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Merge pull request #7489 from minosgalanakis/ecp/7246_xtrack_core_shift_l

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[Bignum]: Introduce left shift from prototype
This commit is contained in:
Paul Elliott
2023-05-16 17:13:19 +01:00
committed by GitHub
parent 55a701afec 99453ad9f0
commit f0806bee66
5 changed files with 150 additions and 1 deletions
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35
library/bignum_core.c
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@ -366,6 +366,41 @@ void mbedtls_mpi_core_shift_r(mbedtls_mpi_uint *X, size_t limbs,
}
}
void mbedtls_mpi_core_shift_l(mbedtls_mpi_uint *X, size_t limbs,
size_t count)
{
size_t i, v0, v1;
mbedtls_mpi_uint r0 = 0, r1;
v0 = count / (biL);
v1 = count & (biL - 1);
/*
* shift by count / limb_size
*/
if (v0 > 0) {
for (i = limbs; i > v0; i--) {
X[i - 1] = X[i - v0 - 1];
}
for (; i > 0; i--) {
X[i - 1] = 0;
}
}
/*
* shift by count % limb_size
*/
if (v1 > 0) {
for (i = v0; i < limbs; i++) {
r1 = X[i] >> (biL - v1);
X[i] <<= v1;
X[i] |= r0;
r0 = r1;
}
}
}
mbedtls_mpi_uint mbedtls_mpi_core_add(mbedtls_mpi_uint *X,
const mbedtls_mpi_uint *A,
const mbedtls_mpi_uint *B,