This is a implementation of find remainder fmod function from standard libm.
The underline algorithm is developed by myself, but probably it was first
invented before.
Some features of the implementation:
1. The code is written on more-or-less modern C++.
2. One general implementation for both float and double precision numbers.
3. Spitted platform/architecture dependent and independent code and tests.
4. Tests covers 100% of the code for both float and double numbers. Tests cases with NaN/Inf etc is copied from glibc.
5. The new implementation in general 2-4 times faster for “regular” x,y values. It can be 20 times faster for x/y huge value, but can also be 2 times slower for double denormalized range (according to perf tests provided).
6. Two different implementation of division loop are provided. In some platforms division can be very time consuming operation. Depend on platform it can be 3-10 times slower than multiplication.
Performance tests:
The test is based on core-math project (https://gitlab.inria.fr/core-math/core-math). By Tue Ly suggestion I took hypot function and use it as template for fmod. Preserving all test cases.
`./check.sh <--special|--worst> fmodf` passed.
`CORE_MATH_PERF_MODE=rdtsc ./perf.sh fmodf` results are
```
GNU libc version: 2.35
GNU libc release: stable
21.166 <-- FPU
51.031 <-- current glibc
37.659 <-- this fmod version.
```
The entrypoint list for windows hasn't been updated in a while, this
adds all of the entrypoints that are working for windows now.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D125058
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
Add inttypes.h to llvm libc. As its first functions strtoimax and
strtoumax are included.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D108736
Adds atoi, atol, atoll, strtol, strtoll, strtoul, and strtoull to the
list of entrypoints for Windows and aarch64 linux, as well as moving
them out of the LLVM_LIBC_FULL_BUILD condition for x86_64 linux.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D108477
Add strncmp as a function to strings.h. Also adds unit tests, and adds
strncmp as an entrypoint for all current platforms.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D106901
All fenv functions are also enabled for windows. Since two tests,
enabled_exceptions_test and feholdexcept_test are still failing on
windows, they have been disabled.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D106808
Included more math functions to Windows's entrypoints
and made a cmake option (-DLLVM_LIBC_MPFR_INSTALL_PATH)
where the user can specify the install path where the MPFR
library was built so it can be linked. The try_compile was
moved to LLVMLibCCheckMPFR.cmake, so the variable that is
set after this process can retain its value in other files
of the same parent file. A direct reason for this is for
LIBC_TESTS_CAN_USE_MPFR to be true when the user specifies
MPFR's path and retain its value even after leaving the file.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D106894
Incorporated the varied functions for nextafter and refactored
NextAfterTest.h to correctly define bitWidthOfType for both
Linux and Windows; by letting FloatProperties take care
of the directives' logic based on the platform being used.
This allows to successfully run nextafter's tests.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D106395
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
Kirill Okhotnikov