contrib/compiler-rt/lib/ppc/divtc3.c

   1 /* This file is distributed under the University of Illinois Open Source
   2  * License. See LICENSE.TXT for details.
   3  */
   4
   5 #include "DD.h"
   6 #include <math.h>
   7
   8 #if !defined(INFINITY) && defined(HUGE_VAL)
   9 #define INFINITY HUGE_VAL
  10 #endif /* INFINITY */
  11
  12 #define makeFinite(x)   { \
  13                                                         (x).s.hi = __builtin_copysign(isinf((x).s.hi) ? 1.0 : 0.0, (x).s.hi); \
  14                                                         (x).s.lo = 0.0; \
  15                                                 }
  16
  17 long double __gcc_qadd(long double, long double);
  18 long double __gcc_qsub(long double, long double);
  19 long double __gcc_qmul(long double, long double);
  20 long double __gcc_qdiv(long double, long double);
  21
  22 long double _Complex
  23 __divtc3(long double a, long double b, long double c, long double d)
  24 {
  25         DD cDD = { .ld = c };
  26         DD dDD = { .ld = d };
  27
  28         int ilogbw = 0;
  29         const double logbw = logb(__builtin_fmax( __builtin_fabs(cDD.s.hi), __builtin_fabs(dDD.s.hi) ));
  30
  31         if (isfinite(logbw))
  32         {
  33                 ilogbw = (int)logbw;
  34
  35                 cDD.s.hi = scalbn(cDD.s.hi, -ilogbw);
  36                 cDD.s.lo = scalbn(cDD.s.lo, -ilogbw);
  37                 dDD.s.hi = scalbn(dDD.s.hi, -ilogbw);
  38                 dDD.s.lo = scalbn(dDD.s.lo, -ilogbw);
  39         }
  40
  41         const long double denom = __gcc_qadd(__gcc_qmul(cDD.ld, cDD.ld), __gcc_qmul(dDD.ld, dDD.ld));
  42         const long double realNumerator = __gcc_qadd(__gcc_qmul(a,cDD.ld), __gcc_qmul(b,dDD.ld));
  43         const long double imagNumerator = __gcc_qsub(__gcc_qmul(b,cDD.ld), __gcc_qmul(a,dDD.ld));
  44
  45         DD real = { .ld = __gcc_qdiv(realNumerator, denom) };
  46         DD imag = { .ld = __gcc_qdiv(imagNumerator, denom) };
  47
  48         real.s.hi = scalbn(real.s.hi, -ilogbw);
  49         real.s.lo = scalbn(real.s.lo, -ilogbw);
  50         imag.s.hi = scalbn(imag.s.hi, -ilogbw);
  51         imag.s.lo = scalbn(imag.s.lo, -ilogbw);
  52
  53         if (isnan(real.s.hi) && isnan(imag.s.hi))
  54         {
  55                 DD aDD = { .ld = a };
  56                 DD bDD = { .ld = b };
  57                 DD rDD = { .ld = denom };
  58
  59                 if ((rDD.s.hi == 0.0) && (!isnan(aDD.s.hi) || !isnan(bDD.s.hi)))
  60                 {
  61                         real.s.hi = __builtin_copysign(INFINITY,cDD.s.hi) * aDD.s.hi;
  62                         real.s.lo = 0.0;
  63                         imag.s.hi = __builtin_copysign(INFINITY,cDD.s.hi) * bDD.s.hi;
  64                         imag.s.lo = 0.0;
  65                 }
  66
  67                 else if ((isinf(aDD.s.hi) || isinf(bDD.s.hi)) && isfinite(cDD.s.hi) && isfinite(dDD.s.hi))
  68                 {
  69                         makeFinite(aDD);
  70                         makeFinite(bDD);
  71                         real.s.hi = INFINITY * (aDD.s.hi*cDD.s.hi + bDD.s.hi*dDD.s.hi);
  72                         real.s.lo = 0.0;
  73                         imag.s.hi = INFINITY * (bDD.s.hi*cDD.s.hi - aDD.s.hi*dDD.s.hi);
  74                         imag.s.lo = 0.0;
  75                 }
  76
  77                 else if ((isinf(cDD.s.hi) || isinf(dDD.s.hi)) && isfinite(aDD.s.hi) && isfinite(bDD.s.hi))
  78                 {
  79                         makeFinite(cDD);
  80                         makeFinite(dDD);
  81                         real.s.hi = __builtin_copysign(0.0,(aDD.s.hi*cDD.s.hi + bDD.s.hi*dDD.s.hi));
  82                         real.s.lo = 0.0;
  83                         imag.s.hi = __builtin_copysign(0.0,(bDD.s.hi*cDD.s.hi - aDD.s.hi*dDD.s.hi));
  84                         imag.s.lo = 0.0;
  85                 }
  86         }
  87
  88         long double _Complex z;
  89         __real__ z = real.ld;
  90         __imag__ z = imag.ld;
  91
  92         return z;
  93 }