gcc/libgfortran/intrinsics/rand.c
Richard Henderson 7d7b8bfe55 acinclude.m4 (LIBGFOR_CHECK_ATTRIBUTE_VISIBILITY): New.
* acinclude.m4 (LIBGFOR_CHECK_ATTRIBUTE_VISIBILITY): New.
        (LIBGFOR_CHECK_ATTRIBUTE_DLLEXPORT): New.
        (LIBGFOR_CHECK_ATTRIBUTE_ALIAS): New.
        * configure.ac: Use them.
        * configure, config.h.in, aclocal.m4: Rebuild.
        * libgfortran.h (prefix): Remove.
        (PREFIX, IPREFIX): New.
        (sym_rename, sym_rename1, sym_rename2): New.
        (internal_proto, export_proto, export_proto_np): New.
        (iexport_proto, iexport): New.
        (iexport_data_proto, iexport_data): New.
        * intrinsics/abort.c, intrinsics/args.c, intrinsics/associated.c,
        intrinsics/cpu_time.c, intrinsics/cshift0.c,
        intrinsics/date_and_time.c, intrinsics/env.c, intrinsics/eoshift0.c,
        intrinsics/eoshift2.c, intrinsics/etime.c, intrinsics/exit.c,
        intrinsics/flush.c, intrinsics/fnum.c, intrinsics/getXid.c,
        intrinsics/getcwd.c, intrinsics/ishftc.c, intrinsics/mvbits.c,
        intrinsics/pack_generic.c, intrinsics/rand.c, intrinsics/random.c,
        intrinsics/reshape_generic.c, intrinsics/size.c,
        intrinsics/spread_generic.c, intrinsics/stat.c,
        intrinsics/string_intrinsics.c, intrinsics/system.c,
        intrinsics/system_clock.c, intrinsics/transpose_generic.c,
        intrinsics/umask.c, intrinsics/unlink.c, intrinsics/unpack_generic.c,
        io/backspace.c, io/close.c, io/endfile.c, io/inquire.c, io/io.h,
        io/open.c, io/rewind.c, io/transfer.c, libgfortran.h, m4/cshift1.m4,
        m4/dotprod.m4, m4/dotprodc.m4, m4/dotprodl.m4, m4/eoshift1.m4,
        m4/eoshift3.m4, m4/exponent.m4, m4/fraction.m4, m4/iforeach.m4,
        m4/ifunction.m4, m4/matmul.m4, m4/matmull.m4, m4/nearest.m4,
        m4/pow.m4, m4/reshape.m4, m4/set_exponent.m4, m4/shape.m4,
        m4/transpose.m4, runtime/environ.c, runtime/error.c,
        runtime/in_pack_generic.c, runtime/in_unpack_generic.c,
        runtime/main.c, runtime/memory.c, runtime/pause.c, runtime/select.c,
        runtime/stop.c: Use them to mark symbols internal or external.
        * generated/*: Rebuild.

From-SVN: r92045
2004-12-12 00:59:05 -08:00

105 lines
2.7 KiB
C

/* Implementation of the IRAND, RAND, and SRAND intrinsics.
Copyright (C) 2004 Free Software Foundation, Inc.
Contributed by Steven G. Kargl <kargls@comcast.net>.
This file is part of the GNU Fortran 95 runtime library (libgfortran).
Libgfortran is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
Libgfortran is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with libgfor; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* Simple multiplicative congruent algorithm.
The period of this generator is approximately 2^31-1, which means that
it should not be used for anything serious. The implementation here
is based of an algorithm from S.K. Park and K.W. Miller, Comm. ACM,
31, 1192-1201 (1988). It is also provided solely for compatibility
with G77. */
#include "config.h"
#include "libgfortran.h"
#define GFC_RAND_A 16807
#define GFC_RAND_M 2147483647
#define GFC_RAND_M1 (GFC_RAND_M - 1)
static GFC_UINTEGER_8 rand_seed = 1;
/* Set the seed of the irand generator. Note 0 is a bad seed. */
static void
srand_internal (GFC_INTEGER_8 i)
{
rand_seed = i ? i : 123459876;
}
extern void PREFIX(srand) (GFC_INTEGER_4 *i);
export_proto_np(PREFIX(srand));
void
PREFIX(srand) (GFC_INTEGER_4 *i)
{
srand_internal (*i);
}
/* Return an INTEGER in the range [1,GFC_RAND_M-1]. */
extern GFC_INTEGER_4 irand (GFC_INTEGER_4 *);
iexport_proto(irand);
GFC_INTEGER_4
irand (GFC_INTEGER_4 *i)
{
GFC_INTEGER_4 j;
if (i)
j = *i;
else
j = 0;
switch (j)
{
/* Return the next RN. */
case 0:
break;
/* Reset the RN sequence to system-dependent sequence and return the
first value. */
case 1:
srand_internal (0);
break;
/* Seed the RN sequence with j and return the first value. */
default:
srand_internal (j);
break;
}
rand_seed = GFC_RAND_A * rand_seed % GFC_RAND_M;
return (GFC_INTEGER_4) rand_seed;
}
iexport(irand);
/* Return a random REAL in the range [0,1). */
extern GFC_REAL_4 PREFIX(rand) (GFC_INTEGER_4 *i);
export_proto_np(PREFIX(rand));
GFC_REAL_4
PREFIX(rand) (GFC_INTEGER_4 *i)
{
return normalize_r4_i4 (irand (i) - 1, GFC_RAND_M1 - 1);
}