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Diffstat (limited to 'gcc-4.2.1-5666.3/libiberty/random.c')
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diff --git a/gcc-4.2.1-5666.3/libiberty/random.c b/gcc-4.2.1-5666.3/libiberty/random.c deleted file mode 100644 index c306698a5..000000000 --- a/gcc-4.2.1-5666.3/libiberty/random.c +++ /dev/null @@ -1,403 +0,0 @@ -/* - * Copyright (c) 1983 Regents of the University of California. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. [rescinded 22 July 1999] - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -/* - * This is derived from the Berkeley source: - * @(#)random.c 5.5 (Berkeley) 7/6/88 - * It was reworked for the GNU C Library by Roland McGrath. - */ - -/* - -@deftypefn Supplement {long int} random (void) -@deftypefnx Supplement void srandom (unsigned int @var{seed}) -@deftypefnx Supplement void* initstate (unsigned int @var{seed}, void *@var{arg_state}, unsigned long @var{n}) -@deftypefnx Supplement void* setstate (void *@var{arg_state}) - -Random number functions. @code{random} returns a random number in the -range 0 to @code{LONG_MAX}. @code{srandom} initializes the random -number generator to some starting point determined by @var{seed} -(else, the values returned by @code{random} are always the same for each -run of the program). @code{initstate} and @code{setstate} allow fine-grained -control over the state of the random number generator. - -@end deftypefn - -*/ - -#include <errno.h> - -#if 0 - -#include <ansidecl.h> -#include <limits.h> -#include <stddef.h> -#include <stdlib.h> - -#else - -#define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF for 32-bits */ -#define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF for 32-bits*/ - -#ifdef __STDC__ -# define PTR void * -# ifndef NULL -# define NULL (void *) 0 -# endif -#else -# define PTR char * -# ifndef NULL -# define NULL (void *) 0 -# endif -#endif - -#endif - -long int random (void); - -/* An improved random number generation package. In addition to the standard - rand()/srand() like interface, this package also has a special state info - interface. The initstate() routine is called with a seed, an array of - bytes, and a count of how many bytes are being passed in; this array is - then initialized to contain information for random number generation with - that much state information. Good sizes for the amount of state - information are 32, 64, 128, and 256 bytes. The state can be switched by - calling the setstate() function with the same array as was initiallized - with initstate(). By default, the package runs with 128 bytes of state - information and generates far better random numbers than a linear - congruential generator. If the amount of state information is less than - 32 bytes, a simple linear congruential R.N.G. is used. Internally, the - state information is treated as an array of longs; the zeroeth element of - the array is the type of R.N.G. being used (small integer); the remainder - of the array is the state information for the R.N.G. Thus, 32 bytes of - state information will give 7 longs worth of state information, which will - allow a degree seven polynomial. (Note: The zeroeth word of state - information also has some other information stored in it; see setstate - for details). The random number generation technique is a linear feedback - shift register approach, employing trinomials (since there are fewer terms - to sum up that way). In this approach, the least significant bit of all - the numbers in the state table will act as a linear feedback shift register, - and will have period 2^deg - 1 (where deg is the degree of the polynomial - being used, assuming that the polynomial is irreducible and primitive). - The higher order bits will have longer periods, since their values are - also influenced by pseudo-random carries out of the lower bits. The - total period of the generator is approximately deg*(2**deg - 1); thus - doubling the amount of state information has a vast influence on the - period of the generator. Note: The deg*(2**deg - 1) is an approximation - only good for large deg, when the period of the shift register is the - dominant factor. With deg equal to seven, the period is actually much - longer than the 7*(2**7 - 1) predicted by this formula. */ - - - -/* For each of the currently supported random number generators, we have a - break value on the amount of state information (you need at least thi - bytes of state info to support this random number generator), a degree for - the polynomial (actually a trinomial) that the R.N.G. is based on, and - separation between the two lower order coefficients of the trinomial. */ - -/* Linear congruential. */ -#define TYPE_0 0 -#define BREAK_0 8 -#define DEG_0 0 -#define SEP_0 0 - -/* x**7 + x**3 + 1. */ -#define TYPE_1 1 -#define BREAK_1 32 -#define DEG_1 7 -#define SEP_1 3 - -/* x**15 + x + 1. */ -#define TYPE_2 2 -#define BREAK_2 64 -#define DEG_2 15 -#define SEP_2 1 - -/* x**31 + x**3 + 1. */ -#define TYPE_3 3 -#define BREAK_3 128 -#define DEG_3 31 -#define SEP_3 3 - -/* x**63 + x + 1. */ -#define TYPE_4 4 -#define BREAK_4 256 -#define DEG_4 63 -#define SEP_4 1 - - -/* Array versions of the above information to make code run faster. - Relies on fact that TYPE_i == i. */ - -#define MAX_TYPES 5 /* Max number of types above. */ - -static int degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 }; -static int seps[MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 }; - - - -/* Initially, everything is set up as if from: - initstate(1, randtbl, 128); - Note that this initialization takes advantage of the fact that srandom - advances the front and rear pointers 10*rand_deg times, and hence the - rear pointer which starts at 0 will also end up at zero; thus the zeroeth - element of the state information, which contains info about the current - position of the rear pointer is just - (MAX_TYPES * (rptr - state)) + TYPE_3 == TYPE_3. */ - -static long int randtbl[DEG_3 + 1] = - { TYPE_3, - 0x9a319039, 0x32d9c024, 0x9b663182, 0x5da1f342, - 0xde3b81e0, 0xdf0a6fb5, 0xf103bc02, 0x48f340fb, - 0x7449e56b, 0xbeb1dbb0, 0xab5c5918, 0x946554fd, - 0x8c2e680f, 0xeb3d799f, 0xb11ee0b7, 0x2d436b86, - 0xda672e2a, 0x1588ca88, 0xe369735d, 0x904f35f7, - 0xd7158fd6, 0x6fa6f051, 0x616e6b96, 0xac94efdc, - 0x36413f93, 0xc622c298, 0xf5a42ab8, 0x8a88d77b, - 0xf5ad9d0e, 0x8999220b, 0x27fb47b9 - }; - -/* FPTR and RPTR are two pointers into the state info, a front and a rear - pointer. These two pointers are always rand_sep places aparts, as they - cycle through the state information. (Yes, this does mean we could get - away with just one pointer, but the code for random is more efficient - this way). The pointers are left positioned as they would be from the call: - initstate(1, randtbl, 128); - (The position of the rear pointer, rptr, is really 0 (as explained above - in the initialization of randtbl) because the state table pointer is set - to point to randtbl[1] (as explained below).) */ - -static long int *fptr = &randtbl[SEP_3 + 1]; -static long int *rptr = &randtbl[1]; - - - -/* The following things are the pointer to the state information table, - the type of the current generator, the degree of the current polynomial - being used, and the separation between the two pointers. - Note that for efficiency of random, we remember the first location of - the state information, not the zeroeth. Hence it is valid to access - state[-1], which is used to store the type of the R.N.G. - Also, we remember the last location, since this is more efficient than - indexing every time to find the address of the last element to see if - the front and rear pointers have wrapped. */ - -static long int *state = &randtbl[1]; - -static int rand_type = TYPE_3; -static int rand_deg = DEG_3; -static int rand_sep = SEP_3; - -static long int *end_ptr = &randtbl[sizeof(randtbl) / sizeof(randtbl[0])]; - -/* Initialize the random number generator based on the given seed. If the - type is the trivial no-state-information type, just remember the seed. - Otherwise, initializes state[] based on the given "seed" via a linear - congruential generator. Then, the pointers are set to known locations - that are exactly rand_sep places apart. Lastly, it cycles the state - information a given number of times to get rid of any initial dependencies - introduced by the L.C.R.N.G. Note that the initialization of randtbl[] - for default usage relies on values produced by this routine. */ -void -srandom (unsigned int x) -{ - state[0] = x; - if (rand_type != TYPE_0) - { - register long int i; - for (i = 1; i < rand_deg; ++i) - state[i] = (1103515145 * state[i - 1]) + 12345; - fptr = &state[rand_sep]; - rptr = &state[0]; - for (i = 0; i < 10 * rand_deg; ++i) - random(); - } -} - -/* Initialize the state information in the given array of N bytes for - future random number generation. Based on the number of bytes we - are given, and the break values for the different R.N.G.'s, we choose - the best (largest) one we can and set things up for it. srandom is - then called to initialize the state information. Note that on return - from srandom, we set state[-1] to be the type multiplexed with the current - value of the rear pointer; this is so successive calls to initstate won't - lose this information and will be able to restart with setstate. - Note: The first thing we do is save the current state, if any, just like - setstate so that it doesn't matter when initstate is called. - Returns a pointer to the old state. */ -PTR -initstate (unsigned int seed, PTR arg_state, unsigned long n) -{ - PTR ostate = (PTR) &state[-1]; - - if (rand_type == TYPE_0) - state[-1] = rand_type; - else - state[-1] = (MAX_TYPES * (rptr - state)) + rand_type; - if (n < BREAK_1) - { - if (n < BREAK_0) - { - errno = EINVAL; - return NULL; - } - rand_type = TYPE_0; - rand_deg = DEG_0; - rand_sep = SEP_0; - } - else if (n < BREAK_2) - { - rand_type = TYPE_1; - rand_deg = DEG_1; - rand_sep = SEP_1; - } - else if (n < BREAK_3) - { - rand_type = TYPE_2; - rand_deg = DEG_2; - rand_sep = SEP_2; - } - else if (n < BREAK_4) - { - rand_type = TYPE_3; - rand_deg = DEG_3; - rand_sep = SEP_3; - } - else - { - rand_type = TYPE_4; - rand_deg = DEG_4; - rand_sep = SEP_4; - } - - state = &((long int *) arg_state)[1]; /* First location. */ - /* Must set END_PTR before srandom. */ - end_ptr = &state[rand_deg]; - srandom(seed); - if (rand_type == TYPE_0) - state[-1] = rand_type; - else - state[-1] = (MAX_TYPES * (rptr - state)) + rand_type; - - return ostate; -} - -/* Restore the state from the given state array. - Note: It is important that we also remember the locations of the pointers - in the current state information, and restore the locations of the pointers - from the old state information. This is done by multiplexing the pointer - location into the zeroeth word of the state information. Note that due - to the order in which things are done, it is OK to call setstate with the - same state as the current state - Returns a pointer to the old state information. */ - -PTR -setstate (PTR arg_state) -{ - register long int *new_state = (long int *) arg_state; - register int type = new_state[0] % MAX_TYPES; - register int rear = new_state[0] / MAX_TYPES; - PTR ostate = (PTR) &state[-1]; - - if (rand_type == TYPE_0) - state[-1] = rand_type; - else - state[-1] = (MAX_TYPES * (rptr - state)) + rand_type; - - switch (type) - { - case TYPE_0: - case TYPE_1: - case TYPE_2: - case TYPE_3: - case TYPE_4: - rand_type = type; - rand_deg = degrees[type]; - rand_sep = seps[type]; - break; - default: - /* State info munged. */ - errno = EINVAL; - return NULL; - } - - state = &new_state[1]; - if (rand_type != TYPE_0) - { - rptr = &state[rear]; - fptr = &state[(rear + rand_sep) % rand_deg]; - } - /* Set end_ptr too. */ - end_ptr = &state[rand_deg]; - - return ostate; -} - -/* If we are using the trivial TYPE_0 R.N.G., just do the old linear - congruential bit. Otherwise, we do our fancy trinomial stuff, which is the - same in all ther other cases due to all the global variables that have been - set up. The basic operation is to add the number at the rear pointer into - the one at the front pointer. Then both pointers are advanced to the next - location cyclically in the table. The value returned is the sum generated, - reduced to 31 bits by throwing away the "least random" low bit. - Note: The code takes advantage of the fact that both the front and - rear pointers can't wrap on the same call by not testing the rear - pointer if the front one has wrapped. Returns a 31-bit random number. */ - -long int -random (void) -{ - if (rand_type == TYPE_0) - { - state[0] = ((state[0] * 1103515245) + 12345) & LONG_MAX; - return state[0]; - } - else - { - long int i; - *fptr += *rptr; - /* Chucking least random bit. */ - i = (*fptr >> 1) & LONG_MAX; - ++fptr; - if (fptr >= end_ptr) - { - fptr = state; - ++rptr; - } - else - { - ++rptr; - if (rptr >= end_ptr) - rptr = state; - } - return i; - } -} |