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Lessen peak memory usage in EC by freeing earlier

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Cuts peak usage by 25% :)
This commit is contained in:
Manuel Pégourié-Gonnard 2013-12-30 17:31:56 +01:00
parent 72c172a13d
commit 1f789b8348
1 changed files with 10 additions and 14 deletions
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24
library/ecp.c
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@ -791,7 +791,16 @@ static int ecp_normalize_jac_many( const ecp_group *grp,
MPI_CHK( mpi_mul_mpi( &T[i]->X, &T[i]->X, &ZZi ) ); MOD_MUL( T[i]->X ); MPI_CHK( mpi_mul_mpi( &T[i]->X, &T[i]->X, &ZZi ) ); MOD_MUL( T[i]->X );
MPI_CHK( mpi_mul_mpi( &T[i]->Y, &T[i]->Y, &ZZi ) ); MOD_MUL( T[i]->Y ); MPI_CHK( mpi_mul_mpi( &T[i]->Y, &T[i]->Y, &ZZi ) ); MOD_MUL( T[i]->Y );
MPI_CHK( mpi_mul_mpi( &T[i]->Y, &T[i]->Y, &Zi ) ); MOD_MUL( T[i]->Y ); MPI_CHK( mpi_mul_mpi( &T[i]->Y, &T[i]->Y, &Zi ) ); MOD_MUL( T[i]->Y );
MPI_CHK( mpi_lset( &T[i]->Z, 1 ) );
/*
* Post-precessing: reclaim some memory by shrinking coordinates
* - not storing Z (always 1)
* - shrinking other coordinates, but still keeping the same number of
* limbs as P, as otherwise it will too likely be regrown too fast.
*/
mpi_shrink( &T[i]->X, grp->P.n );
mpi_shrink( &T[i]->Y, grp->P.n );
mpi_free( &T[i]->Z );
if( i == 0 ) if( i == 0 )
break; break;
@ -1205,19 +1214,6 @@ static int ecp_precompute_comb( const ecp_group *grp,
ecp_normalize_jac_many( grp, TT, k ); ecp_normalize_jac_many( grp, TT, k );
/*
* Post-precessing: reclaim some memory by
* - not storing Z (always 1)
* - shrinking other coordinates
* Keep the same number of limbs as P to avoid re-growing on next use.
*/
for( i = 0; i < ( 1U << (w-1) ); i++ )
{
mpi_free( &T[i].Z );
mpi_shrink( &T[i].X, grp->P.n );
mpi_shrink( &T[i].Y, grp->P.n );
}
cleanup: cleanup:
return( ret ); return( ret );
} }