Commit Graph

5135 Commits (ac4f7ead3b8c32c5655ef8c6b964f9971b70085e)

Author SHA1 Message Date
Yann Collet ac4f7ead3b
Merge pull request #1154 from facebook/altOpt
minor optimal parser optimization
2018-05-30 13:05:51 -07:00
Yann Collet 809f2f9322 minor update of literal cost function
just assert() there is no negative cost evaluation for literals
2018-05-29 15:34:50 -07:00
Yann Collet 463a0fe38b simplified optimal parser
removed "cached" structure.
prices are now saved in the optimal table.

Primarily done for simplification.
Might improve speed by a little.
But actually, and surprisingly, also improves ratio in some circumstances.
2018-05-29 14:07:25 -07:00
Yann Collet bb6eaf6495
Merge pull request #1153 from facebook/dynThreshold
changed dynamic fse threshold for offset
2018-05-26 08:43:45 -07:00
Yann Collet e916c365a1 fixed minor visual warning 2018-05-25 20:43:09 -07:00
Yann Collet c6ccf435ae
Merge pull request #1152 from facebook/lowCompression
btultra accepts blocks with poorer compression ratio
2018-05-25 17:46:11 -07:00
Yann Collet a7fdceeccd changed dynamic fse threshold for offset
recent experienced showed that
default distribution table for offset
can get it wrong pretty quickly with the nb of symbols,
while it remains a reasonable choice much longer for lengths symbols.

Changed the formula,
so that dynamic threshold is now 32 symbols for offsets.
It remains at 64 symbols for lengths.

Detection based on defaultNormLog
2018-05-25 17:41:16 -07:00
Yann Collet 4b3a36d5d8 Merge branch 'dev' into lowCompression 2018-05-25 15:45:03 -07:00
Yann Collet 744f36aac4
Merge pull request #1141 from facebook/staticDictCost
Random stuff on High Compression mode
2018-05-25 15:43:32 -07:00
Yann Collet 5f177f1c53 btultra accepts blocks with poorer compression ratio
zstd rejects blocks which do not compress by at least a certain amount.
In which case, such block is simply emitted uncompressed (even if a little bit of compression could be achieved).
This is better for decompression speed, hence for energy.

The logic is controlled by ZSTD_minGain().
The rule is applied uniformly, at all compression levels.

This change makes btultra accepts blocks with poor compression ratios.
We presume that users of btultra mode prefers compression ratio over some decompress speed gains.

The threshold for minimum gain is lowered for btultra
from s>>6 (~1.5% minimum gain)
to s>>7 (~0.8% minimum gain).

This is a prudent change.
Not sure if it's large enough.
2018-05-25 15:19:52 -07:00
Yann Collet e2c0e3d437 slightly nudge choices towards less sequences
also slightly improve some strange detrimental corner cases.
2018-05-25 14:52:21 -07:00
Yann Collet f6ad59ab5c Merge branch 'dev' into staticDictCost 2018-05-24 16:21:02 -07:00
Yann Collet a7c75740b3
Merge pull request #1149 from terrelln/fuzz-py
Small fixes to fuzz.py
2018-05-24 15:56:09 -07:00
Nick Terrell fdd4d8510f Improve compiler detection to work on Mac 2018-05-24 14:21:12 -07:00
Nick Terrell ac852abb8b Define BIT_DEBUG for --debug 2018-05-24 14:21:12 -07:00
Nick Terrell 2a9975f77b Increase the maximum file size 2018-05-24 14:21:12 -07:00
Nick Terrell e712a3a0a3 Small fixes to fuzz.py 2018-05-24 14:21:12 -07:00
Yann Collet 47d2331ed8
Merge pull request #1150 from facebook/fracFse
fix corner case when requiring cost of an FSE symbol
2018-05-24 14:19:30 -07:00
Yann Collet b5ef32fea7 Merge branch 'dev' into fracFse 2018-05-24 14:09:49 -07:00
Yann Collet 776128d16f fix corner case when requiring cost of an FSE symbol
ensure that, when frequency[symbol]==0,
result is (tableLog + 1) bits
with both upper-bit and fractional-bit estimates.

Also : enable BIT_DEBUG in /tests
2018-05-24 13:59:11 -07:00
Yann Collet 08c5be5db3
Merge pull request #1117 from felixhandte/zstd-fast-in-place-dict
ZSTD_fast: Support Searching the Dictionary Context In-Place
2018-05-23 19:32:25 -07:00
Nick Terrell 06b70179da
Work around bug in zstd decoder (#1147)
Work around bug in zstd decoder

Pull request #1144 exercised a new path in the zstd decoder that proved to
be buggy. Avoid the extremely rare bug by emitting an uncompressed block.
2018-05-23 18:02:30 -07:00
Yann Collet 712318a244
Merge pull request #1146 from terrelln/fse-fix
[zstd] Fix decompression edge case
2018-05-23 16:41:42 -07:00
Nick Terrell f2d0924b87 Variable declarations 2018-05-23 14:58:58 -07:00
W. Felix Handte d9c7e67125 Assert that Dict and Current Window are Adjacent in Index Space 2018-05-23 17:53:03 -04:00
W. Felix Handte 298d24fa57 Make loadedDictEnd an Index, not the Dict Len 2018-05-23 17:53:03 -04:00
W. Felix Handte 7ef85e0618 Fixes in re Comments 2018-05-23 17:53:03 -04:00
W. Felix Handte 582b7f85ed Don't Attach Empty Dict Contents
In weird corner cases, they produce unexpected results...
2018-05-23 17:53:03 -04:00
W. Felix Handte 9c92223468 Avoid Undefined Behavior in Match Ptr Calculation 2018-05-23 17:53:03 -04:00
W. Felix Handte a44ab3b475 Remove Out-of-Date Comment 2018-05-23 17:53:03 -04:00
W. Felix Handte 95bdf20a87 Moar Renames 2018-05-23 17:53:03 -04:00
W. Felix Handte 7e0402e738 Also Attach Dict When Source Size is Unknown 2018-05-23 17:53:03 -04:00
W. Felix Handte 3ba70cc759 Clear the Dictionary When Sliding the Window 2018-05-23 17:53:03 -04:00
W. Felix Handte b05ae9b608 Refine ip Initialization to Avoid ARM Weirdness 2018-05-23 17:53:03 -04:00
W. Felix Handte 1a7b34ef28 Use New Index Invariant to Simplify Conditionals 2018-05-23 17:53:03 -04:00
W. Felix Handte 2d598e6fed Force Working Context Indices Greater than Dict Indices 2018-05-23 17:53:03 -04:00
W. Felix Handte d005e5daf4 Whitespace Fix 2018-05-23 17:53:03 -04:00
W. Felix Handte 154eb09419 Switch to Original Match Calc for noDict Repcode Check 2018-05-23 17:53:03 -04:00
W. Felix Handte 191fc74a51 Rename 'hasDict' to 'dictMode' 2018-05-23 17:53:03 -04:00
W. Felix Handte ae4fcf7816 Respond to PR Comments; Formatting/Style/Lint Fixes 2018-05-23 17:53:03 -04:00
W. Felix Handte ca26cecc7a Rename and Reformat 2018-05-23 17:53:03 -04:00
W. Felix Handte 66bc1ca641 Change Cut-Off to 8 KB 2018-05-23 17:53:03 -04:00
W. Felix Handte c31ee3c7f8 Fix Rep Code Initialization 2018-05-23 17:53:03 -04:00
W. Felix Handte b67196f30d Coalesce hasDictMatchState and extDict Checks into One Enum and Rename Stuff 2018-05-23 17:53:03 -04:00
W. Felix Handte 265c2869d1 Split Wrapper Functions to Cause Inlining 2018-05-23 17:53:03 -04:00
W. Felix Handte 6929964d65 Add bounds check in repcode tests 2018-05-23 17:53:03 -04:00
W. Felix Handte 70a537d1d7 Initial Repcode Check Support for Ext Dict Ctx 2018-05-23 17:53:03 -04:00
W. Felix Handte 8d24ff0353 Preliminary Support in ZSTD_compressBlock_fast_generic() for Ext Dict Ctx 2018-05-23 17:53:03 -04:00
W. Felix Handte d18a405779 Refer to the Dictionary Match State In-Place (Sometimes) 2018-05-23 17:53:03 -04:00
Nick Terrell c92dd11940 Error if reported size is too large in edge case 2018-05-23 14:47:20 -07:00