- Implementation of `tan` for 16-bit floating point inputs scaled by pi.
i.e,. `tanpif16()`
- Implementation of Tanpi in MPFRWrapper for MPFR versions < 4.2
- Exhaustive tests for `tanpif16()`
I have commented out the test for `neg_zero`(creal) because :
1. real(neg_zero + 0.0i) equals zero.
2. real(neg_zero - 0.0i) equals neg_zero.
I am not sure if this is the intended behaviour.
[EDIT]
I have updated tests for `neg_zero` (creal) to be :
```
EXPECT_FP_EQ(func(CFPT(neg_zero - zero * 1.0i)), neg_zero);
EXPECT_FP_EQ(func(CFPT(neg_zero + zero * 1.0i)), zero);
```
because all three [gcc, clang and GNU MPC] also give the same result.
https://godbolt.org/z/hxhcn6aof
and it seems that it is indeed the correct behaviour since Imaginary
types are not supported yet, refer #113671
Implementation of `cos` for half precision floating point inputs scaled
by pi (i.e., `cospi`), correctly rounded for all rounding modes.
---------
Co-authored-by: OverMighty <its.overmighty@gmail.com>
In IEEE 754 and C standards, when calling `frexp` with Inf/Nan inputs,
the exponent result is unspecified. In this case, FreeBSD libc and musl
just passthrough `exp`, while glibc, FreeBSD libm set exp = 0, and MSVC
set exp = -1.
By default, LLVM libc will passthrough `exp` just as FreeBSD libc and
musl, but we also allow users to explicitly choose the return exp value
in this case for compatibility with other libc.
Notice that, gcc did generate passthrough `exp` for `frexp(NaN/Inf,
exp)`: https://godbolt.org/z/sM8fEej4E
Refer: 7.3.1 from [ISO
SPEC](https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3220.pdf)
I have added complex variants of F16 and F128 in libc doc but have
omitted support for them since we will have to first investigate how
their support matrix for clang and gcc looks like, and then add header
guards for them accordingly. Planning to add them in follow up PRs once
this gets landed.
Dyadic floats were an existing option for float to string conversion,
but it had become stale. This patch fixes it up as well as adding proper
config options and test support. Due to the test changes this is a
followup to #110759
This PR implements the iscanonical function as part of the libc math
library.
The addition of this function is crucial for completing the
implementation of remaining math macros, as referenced in #109201
This PR implements the issignaling function as part of the libc math
library, addressing the TODO items mentioned in #110011
The addition of this function is crucial for completing the
implementation of remaining math macros, as referenced in #109201
Summary:
This function can easily be implemented by forwarding it to the host
process. This shows up in a few places that we might want to test the
GPU so it should be provided. Also, I find the idea of the GPU
offloading work to the CPU via `system` very funny.
This patch adds the %m conversion to printf, which prints the
strerror(errno). Explanation of why is below, this patch also updates
the docs, tests, and build system to accomodate this.
The standard for syslog in posix specifies it uses the same format as
printf, but adds %m which prints the error message string for the
current value of errno. For ease of implementation, it's standard
practice for libc implementers to just add %m to printf instead of
creating a separate parser for syslog.
Currently the nan* functions use nullptr dereferencing to crash with
SIGSEGV if the input is nullptr. Both `nan(nullptr)` and `nullptr`
dereferencing are undefined behaviors according to the C standard.
Employing `nullptr` dereference in the `nan` function implementation is
ok if users only linked against the pre-built library, but it might be
completely removed by the compilers' optimizations if it is built from
source together with the users' code.
See for instance: https://godbolt.org/z/fd8KcM9bx
This PR uses volatile load to prevent the undefined behavior if libc is
built without sanitizers, and leave the current undefined behavior if
libc is built with sanitizers, so that the undefined behavior can be
caught for users' codes.
Summary:
The `scanf` function has a "system file" configuration, which is pretty
much what the GPU implementation does at this point. So we should be
able to use it in much the same way.
Since new headergen is now the default for building LLVM-libc, the docs
need to be updated to reflect that. While I was editing those docs, I
took a quick pass at updating other out-of-date pages.
The 32-bit Arm builds of libc define time_t to be `__INTPTR_TYPE__`,
i.e. a 32-bit integer. This is commented in the commit introducing it
(75398f28ebdb600) as being for compatibility with glibc. But in the near
future not even every AArch32 build of glibc will have a 32-bit time_t:
Debian is planning that their next release (trixie) will have switched
to 64-bit. And non-Linux builds of this libc (e.g. baremetal) have no
reason to need glibc compatibility in the first place – and every reason
_not_ to want to start using a 32-bit time_t in 2024 or later.
So I've replaced the `#ifdef` in `llvm-libc-types/time_t.h` with two
versions of the header file, chosen in `CMakeLists.txt` via a new
configuration option. This involved adding an extra parameter to the
cmake `add_header` function to specify different names for the header
file in the source and destination directories.
- added all variations of ffma and fdiv
- will add all new headers into yaml for next patch
- only fsub is left then all basic operations for float is complete
---------
Co-authored-by: OverMighty <its.overmighty@gmail.com>
This PR changes several places in the CMake scripts to make libc build
on Windows. It adds the `errno` entrypoint to the Windows target.
A mistake in the overlay build doc is also fixed.
Tests still cannot be built on Windows because of the lack of osutils.
Prevously, if INT_MIN was passed as a wildcard width to a printf
conversion the parser would attempt to negate it to get the positive
width (and set the left justify flag), but it would underflow and the
width would be treated as 0. This patch corrects the issue by instead
treating a width of INT_MIN as identical to -INT_MAX.
Also includes docs changes to explain this behavior and adding b to the
list of int conversions.
- fadd removed because I need to add for different input types
- finishing rest of basic operations
- noticed duplicates will remove
---------
Co-authored-by: OverMighty <its.overmighty@gmail.com>
