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			61 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Set NaN payload.  ldbl-128ibm version.
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|    Copyright (C) 2016-2025 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library; if not, see
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|    <https://www.gnu.org/licenses/>.  */
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| 
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| #include <math.h>
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| #include <math_private.h>
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| #include <nan-high-order-bit.h>
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| #include <stdint.h>
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| 
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| #define SET_HIGH_BIT (HIGH_ORDER_BIT_IS_SET_FOR_SNAN ? SIG : !SIG)
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| #define BIAS 0x3ff
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| #define PAYLOAD_DIG 51
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| #define EXPLICIT_MANT_DIG 52
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| 
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| int
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| FUNC (long double *x, long double payload)
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| {
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|   double hi, lo;
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|   uint64_t hx, lx;
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| 
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|   ldbl_unpack (payload, &hi, &lo);
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|   EXTRACT_WORDS64 (hx, hi);
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|   EXTRACT_WORDS64 (lx, lo);
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|   int exponent = hx >> EXPLICIT_MANT_DIG;
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|   /* Test if argument is (a) negative or too large; (b) too small,
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|      except for 0 when allowed; (c) not an integer.  All valid
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|      arguments have the low part zero.  */
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|   if ((lx & 0x7fffffffffffffffULL) != 0
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|       || exponent >= BIAS + PAYLOAD_DIG
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|       || (exponent < BIAS && !(SET_HIGH_BIT && hx == 0))
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|       || (hx & ((1ULL << (BIAS + EXPLICIT_MANT_DIG - exponent)) - 1)) != 0)
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|     {
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|       *x = 0.0L;
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|       return 1;
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|     }
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|   if (hx != 0)
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|     {
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|       hx &= (1ULL << EXPLICIT_MANT_DIG) - 1;
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|       hx |= 1ULL << EXPLICIT_MANT_DIG;
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|       hx >>= BIAS + EXPLICIT_MANT_DIG - exponent;
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|     }
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|   hx |= 0x7ff0000000000000ULL | (SET_HIGH_BIT ? 0x8000000000000ULL : 0);
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|   INSERT_WORDS64 (hi, hx);
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|   *x = ldbl_pack (hi, 0.0);
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|   return 0;
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| }
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