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 <emmintrin.h>
29  #include "fn_macros.h"
30  #include "libm_util_amd.h"
31  #include "libm_special.h"
32  
33  /*SSE2 contains an instruction SQRTSS. This instruction Computes the square root
34    of the low-order single-precision floating-point value in an XMM register
35    or in a 32-bit memory location and writes the result in the low-order doubleword
36    of another XMM register. The corresponding intrinsic is _mm_sqrt_ss()*/
37  /*SSE2 contains an instruction SQRTSS. This instruction Computes the square root
38    of the low-order single-precision floating-point value in an XMM register
39    or in a 32-bit memory location and writes the result in the low-order doubleword
40    of another XMM register. The corresponding intrinsic is _mm_sqrt_ss()*/
41  float FN_PROTOTYPE_REF(sqrtf)(float x)
42  {
43    __m128 X128;
44    float result;
45    int xneg;
46    unsigned int ux, ax;
47      //UT32 uresult;
48    GET_BITS_SP32(x, ux);
49    ax = ux & (~SIGNBIT_SP32);
50    xneg = (ux != ax);
51  
52    if (ax > 0x7f800000)   /* x is NaN */
53           #ifdef WINDOWS
54           return __amd_handle_errorf("sqrtf", __amd_squareroot, ux|0x00400000, _DOMAIN, 0, EDOM, x, 0.0, 1);
55           #else
56           {
57            if(!(ax & 0x00400000)) //x is snan
58                return __amd_handle_errorf("sqrtf", __amd_squareroot, ux|0x00400000, _DOMAIN, AMD_F_INVALID, EDOM, x, 0.0, 1);
59            else
60                return x;
61  		 }
62           #endif
63  
64    if(xneg)
65    {
66         if(ax == 0x0) /* x == -0*/
67  	      return -0.0;
68     return __amd_handle_errorf("sqrtf", __amd_squareroot, 0x00000000ffc00000, _DOMAIN, AMD_F_INVALID, EDOM, x, 0.0, 1);
69    }
70  
71      /*Load x into an XMM register*/
72      X128 = _mm_load_ss(&x);
73      /*Calculate sqrt using SQRTSS instrunction*/
74      X128 = _mm_sqrt_ss(X128);
75      /*Store back the result into a single precision floating point number*/
76      _mm_store_ss(&result, X128);
77      return result;
78  }
79  
80  
81