/*
- * 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
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
-#include <stdarg.h>
+#include <string.h>
+#include <stdlib.h>
+
#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.
+ */
+
+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
+
+/*
+ * 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.
*/
-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 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');
}
/*
- * Removed quotes from a string, escapes from \ in string
- * as well. This function shouldn't be used to create a
- * char array that is later freed (it uses pointer arith)
+ * Portable implementation of vasprintf/asprintf. Assumes vsnprintf
+ * exists, otherwise compiler error.
+ *
+ * TODO: fix for MSVC ....
*/
-char *util_strrq(char *s) {
- char *dst = s;
- char *src = s;
- char chr;
- while ((chr = *src++) != '\0') {
- if (chr == '\\') {
- *dst++ = chr;
- if ((chr = *src++) == '\0')
- break;
- *dst++ = chr;
- } else if (chr != '"')
- *dst++ = chr;
- }
- *dst = '\0';
- return dst;
+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);
-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);
+ 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;
}
projects / xonotic / gmqcc.git / blobdiff