diff options
Diffstat (limited to 'sysdeps/powerpc/fpu/e_hypot.c')
| -rw-r--r-- | sysdeps/powerpc/fpu/e_hypot.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/sysdeps/powerpc/fpu/e_hypot.c b/sysdeps/powerpc/fpu/e_hypot.c new file mode 100644 index 0000000000..22bd56371e --- /dev/null +++ b/sysdeps/powerpc/fpu/e_hypot.c @@ -0,0 +1,117 @@ +/* Pythagorean addition using doubles + Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library + Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011 + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; 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 "math.h" +#include "math_private.h" + +static const double two60 = 1.152921504606847e+18; +static const double two500 = 3.2733906078961419e+150; +static const double two600 = 4.149515568880993e+180; +static const double two1022 = 4.49423283715579e+307; +static const double twoM500 = 3.054936363499605e-151; +static const double twoM600 = 4.616489308892868e-128; +static const double pdnum = 2.225073858507201e-308; + +/* __ieee754_hypot(x,y) + * + * This a FP only version without any FP->INT conversion. + * It is similar to default C version, making appropriates + * overflow and underflows checks as well scaling when it + * is needed. + */ + +#ifdef _ARCH_PWR7 +/* POWER7 isinf and isnan optimization are fast. */ +# define TEST_INF_NAN(x, y) \ + if (isinf(x) || isinf(y)) \ + return INFINITY; \ + if (isnan(x) || isnan(y)) \ + return NAN; +# else +/* For POWER6 and below isinf/isnan triggers LHS and PLT calls are + * costly (especially for POWER6). */ +# define GET_TW0_HIGH_WORD(d1,d2,i1,i2) \ + do { \ + ieee_double_shape_type gh_u1; \ + ieee_double_shape_type gh_u2; \ + gh_u1.value = (d1); \ + gh_u2.value = (d2); \ + (i1) = gh_u1.parts.msw; \ + (i2) = gh_u2.parts.msw; \ + } while (0) + +# define TEST_INF_NAN(x, y) \ + do { \ + int32_t hx, hy; \ + GET_TW0_HIGH_WORD(x, y, hx, hy); \ + if (hy > hx) { \ + uint32_t ht = hx; hx = hy; hy = ht; \ + } \ + if (hx >= 0x7ff00000) { \ + if (hx == 0x7ff00000 || hy == 0x7ff00000) \ + return INFINITY; \ + return NAN; \ + } \ + } while (0) + +#endif + + +double +__ieee754_hypot (double x, double y) +{ + x = fabs (x); + y = fabs (y); + + TEST_INF_NAN (x, y); + + if (y > x) + { + double t = x; + x = y; + y = t; + } + if (y == 0.0 || (x / y) > two60) + { + return x + y; + } + if (x > two500) + { + x *= twoM600; + y *= twoM600; + return sqrt (x * x + y * y) / twoM600; + } + if (y < twoM500) + { + if (y <= pdnum) + { + x *= two1022; + y *= two1022; + return sqrt (x * x + y * y) / two1022; + } + else + { + x *= two600; + y *= two600; + return sqrt (x * x + y * y) / two600; + } + } + return sqrt (x * x + y * y); +} |