softfloat/s_roundPackToUI32.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_fast32_t
   9  softfloat_roundPackToUI32(
  10      bool sign, uint_fast64_t sig, int_fast8_t roundingMode, bool exact )
  11 {
  12     bool roundNearestEven;
  13     int roundIncrement, roundBits;
  14     uint_fast32_t z;
  15
  16     roundNearestEven = ( roundingMode == softfloat_round_nearest_even );
  17     roundIncrement = 0x40;
  18     if (
  19            ! roundNearestEven
  20         && ( roundingMode != softfloat_round_nearest_maxMag )
  21     ) {
  22         roundIncrement =
  23                ( roundingMode == softfloat_round_minMag )
  24             || ( roundingMode
  25                      == ( sign ? softfloat_round_max : softfloat_round_min ) )
  26                 ? 0
  27                 : 0x7F;
  28     }
  29     roundBits = sig & 0x7F;
  30     sig += roundIncrement;
  31     if ( sig & UINT64_C( 0xFFFFFF8000000000 ) ) goto invalid;
  32     z = sig>>7;
  33     z &= ~ ( ! ( roundBits ^ 0x40 ) & roundNearestEven );
  34     if ( sign && z ) goto invalid;
  35     if ( exact && roundBits ) {
  36         softfloat_exceptionFlags |= softfloat_flag_inexact;
  37     }
  38     return z;
  39  invalid:
  40     softfloat_raiseFlags( softfloat_flag_invalid );
  41     return 0xFFFFFFFF;
  42
  43 }
  44