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Improve zstd_opt build speed and size
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Use the same trick as we did for zstd_lazy in PR #2828:
* Create one search function specialization for each (dictMode, mls).
* Select the search function pointer at the top of the match finder.

Additionally, we no longer inline `ZSTD_compressBlock_opt_generic` into
every function, since `dictMode` is no longer used as a template. Create
two specializations, for opt levels 0 and 2, and call one of the two
specializations.

Lastly, remove the hack that disabled inlining for zstd_opt for the
Linux Kernel, as we've gotten most of the benefit already.

Compilation speed sees a ~4x reduction:

| Compiler | Flags                            | Dev Time (s) | PR Time (s) | Delta |
|----------|----------------------------------|--------------|-------------|-------|
| gcc      | -O3                              |         10.1 |         2.3 |  -77% |
| gcc      | -O3 -fsanitize=address,undefined |         61.1 |        10.2 |  -83% |
| clang    | -O3                              |          9.0 |         2.1 |  -76% |
| clang    | -O3 -fsanitize=address,undefined |         33.5 |         5.1 |  -84% |

Build size is reduced by 150KB - 200KB:

| Compiler | Dev libzstd.a Size (B) | PR libzstd.a Size (B) | Delta |
|----------|------------------------|-----------------------|-------|
| gcc      |                1327476 |               1177108 |  -11% |
| clang    |                1378324 |               1167780 |  -15% |

There is a <2% speed loss in all cases:

| Compiler | Level | Dev Speed (MB/s) | PR Speed (MB/s) | Delta  |
|----------|-------|------------------|-----------------|--------|
| gcc      |    16 |             4.78 |            4.72 | -1.25% |
| gcc      |    17 |             3.49 |            3.46 | -0.85% |
| gcc      |    18 |             2.92 |            2.86 | -2.04% |
| gcc      |    19 |             2.61 |            2.61 |  0.00% |
| clang    |    16 |             4.69 |            4.80 |  2.34% |
| clang    |    17 |             3.53 |            3.49 | -1.13% |
| clang    |    18 |             2.86 |            2.85 | -0.34% |
| clang    |    19 |             2.61 |            2.61 |  0.00% |

Fixes Issue #2862.
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@terrelln
terrelln committed Dec 2, 2021
1 parent 21e28f5 commit 528f30b
Showing 1 changed file with 100 additions and 46 deletions.
146 changes: 100 additions & 46 deletions lib/compress/zstd_opt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,20 +8,6 @@
* You may select, at your option, one of the above-listed licenses.
*/

/**
* Disable inlining for the optimal parser for the kernel build.
* It is unlikely to be used in the kernel, and where it is used
* latency shouldn't matter because it is very slow to begin with.
* We prefer a ~180KB binary size win over faster optimal parsing.
*
* TODO(https://github.com/facebook/zstd/issues/2862):
* Improve the code size of the optimal parser in general, so we
* don't need this hack for the kernel build.
*/
#ifdef ZSTD_LINUX_KERNEL
#define ZSTD_NO_INLINE 1
#endif

#include "zstd_compress_internal.h"
#include "hist.h"
#include "zstd_opt.h"
Expand Down Expand Up @@ -783,30 +769,83 @@ U32 ZSTD_insertBtAndGetAllMatches (
return mnum;
}


FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
ZSTD_match_t* matches, /* store result (match found, increasing size) in this table */
ZSTD_matchState_t* ms,
U32* nextToUpdate3,
const BYTE* ip, const BYTE* const iHighLimit, const ZSTD_dictMode_e dictMode,
const U32 rep[ZSTD_REP_NUM],
U32 const ll0,
U32 const lengthToBeat)
typedef U32 (*ZSTD_getAllMatchesFn)(
ZSTD_match_t*,
ZSTD_matchState_t*,
U32*,
const BYTE*,
const BYTE*,
const U32 rep[ZSTD_REP_NUM],
U32 const ll0,
U32 const lengthToBeat);

FORCE_INLINE_TEMPLATE U32 ZSTD_btGetAllMatches_internal(
ZSTD_match_t* matches,
ZSTD_matchState_t* ms,
U32* nextToUpdate3,
const BYTE* ip,
const BYTE* const iHighLimit,
const U32 rep[ZSTD_REP_NUM],
U32 const ll0,
U32 const lengthToBeat,
const ZSTD_dictMode_e dictMode,
const U32 mls)
{
const ZSTD_compressionParameters* const cParams = &ms->cParams;
U32 const matchLengthSearch = cParams->minMatch;
DEBUGLOG(8, "ZSTD_BtGetAllMatches");
if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree_internal(ms, ip, iHighLimit, matchLengthSearch, dictMode);
switch(matchLengthSearch)
{
case 3 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 3);
default :
case 4 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 4);
case 5 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 5);
case 7 :
case 6 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 6);
assert(ms->cParams.minMatch == mls);
DEBUGLOG(8, "ZSTD_BtGetAllMatches(dictMode=%d, mls=%u)", (int)dictMode, mls);
if (ip < ms->window.base + ms->nextToUpdate)
return 0; /* skipped area */
ZSTD_updateTree_internal(ms, ip, iHighLimit, mls, dictMode);
return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, mls);
}

#define ZSTD_BT_GET_ALL_MATCHES_FN(dictMode, mls) ZSTD_btGetAllMatches_##dictMode##_##mls

#define GEN_ZSTD_BT_GET_ALL_MATCHES_(dictMode, mls) \
static U32 ZSTD_BT_GET_ALL_MATCHES_FN(dictMode, mls)( \
ZSTD_match_t* matches, \
ZSTD_matchState_t* ms, \
U32* nextToUpdate3, \
const BYTE* ip, \
const BYTE* const iHighLimit, \
const U32 rep[ZSTD_REP_NUM], \
U32 const ll0, \
U32 const lengthToBeat) \
{ \
return ZSTD_btGetAllMatches_internal( \
matches, ms, nextToUpdate3, ip, iHighLimit, \
rep, ll0, lengthToBeat, ZSTD_##dictMode, mls); \
}

#define GEN_ZSTD_BT_GET_ALL_MATCHES(dictMode) \
GEN_ZSTD_BT_GET_ALL_MATCHES_(dictMode, 3) \
GEN_ZSTD_BT_GET_ALL_MATCHES_(dictMode, 4) \
GEN_ZSTD_BT_GET_ALL_MATCHES_(dictMode, 5) \
GEN_ZSTD_BT_GET_ALL_MATCHES_(dictMode, 6)

GEN_ZSTD_BT_GET_ALL_MATCHES(noDict)
GEN_ZSTD_BT_GET_ALL_MATCHES(extDict)
GEN_ZSTD_BT_GET_ALL_MATCHES(dictMatchState)

#define ZSTD_BT_GET_ALL_MATCHES_ARRAY(dictMode) \
{ \
ZSTD_BT_GET_ALL_MATCHES_FN(dictMode, 3), \
ZSTD_BT_GET_ALL_MATCHES_FN(dictMode, 4), \
ZSTD_BT_GET_ALL_MATCHES_FN(dictMode, 5), \
ZSTD_BT_GET_ALL_MATCHES_FN(dictMode, 6) \
}

static ZSTD_getAllMatchesFn ZSTD_selectBtGetAllMatches(ZSTD_matchState_t const* ms, ZSTD_dictMode_e const dictMode)
{
ZSTD_getAllMatchesFn const getAllMatchesFns[3][4] = {
ZSTD_BT_GET_ALL_MATCHES_ARRAY(noDict),
ZSTD_BT_GET_ALL_MATCHES_ARRAY(extDict),
ZSTD_BT_GET_ALL_MATCHES_ARRAY(dictMatchState)
};
U32 const mls = BOUNDED(3, ms->cParams.minMatch, 6);
assert((U32)dictMode < 3);
assert(mls < 4);
return getAllMatchesFns[(int)dictMode][mls - 3];
}

/*************************
Expand Down Expand Up @@ -989,6 +1028,8 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
const BYTE* const prefixStart = base + ms->window.dictLimit;
const ZSTD_compressionParameters* const cParams = &ms->cParams;

ZSTD_getAllMatchesFn getAllMatches = ZSTD_selectBtGetAllMatches(ms, dictMode);

U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
U32 const minMatch = (cParams->minMatch == 3) ? 3 : 4;
U32 nextToUpdate3 = ms->nextToUpdate;
Expand Down Expand Up @@ -1016,7 +1057,7 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
/* find first match */
{ U32 const litlen = (U32)(ip - anchor);
U32 const ll0 = !litlen;
U32 nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, ip, iend, dictMode, rep, ll0, minMatch);
U32 nbMatches = getAllMatches(matches, ms, &nextToUpdate3, ip, iend, rep, ll0, minMatch);
ZSTD_optLdm_processMatchCandidate(&optLdm, matches, &nbMatches,
(U32)(ip-istart), (U32)(iend - ip));
if (!nbMatches) { ip++; continue; }
Expand Down Expand Up @@ -1133,7 +1174,7 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
U32 const litlen = (opt[cur].mlen == 0) ? opt[cur].litlen : 0;
U32 const previousPrice = (U32)opt[cur].price;
U32 const basePrice = previousPrice + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
U32 nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, inr, iend, dictMode, opt[cur].rep, ll0, minMatch);
U32 nbMatches = getAllMatches(matches, ms, &nextToUpdate3, inr, iend, opt[cur].rep, ll0, minMatch);
U32 matchNb;

ZSTD_optLdm_processMatchCandidate(&optLdm, matches, &nbMatches,
Expand Down Expand Up @@ -1257,13 +1298,26 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
return (size_t)(iend - anchor);
}

static size_t ZSTD_compressBlock_opt0(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
const void* src, size_t srcSize, const ZSTD_dictMode_e dictMode)
{
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /* optLevel */, dictMode);
}

static size_t ZSTD_compressBlock_opt2(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
const void* src, size_t srcSize, const ZSTD_dictMode_e dictMode)
{
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /* optLevel */, dictMode);
}

size_t ZSTD_compressBlock_btopt(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
const void* src, size_t srcSize)
{
DEBUGLOG(5, "ZSTD_compressBlock_btopt");
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_noDict);
return ZSTD_compressBlock_opt0(ms, seqStore, rep, src, srcSize, ZSTD_noDict);
}


Expand All @@ -1289,7 +1343,7 @@ ZSTD_initStats_ultra(ZSTD_matchState_t* ms,
assert(ms->window.dictLimit == ms->window.lowLimit); /* no dictionary */
assert(ms->window.dictLimit - ms->nextToUpdate <= 1); /* no prefix (note: intentional overflow, defined as 2-complement) */

ZSTD_compressBlock_opt_generic(ms, seqStore, tmpRep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict); /* generate stats into ms->opt*/
ZSTD_compressBlock_opt2(ms, seqStore, tmpRep, src, srcSize, ZSTD_noDict); /* generate stats into ms->opt*/

/* invalidate first scan from history */
ZSTD_resetSeqStore(seqStore);
Expand All @@ -1305,7 +1359,7 @@ size_t ZSTD_compressBlock_btultra(
const void* src, size_t srcSize)
{
DEBUGLOG(5, "ZSTD_compressBlock_btultra (srcSize=%zu)", srcSize);
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
return ZSTD_compressBlock_opt2(ms, seqStore, rep, src, srcSize, ZSTD_noDict);
}

size_t ZSTD_compressBlock_btultra2(
Expand Down Expand Up @@ -1333,35 +1387,35 @@ size_t ZSTD_compressBlock_btultra2(
ZSTD_initStats_ultra(ms, seqStore, rep, src, srcSize);
}

return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
return ZSTD_compressBlock_opt2(ms, seqStore, rep, src, srcSize, ZSTD_noDict);
}

size_t ZSTD_compressBlock_btopt_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
const void* src, size_t srcSize)
{
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_dictMatchState);
return ZSTD_compressBlock_opt0(ms, seqStore, rep, src, srcSize, ZSTD_dictMatchState);
}

size_t ZSTD_compressBlock_btultra_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
const void* src, size_t srcSize)
{
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_dictMatchState);
return ZSTD_compressBlock_opt2(ms, seqStore, rep, src, srcSize, ZSTD_dictMatchState);
}

size_t ZSTD_compressBlock_btopt_extDict(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
const void* src, size_t srcSize)
{
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_extDict);
return ZSTD_compressBlock_opt0(ms, seqStore, rep, src, srcSize, ZSTD_extDict);
}

size_t ZSTD_compressBlock_btultra_extDict(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
const void* src, size_t srcSize)
{
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_extDict);
return ZSTD_compressBlock_opt2(ms, seqStore, rep, src, srcSize, ZSTD_extDict);
}

/* note : no btultra2 variant for extDict nor dictMatchState,
Expand Down

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