softfloat/f64_to_i32_r_minMag.c

   1
   2 #include <stdbool.h>
   3 #include <stdint.h>
   4 #include "platform.h"
   5 #include "internals.h"
   6 #include "softfloat.h"
   7
   8 int_fast32_t f64_to_i32_r_minMag( float64_t a, bool exact )
   9 {
  10     union ui64_f64 uA;
  11     uint_fast64_t uiA;
  12     int_fast16_t exp;
  13     uint_fast64_t sig;
  14     bool sign;
  15     int_fast16_t shiftCount;
  16     uint_fast32_t absZ;
  17     union { uint32_t ui; int32_t i; } uZ;
  18     int_fast32_t z;
  19
  20     uA.f = a;
  21     uiA = uA.ui;
  22     exp = expF64UI( uiA );
  23     sig = fracF64UI( uiA );
  24     if ( exp < 0x3FF ) {
  25         if ( exact && ( exp | sig ) ) {
  26             softfloat_exceptionFlags |= softfloat_flag_inexact;
  27         }
  28         return 0;
  29     }
  30     sign = signF64UI( uiA );
  31     if ( 0x41E < exp ) {
  32         if ( ( exp == 0x7FF ) && sig ) sign = 0;
  33         goto invalid;
  34     }
  35     sig |= UINT64_C( 0x0010000000000000 );
  36     shiftCount = 0x433 - exp;
  37     absZ = sig>>shiftCount;
  38     uZ.ui = sign ? - absZ : absZ;
  39     z = uZ.i;
  40     if ( ( z < 0 ) != sign ) goto invalid;
  41     if ( exact && ( (uint_fast64_t) absZ<<shiftCount != sig ) ) {
  42         softfloat_exceptionFlags |= softfloat_flag_inexact;
  43     }
  44     return z;
  45  invalid:
  46     softfloat_raiseFlags( softfloat_flag_invalid );
  47     return sign ? -0x7FFFFFFF - 1 : 0x7FFFFFFF;
  48
  49 }
  50