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authorDan Albert <danalbert@google.com>2015-10-13 16:28:19 -0700
committerDan Albert <danalbert@google.com>2015-10-13 16:28:19 -0700
commita8c075f72b231c37823661ba0d7d082a21cd39d9 (patch)
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Remove gcc-4.8.
Change-Id: Iee9c6985c613f58c82e33a91722d371579eb290f
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-/*
- * 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 [rescinded 22 July 1999]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;
- }
-}