softfloat/f32_to_i64_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_fast64_t f32_to_i64_r_minMag( float32_t a, bool exact )
   9 {
  10     union ui32_f32 uA;
  11     uint_fast32_t uiA;
  12     int_fast16_t exp;
  13     uint_fast32_t sig;
  14     bool sign;
  15     int_fast16_t shiftCount;
  16     uint_fast64_t sig64;
  17     int_fast64_t absZ;
  18
  19     uA.f = a;
  20     uiA = uA.ui;
  21     exp = expF32UI( uiA );
  22     sig = fracF32UI( uiA );
  23     if ( exp < 0x7F ) {
  24         if ( exact && ( exp | sig ) ) {
  25             softfloat_exceptionFlags |= softfloat_flag_inexact;
  26         }
  27         return 0;
  28     }
  29     sign = signF32UI( uiA );
  30     shiftCount = 0xBE - exp;
  31     if ( shiftCount <= 0 ) {
  32         if ( uiA != packToF32UI( 1, 0xBE, 0 ) ) {
  33             softfloat_raiseFlags( softfloat_flag_invalid );
  34             if ( ! sign || ( ( exp == 0xFF ) && sig ) ) {
  35                 return INT64_C( 0x7FFFFFFFFFFFFFFF );
  36             }
  37         }
  38         return - INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1;
  39     }
  40     sig |= 0x00800000;
  41     sig64 = (uint_fast64_t) sig<<40;
  42     absZ = sig64>>shiftCount;
  43     shiftCount = 40 - shiftCount;
  44     if (
  45         exact && ( shiftCount < 0 ) && (uint32_t) ( sig<<( shiftCount & 31 ) )
  46     ) {
  47         softfloat_exceptionFlags |= softfloat_flag_inexact;
  48     }
  49     return sign ? - absZ : absZ;
  50
  51 }
  52