gcc/libgfortran/m4/pow.m4
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

72 lines
1.8 KiB
Plaintext

`/* Support routines for the intrinsic power (**) operator.
Copyright 2004 Free Software Foundation, Inc.
Contributed by Paul Brook
This file is part of the GNU Fortran 95 runtime library (libgfor).
Libgfor 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.
Ligbfor 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. */
#include "config.h"
#include "libgfortran.h"'
include(iparm.m4)dnl
/* Use Binary Method to calculate the powi. This is not an optimal but
a simple and reasonable arithmetic. See section 4.6.3, "Evaluation of
Powers" of Donald E. Knuth, "Seminumerical Algorithms", Vol. 2, "The Art
of Computer Programming", 3rd Edition, 1998. */
rtype_name `pow_'rtype_code`_'atype_code (rtype_name a, atype_name b);
export_proto(pow_`'rtype_code`_'atype_code);
rtype_name
`pow_'rtype_code`_'atype_code (rtype_name a, atype_name b)
{
rtype_name pow, x;
atype_name n, u;
n = b;
x = a;
pow = 1;
if (n != 0)
{
if (n < 0)
{
ifelse(rtype_letter,i,`dnl
if (x == 1)
return 1;
if (x == -1)
return (n & 1) ? -1 : 1;
return (x == 0) ? 1 / x : 0;
',`
n = -n;
x = pow / x;
')dnl
}
u = n;
for (;;)
{
if (u & 1)
pow *= x;
u >>= 1;
if (u)
x *= x;
else
break;
}
}
return pow;
}