1 /* Euclidean distance function. Double/Binary64 i386 version.
2 Copyright (C) 2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <math.h>
20 #include <math_private.h>
21 #include <math-narrow-eval.h>
22 #include <math-underflow.h>
23 #include <math-svid-compat.h>
24 #include <libm-alias-finite.h>
25 #include <libm-alias-double.h>
26 #include <errno.h>
27
28 /* The i386 allows to use the default excess of precision to optimize the
29 hypot implementation, since internal multiplication and sqrt is carried
30 with 80-bit FP type. */
31 double
__hypot(double x,double y)32 __hypot (double x, double y)
33 {
34 if (!isfinite (x) || !isfinite (y))
35 {
36 if ((isinf (x) || isinf (y))
37 && !issignaling (x) && !issignaling (y))
38 return INFINITY;
39 return x + y;
40 }
41
42 long double lx = x;
43 long double ly = y;
44 double r = math_narrow_eval ((double) sqrtl (lx * lx + ly * ly));
45 math_check_force_underflow_nonneg (r);
46 if (isinf (r))
47 __set_errno (ERANGE);
48 return r;
49 }
50 strong_alias (__hypot, __ieee754_hypot)
51 #if LIBM_SVID_COMPAT
52 versioned_symbol (libm, __hypot, hypot, GLIBC_2_35);
53 libm_alias_finite (__ieee754_hypot, __hypot)
54 libm_alias_double_other (__hypot, hypot)
55 #else
56 libm_alias_double (__hypot, hypot)
57 #endif
58