1  /*
  2   * Copyright (C) 2008-2020 Advanced Micro Devices, Inc. All rights reserved.
  3   *
  4   * Redistribution and use in source and binary forms, with or without modification,
  5   * are permitted provided that the following conditions are met:
  6   * 1. Redistributions of source code must retain the above copyright notice,
  7   *    this list of conditions and the following disclaimer.
  8   * 2. Redistributions in binary form must reproduce the above copyright notice,
  9   *    this list of conditions and the following disclaimer in the documentation
 10   *    and/or other materials provided with the distribution.
 11   * 3. Neither the name of the copyright holder nor the names of its contributors
 12   *    may be used to endorse or promote products derived from this software without
 13   *    specific prior written permission.
 14   *
 15   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 16   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 17   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 18   * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 19   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 20   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 21   * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 22   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 23   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 24   * POSSIBILITY OF SUCH DAMAGE.
 25   *
 26   */
 27  
 28  #include "libm_amd.h"
 29  #include "libm_util_amd.h"
 30  #include "libm_special.h"
 31  
 32  
 33  
 34  
 35  float FN_PROTOTYPE_REF(nextafterf)(float x, float y)
 36  {
 37  
 38  
 39      UT32 checkbits,checkbitsy;
 40      float dy = y;
 41      checkbits.f32=x;
 42  	checkbitsy.f32 = y;
 43  
 44  
 45  
 46      /* check if the number is nan */
 47      if(((checkbits.u32 & ~SIGNBIT_SP32) > EXPBITS_SP32 ))
 48      {
 49  #ifdef WINDOWS
 50  		return  __amd_handle_errorf("nextafterf", __amd_nextafter, checkbits.u32| QNAN_MASK_32, _DOMAIN, AMD_F_NONE, EDOM, x, 0.0, 1);
 51  #else
 52  	    if (checkbits.u32 & QNAN_MASK_32)
 53  		return  __amd_handle_errorf("nextafterf", __amd_nextafter, checkbits.u32| QNAN_MASK_32, _DOMAIN, AMD_F_NONE, EDOM, x, 0.0, 1);
 54  	    else
 55  		return  __amd_handle_errorf("nextafterf", __amd_nextafter, checkbits.u32| QNAN_MASK_32, _DOMAIN, AMD_F_INVALID, EDOM, x, 0.0, 1);
 56  #endif
 57      }
 58  
 59  
 60      /* check if the number is nan */
 61      if(((checkbitsy.u32 & ~SIGNBIT_SP32) > EXPBITS_SP32 ))
 62      {
 63  #ifdef WINDOWS
 64  		return  __amd_handle_errorf("nextafterf", __amd_nextafter, checkbitsy.u32 | QNAN_MASK_32, _DOMAIN, AMD_F_NONE, EDOM, y, 0.0, 1);
 65  #else
 66  	    if (checkbitsy.u32 & QNAN_MASK_32)
 67  		return  __amd_handle_errorf("nextafterf", __amd_nextafter, checkbitsy.u32 | QNAN_MASK_32, _DOMAIN, AMD_F_NONE, EDOM, y, 0.0, 1);
 68  	    else
 69  		return  __amd_handle_errorf("nextafterf", __amd_nextafter, checkbitsy.u32 | QNAN_MASK_32, _DOMAIN, AMD_F_INVALID, EDOM, y, 0.0, 1);
 70  #endif
 71      }
 72  
 73      /* if x == y return y in the type of x */
 74      if( x == dy )
 75      {
 76          return  dy;
 77      }
 78  
 79  
 80      if( x == 0.0)
 81      {
 82          checkbits.u32 = 1;
 83          if( dy > 0.0 )
 84               return checkbits.f32;
 85          else
 86              return -checkbits.f32;
 87      }
 88  
 89  
 90      /* compute the next heigher or lower value */
 91      if(((x>0.0F) ^ (dy>x)) == 0)
 92      {
 93          checkbits.u32++;
 94      }
 95      else
 96      {
 97          checkbits.u32--;
 98      }
 99  
100      /* check if the result is nan or inf */
101      if(((checkbits.u32 & ~SIGNBIT_SP32) >= EXPBITS_SP32 ))
102      {
103  			return  __amd_handle_errorf("nextafterf", __amd_nextafter, checkbits.u32 | QNAN_MASK_32, _DOMAIN,0, EDOM, x, 0.0, 1);
104      }
105  
106      return checkbits.f32;
107  }
108