X-Git-Url: https://git.xonotic.org/?p=xonotic%2Fgmqcc.git;a=blobdiff_plain;f=util.c;h=a900889e57b90f983d776c44326e02935d9eee7b;hp=76bd44865c8164c1592c8c370dac252e02789b7a;hb=a68f0fcb355db42acabe72da5939fbd1b04f6016;hpb=29a3c02c354a4f6056c0e311a42293f4dc639fd8 diff --git a/util.c b/util.c index 76bd448..ecae505 100644 --- a/util.c +++ b/util.c @@ -1,6 +1,7 @@ /* - * Copyright (C) 2012 - * Dale Weiler + * Copyright (C) 2012, 2013 + * Dale Weiler + * Wolfgang Bumiller * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in @@ -20,74 +21,561 @@ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ -#include -#include #include -#include +#include + #include "gmqcc.h" - -struct memblock_t { - const char *file; - unsigned int line; - unsigned int byte; + +/* + * Initially this was handled with a table in the gmqcc.h header, but + * much to my surprise the contents of the table was duplicated for + * each translation unit, causing all these strings to be duplicated + * for every .c file it was included into. This method culls back on + * it. This is a 'utility' function because the executor also depends + * on this for dissasembled bytecode. + */ +const char *util_instr_str[VINSTR_END] = { + "DONE", "MUL_F", "MUL_V", "MUL_FV", + "MUL_VF", "DIV_F", "ADD_F", "ADD_V", + "SUB_F", "SUB_V", "EQ_F", "EQ_V", + "EQ_S", "EQ_E", "EQ_FNC", "NE_F", + "NE_V", "NE_S", "NE_E", "NE_FNC", + "LE", "GE", "LT", "GT", + "LOAD_F", "LOAD_V", "LOAD_S", "LOAD_ENT", + "LOAD_FLD", "LOAD_FNC", "ADDRESS", "STORE_F", + "STORE_V", "STORE_S", "STORE_ENT", "STORE_FLD", + "STORE_FNC", "STOREP_F", "STOREP_V", "STOREP_S", + "STOREP_ENT", "STOREP_FLD", "STOREP_FNC", "RETURN", + "NOT_F", "NOT_V", "NOT_S", "NOT_ENT", + "NOT_FNC", "IF", "IFNOT", "CALL0", + "CALL1", "CALL2", "CALL3", "CALL4", + "CALL5", "CALL6", "CALL7", "CALL8", + "STATE", "GOTO", "AND", "OR", + "BITAND", "BITOR" }; -void *util_memory_a(unsigned int byte, unsigned int line, const char *file) { - struct memblock_t *data = malloc(sizeof(struct memblock_t) + byte); - if (!data) return NULL; - data->line = line; - data->byte = byte; - data->file = file; - - util_debug("MEM", "allocation: %08u (bytes) at %s:%u\n", byte, file, line); - return (void*)((uintptr_t)data+sizeof(struct memblock_t)); -} +void util_debug(const char *area, const char *ms, ...) { + va_list va; + if (!OPTS_OPTION_BOOL(OPTION_DEBUG)) + return; + + if (!strcmp(area, "MEM") && !OPTS_OPTION_BOOL(OPTION_MEMCHK)) + return; -void util_memory_d(void *ptrn, unsigned int line, const char *file) { - if (!ptrn) return; - void *data = (void*)((uintptr_t)ptrn-sizeof(struct memblock_t)); - struct memblock_t *info = (struct memblock_t*)data; - - util_debug("MEM", "released: %08u (bytes) at %s:%u\n", info->byte, file, line); - free(data); + va_start(va, ms); + con_out ("[%s] ", area); + con_vout(ms, va); + va_end (va); } -#ifndef mem_d -#define mem_d(x) util_memory_d((x), __LINE__, __FILE__) +/* + * only required if big endian .. otherwise no need to swap + * data. + */ +#if PLATFORM_BYTE_ORDER == GMQCC_BYTE_ORDER_BIG + static GMQCC_INLINE void util_swap16(uint16_t *d, size_t l) { + while (l--) { + d[l] = (d[l] << 8) | (d[l] >> 8); + } + } + + static GMQCC_INLINE void util_swap32(uint32_t *d, size_t l) { + while (l--) { + uint32_t v; + v = ((d[l] << 8) & 0xFF00FF00) | ((d[l] >> 8) & 0x00FF00FF); + d[l] = (v << 16) | (v >> 16); + } + } + + /* Some strange system doesn't like constants that big, AND doesn't recognize an ULL suffix + * so let's go the safe way + */ + static GMQCC_INLINE void util_swap64(uint32_t *d, size_t l) { + /* + while (l--) { + uint64_t v; + v = ((d[l] << 8) & 0xFF00FF00FF00FF00) | ((d[l] >> 8) & 0x00FF00FF00FF00FF); + v = ((v << 16) & 0xFFFF0000FFFF0000) | ((v >> 16) & 0x0000FFFF0000FFFF); + d[l] = (v << 32) | (v >> 32); + } + */ + size_t i; + for (i = 0; i < l; i += 2) { + uint32_t v1 = d[i]; + d[i] = d[i+1]; + d[i+1] = v1; + util_swap32(d+i, 2); + } + } #endif -#ifndef mem_a -#define mem_a(x) util_memory_a((x), __LINE__, __FILE__) + +void util_endianswap(void *_data, size_t length, unsigned int typesize) { +# if PLATFORM_BYTE_ORDER == -1 /* runtime check */ + if (*((char*)&typesize)) + return; +#else + /* prevent unused warnings */ + (void) _data; + (void) length; + (void) typesize; + +# if PLATFORM_BYTE_ORDER == GMQCC_BYTE_ORDER_LITTLE + return; +# else + switch (typesize) { + case 1: return; + case 2: + util_swap16((uint16_t*)_data, length>>1); + return; + case 4: + util_swap32((uint32_t*)_data, length>>2); + return; + case 8: + util_swap64((uint32_t*)_data, length>>3); + return; + + default: exit(EXIT_FAILURE); /* please blow the fuck up! */ + } +# endif #endif +} /* - * Some string utility functions, because strdup uses malloc, and we want - * to track all memory (without replacing malloc). + * CRC algorithms vary in the width of the polynomial, the value of said polynomial, + * the initial value used for the register, weather the bits of each byte are reflected + * before being processed, weather the algorithm itself feeds input bytes through the + * register or XORs them with a byte from one end and then straight into the table, as + * well as (but not limited to the idea of reflected versions) where the final register + * value becomes reversed, and finally weather the value itself is used to XOR the final + * register value. AS such you can already imagine how painfully annoying CRCs are, + * of course we stand to target Quake, which expects it's certian set of rules for proper + * calculation of a CRC. + * + * In most traditional CRC algorithms on uses a reflected table driven method where a value + * or register is reflected if it's bits are swapped around it's center. For example: + * take the bits 0101 is the 4-bit reflection of 1010, and respectfully 0011 would be the + * reflection of 1100. Quake however expects a NON-Reflected CRC on the output, but still + * requires a final XOR on the values (0xFFFF and 0x0000) this is a standard CCITT CRC-16 + * which I respectfully as a programmer don't agree with. + * + * So now you know what we target, and why we target it, despite how unsettling it may seem + * but those are what Quake seems to request. */ -char *util_strdup(const char *s) { - size_t len; - char *ptr; - - if (!s) - return NULL; - - len = strlen(s); - ptr = mem_a (len+1); - - if (ptr && len) { - memcpy(ptr, s, len); - ptr[len] = '\0'; - } - - return ptr; + +static const uint16_t util_crc16_table[] = { + 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, + 0x60C6, 0x70E7, 0x8108, 0x9129, 0xA14A, 0xB16B, + 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF, 0x1231, 0x0210, + 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6, + 0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, + 0xF3FF, 0xE3DE, 0x2462, 0x3443, 0x0420, 0x1401, + 0x64E6, 0x74C7, 0x44A4, 0x5485, 0xA56A, 0xB54B, + 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D, + 0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, + 0x5695, 0x46B4, 0xB75B, 0xA77A, 0x9719, 0x8738, + 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC, 0x48C4, 0x58E5, + 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823, + 0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, + 0xA90A, 0xB92B, 0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, + 0x1A71, 0x0A50, 0x3A33, 0x2A12, 0xDBFD, 0xCBDC, + 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A, + 0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, + 0x0C60, 0x1C41, 0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, + 0xAD2A, 0xBD0B, 0x8D68, 0x9D49, 0x7E97, 0x6EB6, + 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70, + 0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, + 0x9F59, 0x8F78, 0x9188, 0x81A9, 0xB1CA, 0xA1EB, + 0xD10C, 0xC12D, 0xF14E, 0xE16F, 0x1080, 0x00A1, + 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067, + 0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, + 0xE37F, 0xF35E, 0x02B1, 0x1290, 0x22F3, 0x32D2, + 0x4235, 0x5214, 0x6277, 0x7256, 0xB5EA, 0xA5CB, + 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D, + 0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, + 0x5424, 0x4405, 0xA7DB, 0xB7FA, 0x8799, 0x97B8, + 0xE75F, 0xF77E, 0xC71D, 0xD73C, 0x26D3, 0x36F2, + 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634, + 0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, + 0xB98A, 0xA9AB, 0x5844, 0x4865, 0x7806, 0x6827, + 0x18C0, 0x08E1, 0x3882, 0x28A3, 0xCB7D, 0xDB5C, + 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A, + 0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, + 0x2AB3, 0x3A92, 0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, + 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9, 0x7C26, 0x6C07, + 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1, + 0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, + 0x8FD9, 0x9FF8, 0x6E17, 0x7E36, 0x4E55, 0x5E74, + 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0 +}; + +/* Non - Reflected */ +uint16_t util_crc16(uint16_t current, const char *k, size_t len) { + register uint16_t h = current; + for (; len; --len, ++k) + h = util_crc16_table[(h>>8)^((unsigned char)*k)]^(h<<8); + return h; } +/* Reflective Varation (for reference) */ +#if 0 +uint16_t util_crc16(const char *k, int len, const short clamp) { + register uint16_t h= (uint16_t)0xFFFFFFFF; + for (; len; --len, ++k) + h = util_crc16_table[(h^((unsigned char)*k))&0xFF]^(h>>8); + return (~h)%clamp; +} +#endif -void util_debug(const char *area, const char *ms, ...) { - va_list va; - va_start(va, ms); - fprintf (stdout, "DEBUG: "); - fputc ('[', stdout); - fprintf (stdout, area); - fputs ("] ", stdout); - vfprintf(stdout, ms, va); - va_end (va); +/* + * modifier is the match to make and the transpsition from it, while add is the upper-value that determines the + * transposion from uppercase to lower case. + */ +static GMQCC_INLINE size_t util_strtransform(const char *in, char *out, size_t outsz, const char *mod, int add) { + size_t sz = 1; + for (; *in && sz < outsz; ++in, ++out, ++sz) { + *out = (*in == mod[0]) + ? mod[1] + : (util_isalpha(*in) && util_isupper(*in + add)) + ? *in + add + : *in; + } + *out = 0; + return sz-1; +} + +size_t util_strtocmd(const char *in, char *out, size_t outsz) { + return util_strtransform(in, out, outsz, "-_", 'A'-'a'); +} +size_t util_strtononcmd(const char *in, char *out, size_t outsz) { + return util_strtransform(in, out, outsz, "_-", 'a'-'A'); +} +size_t util_optimizationtostr(const char *in, char *out, size_t outsz) { + return util_strtransform(in, out, outsz, "_ ", 'a'-'A'); +} + +/* + * Portable implementation of vasprintf/asprintf. Assumes vsnprintf + * exists, otherwise compiler error. + * + * TODO: fix for MSVC .... + */ +int util_vasprintf(char **dat, const char *fmt, va_list args) { + int ret; + int len; + char *tmp = NULL; + + /* + * For visuals tido _vsnprintf doesn't tell you the length of a + * formatted string if it overflows. However there is a MSVC + * intrinsic (which is documented wrong) called _vcsprintf which + * will return the required amount to allocate. + */ + #ifdef _MSC_VER + if ((len = _vscprintf(fmt, args)) < 0) { + *dat = NULL; + return -1; + } + + tmp = (char*)mem_a(len + 1); + if ((ret = _vsnprintf_s(tmp, len+1, len+1, fmt, args)) != len) { + mem_d(tmp); + *dat = NULL; + return -1; + } + *dat = tmp; + return len; + #else + /* + * For everything else we have a decent conformint vsnprintf that + * returns the number of bytes needed. We give it a try though on + * a short buffer, since efficently speaking, it could be nice to + * above a second vsnprintf call. + */ + char buf[128]; + va_list cpy; + va_copy(cpy, args); + len = vsnprintf(buf, sizeof(buf), fmt, cpy); + va_end (cpy); + + if (len < (int)sizeof(buf)) { + *dat = util_strdup(buf); + return len; + } + + /* not large enough ... */ + tmp = (char*)mem_a(len + 1); + if ((ret = vsnprintf(tmp, len + 1, fmt, args)) != len) { + mem_d(tmp); + *dat = NULL; + return -1; + } + + *dat = tmp; + return len; + #endif +} +int util_asprintf(char **ret, const char *fmt, ...) { + va_list args; + int read; + va_start(args, fmt); + read = util_vasprintf(ret, fmt, args); + va_end (args); + + return read; +} + +/* + * These are various re-implementations (wrapping the real ones) of + * string functions that MSVC consideres unsafe. We wrap these up and + * use the safe varations on MSVC. + */ +#ifdef _MSC_VER + static char **util_strerror_allocated() { + static char **data = NULL; + return data; + } + + static void util_strerror_cleanup(void) { + size_t i; + char **data = util_strerror_allocated(); + for (i = 0; i < vec_size(data); i++) + mem_d(data[i]); + vec_free(data); + } + + const char *util_strerror(int num) { + char *allocated = NULL; + static bool install = false; + static size_t tries = 0; + char **vector = util_strerror_allocated(); + + /* try installing cleanup handler */ + while (!install) { + if (tries == 32) + return "(unknown)"; + + install = !atexit(&util_strerror_cleanup); + tries ++; + } + + allocated = (char*)mem_a(4096); /* A page must be enough */ + strerror_s(allocated, 4096, num); + + vec_push(vector, allocated); + return (const char *)allocated; + } + + int util_snprintf(char *src, size_t bytes, const char *format, ...) { + int rt; + va_list va; + va_start(va, format); + + rt = vsprintf_s(src, bytes, format, va); + va_end (va); + + return rt; + } + + char *util_strcat(char *dest, const char *src) { + strcat_s(dest, strlen(src), src); + return dest; + } + + char *util_strncpy(char *dest, const char *src, size_t num) { + strncpy_s(dest, num, src, num); + return dest; + } +#else + const char *util_strerror(int num) { + return strerror(num); + } + + int util_snprintf(char *src, size_t bytes, const char *format, ...) { + int rt; + va_list va; + va_start(va, format); + rt = vsnprintf(src, bytes, format, va); + va_end (va); + + return rt; + } + + char *util_strcat(char *dest, const char *src) { + return strcat(dest, src); + } + + char *util_strncpy(char *dest, const char *src, size_t num) { + return strncpy(dest, src, num); + } + +#endif /*! _MSC_VER */ + +/* + * Implementation of the Mersenne twister PRNG (pseudo random numer + * generator). Implementation of MT19937. Has a period of 2^19937-1 + * which is a Mersenne Prime (hence the name). + * + * Implemented from specification and original paper: + * http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/ARTICLES/mt.pdf + * + * This code is placed in the public domain by me personally + * (Dale Weiler, a.k.a graphitemaster). + */ + +#define MT_SIZE 624 +#define MT_PERIOD 397 +#define MT_SPACE (MT_SIZE - MT_PERIOD) + +static uint32_t mt_state[MT_SIZE]; +static size_t mt_index = 0; + +static GMQCC_INLINE void mt_generate(void) { + /* + * The loop has been unrolled here: the original paper and implemenation + * Called for the following code: + * for (register unsigned i = 0; i < MT_SIZE; ++i) { + * register uint32_t load; + * load = (0x80000000 & mt_state[i]) // most significant 32nd bit + * load |= (0x7FFFFFFF & mt_state[(i + 1) % MT_SIZE]) // least significant 31nd bit + * + * mt_state[i] = mt_state[(i + MT_PERIOD) % MT_SIZE] ^ (load >> 1); + * + * if (load & 1) mt_state[i] ^= 0x9908B0DF; + * } + * + * This essentially is a waste: we have two modulus operations, and + * a branch that is executed every iteration from [0, MT_SIZE). + * + * Please see: http://www.quadibloc.com/crypto/co4814.htm for more + * information on how this clever trick works. + */ + static const uint32_t matrix[2] = { + 0x00000000, + 0x9908B0Df + }; + /* + * This register gives up a little more speed by instructing the compiler + * to force these into CPU registers (they're counters for indexing mt_state + * which we can force the compiler to generate prefetch instructions for) + */ + register uint32_t y; + register uint32_t i; + + /* + * Said loop has been unrolled for MT_SPACE (226 iterations), opposed + * to [0, MT_SIZE) (634 iterations). + */ + for (i = 0; i < MT_SPACE-1; ++i) { + y = (0x80000000 & mt_state[i]) | (0x7FFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i + MT_PERIOD] ^ (y >> 1) ^ matrix[y & 1]; + + i ++; /* loop unroll */ + + y = (0x80000000 & mt_state[i]) | (0x7FFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i + MT_PERIOD] ^ (y >> 1) ^ matrix[y & 1]; + } + + /* + * collapsing the walls unrolled (evenly dividing 396 [632-227 = 396 + * = 2*2*3*3*11]) + */ + i = MT_SPACE; + while (i < MT_SIZE-2) { + /* + * We expand this 11 times .. manually, no macros are required + * here. This all fits in the CPU cache. + */ + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + y = (0x80000000 & mt_state[i]) | (0x7FFFFFFF & mt_state[i + 1]); + mt_state[i] = mt_state[i - MT_SPACE] ^ (y >> 1) ^ matrix[y & 1]; + ++i; + } + + /* i = mt_state[623] */ + y = (0x80000000 & mt_state[MT_SIZE - 1]) | (0x7FFFFFFF & mt_state[MT_SIZE - 1]); + mt_state[MT_SIZE - 1] = mt_state[MT_PERIOD - 1] ^ (y >> 1) ^ matrix[y & 1]; +} + +void util_seed(uint32_t value) { + /* + * We seed the mt_state with a LCG (linear congruential generator) + * We're operating exactly on exactly m=32, so there is no need to + * use modulus. + * + * The multipler of choice is 0x6C07865, also knows as the Borosh- + * Niederreiter multipler used for modulus 2^32. More can be read + * about this in Knuth's TAOCP Volume 2, page 106. + * + * If you don't own TAOCP something is wrong with you :-) .. so I + * also provided a link to the original paper by Borosh and + * Niederreiter. It's called "Optional Multipliers for PRNG by The + * Linear Congruential Method" (1983). + * http://en.wikipedia.org/wiki/Linear_congruential_generator + * + * From said page, it says the following: + * "A common Mersenne twister implementation, interestingly enough + * used an LCG to generate seed data." + * + * Remarks: + * The data we're operating on is 32-bits for the mt_state array, so + * there is no masking required with 0xFFFFFFFF + */ + register size_t i; + + mt_state[0] = value; + for (i = 1; i < MT_SIZE; ++i) + mt_state[i] = 0x6C078965 * (mt_state[i - 1] ^ mt_state[i - 1] >> 30) + i; +} + +uint32_t util_rand() { + register uint32_t y; + + /* + * This is inlined with any sane compiler (I checked) + * for some reason though, SubC seems to be generating invalid + * code when it inlines this. + */ + if (!mt_index) + mt_generate(); + + y = mt_state[mt_index]; + + /* Standard tempering */ + y ^= y >> 11; /* +7 */ + y ^= y << 7 & 0x9D2C5680; /* +4 */ + y ^= y << 15 & 0xEFC60000; /* -4 */ + y ^= y >> 18; /* -7 */ + + if(++mt_index == MT_SIZE) + mt_index = 0; + + return y; }