softfloat/f32_to_ui64.c

   1
   2 #include <stdbool.h>
   3 #include <stdint.h>
   4 #include "platform.h"
   5 #include "primitives.h"
   6 #include "internals.h"
   7 #include "softfloat.h"
   8
   9 uint_fast64_t f32_to_ui64( float32_t a, int_fast8_t roundingMode, bool exact )
  10 {
  11     union ui32_f32 uA;
  12     uint_fast32_t uiA;
  13     bool sign;
  14     int_fast16_t exp;
  15     uint_fast32_t sig;
  16     int_fast16_t shiftCount;
  17     uint_fast64_t sig64, extra;
  18     struct uint64_extra sig64Extra;
  19
  20     uA.f = a;
  21     uiA = uA.ui;
  22     sign = signF32UI( uiA );
  23     exp = expF32UI( uiA );
  24     sig = fracF32UI( uiA );
  25     shiftCount = 0xBE - exp;
  26     if ( shiftCount < 0 ) {
  27         softfloat_raiseFlags( softfloat_flag_invalid );
  28         return UINT64_C( 0xFFFFFFFFFFFFFFFF );
  29     }
  30     if ( exp ) sig |= 0x00800000;
  31     sig64 = (uint_fast64_t) sig<<40;
  32     extra = 0;
  33     if ( shiftCount ) {
  34         sig64Extra = softfloat_shift64ExtraRightJam( sig64, 0, shiftCount );
  35         sig64 = sig64Extra.v;
  36         extra = sig64Extra.extra;
  37     }
  38     return
  39         softfloat_roundPackToUI64( sign, sig64, extra, roundingMode, exact );
  40
  41 }
  42