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x86: Add seperate non-temporal tunable for memset
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6b628d36 1/* mpn_lshift -- Shift left low level.
28f540f4 2
dff8da6b 3Copyright (C) 1991-2024 Free Software Foundation, Inc.
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4
5This file is part of the GNU MP Library.
6
7The GNU MP Library is free software; you can redistribute it and/or modify
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8it under the terms of the GNU Lesser General Public License as published by
9the Free Software Foundation; either version 2.1 of the License, or (at your
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10option) any later version.
11
12The GNU MP Library is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
6d84f89a 14or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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15License for more details.
16
6d84f89a 17You should have received a copy of the GNU Lesser General Public License
59ba27a6 18along with the GNU MP Library; see the file COPYING.LIB. If not, see
5a82c748 19<https://www.gnu.org/licenses/>. */
28f540f4 20
9d13fb24 21#include <gmp.h>
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22#include "gmp-impl.h"
23
24/* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left
25 and store the USIZE least significant digits of the result at WP.
26 Return the bits shifted out from the most significant digit.
27
28 Argument constraints:
29 1. 0 < CNT < BITS_PER_MP_LIMB
30 2. If the result is to be written over the input, WP must be >= UP.
31*/
32
b928942e 33mp_limb_t
6b628d36 34mpn_lshift (register mp_ptr wp,
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35 register mp_srcptr up, mp_size_t usize,
36 register unsigned int cnt)
28f540f4 37{
b928942e 38 register mp_limb_t high_limb, low_limb;
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39 register unsigned sh_1, sh_2;
40 register mp_size_t i;
b928942e 41 mp_limb_t retval;
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42
43#ifdef DEBUG
44 if (usize == 0 || cnt == 0)
45 abort ();
46#endif
47
48 sh_1 = cnt;
49#if 0
50 if (sh_1 == 0)
51 {
52 if (wp != up)
53 {
54 /* Copy from high end to low end, to allow specified input/output
55 overlapping. */
56 for (i = usize - 1; i >= 0; i--)
57 wp[i] = up[i];
58 }
59 return 0;
60 }
61#endif
62
63 wp += 1;
64 sh_2 = BITS_PER_MP_LIMB - sh_1;
65 i = usize - 1;
66 low_limb = up[i];
67 retval = low_limb >> sh_2;
68 high_limb = low_limb;
69 while (--i >= 0)
70 {
71 low_limb = up[i];
72 wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);
73 high_limb = low_limb;
74 }
75 wp[i] = high_limb << sh_1;
76
77 return retval;
78}