1 /*-
2  * Copyright (c) 2017 embedded brains GmbH
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #if (__ARM_FP & 0x4) && !defined(__SOFTFP__)
28 #include "fdlibm.h"
29 #include <stdio.h>
30 
31 float
sqrtf(float x)32 sqrtf(float x)
33 {
34 	float result;
35 #ifdef _WANT_MATH_ERRNO
36         if (isless(x, 0.0f))
37             errno = EDOM;
38 #endif
39 #if __ARM_ARCH >= 6
40 	__asm__("vsqrt.f32 %0, %1" : "=w" (result) : "w" (x));
41 #else
42 	/* VFP9 Erratum 760019, see GCC sources "gcc/config/arm/vfp.md" */
43 	__asm__("vsqrt.f32 %0, %1" : "=&w" (result) : "w" (x));
44 #endif
45 	return result;
46 }
47 
48 #else
49 #include "../../math/sf_sqrt.c"
50 #endif
51