softfloat/s_addMagsF32.c

   1
   2 #include <stdbool.h>
   3 #include <stdint.h>
   4 #include "platform.h"
   5 #include "primitives.h"
   6 #include "internals.h"
   7 #include "specialize.h"
   8
   9 float32_t
  10  softfloat_addMagsF32( uint_fast32_t uiA, uint_fast32_t uiB, bool signZ )
  11 {
  12     int_fast16_t expA;
  13     uint_fast32_t sigA;
  14     int_fast16_t expB;
  15     uint_fast32_t sigB;
  16     int_fast16_t expDiff;
  17     uint_fast32_t uiZ;
  18     int_fast16_t expZ;
  19     uint_fast32_t sigZ;
  20     union ui32_f32 uZ;
  21
  22     expA = expF32UI( uiA );
  23     sigA = fracF32UI( uiA );
  24     expB = expF32UI( uiB );
  25     sigB = fracF32UI( uiB );
  26     expDiff = expA - expB;
  27     sigA <<= 6;
  28     sigB <<= 6;
  29     if ( ! expDiff ) {
  30         if ( expA == 0xFF ) {
  31             if ( sigA | sigB ) goto propagateNaN;
  32             uiZ = uiA;
  33             goto uiZ;
  34         }
  35         if ( ! expA ) {
  36             uiZ = packToF32UI( signZ, 0, ( uiA + uiB ) & 0x7FFFFFFF );
  37             goto uiZ;
  38         }
  39         expZ = expA;
  40         sigZ = 0x40000000 + sigA + sigB;
  41     } else {
  42         if ( expDiff < 0 ) {
  43             if ( expB == 0xFF ) {
  44                 if ( sigB ) goto propagateNaN;
  45                 uiZ = packToF32UI( signZ, 0xFF, 0 );
  46                 goto uiZ;
  47             }
  48             expZ = expB;
  49             sigA += expA ? 0x20000000 : sigA;
  50             sigA = softfloat_shift32RightJam( sigA, - expDiff );
  51         } else {
  52             if ( expA == 0xFF ) {
  53                 if ( sigA ) goto propagateNaN;
  54                 uiZ = uiA;
  55                 goto uiZ;
  56             }
  57             expZ = expA;
  58             sigB += expB ? 0x20000000 : sigB;
  59             sigB = softfloat_shift32RightJam( sigB, expDiff );
  60         }
  61         sigZ = 0x20000000 + sigA + sigB;
  62         if ( sigZ < 0x40000000 ) {
  63             --expZ;
  64             sigZ <<= 1;
  65         }
  66     }
  67     return softfloat_roundPackToF32( signZ, expZ, sigZ );
  68  propagateNaN:
  69     uiZ = softfloat_propagateNaNF32UI( uiA, uiB );
  70  uiZ:
  71     uZ.ui = uiZ;
  72     return uZ.f;
  73
  74 }
  75