contrib/compiler-rt/lib/builtins/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 "../int_math.h"
   7 // Use DOUBLE_PRECISION because the soft-fp method we use is logb (on the upper
   8 // half of the long doubles), even though this file defines complex division for
   9 // 128-bit floats.
  10 #define DOUBLE_PRECISION
  11 #include "../fp_lib.h"
  12
  13 #if !defined(CRT_INFINITY) && defined(HUGE_VAL)
  14 #define CRT_INFINITY HUGE_VAL
  15 #endif /* CRT_INFINITY */
  16
  17 #define makeFinite(x) { \
  18     (x).s.hi = crt_copysign(crt_isinf((x).s.hi) ? 1.0 : 0.0, (x).s.hi); \
  19     (x).s.lo = 0.0;                                                     \
  20   }
  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 = __compiler_rt_logb(
  30                 crt_fmax(crt_fabs(cDD.s.hi), crt_fabs(dDD.s.hi)));
  31
  32         if (crt_isfinite(logbw))
  33         {
  34                 ilogbw = (int)logbw;
  35
  36                 cDD.s.hi = crt_scalbn(cDD.s.hi, -ilogbw);
  37                 cDD.s.lo = crt_scalbn(cDD.s.lo, -ilogbw);
  38                 dDD.s.hi = crt_scalbn(dDD.s.hi, -ilogbw);
  39                 dDD.s.lo = crt_scalbn(dDD.s.lo, -ilogbw);
  40         }
  41
  42         const long double denom = __gcc_qadd(__gcc_qmul(cDD.ld, cDD.ld), __gcc_qmul(dDD.ld, dDD.ld));
  43         const long double realNumerator = __gcc_qadd(__gcc_qmul(a,cDD.ld), __gcc_qmul(b,dDD.ld));
  44         const long double imagNumerator = __gcc_qsub(__gcc_qmul(b,cDD.ld), __gcc_qmul(a,dDD.ld));
  45
  46         DD real = { .ld = __gcc_qdiv(realNumerator, denom) };
  47         DD imag = { .ld = __gcc_qdiv(imagNumerator, denom) };
  48
  49         real.s.hi = crt_scalbn(real.s.hi, -ilogbw);
  50         real.s.lo = crt_scalbn(real.s.lo, -ilogbw);
  51         imag.s.hi = crt_scalbn(imag.s.hi, -ilogbw);
  52         imag.s.lo = crt_scalbn(imag.s.lo, -ilogbw);
  53
  54         if (crt_isnan(real.s.hi) && crt_isnan(imag.s.hi))
  55         {
  56                 DD aDD = { .ld = a };
  57                 DD bDD = { .ld = b };
  58                 DD rDD = { .ld = denom };
  59
  60                 if ((rDD.s.hi == 0.0) && (!crt_isnan(aDD.s.hi) ||
  61                                           !crt_isnan(bDD.s.hi)))
  62                 {
  63                         real.s.hi = crt_copysign(CRT_INFINITY,cDD.s.hi) * aDD.s.hi;
  64                         real.s.lo = 0.0;
  65                         imag.s.hi = crt_copysign(CRT_INFINITY,cDD.s.hi) * bDD.s.hi;
  66                         imag.s.lo = 0.0;
  67                 }
  68
  69                 else if ((crt_isinf(aDD.s.hi) || crt_isinf(bDD.s.hi)) &&
  70                          crt_isfinite(cDD.s.hi) && crt_isfinite(dDD.s.hi))
  71                 {
  72                         makeFinite(aDD);
  73                         makeFinite(bDD);
  74                         real.s.hi = CRT_INFINITY * (aDD.s.hi*cDD.s.hi + bDD.s.hi*dDD.s.hi);
  75                         real.s.lo = 0.0;
  76                         imag.s.hi = CRT_INFINITY * (bDD.s.hi*cDD.s.hi - aDD.s.hi*dDD.s.hi);
  77                         imag.s.lo = 0.0;
  78                 }
  79
  80                 else if ((crt_isinf(cDD.s.hi) || crt_isinf(dDD.s.hi)) &&
  81                          crt_isfinite(aDD.s.hi) && crt_isfinite(bDD.s.hi))
  82                 {
  83                         makeFinite(cDD);
  84                         makeFinite(dDD);
  85                         real.s.hi = crt_copysign(0.0,(aDD.s.hi*cDD.s.hi + bDD.s.hi*dDD.s.hi));
  86                         real.s.lo = 0.0;
  87                         imag.s.hi = crt_copysign(0.0,(bDD.s.hi*cDD.s.hi - aDD.s.hi*dDD.s.hi));
  88                         imag.s.lo = 0.0;
  89                 }
  90         }
  91
  92         long double _Complex z;
  93         __real__ z = real.ld;
  94         __imag__ z = imag.ld;
  95
  96         return z;
  97 }