diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | gmp-h.in | 4 | ||||
| -rw-r--r-- | mpn/generic/sec_div.c | 55 | ||||
| -rw-r--r-- | tests/mpn/t-div.c | 4 |
4 files changed, 43 insertions, 27 deletions
@@ -1,3 +1,10 @@ +2014-01-01 Torbjorn Granlund <tege@gmplib.org> + + * mpn/generic/sec_div.c: Rewrite to make mpn_sec_div_qr return high + quotient limb. + * gmp-h.in (mpn_sec_div_qr): Update declaration. + * tests/mpn/t-div.c: Adapt. + 2013-12-31 Niels Möller <nisse@lysator.liu.se> * doc/gmp.texi (Low-level Functions for cryptography): Document @@ -1,6 +1,6 @@ /* Definitions for GNU multiple precision functions. -*- mode: c -*- -Copyright 1991, 1993-1997, 1999-2013 Free Software Foundation, Inc. +Copyright 1991, 1993-1997, 1999-2014 Free Software Foundation, Inc. This file is part of the GNU MP Library. @@ -1645,7 +1645,7 @@ __GMP_DECLSPEC mp_size_t mpn_sec_powm_itch (mp_size_t, mp_size_t, mp_size_t); __GMP_DECLSPEC void mpn_sec_tabselect (volatile mp_limb_t *, volatile mp_limb_t *, mp_size_t, mp_size_t, mp_size_t); #define mpn_sec_div_qr __MPN(sec_div_qr) -__GMP_DECLSPEC void mpn_sec_div_qr (mp_ptr, mp_ptr, mp_size_t, mp_srcptr, mp_size_t, mp_ptr); +__GMP_DECLSPEC mp_limb_t mpn_sec_div_qr (mp_ptr, mp_ptr, mp_size_t, mp_srcptr, mp_size_t, mp_ptr); #define mpn_sec_div_qr_itch __MPN(sec_div_qr_itch) __GMP_DECLSPEC mp_size_t mpn_sec_div_qr_itch (mp_size_t, mp_size_t); #define mpn_sec_div_r __MPN(sec_div_r) diff --git a/mpn/generic/sec_div.c b/mpn/generic/sec_div.c index 0d84f4e45..ccbe233de 100644 --- a/mpn/generic/sec_div.c +++ b/mpn/generic/sec_div.c @@ -1,14 +1,10 @@ -/* mpn_sec_div_qr, mpn_sec_div_r -- Compute Q = floor(U / V), U = U mod - V. Side-channel silent under the assumption that the used instructions are +/* mpn_sec_div_qr, mpn_sec_div_r -- Compute Q = floor(U / V), U = U mod V. + Side-channel silent under the assumption that the used instructions are side-channel silent. Contributed to the GNU project by Torbjörn Granlund. - THE FUNCTIONS IN THIS FILE ARE INTERNAL WITH MUTABLE INTERFACES. IT IS ONLY - SAFE TO REACH THEM THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST - GUARANTEED THAT THEY WILL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE. - -Copyright 2011-2013 Free Software Foundation, Inc. +Copyright 2011-2014 Free Software Foundation, Inc. This file is part of the GNU MP Library. @@ -33,11 +29,13 @@ with the GNU MP Library. If not, see https://www.gnu.org/licenses/. */ #define FNAME mpn_sec_div_qr #define FNAME_itch mpn_sec_div_qr_itch #define Q(q) q, +#define RETTYPE mp_limb_t #endif #if OPERATION_sec_div_r #define FNAME mpn_sec_div_r #define FNAME_itch mpn_sec_div_r_itch #define Q(q) +#define RETTYPE void #endif mp_size_t @@ -56,7 +54,7 @@ FNAME_itch (mp_size_t nn, mp_size_t dn) #endif } -void +RETTYPE FNAME (Q(mp_ptr qp) mp_ptr np, mp_size_t nn, mp_srcptr dp, mp_size_t dn, @@ -84,6 +82,23 @@ FNAME (Q(mp_ptr qp) np2 = tp + dn; /* (nn + 1) limbs */ cy = mpn_lshift (np2, np, nn, cnt); np2[nn++] = cy; + + d0 = dp2[dn - 1]; + d0 += (~d0 != 0); + invert_limb (inv32, d0); + + /* We add nn + dn to tp here, not nn + 1 + dn, as expected. This is + since nn here will have been incremented. */ +#if OPERATION_sec_div_qr + qh = mpn_sec_pi1_div_qr (np2 + dn, np2, nn, dp2, dn, inv32, tp + nn + dn); + ASSERT (qh == 0); /* FIXME: this indicates inefficiency! */ + MPN_COPY (qp, np2 + dn, nn - dn - 1); + qh = np2[nn - 1]; +#else + mpn_sec_pi1_div_r (np2, nn, dp2, dn, inv32, tp + nn + dn); +#endif + + mpn_rshift (np, np2, dn, cnt); } else { @@ -92,27 +107,21 @@ FNAME (Q(mp_ptr qp) assume nn > dn. */ dp2 = (mp_ptr) dp; np2 = np; - } - d0 = dp2[dn - 1]; - d0 += (~d0 != 0); - invert_limb (inv32, d0); + d0 = dp2[dn - 1]; + d0 += (~d0 != 0); + invert_limb (inv32, d0); - /* We add nn + dn to tp here, not nn + 1 + dn, as expected. This is since nn - here will have been incremented. */ + /* We add nn + dn to tp here, not nn + 1 + dn, as expected. This is + since nn here will have been incremented. */ #if OPERATION_sec_div_qr - qh = mpn_sec_pi1_div_qr (qp, np2, nn, dp2, dn, inv32, tp + nn + dn); + qh = mpn_sec_pi1_div_qr (qp, np2, nn, dp2, dn, inv32, tp + nn + dn); #else - mpn_sec_pi1_div_r (np2, nn, dp2, dn, inv32, tp + nn + dn); + mpn_sec_pi1_div_r (np2, nn, dp2, dn, inv32, tp + nn + dn); #endif - - if (cnt == 0) - ; /* we have np = np2 here. */ - else - mpn_rshift (np, np2, dn, cnt); + } #if OPERATION_sec_div_qr - if (cnt == 0) - qp[nn - dn] = qh; + return qh; #endif } diff --git a/tests/mpn/t-div.c b/tests/mpn/t-div.c index db50aa75c..477f902b4 100644 --- a/tests/mpn/t-div.c +++ b/tests/mpn/t-div.c @@ -1,4 +1,4 @@ -/* Copyright 2006, 2007, 2009, 2010, 2013 Free Software Foundation, Inc. +/* Copyright 2006, 2007, 2009, 2010, 2013, 2014 Free Software Foundation, Inc. This file is part of the GNU MP Library test suite. @@ -306,7 +306,7 @@ main (int argc, char **argv) MPN_COPY (rp, np, nn); if (nn >= dn) MPN_COPY (qp, junkp, nn - dn + 1); - mpn_sec_div_qr (qp, rp, nn, dup, dn, scratch); + qp[nn - dn] = mpn_sec_div_qr (qp, rp, nn, dup, dn, scratch); ASSERT_ALWAYS (ran == scratch[itch]); check_one (qp, rp, np, nn, dup, dn, "mpn_sec_div_qr", 0); |