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[libzstd][opt] Simplify repcode logic

dev
Nick Terrell 2017-09-27 15:29:07 -07:00
parent 91ffe71ec8
commit b555b7ef41
1 changed files with 10 additions and 2 deletions
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12
lib/compress/zstd_opt.c
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@ -529,7 +529,14 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
} else {
opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
/* If opt[cur].off == ZSTD_REP_MOVE_OPT, then mlen != 1.
* offset ZSTD_REP_MOVE_OPT is used for the special case
* litLength == 0, where offset 0 means something special.
* mlen == 1 means the previous byte was stored as a literal,
* so they are mutually exclusive.
*/
assert(!(opt[cur].off == ZSTD_REP_MOVE_OPT && mlen == 1));
opt[cur].rep[0] = (opt[cur].off == ZSTD_REP_MOVE_OPT) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
}
best_mlen = minMatch;
@ -804,7 +811,8 @@ size_t ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
} else {
opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
assert(!(opt[cur].off == ZSTD_REP_MOVE_OPT && mlen == 1));
opt[cur].rep[0] = (opt[cur].off == ZSTD_REP_MOVE_OPT) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
}
best_mlen = minMatch;