| 1 | /* Test for signaling NaN. |
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| 2 | Copyright (C) 2013-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <math.h> |
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| 20 | #include <math_private.h> |
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| 21 | #include <nan-high-order-bit.h> |
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| 22 | |
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| 23 | int |
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| 24 | __issignalingf (float x) |
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| 25 | { |
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| 26 | uint32_t xi; |
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| 27 | GET_FLOAT_WORD (xi, x); |
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| 28 | #if HIGH_ORDER_BIT_IS_SET_FOR_SNAN |
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| 29 | /* We only have to care about the high-order bit of x's significand, because |
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| 30 | having it set (sNaN) already makes the significand different from that |
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| 31 | used to designate infinity. */ |
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| 32 | return (xi & 0x7fc00000) == 0x7fc00000; |
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| 33 | #else |
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| 34 | /* To keep the following comparison simple, toggle the quiet/signaling bit, |
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| 35 | so that it is set for sNaNs. This is inverse to IEEE 754-2008 (as well as |
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| 36 | common practice for IEEE 754-1985). */ |
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| 37 | xi ^= 0x00400000; |
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| 38 | /* We have to compare for greater (instead of greater or equal), because x's |
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| 39 | significand being all-zero designates infinity not NaN. */ |
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| 40 | return (xi & 0x7fffffff) > 0x7fc00000; |
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| 41 | #endif |
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| 42 | } |
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| 43 | libm_hidden_def (__issignalingf) |
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| 44 | |
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