newlib-cygwin/newlib/libm/machine/i386/f_exp.c

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* Makefile.shared: New file. * libc/sys/linux/shared.ld: New file. * libm/machine/*: New files. * libm/machine/i386/*: New files. * Makefile.am: Add libtool support. Change math and mathfp references to variables. * configure.host: Add variables for libtool support. Add libm_machine_dir variable. * configure.in: Add objectlist variables, for libtool support. Add CC_FOR_BUILD tests. * libc/Makefile.am: Add libtool support. Change crt0.o reference to be a variable reference. * libc/configure.in: Add libtool support. Change sublib names to be lib${subdir}.la when using libtool. * libc/ctype/Makefile.am: Add libtool support. * libc/errno/Makefile.am: Likewise. * libc/locale/Makefile.am: Likewise. * libc/machine/Makefile.am: Likewise. * libc/machine/configure.in: Likewise. * libc/machine/i386/Makefile.am: Likewise. * libc/machine/i386/configure.in: Likewise. * libc/misc/Makefile.am: Likewise. * libc/posix/Makefile.am: Likewise. * libc/reent/Makefile.am: Likewise. * libc/signal/Makefile.am: Likewise. * libc/stdio/Makefile.am: Likewise. * libc/stdlib/Makefile.am: Likewise. * libc/string/Makefile.am: Likewise. * libc/sys/Makefile.am: Likewise. * libc/sys/configure.in: Likewise. * libc/sys/linux/Makefile.am: Add libtool support. Change awk reference to a variable reference. Change signal.h reference to a variable reference. * libc/sys/linux/configure.in: Add libtool support. * libc/syscalls/Makefile.am: Likewise. * libc/time/Makefile.am: Likewise. * libc/unix/Makefile.am: Likewise. * libm/Makefile.am: Add libtool support. Change math and mathfp references to variables. * libm/configure.in: Add libtool support. Add LIBM_MACHINE_LIB variable. * libm/common/Makefile.am: Add libtool support. * libm/math/Makefile.am: Likewise. * libm/mathfp/Makefile.am: Likewise. Regenerate all Makefile.in, aclocal.m4, and configure.
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/*
* ====================================================
* Copyright (C) 1998 by Cygnus Solutions. All rights reserved.
*
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if !defined(_SOFT_FLOAT)
* Makefile.shared: New file. * libc/sys/linux/shared.ld: New file. * libm/machine/*: New files. * libm/machine/i386/*: New files. * Makefile.am: Add libtool support. Change math and mathfp references to variables. * configure.host: Add variables for libtool support. Add libm_machine_dir variable. * configure.in: Add objectlist variables, for libtool support. Add CC_FOR_BUILD tests. * libc/Makefile.am: Add libtool support. Change crt0.o reference to be a variable reference. * libc/configure.in: Add libtool support. Change sublib names to be lib${subdir}.la when using libtool. * libc/ctype/Makefile.am: Add libtool support. * libc/errno/Makefile.am: Likewise. * libc/locale/Makefile.am: Likewise. * libc/machine/Makefile.am: Likewise. * libc/machine/configure.in: Likewise. * libc/machine/i386/Makefile.am: Likewise. * libc/machine/i386/configure.in: Likewise. * libc/misc/Makefile.am: Likewise. * libc/posix/Makefile.am: Likewise. * libc/reent/Makefile.am: Likewise. * libc/signal/Makefile.am: Likewise. * libc/stdio/Makefile.am: Likewise. * libc/stdlib/Makefile.am: Likewise. * libc/string/Makefile.am: Likewise. * libc/sys/Makefile.am: Likewise. * libc/sys/configure.in: Likewise. * libc/sys/linux/Makefile.am: Add libtool support. Change awk reference to a variable reference. Change signal.h reference to a variable reference. * libc/sys/linux/configure.in: Add libtool support. * libc/syscalls/Makefile.am: Likewise. * libc/time/Makefile.am: Likewise. * libc/unix/Makefile.am: Likewise. * libm/Makefile.am: Add libtool support. Change math and mathfp references to variables. * libm/configure.in: Add libtool support. Add LIBM_MACHINE_LIB variable. * libm/common/Makefile.am: Add libtool support. * libm/math/Makefile.am: Likewise. * libm/mathfp/Makefile.am: Likewise. Regenerate all Makefile.in, aclocal.m4, and configure.
2001-12-14 07:50:11 +08:00
/*
Fast version of exp using Intel float instructions.
double _f_exp (double x);
Function computes e ** x. The following special cases exist:
1. if x is 0.0 ==> return 1.0
2. if x is infinity ==> return infinity
3. if x is -infinity ==> return 0.0
4. if x is NaN ==> return x
There is no error checking or setting of errno.
*/
#include <math.h>
#include <ieeefp.h>
#include "f_math.h"
double _f_exp (double x)
{
if (check_finite(x))
{
double result;
asm ("fldl2e; fmulp; fld %%st; frndint; fsub %%st,%%st(1); fxch;" \
"fchs; f2xm1; fld1; faddp; fxch; fld1; fscale; fstp %%st(1); fmulp" :
"=t"(result) : "0"(x));
return result;
}
else if (x == -infinity())
return 0.0;
return x;
}
#endif