add FSE decoding tables for predefined distributions to spec

They can so serve as a sample result of the table construction algorithm.

diff --git a/zstd_compression_format.md b/zstd_compression_format.md
index b14f55534835a38617b85bf93a989dbb35590e61..f350cdabe9fe8a614375c081b961226106524729 100644 (file)
--- a/zstd_compression_format.md
+++ b/zstd_compression_format.md
@@ -1164,6 +1164,188 @@ __`Content`__ : The rest of the dictionary is its content.
 
 [compressed blocks]: #the-format-of-compressed_block
 
+Appendix A - Decoding tables for predefined codes
+-------------------------------------------------
+
+This appendix contains FSE decoding tables for the predefined literal length, match length, and offset
+codes. The tables have been constructed using the algorithm as given above in the
+"from normalized distribution to decoding tables" chapter. The tables here can be used as examples
+to crosscheck that an implementation implements the decoding table generation algorithm correctly.
+
+#### Literal Length Code:
+
+| State | Symbol | Number_Of_Bits | Base |
+| ----- | ------ | -------------- | ---- |
+|     0 |      0 |              4 |    0 |
+|     1 |      0 |              4 |   16 |
+|     2 |      1 |              5 |   32 |
+|     3 |      3 |              5 |    0 |
+|     4 |      4 |              5 |    0 |
+|     5 |      6 |              5 |    0 |
+|     6 |      7 |              5 |    0 |
+|     7 |      9 |              5 |    0 |
+|     8 |     10 |              5 |    0 |
+|     9 |     12 |              5 |    0 |
+|    10 |     14 |              6 |    0 |
+|    11 |     16 |              5 |    0 |
+|    12 |     18 |              5 |    0 |
+|    13 |     19 |              5 |    0 |
+|    14 |     21 |              5 |    0 |
+|    15 |     22 |              5 |    0 |
+|    16 |     24 |              5 |    0 |
+|    17 |     25 |              5 |   32 |
+|    18 |     26 |              5 |    0 |
+|    19 |     27 |              6 |    0 |
+|    20 |     29 |              6 |    0 |
+|    21 |     31 |              6 |    0 |
+|    22 |      0 |              4 |   32 |
+|    23 |      1 |              4 |    0 |
+|    24 |      2 |              5 |    0 |
+|    25 |      4 |              5 |   32 |
+|    26 |      5 |              5 |    0 |
+|    27 |      7 |              5 |   32 |
+|    28 |      8 |              5 |    0 |
+|    29 |     10 |              5 |   32 |
+|    30 |     11 |              5 |    0 |
+|    31 |     13 |              6 |    0 |
+|    32 |     16 |              5 |   32 |
+|    33 |     17 |              5 |    0 |
+|    34 |     19 |              5 |   32 |
+|    35 |     20 |              5 |    0 |
+|    36 |     22 |              5 |   32 |
+|    37 |     23 |              5 |    0 |
+|    38 |     25 |              4 |    0 |
+|    39 |     25 |              4 |   16 |
+|    40 |     26 |              5 |   32 |
+|    41 |     28 |              6 |    0 |
+|    42 |     30 |              6 |    0 |
+|    43 |      0 |              4 |   48 |
+|    44 |      1 |              4 |   16 |
+|    45 |      2 |              5 |   32 |
+|    46 |      3 |              5 |   32 |
+|    47 |      5 |              5 |   32 |
+|    48 |      6 |              5 |   32 |
+|    49 |      8 |              5 |   32 |
+|    50 |      9 |              5 |   32 |
+|    51 |     11 |              5 |   32 |
+|    52 |     12 |              5 |   32 |
+|    53 |     15 |              6 |    0 |
+|    54 |     17 |              5 |   32 |
+|    55 |     18 |              5 |   32 |
+|    56 |     20 |              5 |   32 |
+|    57 |     21 |              5 |   32 |
+|    58 |     23 |              5 |   32 |
+|    59 |     24 |              5 |   32 |
+|    60 |     35 |              6 |    0 |
+|    61 |     34 |              6 |    0 |
+|    62 |     33 |              6 |    0 |
+|    63 |     32 |              6 |    0 |
+
+#### Match Length Code:
+
+| State | Symbol | Number_Of_Bits | Base |
+| ----- | ------ | -------------- | ---- |
+|     0 |      0 |              6 |    0 |
+|     1 |      1 |              4 |    0 |
+|     2 |      2 |              5 |   32 |
+|     3 |      3 |              5 |    0 |
+|     4 |      5 |              5 |    0 |
+|     5 |      6 |              5 |    0 |
+|     6 |      8 |              5 |    0 |
+|     7 |     10 |              6 |    0 |
+|     8 |     13 |              6 |    0 |
+|     9 |     16 |              6 |    0 |
+|    10 |     19 |              6 |    0 |
+|    11 |     22 |              6 |    0 |
+|    12 |     25 |              6 |    0 |
+|    13 |     28 |              6 |    0 |
+|    14 |     31 |              6 |    0 |
+|    15 |     33 |              6 |    0 |
+|    16 |     35 |              6 |    0 |
+|    17 |     37 |              6 |    0 |
+|    18 |     39 |              6 |    0 |
+|    19 |     41 |              6 |    0 |
+|    20 |     43 |              6 |    0 |
+|    21 |     45 |              6 |    0 |
+|    22 |      1 |              4 |   16 |
+|    23 |      2 |              4 |    0 |
+|    24 |      3 |              5 |   32 |
+|    25 |      4 |              5 |    0 |
+|    26 |      6 |              5 |   32 |
+|    27 |      7 |              5 |    0 |
+|    28 |      9 |              6 |    0 |
+|    29 |     12 |              6 |    0 |
+|    30 |     15 |              6 |    0 |
+|    31 |     18 |              6 |    0 |
+|    32 |     21 |              6 |    0 |
+|    33 |     24 |              6 |    0 |
+|    34 |     27 |              6 |    0 |
+|    35 |     30 |              6 |    0 |
+|    36 |     32 |              6 |    0 |
+|    37 |     34 |              6 |    0 |
+|    38 |     36 |              6 |    0 |
+|    39 |     38 |              6 |    0 |
+|    40 |     40 |              6 |    0 |
+|    41 |     42 |              6 |    0 |
+|    42 |     44 |              6 |    0 |
+|    43 |      1 |              4 |   32 |
+|    44 |      1 |              4 |   48 |
+|    45 |      2 |              4 |   16 |
+|    46 |      4 |              5 |   32 |
+|    47 |      5 |              5 |   32 |
+|    48 |      7 |              5 |   32 |
+|    49 |      8 |              5 |   32 |
+|    50 |     11 |              6 |    0 |
+|    51 |     14 |              6 |    0 |
+|    52 |     17 |              6 |    0 |
+|    53 |     20 |              6 |    0 |
+|    54 |     23 |              6 |    0 |
+|    55 |     26 |              6 |    0 |
+|    56 |     29 |              6 |    0 |
+|    57 |     52 |              6 |    0 |
+|    58 |     51 |              6 |    0 |
+|    59 |     50 |              6 |    0 |
+|    60 |     49 |              6 |    0 |
+|    61 |     48 |              6 |    0 |
+|    62 |     47 |              6 |    0 |
+|    63 |     46 |              6 |    0 |
+
+#### Offset Code:
+
+| State | Symbol | Number_Of_Bits | Base |
+| ----- | ------ | -------------- | ---- |
+|     0 |      0 |              5 |    0 |
+|     1 |      6 |              4 |    0 |
+|     2 |      9 |              5 |    0 |
+|     3 |     15 |              5 |    0 |
+|     4 |     21 |              5 |    0 |
+|     5 |      3 |              5 |    0 |
+|     6 |      7 |              4 |    0 |
+|     7 |     12 |              5 |    0 |
+|     8 |     18 |              5 |    0 |
+|     9 |     23 |              5 |    0 |
+|    10 |      5 |              5 |    0 |
+|    11 |      8 |              4 |    0 |
+|    12 |     14 |              5 |    0 |
+|    13 |     20 |              5 |    0 |
+|    14 |      2 |              5 |    0 |
+|    15 |      7 |              4 |   16 |
+|    16 |     11 |              5 |    0 |
+|    17 |     17 |              5 |    0 |
+|    18 |     22 |              5 |    0 |
+|    19 |      4 |              5 |    0 |
+|    20 |      8 |              4 |   16 |
+|    21 |     13 |              5 |    0 |
+|    22 |     19 |              5 |    0 |
+|    23 |      1 |              5 |    0 |
+|    24 |      6 |              4 |   16 |
+|    25 |     10 |              5 |    0 |
+|    26 |     16 |              5 |    0 |
+|    27 |     28 |              5 |    0 |
+|    28 |     27 |              5 |    0 |
+|    29 |     26 |              5 |    0 |
+|    30 |     25 |              5 |    0 |
+|    31 |     24 |              5 |    0 |
 
 Version changes
 ---------------