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 "fn_macros.h"
 29  #include "libm_util_amd.h"
 30  #include "libm_special.h"
 31  
 32  double FN_PROTOTYPE_REF(ldexp)(double x, int n)
 33  {
 34      UT64 val,val_x;
 35      unsigned int sign;
 36      int exponent;
 37      val.f64 = x;
 38  	val_x.f64 = x;
 39      sign = val.u32[1] & 0x80000000;
 40      val.u32[1] = val.u32[1] & 0x7fffffff; /* remove the sign bit */
 41  
 42      if (val.u64 > 0x7ff0000000000000)     /* x is NaN */
 43          #ifdef WINDOWS
 44          return __amd_handle_error("ldexp", __amd_ldexp, val_x.u64|0x0008000000000000, _DOMAIN, 0, EDOM, x, n, 2);
 45          #else
 46          {
 47          if(!(val.u64 & 0x0008000000000000))// x is snan
 48             return __amd_handle_error("ldexp", __amd_ldexp, val_x.u64|0x0008000000000000, _DOMAIN, AMD_F_INVALID, EDOM, x, n, 2);
 49          else
 50             return x;
 51  	    }
 52          #endif
 53  
 54      if(val.u64 == 0x7ff0000000000000)/* x = +-inf*/
 55          return x;
 56  
 57      if((val.u64 == 0x0000000000000000) || (n==0))
 58          return x; /* x= +-0 or n= 0*/
 59  
 60      exponent = val.u32[1] >> 20; /* get the exponent */
 61  
 62      if(exponent == 0)/*x is denormal*/
 63      {
 64  		val.f64 = val.f64 * VAL_2PMULTIPLIER_DP;/*multiply by 2^53 to bring it to the normal range*/
 65          exponent = val.u32[1] >> 20; /* get the exponent */
 66  		exponent = exponent + n - MULTIPLIER_DP;
 67  		if(exponent < -MULTIPLIER_DP)/*underflow*/
 68  		{
 69  			val.u32[1] = sign | 0x00000000;
 70  			val.u32[0] = 0x00000000;
 71              return __amd_handle_error("ldexp", __amd_ldexp, val.u64, _UNDERFLOW, AMD_F_INEXACT|AMD_F_UNDERFLOW, ERANGE, x, (double)n, 2);
 72  		}
 73  		if(exponent > 2046)/*overflow*/
 74  		{
 75  			val.u32[1] = sign | 0x7ff00000;
 76  			val.u32[0] = 0x00000000;
 77  			return __amd_handle_error("ldexp", __amd_ldexp, val.u64, _OVERFLOW, AMD_F_INEXACT|AMD_F_OVERFLOW, ERANGE ,x, (double)n, 2);
 78  		}
 79  
 80  		exponent += MULTIPLIER_DP;
 81  		val.u32[1] = sign | (exponent << 20) | (val.u32[1] & 0x000fffff);
 82  		val.f64 = val.f64 * VAL_2PMMULTIPLIER_DP;
 83          return val.f64;
 84      }
 85  
 86      exponent += n;
 87  
 88      if(exponent < -MULTIPLIER_DP)/*underflow*/
 89  	{
 90  		val.u32[1] = sign | 0x00000000;
 91  		val.u32[0] = 0x00000000;
 92          return __amd_handle_error("ldexp", __amd_ldexp, val.u64, _UNDERFLOW, AMD_F_INEXACT|AMD_F_UNDERFLOW, ERANGE, x, (double)n, 2);
 93  	}
 94  
 95      if(exponent < 1)/*x is normal but output is debnormal*/
 96      {
 97  		exponent += MULTIPLIER_DP;
 98  		val.u32[1] = sign | (exponent << 20) | (val.u32[1] & 0x000fffff);
 99  		val.f64 = val.f64 * VAL_2PMMULTIPLIER_DP;
100          return val.f64;
101      }
102  
103      if(exponent > 2046)/*overflow*/
104  	{
105  		val.u32[1] = sign | 0x7ff00000;
106  		val.u32[0] = 0x00000000;
107  	return __amd_handle_error("ldexp", __amd_ldexp, val.u64, _OVERFLOW, AMD_F_INEXACT|AMD_F_OVERFLOW, ERANGE ,x, (double)n, 2);
108  	}
109  
110      val.u32[1] = sign | (exponent << 20) | (val.u32[1] & 0x000fffff);
111      return val.f64;
112  }
113  
114  
115  
116