diff options
| -rw-r--r-- | lib/mpi/mpicoder.c | 39 |
1 files changed, 21 insertions, 18 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index ec533a6..eb15e7d 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -128,6 +128,23 @@ leave: } EXPORT_SYMBOL_GPL(mpi_read_from_buffer); +static int count_lzeros(MPI a) +{ + mpi_limb_t alimb; + int i, lzeros = 0; + + for (i = a->nlimbs - 1; i >= 0; i--) { + alimb = a->d[i]; + if (alimb == 0) { + lzeros += sizeof(mpi_limb_t); + } else { + lzeros += count_leading_zeros(alimb) / 8; + break; + } + } + return lzeros; +} + /** * mpi_read_buffer() - read MPI to a bufer provided by user (msb first) * @@ -148,7 +165,7 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, uint8_t *p; mpi_limb_t alimb; unsigned int n = mpi_get_size(a); - int i, lzeros = 0; + int i, lzeros; if (!buf || !nbytes) return -EINVAL; @@ -156,14 +173,7 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, if (sign) *sign = a->sign; - p = (void *)&a->d[a->nlimbs] - 1; - - for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) { - if (!*p) - lzeros++; - else - break; - } + lzeros = count_lzeros(a); if (buf_len < n - lzeros) { *nbytes = n - lzeros; @@ -351,7 +361,7 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, u8 *p, *p2; mpi_limb_t alimb, alimb2; unsigned int n = mpi_get_size(a); - int i, x, y = 0, lzeros = 0, buf_len; + int i, x, y = 0, lzeros, buf_len; if (!nbytes) return -EINVAL; @@ -359,14 +369,7 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, if (sign) *sign = a->sign; - p = (void *)&a->d[a->nlimbs] - 1; - - for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) { - if (!*p) - lzeros++; - else - break; - } + lzeros = count_lzeros(a); if (*nbytes < n - lzeros) { *nbytes = n - lzeros; |
