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authorDmitry Kasatkin <dmitry.kasatkin@intel.com>2012-05-09 17:37:56 +0300
committerJames Morris <james.l.morris@oracle.com>2012-05-26 11:51:03 +1000
commit7cf4206a99d1b3e61bdbc7cbbf4a7bf6a9dfcc68 (patch)
treea77ad8cffa35427352cd18f94ed9339640e4d473 /lib/mpi/mpih-div.c
parent9e235dcaf4f63d88a7e9ce5735ba5c2eb2719603 (diff)
Remove unused code from MPI library
MPI library is used by RSA verification implementation. Few files contains functions which are never called. James Morris has asked to remove all of them. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Requested-by: James Morris <james.l.morris@oracle.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'lib/mpi/mpih-div.c')
-rw-r--r--lib/mpi/mpih-div.c309
1 files changed, 0 insertions, 309 deletions
diff --git a/lib/mpi/mpih-div.c b/lib/mpi/mpih-div.c
index cde1aaec18da..c57d1d46295e 100644
--- a/lib/mpi/mpih-div.c
+++ b/lib/mpi/mpih-div.c
@@ -37,159 +37,6 @@
#define UDIV_TIME UMUL_TIME
#endif
-/* FIXME: We should be using invert_limb (or invert_normalized_limb)
- * here (not udiv_qrnnd).
- */
-
-mpi_limb_t
-mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
- mpi_limb_t divisor_limb)
-{
- mpi_size_t i;
- mpi_limb_t n1, n0, r;
- int dummy;
-
- /* Botch: Should this be handled at all? Rely on callers? */
- if (!dividend_size)
- return 0;
-
- /* If multiplication is much faster than division, and the
- * dividend is large, pre-invert the divisor, and use
- * only multiplications in the inner loop.
- *
- * This test should be read:
- * Does it ever help to use udiv_qrnnd_preinv?
- * && Does what we save compensate for the inversion overhead?
- */
- if (UDIV_TIME > (2 * UMUL_TIME + 6)
- && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
- int normalization_steps;
-
- count_leading_zeros(normalization_steps, divisor_limb);
- if (normalization_steps) {
- mpi_limb_t divisor_limb_inverted;
-
- divisor_limb <<= normalization_steps;
-
- /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
- * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
- * most significant bit (with weight 2**N) implicit.
- *
- * Special case for DIVISOR_LIMB == 100...000.
- */
- if (!(divisor_limb << 1))
- divisor_limb_inverted = ~(mpi_limb_t) 0;
- else
- udiv_qrnnd(divisor_limb_inverted, dummy,
- -divisor_limb, 0, divisor_limb);
-
- n1 = dividend_ptr[dividend_size - 1];
- r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
-
- /* Possible optimization:
- * if (r == 0
- * && divisor_limb > ((n1 << normalization_steps)
- * | (dividend_ptr[dividend_size - 2] >> ...)))
- * ...one division less...
- */
- for (i = dividend_size - 2; i >= 0; i--) {
- n0 = dividend_ptr[i];
- UDIV_QRNND_PREINV(dummy, r, r,
- ((n1 << normalization_steps)
- | (n0 >>
- (BITS_PER_MPI_LIMB -
- normalization_steps))),
- divisor_limb,
- divisor_limb_inverted);
- n1 = n0;
- }
- UDIV_QRNND_PREINV(dummy, r, r,
- n1 << normalization_steps,
- divisor_limb, divisor_limb_inverted);
- return r >> normalization_steps;
- } else {
- mpi_limb_t divisor_limb_inverted;
-
- /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
- * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
- * most significant bit (with weight 2**N) implicit.
- *
- * Special case for DIVISOR_LIMB == 100...000.
- */
- if (!(divisor_limb << 1))
- divisor_limb_inverted = ~(mpi_limb_t) 0;
- else
- udiv_qrnnd(divisor_limb_inverted, dummy,
- -divisor_limb, 0, divisor_limb);
-
- i = dividend_size - 1;
- r = dividend_ptr[i];
-
- if (r >= divisor_limb)
- r = 0;
- else
- i--;
-
- for (; i >= 0; i--) {
- n0 = dividend_ptr[i];
- UDIV_QRNND_PREINV(dummy, r, r,
- n0, divisor_limb,
- divisor_limb_inverted);
- }
- return r;
- }
- } else {
- if (UDIV_NEEDS_NORMALIZATION) {
- int normalization_steps;
-
- count_leading_zeros(normalization_steps, divisor_limb);
- if (normalization_steps) {
- divisor_limb <<= normalization_steps;
-
- n1 = dividend_ptr[dividend_size - 1];
- r = n1 >> (BITS_PER_MPI_LIMB -
- normalization_steps);
-
- /* Possible optimization:
- * if (r == 0
- * && divisor_limb > ((n1 << normalization_steps)
- * | (dividend_ptr[dividend_size - 2] >> ...)))
- * ...one division less...
- */
- for (i = dividend_size - 2; i >= 0; i--) {
- n0 = dividend_ptr[i];
- udiv_qrnnd(dummy, r, r,
- ((n1 << normalization_steps)
- | (n0 >>
- (BITS_PER_MPI_LIMB -
- normalization_steps))),
- divisor_limb);
- n1 = n0;
- }
- udiv_qrnnd(dummy, r, r,
- n1 << normalization_steps,
- divisor_limb);
- return r >> normalization_steps;
- }
- }
- /* No normalization needed, either because udiv_qrnnd doesn't require
- * it, or because DIVISOR_LIMB is already normalized. */
- i = dividend_size - 1;
- r = dividend_ptr[i];
-
- if (r >= divisor_limb)
- r = 0;
- else
- i--;
-
- for (; i >= 0; i--) {
- n0 = dividend_ptr[i];
- udiv_qrnnd(dummy, r, r, n0, divisor_limb);
- }
- return r;
- }
-}
-
/* Divide num (NP/NSIZE) by den (DP/DSIZE) and write
* the NSIZE-DSIZE least significant quotient limbs at QP
* and the DSIZE long remainder at NP. If QEXTRA_LIMBS is
@@ -387,159 +234,3 @@ q_test:
return most_significant_q_limb;
}
-
-/****************
- * Divide (DIVIDEND_PTR,,DIVIDEND_SIZE) by DIVISOR_LIMB.
- * Write DIVIDEND_SIZE limbs of quotient at QUOT_PTR.
- * Return the single-limb remainder.
- * There are no constraints on the value of the divisor.
- *
- * QUOT_PTR and DIVIDEND_PTR might point to the same limb.
- */
-
-mpi_limb_t
-mpihelp_divmod_1(mpi_ptr_t quot_ptr,
- mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
- mpi_limb_t divisor_limb)
-{
- mpi_size_t i;
- mpi_limb_t n1, n0, r;
- int dummy;
-
- if (!dividend_size)
- return 0;
-
- /* If multiplication is much faster than division, and the
- * dividend is large, pre-invert the divisor, and use
- * only multiplications in the inner loop.
- *
- * This test should be read:
- * Does it ever help to use udiv_qrnnd_preinv?
- * && Does what we save compensate for the inversion overhead?
- */
- if (UDIV_TIME > (2 * UMUL_TIME + 6)
- && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
- int normalization_steps;
-
- count_leading_zeros(normalization_steps, divisor_limb);
- if (normalization_steps) {
- mpi_limb_t divisor_limb_inverted;
-
- divisor_limb <<= normalization_steps;
-
- /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
- * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
- * most significant bit (with weight 2**N) implicit.
- */
- /* Special case for DIVISOR_LIMB == 100...000. */
- if (!(divisor_limb << 1))
- divisor_limb_inverted = ~(mpi_limb_t) 0;
- else
- udiv_qrnnd(divisor_limb_inverted, dummy,
- -divisor_limb, 0, divisor_limb);
-
- n1 = dividend_ptr[dividend_size - 1];
- r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
-
- /* Possible optimization:
- * if (r == 0
- * && divisor_limb > ((n1 << normalization_steps)
- * | (dividend_ptr[dividend_size - 2] >> ...)))
- * ...one division less...
- */
- for (i = dividend_size - 2; i >= 0; i--) {
- n0 = dividend_ptr[i];
- UDIV_QRNND_PREINV(quot_ptr[i + 1], r, r,
- ((n1 << normalization_steps)
- | (n0 >>
- (BITS_PER_MPI_LIMB -
- normalization_steps))),
- divisor_limb,
- divisor_limb_inverted);
- n1 = n0;
- }
- UDIV_QRNND_PREINV(quot_ptr[0], r, r,
- n1 << normalization_steps,
- divisor_limb, divisor_limb_inverted);
- return r >> normalization_steps;
- } else {
- mpi_limb_t divisor_limb_inverted;
-
- /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
- * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
- * most significant bit (with weight 2**N) implicit.
- */
- /* Special case for DIVISOR_LIMB == 100...000. */
- if (!(divisor_limb << 1))
- divisor_limb_inverted = ~(mpi_limb_t) 0;
- else
- udiv_qrnnd(divisor_limb_inverted, dummy,
- -divisor_limb, 0, divisor_limb);
-
- i = dividend_size - 1;
- r = dividend_ptr[i];
-
- if (r >= divisor_limb)
- r = 0;
- else
- quot_ptr[i--] = 0;
-
- for (; i >= 0; i--) {
- n0 = dividend_ptr[i];
- UDIV_QRNND_PREINV(quot_ptr[i], r, r,
- n0, divisor_limb,
- divisor_limb_inverted);
- }
- return r;
- }
- } else {
- if (UDIV_NEEDS_NORMALIZATION) {
- int normalization_steps;
-
- count_leading_zeros(normalization_steps, divisor_limb);
- if (normalization_steps) {
- divisor_limb <<= normalization_steps;
-
- n1 = dividend_ptr[dividend_size - 1];
- r = n1 >> (BITS_PER_MPI_LIMB -
- normalization_steps);
-
- /* Possible optimization:
- * if (r == 0
- * && divisor_limb > ((n1 << normalization_steps)
- * | (dividend_ptr[dividend_size - 2] >> ...)))
- * ...one division less...
- */
- for (i = dividend_size - 2; i >= 0; i--) {
- n0 = dividend_ptr[i];
- udiv_qrnnd(quot_ptr[i + 1], r, r,
- ((n1 << normalization_steps)
- | (n0 >>
- (BITS_PER_MPI_LIMB -
- normalization_steps))),
- divisor_limb);
- n1 = n0;
- }
- udiv_qrnnd(quot_ptr[0], r, r,
- n1 << normalization_steps,
- divisor_limb);
- return r >> normalization_steps;
- }
- }
- /* No normalization needed, either because udiv_qrnnd doesn't require
- * it, or because DIVISOR_LIMB is already normalized. */
- i = dividend_size - 1;
- r = dividend_ptr[i];
-
- if (r >= divisor_limb)
- r = 0;
- else
- quot_ptr[i--] = 0;
-
- for (; i >= 0; i--) {
- n0 = dividend_ptr[i];
- udiv_qrnnd(quot_ptr[i], r, r, n0, divisor_limb);
- }
- return r;
- }
-}