This is needed to avoid the following error when using
-fsanitize=undefined with gcc:
lib/x86/adler32_impl.h:214:2: runtime error: signed integer overflow:
1951294680 + 1956941400 cannot be represented in type 'int'
Note that this isn't seen when using -fsanitize=undefined with clang.
Old compilers don't have unsigned vector types, so work around that.
Add a CRC32 implementation that uses the ARM CRC32 instructions.
This is simpler and faster than the PMULL implementation. On AWS
Graviton2, the performance improvement is about 70%. On Hikey960, the
performance improvement is about 30% for the Cortex-A53 cores or about
5% for the Cortex-A73 cores.
Based on work by Greg V <greg@unrelenting.technology>
(https://github.com/ebiggers/libdeflate/pull/45)
and Andrew Steinborn <git@steinborn.me>
(https://github.com/ebiggers/libdeflate/pull/76).
If support for CRC32 instructions is detected, set
ARM_CPU_FEATURE_CRC32. Also define
COMPILER_SUPPORTS_CRC32_TARGET_INTRINSICS when appropriate, and update
run_tests.sh to toggle the crc32 feature for testing.
android_build.sh no longer works with recent NDKs, and it has a lot of
logic to use old NDKs directly that wasn't really necessary because it
could have just required standalone toolchains instead.
Recent NDKs (r19 and later) come with standalone toolchains by default.
Also, they now only include clang, not gcc.
Modify the script to just support these recent NDKs. Also, default to
arm64 and add support for enabling CRC instructions.
Some users may require a valid DEFLATE, zlib, or gzip stream but know
ahead of time that particular inputs are not compressible. zlib
supports "level 0" for this use case. Support this in libdeflate too.
Resolves https://github.com/ebiggers/libdeflate/issues/86
To test the different CRC-32 and Adler-32 implementations, use
LIBDEFLATE_DISABLE_CPU_FEATURES instead of running some hack-ish
'sed' commands to edit the source code.
Make test-only builds of libdeflate support an environmental variable
LIBDEFLATE_DISABLE_CPU_FEATURES that contains a list of CPU features to
disable like "avx512bw,avx2,sse2".
This makes it possible to test all the variants of dynamically
dispatched code without editing the source code.
Note, this environmental variable is not a stable interface, so put the
support for it behind a scary-looking option TEST_SUPPORT__DO_NOT_USE.
In cpuid() in the '__i386__ && __PIC__' case, the second output operand
is written to before the input operands are used. So the second output
operand needs the earlyclobber constraint.
Don't assume that lib_common.h and libdeflate.h don't include
<stdlib.h>. Currently this change doesn't matter unless someone uses
-DFREESTANDING for a Windows build, which isn't supported anyway, but we
might as well clean this up.
Update https://github.com/ebiggers/libdeflate/pull/68
gcc 10 is miscompiling libdeflate on x86_64 at -O3 due to a regression
in how packed structs are handled
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94994).
Work around this by just always using memcpy() for unaligned accesses.
It's unclear that the "packed struct" approach is worthwhile to maintain
anymore. Currently I'm only aware that it's useful with old gcc's on
arm32. Hopefully, compilers are good enough now that we can simply use
memcpy() everywhere.
Update https://github.com/ebiggers/libdeflate/issues/64
For consistency, make the implementations of libdeflate_gzip_compress()
and libdeflate_zlib_compress() use the same parameter name that their
declarations and everywhere else use.
stdint.h is better compatible with freestanding support as it can be
compiled even if target platform lacks I/O capabilities.
[EB - adjusted the include locations, and avoided breaking the build
for old MSVC versions.]
Allow building libdeflate without linking to any libc functions by using
'make FREESTANDING=1'. When using such a library build, the user will
need to call libdeflate_set_memory_allocator() before anything else,
since malloc() and free() will be unavailable.
[Folded in fix from Ingvar Stepanyan to use -nostdlib, and made
freestanding_tests() check that no libs are linked to.]
Update https://github.com/ebiggers/libdeflate/issues/62
In preparation for adding custom memory allocator support, don't call
the standard memory allocation functions directly but rather wrap them
with libdeflate_malloc() and libdeflate_free().
Adds programs/test_zlib.c which currently does the following:
1. Create some dummy data and compress it
2. Try to decompress with libdeflate_zlib_decompress
3. Try to decompress with libdeflate_zlib_decompress, with unnecessary
trailing bytes after the compressed data
4. Try to decompress with libdeflate_zlib_decompress_ex, with
unnecessary trailing bytes after the compressed data
In each step, we check that we get back the original data.
Additionally, libdeflate_zlib_decompress now returns successfully in
case there are additional trailing bytes in the input buffer after the
compressed stream.
Unfortunately, MSVC only accepts __stdcall after the return type, while
gcc only accepts __attribute__((visibility("default"))) before the
return type. So we need a macro in each location.
Also, MSVC doesn't define __i386__; that's gcc specific. So instead use
'_WIN32 && !_WIN64' to detect 32-bit Windows.
