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>
Scanf parsing reads the longest possibly valid prefix for a given
conversion. Then, it performs the conversion on that string. In the case
of "0xZ" with a hex conversion (either "%x" or "%i") the longest
possibly valid prefix is "0x", which makes it the "input item" (per the
standard). The sequence "0x" is not a "matching sequence" for a hex
conversion, meaning it results in a matching failure, and parsing ends.
This is because to know that there's no valid digit after "0x" it reads
the 'Z', but it can only put back one character (the 'Z') leaving it
with consuming an invalid sequence.
(inspired by a thread on the libc-coord mailing list:
https://www.openwall.com/lists/libc-coord/2024/10/15/1, see 7.32.6.2 in
the standard for more details.)
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
Previously you could cast between bigints with different numbers of
bits, but only if they had the same underlying type. This patch adds the
ability to cast between bigints with different underlying types, which
is needed for #110894
Fixes https://github.com/llvm/llvm-project/issues/110122
- Create remap_file_pages.h/.cpp wrapper for the linux sys call.
- Add UnitTests for remap_file_pages
- Add function to libc/spec/linux.td
- Add Function spec to mman.yaml
- Improve the accuracy of fast pass' range reduction.
- Provide tighter error estimations.
- Reduce the table size when `LIBC_MATH_SMALL_TABLES` flag is set.
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
The sprintf tests have a macro named "ASSERT_STREQ_LEN" which was used
in about half of the tests. This patch moves all of the tests which can
to using that macro. This patch also enables long double tests for %e
and %g, since those never got finished. There's still some work to do
enabling long double testing for long doubles other than the intel 80
bit format, but that can land in a followup.
The `#ifdef LIBC_COPT_FLOAT_TO_STR_REDUCED_PRECISION` lines are for a
followup patch.
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:
The GPU handling for a lot of `FILE *` functions pretty much just
forwards it to the host via RPC. This test checks for implementation
defined behavior, which sometimes passes and sometimes doesn't. We just
disable it here so it works on the standard semantics.
We do this forwarding primarily for interopt w/ the host if the user is
compiling from an offloading language (e.g. CUDA).
Fixes#106467.
Bind was accidentally removed while trying to clean up functions that
didn't end up being needed. The GCC issue was just a warning treated as
an error.
This patch adds the necessary functions to send and receive messages
over a socket. Those functions are: recv, recvfrom, recvmsg, send,
sendto, sendmsg, and socketpair for testing.
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.
This is an implementation of `ctime` and includes `ctime_r`.
According to documentation, `ctime` and `ctime_r` are defined as the
following:
```c
char *ctime(const time_t *timep);
char *ctime_r(const time_t *restrict timep, char buf[restrict 26]);
```
closes#86567
```
Performance tests with inputs in denormal range:
-- My function --
Total time : 2731072304 ns
Average runtime : 68.2767 ns/op
Ops per second : 14646276 op/s
-- Other function --
Total time : 3259744268 ns
Average runtime : 81.4935 ns/op
Ops per second : 12270913 op/s
-- Average runtime ratio --
Mine / Other's : 0.837818
Performance tests with inputs in normal range:
-- My function --
Total time : 93467258 ns
Average runtime : 2.33668 ns/op
Ops per second : 427957777 op/s
-- Other function --
Total time : 637295452 ns
Average runtime : 15.9324 ns/op
Ops per second : 62765299 op/s
-- Average runtime ratio --
Mine / Other's : 0.146662
Performance tests with inputs in normal range with exponents close to each other:
-- My function --
Total time : 95764894 ns
Average runtime : 2.39412 ns/op
Ops per second : 417690014 op/s
-- Other function --
Total time : 639866770 ns
Average runtime : 15.9967 ns/op
Ops per second : 62513075 op/s
-- Average runtime ratio --
Mine / Other's : 0.149664
```
---------
Co-authored-by: Tue Ly <lntue@google.com>
This PR first adds osutils for Windows, and changes some libc code to
make libc and its tests build on the Windows target. It then temporarily
disables some libc tests that are currently problematic on Windows.
Specifically, the changes besides the addition of osutils include:
- Macro `LIBC_TYPES_HAS_FLOAT16` is disabled on Windows. `clang-cl`
generates calls to functions in `compiler-rt` to handle float16
arithmetic and these functions are currently not linked in on Windows.
- Macro `LIBC_TYPES_HAS_INT128` is disabled on Windows.
- The invocation to `::aligned_malloc` is changed to an invocation to
`::_aligned_malloc`.
- The following unit tests are temporarily disabled because they
currently fail on Windows:
- `test.src.__support.big_int_test`
- `test.src.__support.arg_list_test`
- `test.src.fenv.getenv_and_setenv_test`
- Tests involving `__m128i`, `__m256i`, and `__m512i` in
`test.src.string.memory_utils.op_tests.cpp`
- `test_range_errors` in `libc/test/src/math/smoke/AddTest.h` and
`libc/test/src/math/smoke/SubTest.h`
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.
Added proxy header for the jmp_buf type and changed all use instances
from __jmp_buf * to the typedef alias jmp_buf , fixed the link to LLVM
in stack_t.h description
In patch #105293 tests for vfscanf were added, meant to be identical to
the fscanf tests. Unfortunately, the author forgot to rename the target
file causing an occasional test flake where one test writes to the file
while the other is trying to read it. This patch fixes the issue by
renaming the target test file for the vfscanf test.
