github.com/igggame/nebulas-go@v2.1.0+incompatible/nbre/3rd_party/SoftFloat-3e/source/extF80M_mul.c (about)

     1  
     2  /*============================================================================
     3  
     4  This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
     5  Package, Release 3e, by John R. Hauser.
     6  
     7  Copyright 2011, 2012, 2013, 2014 The Regents of the University of California.
     8  All rights reserved.
     9  
    10  Redistribution and use in source and binary forms, with or without
    11  modification, are permitted provided that the following conditions are met:
    12  
    13   1. Redistributions of source code must retain the above copyright notice,
    14      this list of conditions, and the following disclaimer.
    15  
    16   2. Redistributions in binary form must reproduce the above copyright notice,
    17      this list of conditions, and the following disclaimer in the documentation
    18      and/or other materials provided with the distribution.
    19  
    20   3. Neither the name of the University nor the names of its contributors may
    21      be used to endorse or promote products derived from this software without
    22      specific prior written permission.
    23  
    24  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
    25  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    26  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
    27  DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
    28  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    29  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    30  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    31  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    32  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    33  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    34  
    35  =============================================================================*/
    36  
    37  #include <stdbool.h>
    38  #include <stdint.h>
    39  #include "platform.h"
    40  #include "internals.h"
    41  #include "specialize.h"
    42  #include "softfloat.h"
    43  
    44  #ifdef SOFTFLOAT_FAST_INT64
    45  
    46  void
    47   extF80M_mul(
    48       const extFloat80_t *aPtr, const extFloat80_t *bPtr, extFloat80_t *zPtr )
    49  {
    50  
    51      *zPtr = extF80_mul( *aPtr, *bPtr );
    52  
    53  }
    54  
    55  #else
    56  
    57  void
    58   extF80M_mul(
    59       const extFloat80_t *aPtr, const extFloat80_t *bPtr, extFloat80_t *zPtr )
    60  {
    61      const struct extFloat80M *aSPtr, *bSPtr;
    62      struct extFloat80M *zSPtr;
    63      uint_fast16_t uiA64;
    64      int32_t expA;
    65      uint_fast16_t uiB64;
    66      int32_t expB;
    67      bool signZ;
    68      uint_fast16_t exp, uiZ64;
    69      uint64_t uiZ0, sigA, sigB;
    70      int32_t expZ;
    71      uint32_t sigProd[4], *extSigZPtr;
    72  
    73      /*------------------------------------------------------------------------
    74      *------------------------------------------------------------------------*/
    75      aSPtr = (const struct extFloat80M *) aPtr;
    76      bSPtr = (const struct extFloat80M *) bPtr;
    77      zSPtr = (struct extFloat80M *) zPtr;
    78      /*------------------------------------------------------------------------
    79      *------------------------------------------------------------------------*/
    80      uiA64 = aSPtr->signExp;
    81      expA = expExtF80UI64( uiA64 );
    82      uiB64 = bSPtr->signExp;
    83      expB = expExtF80UI64( uiB64 );
    84      signZ = signExtF80UI64( uiA64 ) ^ signExtF80UI64( uiB64 );
    85      /*------------------------------------------------------------------------
    86      *------------------------------------------------------------------------*/
    87      if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) {
    88          if ( softfloat_tryPropagateNaNExtF80M( aSPtr, bSPtr, zSPtr ) ) return;
    89          if (
    90                 (! aSPtr->signif && (expA != 0x7FFF))
    91              || (! bSPtr->signif && (expB != 0x7FFF))
    92          ) {
    93              softfloat_invalidExtF80M( zSPtr );
    94              return;
    95          }
    96          uiZ64 = packToExtF80UI64( signZ, 0x7FFF );
    97          uiZ0  = UINT64_C( 0x8000000000000000 );
    98          goto uiZ;
    99      }
   100      /*------------------------------------------------------------------------
   101      *------------------------------------------------------------------------*/
   102      if ( ! expA ) expA = 1;
   103      sigA = aSPtr->signif;
   104      if ( ! (sigA & UINT64_C( 0x8000000000000000 )) ) {
   105          if ( ! sigA ) goto zero;
   106          expA += softfloat_normExtF80SigM( &sigA );
   107      }
   108      if ( ! expB ) expB = 1;
   109      sigB = bSPtr->signif;
   110      if ( ! (sigB & UINT64_C( 0x8000000000000000 )) ) {
   111          if ( ! sigB ) goto zero;
   112          expB += softfloat_normExtF80SigM( &sigB );
   113      }
   114      /*------------------------------------------------------------------------
   115      *------------------------------------------------------------------------*/
   116      expZ = expA + expB - 0x3FFE;
   117      softfloat_mul64To128M( sigA, sigB, sigProd );
   118      if ( sigProd[indexWordLo( 4 )] ) sigProd[indexWord( 4, 1 )] |= 1;
   119      extSigZPtr = &sigProd[indexMultiwordHi( 4, 3 )];
   120      if ( sigProd[indexWordHi( 4 )] < 0x80000000 ) {
   121          --expZ;
   122          softfloat_add96M( extSigZPtr, extSigZPtr, extSigZPtr );
   123      }
   124      softfloat_roundPackMToExtF80M(
   125          signZ, expZ, extSigZPtr, extF80_roundingPrecision, zSPtr );
   126      return;
   127      /*------------------------------------------------------------------------
   128      *------------------------------------------------------------------------*/
   129   zero:
   130      uiZ64 = packToExtF80UI64( signZ, 0 );
   131      uiZ0  = 0;
   132   uiZ:
   133      zSPtr->signExp = uiZ64;
   134      zSPtr->signif  = uiZ0;
   135  
   136  }
   137  
   138  #endif
   139