requires that on Linux, all linker input files are marked as CET enabled
in .note.gnu.property section. For high-level language source codes,
.note.gnu.property section is added by compiler with the -fcf-protection
option. For assembly sources, include <cet.h> to add .note.gnu.property
section.
H.J. Lu [Tue, 11 Jan 2022 16:09:58 +0000 (08:09 -0800)]
x86-64: Hide internal assembly functions
Hide x86-64 internal assembly functions. Before
$ nm -D lib/libzstd.so.1 | grep usingDTable_internal_bmi2_asm_loop 00000000000c23c0 T _HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop 00000000000c23c0 T HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop 00000000000c283d T _HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop 00000000000c283d T HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop
$
Nick Terrell [Fri, 7 Jan 2022 23:09:56 +0000 (15:09 -0800)]
Fix stderr progress logging for decompression
When decompressing with `-q` and an output file, the progress bar was mistakenly printed. This is a minimal fix, with a larger refactor to be stacked on top of it.
Nick Terrell [Fri, 7 Jan 2022 00:00:02 +0000 (16:00 -0800)]
[opt] Fix oss-fuzz bug in optimal parser
oss-fuzz uncovered a scenario where we're evaluating the cost of litLength = 131072,
which can't be represented in the zstd format, so we accessed 1 beyond LL_bits.
Fix the issue by making it cost 1 bit more than litLength = 131071.
There are still follow ups:
1. This happened because literals_cost[0] = 0, so the optimal parser chose 36 literals
over a match. Should we bound literals_cost[literal] > 0, unless the block truly only
has one literal value?
2. When no matches are found, the cost model isn't updated. In this case no matches were
found for an entire block. So the literals cost model wasn't updated at all. That made
the optimal parser think literals_cost[0] = 0, where it is actually quite high, since
the block was entirely random noise.
W. Felix Handte [Thu, 6 Jan 2022 05:20:49 +0000 (00:20 -0500)]
Avoid xxHash Dependency by Inlining
xxHash symbols are present in `libzstd.so`, but they are local and therefore
unavailable outside the lib. There are two possible solutions to the problem.
We could make those symbols global, or we could remove the dependency.
This commit chooses the latter approach. I suppose this comes at the cost of
code size / build time. I'm open to comments on whether this is a good thing
to do, especially since this will apply even when we are statically linking
everything.
W. Felix Handte [Thu, 23 Dec 2021 19:57:16 +0000 (14:57 -0500)]
Improve Module Map File
This commit makes several changes:
1. It adds modules for the dictionary builder and errors headers.
2. It captures all of the macros that are used to configure these headers.
When the headers are imported as modules and one of these macros is defined
the compiler issues a warning that it needs to be defined on the CLI.
3. It promotes the modulemap file into the root of the lib directory.
Experimentation shows that clang's `-fimplicit-module-maps` will find the
modulemap when placed here, but not when it's put in a subdirectory.
Nick Terrell [Wed, 5 Jan 2022 00:05:59 +0000 (16:05 -0800)]
[meson] Explicitly disable assembly for non clang/gcc copmilers
After merging #2951 I realized that we will want to explicitly disable
assembly when we aren't including the assembly source file. Otherwise,
if some non clang/gcc compiler does support assembly, it would fail to
build.
Yann Collet [Fri, 31 Dec 2021 21:03:12 +0000 (13:03 -0800)]
fix performance issue in scenario #2966 (part 1)
When re-using a compression state, across multiple successive compressions,
the state should minimize the amount of allocation and initialization required.
This mostly matters in situations where initialization is an overwhelming task
compared to compression itself.
This can happen when the amount to compress is small,
while the compression state was given the impression that it would be much larger,
aka, streaming mode without providing a srcSize hint.
This commit fixes it, making this scenario once again on par with v1.4.9.
Note that this does not completely fix #2966,
since another heavy initialization, specific to row mode,
is also happening (and was not present in v1.4.9).
This will be fixed in a separate commit.
W. Felix Handte [Thu, 30 Dec 2021 01:47:12 +0000 (17:47 -0800)]
Mark Huffman Decoder Assembly `noexecstack` on All Architectures
Apparently, even when the assembly file is empty (because
`ZSTD_ENABLE_ASM_X86_64_BMI2` is false), it still is marked as possibly
needing an executable stack and so the whole library is marked as such. This
commit applies a simple patch for this problem by moving the noexecstack
indication outside the macro guard.
Yann Collet [Tue, 28 Dec 2021 19:46:15 +0000 (11:46 -0800)]
separate newRep() from updateRep()
the new contracts seems to make more sense :
updateRep() updates an array of repeat offsets _in place_,
while newRep() generates a new structure with the updated repeat-offset array.
Most callers are actually expecting the in-place variant,
and a limited sub-section, in `zstd_opt.c` mainly, prefer `newRep()`.
Yann Collet [Fri, 24 Dec 2021 05:58:08 +0000 (21:58 -0800)]
introduce macros STORE_OFFSET() and STORE_REPCODE()
this meant to abstract the sumtype representation required
to transfert `offcode` to `ZSTD_storeSeq()`.
Unfortunately, the sumtype numeric representation is currently a leaky abstraction
that has permeated many other parts of the code,
especially within `zstd_lazy.c` and also within `zstd_opt.c` and `zstd_compress.c`.
While this PR makes a good job a transfering a large nb of call sites
to using the new macros, there are still a few sites where this transformation is more complex,
or where the numeric representation itself it used "as is".
One of the problematics area is the decision to use the numeric format of the sumtype
within the match finders of `zstd_lazy`.
This commit doesn't change the behavior, it only introduces and employes the macros,
but eventually the resulting code remains identical.
At target, if the numeric representation of the sumtype can be completely abstracted
and no other part of the code depends on it,
it will be possible to move it towards something slightly more efficient.
Yann Collet [Thu, 23 Dec 2021 21:39:46 +0000 (13:39 -0800)]
changed seqDef.matchLength into seqDef.mlBase
since this is effectively what is stored in this field (== matchLength - MINMATCH).
This makes it clearer what needs to be done when reading from / writing to this field.
Eli Schwartz [Thu, 23 Dec 2021 01:17:16 +0000 (20:17 -0500)]
meson: fix MSVC support
Regression from commit a5f2c45528032ed20c33e0f8cd2c163a800a0017. It is
not possible to unconditionally add the asm sources, since not all
compilers understand the .s file extension.
Specifically for meson, only compilers inheriting from the GNU mixin
will allow a .s file at configure time.
zstd doesn't support asm for MSVC for the same basic reason; if/when
Windows asm support is added, it would involve preprocessing with nasm,
most likely.
Yann Collet [Wed, 15 Dec 2021 22:37:05 +0000 (14:37 -0800)]
fixed incorrect rowlog initialization
the variable has only very limited usage,
being only used once at the beginning of the block for prefetching only,
hence the error had no impact on compression ratio.
projects / thirdparty / zstd.git / log
