| 1 | /* Compute x^2 + y^2 - 1, without large cancellation error. |
|---|
| 2 | Copyright (C) 2012-2022 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 <float.h> |
|---|
| 22 | |
|---|
| 23 | #if FLT_EVAL_METHOD == 0 |
|---|
| 24 | |
|---|
| 25 | # include <sysdeps/ieee754/dbl-64/x2y2m1.c> |
|---|
| 26 | |
|---|
| 27 | #else |
|---|
| 28 | |
|---|
| 29 | /* Return X^2 + Y^2 - 1, computed without large cancellation error. |
|---|
| 30 | It is given that 1 > X >= Y >= epsilon / 2, and that X^2 + Y^2 >= |
|---|
| 31 | 0.5. */ |
|---|
| 32 | |
|---|
| 33 | double |
|---|
| 34 | __x2y2m1 (double x, double y) |
|---|
| 35 | { |
|---|
| 36 | return (double) __x2y2m1l (x, y); |
|---|
| 37 | } |
|---|
| 38 | |
|---|
| 39 | #endif |
|---|
| 40 | |
|---|
