softfloat/s_roundPackToUI64.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
   9  softfloat_roundPackToUI64(
  10      bool sign,
  11      uint_fast64_t sig64,
  12      uint_fast64_t sig0,
  13      int_fast8_t roundingMode,
  14      bool exact
  15  )
  16 {
  17     bool roundNearestEven, increment;
  18
  19     roundNearestEven = ( roundingMode == softfloat_round_nearest_even );
  20     increment = ( UINT64_C( 0x8000000000000000 ) <= sig0 );
  21     if (
  22            ! roundNearestEven
  23         && ( roundingMode != softfloat_round_nearest_maxMag )
  24     ) {
  25         increment =
  26                ( roundingMode != softfloat_round_minMag )
  27             && ( roundingMode
  28                      == ( sign ? softfloat_round_min : softfloat_round_max ) )
  29             && sig0;
  30     }
  31     if ( increment ) {
  32         ++sig64;
  33         if ( ! sig64 ) goto invalid;
  34         sig64 &=
  35             ~ ( ! ( sig0 & UINT64_C( 0x7FFFFFFFFFFFFFFF ) )
  36                     & roundNearestEven );
  37     }
  38     if ( sign && sig64 ) goto invalid;
  39     if ( exact && sig0 ) softfloat_exceptionFlags |= softfloat_flag_inexact;
  40     return sig64;
  41  invalid:
  42     softfloat_raiseFlags( softfloat_flag_invalid );
  43     return UINT64_C( 0xFFFFFFFFFFFFFFFF );
  44
  45 }
  46