| 7912 | |
| 7913 | |
| 7914 | size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog, |
| 7915 | const unsigned* count, size_t total, |
| 7916 | unsigned maxSymbolValue) |
| 7917 | { |
| 7918 | /* Sanity checks */ |
| 7919 | if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG; |
| 7920 | if (tableLog < FSE_MIN_TABLELOG) return ERROR(GENERIC); /* Unsupported size */ |
| 7921 | if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge); /* Unsupported size */ |
| 7922 | if (tableLog < FSE_minTableLog(total, maxSymbolValue)) return ERROR(GENERIC); /* Too small tableLog, compression potentially impossible */ |
| 7923 | |
| 7924 | { static U32 const rtbTable[] = { 0, 473195, 504333, 520860, 550000, 700000, 750000, 830000 }; |
| 7925 | U64 const scale = 62 - tableLog; |
| 7926 | U64 const step = ((U64)1<<62) / total; /* <== here, one division ! */ |
| 7927 | U64 const vStep = 1ULL<<(scale-20); |
| 7928 | int stillToDistribute = 1<<tableLog; |
| 7929 | unsigned s; |
| 7930 | unsigned largest=0; |
| 7931 | short largestP=0; |
| 7932 | U32 lowThreshold = (U32)(total >> tableLog); |
| 7933 | |
| 7934 | for (s=0; s<=maxSymbolValue; s++) { |
| 7935 | if (count[s] == total) return 0; /* rle special case */ |
| 7936 | if (count[s] == 0) { normalizedCounter[s]=0; continue; } |
| 7937 | if (count[s] <= lowThreshold) { |
| 7938 | normalizedCounter[s] = -1; |
| 7939 | stillToDistribute--; |
| 7940 | } else { |
| 7941 | short proba = (short)((count[s]*step) >> scale); |
| 7942 | if (proba<8) { |
| 7943 | U64 restToBeat = vStep * rtbTable[proba]; |
| 7944 | proba += (count[s]*step) - ((U64)proba<<scale) > restToBeat; |
| 7945 | } |
| 7946 | if (proba > largestP) { largestP=proba; largest=s; } |
| 7947 | normalizedCounter[s] = proba; |
| 7948 | stillToDistribute -= proba; |
| 7949 | } } |
| 7950 | if (-stillToDistribute >= (normalizedCounter[largest] >> 1)) { |
| 7951 | /* corner case, need another normalization method */ |
| 7952 | size_t const errorCode = FSE_normalizeM2(normalizedCounter, tableLog, count, total, maxSymbolValue); |
| 7953 | if (FSE_isError(errorCode)) return errorCode; |
| 7954 | } |
| 7955 | else normalizedCounter[largest] += (short)stillToDistribute; |
| 7956 | } |
| 7957 | |
| 7958 | #if 0 |
| 7959 | { /* Print Table (debug) */ |
| 7960 | U32 s; |
| 7961 | U32 nTotal = 0; |
| 7962 | for (s=0; s<=maxSymbolValue; s++) |
| 7963 | RAWLOG(2, "%3i: %4i \n", s, normalizedCounter[s]); |
| 7964 | for (s=0; s<=maxSymbolValue; s++) |
| 7965 | nTotal += abs(normalizedCounter[s]); |
| 7966 | if (nTotal != (1U<<tableLog)) |
| 7967 | RAWLOG(2, "Warning !!! Total == %u != %u !!!", nTotal, 1U<<tableLog); |
| 7968 | getchar(); |
| 7969 | } |
| 7970 | #endif |
| 7971 |
no test coverage detected