Split the code for parsing hexadecimal floating point numbers from the
code for parsing the decimal floating point numbers so that the parsing
can be faster for both of them.
This decreases the time for the benchmark in release mode by about 15%,
which noticeably beats GLibc.
Old version: 2.299s
New version: 1.893s
GLibc: 2.133s
Tests run by running the following command 10 times for each version:
time ~/llvm-project/build/bin/libc_str_to_float_comparison_test ~/parse-number-fxx-test-data/data/*
the parse-number-fxx-test-data-repository is here:
fe94de252c
It's important to build llvm-libc in Release mode for accurate
performance comparisons against glibc (set -DCMAKE_BUILD_TYPE=Release in
your cmake).
You also have to build the libc_str_to_float_comparison_test target.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D113036
Adds an implementation for stpcpy and stpncpy, which are posix extension
functions.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D111913
This allows shipping individual functions without also having to provide
memset or bzero at the expense of bigger functions.
Similar to D113097.
Differential Revision: https://reviews.llvm.org/D113108
Similar to D113097 although not strictly necessary for now. It helps
keeping the same structure for all memory functions.
Differential Revision: https://reviews.llvm.org/D113103
This allows shipping individual functions without also having to provide
`memcpy` at the expense of bigger functions.
Next is to use this `inlined_memcpy` in:
- loader/linux/x86_64/start.cpp
- src/string/memmove.cpp
- src/string/mempcpy.cpp
- src/string/strcpy.cpp
- src/string/strdup.cpp
- src/string/strndup.cpp
Differential Revision: https://reviews.llvm.org/D113097
rename str_conv_utils to str_to_integer to be more
in line with str_to_float.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D113061
We may want to restrict the detected platforms to only `x86_64` and `aarch64`.
There are still custom detection in api.td but I don't think we can handle these:
- config/linux/api.td:205
- config/linux/api.td:199
Differential Revision: https://reviews.llvm.org/D112818
We may want to restrict the detected platforms to only `x86_64` and `aarch64`.
There are still custom detection in api.td but I don't think we can handle these:
- config/linux/api.td:205
- config/linux/api.td:199
Differential Revision: https://reviews.llvm.org/D112818
Add the fast path first described by Clinger [1] with additions by Gay [2].
This speeds up conversion by about 10% by handling numbers with fewer digits
more efficiently.
[1] Clinger WD. How to Read Floating Point Numbers Accurately.
SIGPLAN Not 1990 Jun;25(6):92–101. https://doi.org/10.1145/93548.93557.
[2] Gay DM, Correctly rounded binary-decimal and decimal-binary conversions;
1990. AT&T Bell Laboratories Numerical Analysis Manuscript 90-10.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D112580
The idea is to move all pieces related to the actual libc sources to the
"src" directory. This allows downstream users to ship and build just the
"src" directory.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D112653
malloc, calloc, realloc, and free are all functions that other libc
functions depend on, but are pulled from external sources, instead of
having an internal implementation. This patch adds a way to include
functions like that as entrypoints in the list of external entrypoints,
and includes the malloc functions using this new path.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D112104
Previously, strtol/ll/ul/ull would return a pointer to the end of its
parsing, regardless of if it detected a number. Now it will return a
length of 0 when it doesn't find a number.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D112176
Add an implementation for memccpy and mempcpy. These functions are
posix extensions for the moment.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D111762
This adds strncat to llvm libc. In addition, an error was found with
strcat and that was fixed.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D111583
Also, this adds unit tests to check that limits.h complies with the C
standard.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D110643
The C standard only guarantees the sign of return value. The exact return
value is implementation defined.
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D109588
- Replace `move_byte_forward()` with `memcpy`. In `memcpy` implementation,
it copies bytes forward from beginning to end. Otherwise, `memmove` unit
tests will break.
- Make `memmove` unit tests work.
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D109316
Michael Jones