diff options
Diffstat (limited to 'sysdeps/m68k/fpu/e_pow.c')
| -rw-r--r-- | sysdeps/m68k/fpu/e_pow.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/sysdeps/m68k/fpu/e_pow.c b/sysdeps/m68k/fpu/e_pow.c new file mode 100644 index 0000000000..0b6cee6f15 --- /dev/null +++ b/sysdeps/m68k/fpu/e_pow.c @@ -0,0 +1,126 @@ +/* Copyright (C) 1997, 1999 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library 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. + + The GNU C Library 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 the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <math.h> +#include "math_private.h" +#include "mathimpl.h" + +#ifndef SUFF +#define SUFF +#endif +#ifndef float_type +#define float_type double +#endif + +#define CONCATX(a,b) __CONCAT(a,b) +#define s(name) CONCATX(name,SUFF) +#define m81(func) __m81_u(s(func)) + +float_type +s(__ieee754_pow) (float_type x, float_type y) +{ + float_type z; + float_type ax; + unsigned long x_cond, y_cond; + + y_cond = __m81_test (y); + if (y_cond & __M81_COND_ZERO) + return 1.0; + if (y_cond & __M81_COND_NAN) + return x == 1.0 ? x : x + y; + + x_cond = __m81_test (x); + if (x_cond & __M81_COND_NAN) + return x + y; + + if (y_cond & __M81_COND_INF) + { + ax = s(fabs) (x); + if (ax == 1.0) + return ax; + if (ax > 1.0) + return y_cond & __M81_COND_NEG ? 0 : y; + else + return y_cond & __M81_COND_NEG ? -y : 0; + } + + if (s(fabs) (y) == 1.0) + return y_cond & __M81_COND_NEG ? 1 / x : x; + + if (y == 2) + return x * x; + if (y == 0.5 && !(x_cond & __M81_COND_NEG)) + return m81(__ieee754_sqrt) (x); + + if (x == 10.0) + { + __asm ("ftentox%.x %1, %0" : "=f" (z) : "f" (y)); + return z; + } + if (x == 2.0) + { + __asm ("ftwotox%.x %1, %0" : "=f" (z) : "f" (y)); + return z; + } + + ax = s(fabs) (x); + if (x_cond & (__M81_COND_INF | __M81_COND_ZERO) || ax == 1.0) + { + z = ax; + if (y_cond & __M81_COND_NEG) + z = 1 / z; + if (x_cond & __M81_COND_NEG) + { + if (y != m81(__rint) (y)) + { + if (x == -1) + z = (z - z) / (z - z); + } + else + goto maybe_negate; + } + return z; + } + + if (x_cond & __M81_COND_NEG) + { + if (y == m81(__rint) (y)) + { + z = m81(__ieee754_exp) (y * m81(__ieee754_log) (-x)); + maybe_negate: + /* We always use the long double format, since y is already in + this format and rounding won't change the result. */ + { + int32_t exponent; + u_int32_t i0, i1; + GET_LDOUBLE_WORDS (exponent, i0, i1, y); + exponent = (exponent & 0x7fff) - 0x3fff; + if (exponent <= 31 + ? i0 & (1 << (31 - exponent)) + : (exponent <= 63 + && i1 & (1 << (63 - exponent)))) + z = -z; + } + } + else + z = (y - y) / (y - y); + } + else + z = m81(__ieee754_exp) (y * m81(__ieee754_log) (x)); + return z; +} |