diff options
author | Thomas Zimmermann <[email protected]> | 2023-10-11 09:50:59 +0200 |
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committer | Thomas Zimmermann <[email protected]> | 2023-10-11 09:50:59 +0200 |
commit | 57390019b68b83f96eb98f490367b9df1f2d77cb (patch) | |
tree | e6d4b6c75efdd2d7fb7d37f980688c491be3ff6a /lib/crypto/mpi/generic_mpih-mul3.c | |
parent | e5f9d543419c78ac58f3b3557bc5a76b20ff600b (diff) | |
parent | 389af786f92ecdff35883551d54bf4e507ffcccb (diff) |
Merge drm/drm-next into drm-misc-next
Updating drm-misc-next to the state of Linux v6.6-rc2.
Signed-off-by: Thomas Zimmermann <[email protected]>
Diffstat (limited to 'lib/crypto/mpi/generic_mpih-mul3.c')
-rw-r--r-- | lib/crypto/mpi/generic_mpih-mul3.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/lib/crypto/mpi/generic_mpih-mul3.c b/lib/crypto/mpi/generic_mpih-mul3.c new file mode 100644 index 000000000000..ccdbab4121e0 --- /dev/null +++ b/lib/crypto/mpi/generic_mpih-mul3.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* mpihelp-mul_3.c - MPI helper functions + * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * Note: This code is heavily based on the GNU MP Library. + * Actually it's the same code with only minor changes in the + * way the data is stored; this is to support the abstraction + * of an optional secure memory allocation which may be used + * to avoid revealing of sensitive data due to paging etc. + * The GNU MP Library itself is published under the LGPL; + * however I decided to publish this code under the plain GPL. + */ + +#include "mpi-internal.h" +#include "longlong.h" + +mpi_limb_t +mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, + mpi_size_t s1_size, mpi_limb_t s2_limb) +{ + mpi_limb_t cy_limb; + mpi_size_t j; + mpi_limb_t prod_high, prod_low; + mpi_limb_t x; + + /* The loop counter and index J goes from -SIZE to -1. This way + * the loop becomes faster. */ + j = -s1_size; + res_ptr -= j; + s1_ptr -= j; + + cy_limb = 0; + do { + umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); + + prod_low += cy_limb; + cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high; + + x = res_ptr[j]; + prod_low = x - prod_low; + cy_limb += prod_low > x ? 1 : 0; + res_ptr[j] = prod_low; + } while (++j); + + return cy_limb; +} |