat to float format has been changed
to round to nearest. Also, a bug in NormalFloat to subnormal number
conversion has been fixed.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D91591
This is mostly changing stringref to std::string, outs() to cout,
and small supporting changes. This will make running unit tests possible
on systems that are only grabbing the libc part of llvm.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D91568
This is acheived by making the RunContext a state variable of the test
classes.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D90805
This corrects WrapperGen generating incorrect wrappers for functions
that take no arguments. Previously it would generate a wrapper with a
single argument of type `void`.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D90800
The function listings in api.td are removed. The same lists are now deduced using the information
in entrypoints.txt.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D89267
The implementation is not fully standards compliant in the sense that
errno is not set on error, and floating point exceptions are not raised.
Subnormal range and normal range are tested separately in the tests.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D86666
Tests for frexp[f|l] now use the new capability. Not all input-output
combinations have been addressed by this change. Support for newer combinations
can be added in future as needed.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D86506
This class helps in dealing with normal and subnormal numbers uniformly.
Moreover, since this class has been designed to handle all floating
formats across platforms, it helps implement floating point functions in
a uniform manner.
The implementations of frexp and logb have been switched to use this new
class as it allows us to use just one implementation across all
different floating point formats.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D86241
This eliminates UnitTest's dependency on FPUtil and hence prevents
non-math tests from depending indirectly on FPUtil. The patch
essentially moves some of the existing pieces into a library of its own.
Along the way, renamed add_math_unittest to add_fp_unittest.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D85486
This tool will be used to generate C wrappers for the C++ LLVM libc
implementations. This change does not hook this tool up to anything yet.
However, it can be useful for cases where one does not want to run the
objcopy step (to insert the C symbol in the object file) but can make use
of LTO to eliminate the cost of the additional wrapper call. This can be
relevant for certain downstream platforms. If this tool can benefit other
libc platforms in general, then it can be integrated into the build system
with options to use or not use the wrappers. An example of such a
platform is CUDA.
Reviewed By: abrachet
Differential Revision: https://reviews.llvm.org/D84848
This class is currently used by two tools: HdrGen and PrototypeTestGen.
We will be adding more tools based on this class so it is convenient to
keep it in a util library of its own.
Summary: Update Test (EXPECT_EQ and friends) to accept __uint128_t and floating point types (float, double, long double).
Reviewers: sivachandra
Subscribers: mgorny, libc-commits
Tags: #libc-project
Differential Revision: https://reviews.llvm.org/D83931
Added IsSameV as a convenience variable and used it where convenient.
Reviewers: abrachet, lntue
Differential Revision: https://reviews.llvm.org/D83980
Siva Chandra