github.com/igggame/nebulas-go@v2.1.0+incompatible/nbre/3rd_party/SoftFloat-3e/source/f128M_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, 2015, 2016 The Regents of the University of
     8  California.  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   f128M_mul( const float128_t *aPtr, const float128_t *bPtr, float128_t *zPtr )
    48  {
    49  
    50      *zPtr = f128_mul( *aPtr, *bPtr );
    51  
    52  }
    53  
    54  #else
    55  
    56  void
    57   f128M_mul( const float128_t *aPtr, const float128_t *bPtr, float128_t *zPtr )
    58  {
    59      const uint32_t *aWPtr, *bWPtr;
    60      uint32_t *zWPtr;
    61      uint32_t uiA96;
    62      int32_t expA;
    63      uint32_t uiB96;
    64      int32_t expB;
    65      bool signZ;
    66      const uint32_t *ptr;
    67      uint32_t uiZ96, sigA[4];
    68      uint_fast8_t shiftDist;
    69      uint32_t sigB[4];
    70      int32_t expZ;
    71      uint32_t sigProd[8], *extSigZPtr;
    72  
    73      /*------------------------------------------------------------------------
    74      *------------------------------------------------------------------------*/
    75      aWPtr = (const uint32_t *) aPtr;
    76      bWPtr = (const uint32_t *) bPtr;
    77      zWPtr = (uint32_t *) zPtr;
    78      /*------------------------------------------------------------------------
    79      *------------------------------------------------------------------------*/
    80      uiA96 = aWPtr[indexWordHi( 4 )];
    81      expA = expF128UI96( uiA96 );
    82      uiB96 = bWPtr[indexWordHi( 4 )];
    83      expB = expF128UI96( uiB96 );
    84      signZ = signF128UI96( uiA96 ) ^ signF128UI96( uiB96 );
    85      /*------------------------------------------------------------------------
    86      *------------------------------------------------------------------------*/
    87      if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) {
    88          if ( softfloat_tryPropagateNaNF128M( aWPtr, bWPtr, zWPtr ) ) return;
    89          ptr = aWPtr;
    90          if ( ! expA ) goto possiblyInvalid;
    91          if ( ! expB ) {
    92              ptr = bWPtr;
    93       possiblyInvalid:
    94              if (
    95                  ! fracF128UI96( ptr[indexWordHi( 4 )] )
    96                      && ! (ptr[indexWord( 4, 2 )] | ptr[indexWord( 4, 1 )]
    97                                | ptr[indexWord( 4, 0 )])
    98              ) {
    99                  softfloat_invalidF128M( zWPtr );
   100                  return;
   101              }
   102          }
   103          uiZ96 = packToF128UI96( signZ, 0x7FFF, 0 );
   104          goto uiZ96;
   105      }
   106      /*------------------------------------------------------------------------
   107      *------------------------------------------------------------------------*/
   108      if ( expA ) {
   109          sigA[indexWordHi( 4 )] = fracF128UI96( uiA96 ) | 0x00010000;
   110          sigA[indexWord( 4, 2 )] = aWPtr[indexWord( 4, 2 )];
   111          sigA[indexWord( 4, 1 )] = aWPtr[indexWord( 4, 1 )];
   112          sigA[indexWord( 4, 0 )] = aWPtr[indexWord( 4, 0 )];
   113      } else {
   114          expA = softfloat_shiftNormSigF128M( aWPtr, 0, sigA );
   115          if ( expA == -128 ) goto zero;
   116      }
   117      if ( expB ) {
   118          sigB[indexWordHi( 4 )] = fracF128UI96( uiB96 ) | 0x00010000;
   119          sigB[indexWord( 4, 2 )] = bWPtr[indexWord( 4, 2 )];
   120          sigB[indexWord( 4, 1 )] = bWPtr[indexWord( 4, 1 )];
   121          sigB[indexWord( 4, 0 )] = bWPtr[indexWord( 4, 0 )];
   122      } else {
   123          expB = softfloat_shiftNormSigF128M( bWPtr, 0, sigB );
   124          if ( expB == -128 ) goto zero;
   125      }
   126      /*------------------------------------------------------------------------
   127      *------------------------------------------------------------------------*/
   128      expZ = expA + expB - 0x4000;
   129      softfloat_mul128MTo256M( sigA, sigB, sigProd );
   130      if (
   131          sigProd[indexWord( 8, 2 )]
   132              || (sigProd[indexWord( 8, 1 )] | sigProd[indexWord( 8, 0 )])
   133      ) {
   134          sigProd[indexWord( 8, 3 )] |= 1;
   135      }
   136      extSigZPtr = &sigProd[indexMultiwordHi( 8, 5 )];
   137      shiftDist = 16;
   138      if ( extSigZPtr[indexWordHi( 5 )] & 2 ) {
   139          ++expZ;
   140          shiftDist = 15;
   141      }
   142      softfloat_shortShiftLeft160M( extSigZPtr, shiftDist, extSigZPtr );
   143      softfloat_roundPackMToF128M( signZ, expZ, extSigZPtr, zWPtr );
   144      return;
   145      /*------------------------------------------------------------------------
   146      *------------------------------------------------------------------------*/
   147   zero:
   148      uiZ96 = packToF128UI96( signZ, 0, 0 );
   149   uiZ96:
   150      zWPtr[indexWordHi( 4 )] = uiZ96;
   151      zWPtr[indexWord( 4, 2 )] = 0;
   152      zWPtr[indexWord( 4, 1 )] = 0;
   153      zWPtr[indexWord( 4, 0 )] = 0;
   154  
   155  }
   156  
   157  #endif
   158