--- /dev/null
+/* ******************************************************************
+ * Common functions of New Generation Entropy library
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * You can contact the author at :
+ * - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
+ * - Public forum : https://groups.google.com/forum/#!forum/lz4c
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+****************************************************************** */
+
+/* *************************************
+* Dependencies
+***************************************/
+#include "mem.h"
+#include "error_private.h" /* ERR_*, ERROR */
+#define FSE_STATIC_LINKING_ONLY /* FSE_MIN_TABLELOG */
+#include "fse.h"
+#include "huf.h"
+#include "bits.h" /* ZSDT_highbit32, ZSTD_countTrailingZeros32 */
+
+
+/*=== Version ===*/
+unsigned FSE_versionNumber(void) { return FSE_VERSION_NUMBER; }
+
+
+/*=== Error Management ===*/
+unsigned FSE_isError(size_t code) { return ERR_isError(code); }
+const char* FSE_getErrorName(size_t code) { return ERR_getErrorName(code); }
+
+unsigned HUF_isError(size_t code) { return ERR_isError(code); }
+const char* HUF_getErrorName(size_t code) { return ERR_getErrorName(code); }
+
+
+/*-**************************************************************
+* FSE NCount encoding-decoding
+****************************************************************/
+FORCE_INLINE_TEMPLATE
+size_t FSE_readNCount_body(short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
+ const void* headerBuffer, size_t hbSize)
+{
+ const BYTE* const istart = (const BYTE*) headerBuffer;
+ const BYTE* const iend = istart + hbSize;
+ const BYTE* ip = istart;
+ int nbBits;
+ int remaining;
+ int threshold;
+ U32 bitStream;
+ int bitCount;
+ unsigned charnum = 0;
+ unsigned const maxSV1 = *maxSVPtr + 1;
+ int previous0 = 0;
+
+ if (hbSize < 8) {
+ /* This function only works when hbSize >= 8 */
+ char buffer[8] = {0};
+ ZSTD_memcpy(buffer, headerBuffer, hbSize);
+ { size_t const countSize = FSE_readNCount(normalizedCounter, maxSVPtr, tableLogPtr,
+ buffer, sizeof(buffer));
+ if (FSE_isError(countSize)) return countSize;
+ if (countSize > hbSize) return ERROR(corruption_detected);
+ return countSize;
+ } }
+ assert(hbSize >= 8);
+
+ /* init */
+ ZSTD_memset(normalizedCounter, 0, (*maxSVPtr+1) * sizeof(normalizedCounter[0])); /* all symbols not present in NCount have a frequency of 0 */
+ bitStream = MEM_readLE32(ip);
+ nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG; /* extract tableLog */
+ if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
+ bitStream >>= 4;
+ bitCount = 4;
+ *tableLogPtr = nbBits;
+ remaining = (1<<nbBits)+1;
+ threshold = 1<<nbBits;
+ nbBits++;
+
+ for (;;) {
+ if (previous0) {
+ /* Count the number of repeats. Each time the
+ * 2-bit repeat code is 0b11 there is another
+ * repeat.
+ * Avoid UB by setting the high bit to 1.
+ */
+ int repeats = ZSTD_countTrailingZeros32(~bitStream | 0x80000000) >> 1;
+ while (repeats >= 12) {
+ charnum += 3 * 12;
+ if (LIKELY(ip <= iend-7)) {
+ ip += 3;
+ } else {
+ bitCount -= (int)(8 * (iend - 7 - ip));
+ bitCount &= 31;
+ ip = iend - 4;
+ }
+ bitStream = MEM_readLE32(ip) >> bitCount;
+ repeats = ZSTD_countTrailingZeros32(~bitStream | 0x80000000) >> 1;
+ }
+ charnum += 3 * repeats;
+ bitStream >>= 2 * repeats;
+ bitCount += 2 * repeats;
+
+ /* Add the final repeat which isn't 0b11. */
+ assert((bitStream & 3) < 3);
+ charnum += bitStream & 3;
+ bitCount += 2;
+
+ /* This is an error, but break and return an error
+ * at the end, because returning out of a loop makes
+ * it harder for the compiler to optimize.
+ */
+ if (charnum >= maxSV1) break;
+
+ /* We don't need to set the normalized count to 0
+ * because we already memset the whole buffer to 0.
+ */
+
+ if (LIKELY(ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
+ assert((bitCount >> 3) <= 3); /* For first condition to work */
+ ip += bitCount>>3;
+ bitCount &= 7;
+ } else {
+ bitCount -= (int)(8 * (iend - 4 - ip));
+ bitCount &= 31;
+ ip = iend - 4;
+ }
+ bitStream = MEM_readLE32(ip) >> bitCount;
+ }
+ {
+ int const max = (2*threshold-1) - remaining;
+ int count;
+
+ if ((bitStream & (threshold-1)) < (U32)max) {
+ count = bitStream & (threshold-1);
+ bitCount += nbBits-1;
+ } else {
+ count = bitStream & (2*threshold-1);
+ if (count >= threshold) count -= max;
+ bitCount += nbBits;
+ }
+
+ count--; /* extra accuracy */
+ /* When it matters (small blocks), this is a
+ * predictable branch, because we don't use -1.
+ */
+ if (count >= 0) {
+ remaining -= count;
+ } else {
+ assert(count == -1);
+ remaining += count;
+ }
+ normalizedCounter[charnum++] = (short)count;
+ previous0 = !count;
+
+ assert(threshold > 1);
+ if (remaining < threshold) {
+ /* This branch can be folded into the
+ * threshold update condition because we
+ * know that threshold > 1.
+ */
+ if (remaining <= 1) break;
+ nbBits = ZSTD_highbit32(remaining) + 1;
+ threshold = 1 << (nbBits - 1);
+ }
+ if (charnum >= maxSV1) break;
+
+ if (LIKELY(ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
+ ip += bitCount>>3;
+ bitCount &= 7;
+ } else {
+ bitCount -= (int)(8 * (iend - 4 - ip));
+ bitCount &= 31;
+ ip = iend - 4;
+ }
+ bitStream = MEM_readLE32(ip) >> bitCount;
+ } }
+ if (remaining != 1) return ERROR(corruption_detected);
+ /* Only possible when there are too many zeros. */
+ if (charnum > maxSV1) return ERROR(maxSymbolValue_tooSmall);
+ if (bitCount > 32) return ERROR(corruption_detected);
+ *maxSVPtr = charnum-1;
+
+ ip += (bitCount+7)>>3;
+ return ip-istart;
+}
+
+/* Avoids the FORCE_INLINE of the _body() function. */
+static size_t FSE_readNCount_body_default(
+ short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
+ const void* headerBuffer, size_t hbSize)
+{
+ return FSE_readNCount_body(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
+}
+
+#if DYNAMIC_BMI2
+BMI2_TARGET_ATTRIBUTE static size_t FSE_readNCount_body_bmi2(
+ short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
+ const void* headerBuffer, size_t hbSize)
+{
+ return FSE_readNCount_body(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
+}
+#endif
+
+size_t FSE_readNCount_bmi2(
+ short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
+ const void* headerBuffer, size_t hbSize, int bmi2)
+{
+#if DYNAMIC_BMI2
+ if (bmi2) {
+ return FSE_readNCount_body_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
+ }
+#endif
+ (void)bmi2;
+ return FSE_readNCount_body_default(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
+}
+
+size_t FSE_readNCount(
+ short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
+ const void* headerBuffer, size_t hbSize)
+{
+ return FSE_readNCount_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize, /* bmi2 */ 0);
+}
+
+
+/*! HUF_readStats() :
+ Read compact Huffman tree, saved by HUF_writeCTable().
+ `huffWeight` is destination buffer.
+ `rankStats` is assumed to be a table of at least HUF_TABLELOG_MAX U32.
+ @return : size read from `src` , or an error Code .
+ Note : Needed by HUF_readCTable() and HUF_readDTableX?() .
+*/
+size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
+ U32* nbSymbolsPtr, U32* tableLogPtr,
+ const void* src, size_t srcSize)
+{
+ U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
+ return HUF_readStats_wksp(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* flags */ 0);
+}
+
+FORCE_INLINE_TEMPLATE size_t
+HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
+ U32* nbSymbolsPtr, U32* tableLogPtr,
+ const void* src, size_t srcSize,
+ void* workSpace, size_t wkspSize,
+ int bmi2)
+{
+ U32 weightTotal;
+ const BYTE* ip = (const BYTE*) src;
+ size_t iSize;
+ size_t oSize;
+
+ if (!srcSize) return ERROR(srcSize_wrong);
+ iSize = ip[0];
+ /* ZSTD_memset(huffWeight, 0, hwSize); *//* is not necessary, even though some analyzer complain ... */
+
+ if (iSize >= 128) { /* special header */
+ oSize = iSize - 127;
+ iSize = ((oSize+1)/2);
+ if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
+ if (oSize >= hwSize) return ERROR(corruption_detected);
+ ip += 1;
+ { U32 n;
+ for (n=0; n<oSize; n+=2) {
+ huffWeight[n] = ip[n/2] >> 4;
+ huffWeight[n+1] = ip[n/2] & 15;
+ } } }
+ else { /* header compressed with FSE (normal case) */
+ if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
+ /* max (hwSize-1) values decoded, as last one is implied */
+ oSize = FSE_decompress_wksp_bmi2(huffWeight, hwSize-1, ip+1, iSize, 6, workSpace, wkspSize, bmi2);
+ if (FSE_isError(oSize)) return oSize;
+ }
+
+ /* collect weight stats */
+ ZSTD_memset(rankStats, 0, (HUF_TABLELOG_MAX + 1) * sizeof(U32));
+ weightTotal = 0;
+ { U32 n; for (n=0; n<oSize; n++) {
+ if (huffWeight[n] > HUF_TABLELOG_MAX) return ERROR(corruption_detected);
+ rankStats[huffWeight[n]]++;
+ weightTotal += (1 << huffWeight[n]) >> 1;
+ } }
+ if (weightTotal == 0) return ERROR(corruption_detected);
+
+ /* get last non-null symbol weight (implied, total must be 2^n) */
+ { U32 const tableLog = ZSTD_highbit32(weightTotal) + 1;
+ if (tableLog > HUF_TABLELOG_MAX) return ERROR(corruption_detected);
+ *tableLogPtr = tableLog;
+ /* determine last weight */
+ { U32 const total = 1 << tableLog;
+ U32 const rest = total - weightTotal;
+ U32 const verif = 1 << ZSTD_highbit32(rest);
+ U32 const lastWeight = ZSTD_highbit32(rest) + 1;
+ if (verif != rest) return ERROR(corruption_detected); /* last value must be a clean power of 2 */
+ huffWeight[oSize] = (BYTE)lastWeight;
+ rankStats[lastWeight]++;
+ } }
+
+ /* check tree construction validity */
+ if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected); /* by construction : at least 2 elts of rank 1, must be even */
+
+ /* results */
+ *nbSymbolsPtr = (U32)(oSize+1);
+ return iSize+1;
+}
+
+/* Avoids the FORCE_INLINE of the _body() function. */
+static size_t HUF_readStats_body_default(BYTE* huffWeight, size_t hwSize, U32* rankStats,
+ U32* nbSymbolsPtr, U32* tableLogPtr,
+ const void* src, size_t srcSize,
+ void* workSpace, size_t wkspSize)
+{
+ return HUF_readStats_body(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize, 0);
+}
+
+#if DYNAMIC_BMI2
+static BMI2_TARGET_ATTRIBUTE size_t HUF_readStats_body_bmi2(BYTE* huffWeight, size_t hwSize, U32* rankStats,
+ U32* nbSymbolsPtr, U32* tableLogPtr,
+ const void* src, size_t srcSize,
+ void* workSpace, size_t wkspSize)
+{
+ return HUF_readStats_body(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize, 1);
+}
+#endif
+
+size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize, U32* rankStats,
+ U32* nbSymbolsPtr, U32* tableLogPtr,
+ const void* src, size_t srcSize,
+ void* workSpace, size_t wkspSize,
+ int flags)
+{
+#if DYNAMIC_BMI2
+ if (flags & HUF_flags_bmi2) {
+ return HUF_readStats_body_bmi2(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
+ }
+#endif
+ (void)flags;
+ return HUF_readStats_body_default(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
+}
notaz.gp2x.de / pcsx_rearmed.git / blobdiff