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_mulkc3.c revision 1.1.1.9 
      1 /* Copyright (C) 1989-2024 Free Software Foundation, Inc.
      2 
      3 This file is part of GCC.
      4 
      5 GCC is free software; you can redistribute it and/or modify it under
      6 the terms of the GNU General Public License as published by the Free
      7 Software Foundation; either version 3, or (at your option) any later
      8 version.
      9 
     10 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
     11 WARRANTY; without even the implied warranty of MERCHANTABILITY or
     12 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     13 for more details.
     14 
     15 Under Section 7 of GPL version 3, you are granted additional
     16 permissions described in the GCC Runtime Library Exception, version
     17 3.1, as published by the Free Software Foundation.
     18 
     19 You should have received a copy of the GNU General Public License and
     20 a copy of the GCC Runtime Library Exception along with this program;
     21 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
     22 <http://www.gnu.org/licenses/>.  */
     23 
     24 /* This is a temporary specialization of code from libgcc/libgcc2.c.  */
     25 
     26 #include "soft-fp.h"
     27 #include "quad-float128.h"
     28 
     29 /* Use the correct built-in function based on whether TFmode is _Float128 or
     30    long double.  See quad-float128.h for more details.  */
     31 #ifndef __LONG_DOUBLE_IEEE128__
     32 #define COPYSIGN(x,y) __builtin_copysignf128 (x, y)
     33 #define INFINITY __builtin_inff128 ()
     34 
     35 #else
     36 #define COPYSIGN(x,y) __builtin_copysignl (x, y)
     37 #define INFINITY __builtin_infl ()
     38 #endif
     39 
     40 #define isnan __builtin_isnan
     41 #define isinf __builtin_isinf
     42 
     43 #if defined(FLOAT128_HW_INSNS) && !defined(__mulkc3)
     44 #define __mulkc3 __mulkc3_sw
     45 #endif
     46 
     47 TCtype
     48 __mulkc3 (TFtype a, TFtype b, TFtype c, TFtype d)
     49 {
     50   TFtype ac, bd, ad, bc, x, y;
     51   TCtype res;
     52 
     53   ac = a * c;
     54   bd = b * d;
     55   ad = a * d;
     56   bc = b * c;
     57 
     58   x = ac - bd;
     59   y = ad + bc;
     60 
     61   if (isnan (x) && isnan (y))
     62     {
     63       /* Recover infinities that computed as NaN + iNaN.  */
     64       _Bool recalc = 0;
     65       if (isinf (a) || isinf (b))
     66 	{
     67 	  /* z is infinite.  "Box" the infinity and change NaNs in
     68 	     the other factor to 0.  */
     69 	  a = COPYSIGN (isinf (a) ? 1 : 0, a);
     70 	  b = COPYSIGN (isinf (b) ? 1 : 0, b);
     71 	  if (isnan (c)) c = COPYSIGN (0, c);
     72 	  if (isnan (d)) d = COPYSIGN (0, d);
     73           recalc = 1;
     74 	}
     75      if (isinf (c) || isinf (d))
     76 	{
     77 	  /* w is infinite.  "Box" the infinity and change NaNs in
     78 	     the other factor to 0.  */
     79 	  c = COPYSIGN (isinf (c) ? 1 : 0, c);
     80 	  d = COPYSIGN (isinf (d) ? 1 : 0, d);
     81 	  if (isnan (a)) a = COPYSIGN (0, a);
     82 	  if (isnan (b)) b = COPYSIGN (0, b);
     83 	  recalc = 1;
     84 	}
     85      if (!recalc
     86 	  && (isinf (ac) || isinf (bd)
     87 	      || isinf (ad) || isinf (bc)))
     88 	{
     89 	  /* Recover infinities from overflow by changing NaNs to 0.  */
     90 	  if (isnan (a)) a = COPYSIGN (0, a);
     91 	  if (isnan (b)) b = COPYSIGN (0, b);
     92 	  if (isnan (c)) c = COPYSIGN (0, c);
     93 	  if (isnan (d)) d = COPYSIGN (0, d);
     94 	  recalc = 1;
     95 	}
     96       if (recalc)
     97 	{
     98 	  x = INFINITY * (a * c - b * d);
     99 	  y = INFINITY * (a * d + b * c);
    100 	}
    101     }
    102 
    103   __real__ res = x;
    104   __imag__ res = y;
    105   return res;
    106 }
    107 
    108