softfloat/f64_to_ui64_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 uint_fast64_t f64_to_ui64_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     int_fast16_t shiftCount;
  15     uint_fast64_t z;
  16
  17     uA.f = a;
  18     uiA = uA.ui;
  19     exp = expF64UI( uiA );
  20     sig = fracF64UI( uiA );
  21     if ( exp < 0x3FF ) {
  22         if ( exact && ( exp | sig ) ) {
  23             softfloat_exceptionFlags |= softfloat_flag_inexact;
  24         }
  25         return 0;
  26     }
  27     if ( signF64UI( uiA ) ) goto invalid;
  28     shiftCount = exp - 0x433;
  29     if ( 0 <= shiftCount ) {
  30         if ( 0x43E < exp ) goto invalid;
  31         z = ( sig | UINT64_C( 0x0010000000000000 ) )<<shiftCount;
  32     } else {
  33         sig |= UINT64_C( 0x0010000000000000 );
  34         z = sig>>( - shiftCount );
  35         if ( exact && (uint64_t) ( sig<<( shiftCount & 63 ) ) ) {
  36             softfloat_exceptionFlags |= softfloat_flag_inexact;
  37         }
  38     }
  39     return z;
  40  invalid:
  41     softfloat_raiseFlags( softfloat_flag_invalid );
  42     return UINT64_C( 0xFFFFFFFFFFFFFFFF );
  43
  44 }
  45