softfloat/s_addMagsF64.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 float64_t
  10  softfloat_addMagsF64( uint_fast64_t uiA, uint_fast64_t uiB, bool signZ )
  11 {
  12     int_fast16_t expA;
  13     uint_fast64_t sigA;
  14     int_fast16_t expB;
  15     uint_fast64_t sigB;
  16     int_fast16_t expDiff;
  17     uint_fast64_t uiZ;
  18     int_fast16_t expZ;
  19     uint_fast64_t sigZ;
  20     union ui64_f64 uZ;
  21
  22     expA = expF64UI( uiA );
  23     sigA = fracF64UI( uiA );
  24     expB = expF64UI( uiB );
  25     sigB = fracF64UI( uiB );
  26     expDiff = expA - expB;
  27     sigA <<= 9;
  28     sigB <<= 9;
  29     if ( ! expDiff ) {
  30         if ( expA == 0x7FF ) {
  31             if ( sigA | sigB ) goto propagateNaN;
  32             uiZ = uiA;
  33             goto uiZ;
  34         }
  35         if ( ! expA ) {
  36             uiZ =
  37                 packToF64UI(
  38                     signZ, 0, ( uiA + uiB ) & UINT64_C( 0x7FFFFFFFFFFFFFFF ) );
  39             goto uiZ;
  40         }
  41         expZ = expA;
  42         sigZ = UINT64_C( 0x4000000000000000 ) + sigA + sigB;
  43     } else {
  44         if ( expDiff < 0 ) {
  45             if ( expB == 0x7FF ) {
  46                 if ( sigB ) goto propagateNaN;
  47                 uiZ = packToF64UI( signZ, 0x7FF, 0 );
  48                 goto uiZ;
  49             }
  50             expZ = expB;
  51             sigA += expA ? UINT64_C( 0x2000000000000000 ) : sigA;
  52             sigA = softfloat_shift64RightJam( sigA, - expDiff );
  53         } else {
  54             if ( expA == 0x7FF ) {
  55                 if ( sigA ) goto propagateNaN;
  56                 uiZ = uiA;
  57                 goto uiZ;
  58             }
  59             expZ = expA;
  60             sigB += expB ? UINT64_C( 0x2000000000000000 ) : sigB;
  61             sigB = softfloat_shift64RightJam( sigB, expDiff );
  62         }
  63         sigZ = UINT64_C( 0x2000000000000000 ) + sigA + sigB;
  64         if ( sigZ < UINT64_C( 0x4000000000000000 ) ) {
  65             --expZ;
  66             sigZ <<= 1;
  67         }
  68     }
  69     return softfloat_roundPackToF64( signZ, expZ, sigZ );
  70  propagateNaN:
  71     uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
  72  uiZ:
  73     uZ.ui = uiZ;
  74     return uZ.f;
  75
  76 }
  77