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77a2a8b4 | 1 | /* Pythagorean addition using floats |
d4697bc9 | 2 | Copyright (C) 2011-2014 Free Software Foundation, Inc. |
77a2a8b4 AZ |
3 | This file is part of the GNU C Library. |
4 | Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011 | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Library General Public License as | |
8 | published by the Free Software Foundation; either version 2 of the | |
9 | License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Library General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Library General Public | |
59ba27a6 PE |
17 | License along with the GNU C Library; see the file COPYING.LIB. If |
18 | not, see <http://www.gnu.org/licenses/>. */ | |
77a2a8b4 | 19 | |
1ed0291c RH |
20 | #include <math.h> |
21 | #include <math_private.h> | |
e054f494 | 22 | #include <stdint.h> |
77a2a8b4 AZ |
23 | |
24 | static const float two30 = 1.0737418e09; | |
77a2a8b4 AZ |
25 | |
26 | /* __ieee754_hypotf(x,y) | |
11e0098e AS |
27 | |
28 | This a FP only version without any FP->INT conversion. | |
29 | It is similar to default C version, making appropriates | |
30 | overflow and underflows checks as using double precision | |
31 | instead of scaling. */ | |
77a2a8b4 AZ |
32 | |
33 | #ifdef _ARCH_PWR7 | |
34 | /* POWER7 isinf and isnan optimizations are fast. */ | |
35 | # define TEST_INF_NAN(x, y) \ | |
36 | if (isinff(x) || isinff(y)) \ | |
37 | return INFINITY; \ | |
38 | if (isnanf(x) || isnanf(y)) \ | |
39 | return NAN; | |
40 | # else | |
41 | /* For POWER6 and below isinf/isnan triggers LHS and PLT calls are | |
42 | * costly (especially for POWER6). */ | |
43 | # define GET_TWO_FLOAT_WORD(f1,f2,i1,i2) \ | |
44 | do { \ | |
45 | ieee_float_shape_type gf_u1; \ | |
46 | ieee_float_shape_type gf_u2; \ | |
47 | gf_u1.value = (f1); \ | |
48 | gf_u2.value = (f2); \ | |
13d3b41a AZ |
49 | (i1) = gf_u1.word & 0x7fffffff; \ |
50 | (i2) = gf_u2.word & 0x7fffffff; \ | |
77a2a8b4 AZ |
51 | } while (0) |
52 | ||
53 | # define TEST_INF_NAN(x, y) \ | |
54 | do { \ | |
13d3b41a | 55 | uint32_t hx, hy; \ |
77a2a8b4 AZ |
56 | GET_TWO_FLOAT_WORD(x, y, hx, hy); \ |
57 | if (hy > hx) { \ | |
58 | uint32_t ht = hx; hx = hy; hy = ht; \ | |
59 | } \ | |
60 | if (hx >= 0x7f800000) { \ | |
61 | if (hx == 0x7f800000 || hy == 0x7f800000) \ | |
62 | return INFINITY; \ | |
63 | return NAN; \ | |
64 | } \ | |
65 | } while (0) | |
66 | #endif | |
67 | ||
68 | ||
69 | float | |
70 | __ieee754_hypotf (float x, float y) | |
71 | { | |
77a2a8b4 AZ |
72 | TEST_INF_NAN (x, y); |
73 | ||
11e0098e | 74 | return __ieee754_sqrt ((double) x * x + (double) y * y); |
77a2a8b4 | 75 | } |
0ac5ae23 | 76 | strong_alias (__ieee754_hypotf, __hypotf_finite) |