diff options
Diffstat (limited to 'libgcc/config/rs6000/_divkc3.c')
-rw-r--r-- | libgcc/config/rs6000/_divkc3.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/libgcc/config/rs6000/_divkc3.c b/libgcc/config/rs6000/_divkc3.c new file mode 100644 index 0000000000..638e18336a --- /dev/null +++ b/libgcc/config/rs6000/_divkc3.c @@ -0,0 +1,89 @@ +/* Copyright (C) 1989-2016 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC 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 General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +/* This is a temporary specialization of code from libgcc/libgcc2.c. */ + +typedef float KFtype __attribute__ ((mode (KF))); +typedef __complex float KCtype __attribute__ ((mode (KC))); + +#define COPYSIGN(x,y) __builtin_copysignq (x, y) +#define INFINITY __builtin_infq () +#define FABS __builtin_fabsq +#define isnan __builtin_isnan +#define isinf __builtin_isinf +#define isfinite __builtin_isfinite + +KCtype +__divkc3 (KFtype a, KFtype b, KFtype c, KFtype d) +{ + KFtype denom, ratio, x, y; + KCtype res; + + /* ??? We can get better behavior from logarithmic scaling instead of + the division. But that would mean starting to link libgcc against + libm. We could implement something akin to ldexp/frexp as gcc builtins + fairly easily... */ + if (FABS (c) < FABS (d)) + { + ratio = c / d; + denom = (c * ratio) + d; + x = ((a * ratio) + b) / denom; + y = ((b * ratio) - a) / denom; + } + else + { + ratio = d / c; + denom = (d * ratio) + c; + x = ((b * ratio) + a) / denom; + y = (b - (a * ratio)) / denom; + } + + /* Recover infinities and zeros that computed as NaN+iNaN; the only cases + are nonzero/zero, infinite/finite, and finite/infinite. */ + if (isnan (x) && isnan (y)) + { + if (c == 0.0 && d == 0.0 && (!isnan (a) || !isnan (b))) + { + x = COPYSIGN (INFINITY, c) * a; + y = COPYSIGN (INFINITY, c) * b; + } + else if ((isinf (a) || isinf (b)) && isfinite (c) && isfinite (d)) + { + a = COPYSIGN (isinf (a) ? 1 : 0, a); + b = COPYSIGN (isinf (b) ? 1 : 0, b); + x = INFINITY * (a * c + b * d); + y = INFINITY * (b * c - a * d); + } + else if ((isinf (c) || isinf (d)) && isfinite (a) && isfinite (b)) + { + c = COPYSIGN (isinf (c) ? 1 : 0, c); + d = COPYSIGN (isinf (d) ? 1 : 0, d); + x = 0.0 * (a * c + b * d); + y = 0.0 * (b * c - a * d); + } + } + + __real__ res = x; + __imag__ res = y; + return res; +} |