Fixed a bug in multiply_plain_inplace when plain is a monomial and us…

…ing_fast_plain_lift is enabled.
microsoft · Apr 30, 2020 · 71ff582 · 71ff582
1 parent 3514838
commit 71ff582
Showing 1 changed file with 17 additions and 14 deletions.
diff --git a/native/src/seal/evaluator.cpp b/native/src/seal/evaluator.cpp
@@ -1697,18 +1697,6 @@ namespace seal
             // Multiplying by a monomial?
             size_t mono_exponent = plain.significant_coeff_count() - 1;
 
-            // RNS monomial multiplication: monomial and multiplicand polynomial are in RNS form
-            auto rns_monomial_multiply = [&](PolyIter in_iter, ConstCoeffIter mono_iter) {
-                for_each_n(in_iter, encrypted_size, [&](auto I) {
-                    for_each_n(
-                        IterTuple<RNSIter, ConstCoeffIter, PtrIter<const Modulus *>>(I, mono_iter, coeff_modulus),
-                        coeff_modulus_size, [&](auto J) {
-                            negacyclic_multiply_poly_mono_coeffmod(
-                                get<0>(J), coeff_count, *get<1>(J), mono_exponent, *get<2>(J), get<0>(J), pool);
-                        });
-                });
-            };
-
             if (plain[mono_exponent] >= plain_upper_half_threshold)
             {
                 if (!context_data.qualifiers().using_fast_plain_lift)
@@ -1723,13 +1711,28 @@ namespace seal
                     // addition we decompose the multi-precision integer into RNS components, and then multiply.
                     add_uint_uint64(plain_upper_half_increment, plain[mono_exponent], coeff_modulus_size, temp.get());
                     context_data.rns_tool()->base_q()->decompose(temp.get(), pool);
-                    rns_monomial_multiply(encrypted, temp.get());
+                    for_each_n(PolyIter(encrypted), encrypted_size, [&](auto I) {
+                        for_each_n(
+                            IterTuple<RNSIter, ConstCoeffIter, PtrIter<const Modulus *>>(I, temp.get(), coeff_modulus),
+                            coeff_modulus_size, [&](auto J) {
+                                negacyclic_multiply_poly_mono_coeffmod(
+                                    get<0>(J), coeff_count, *get<1>(J), mono_exponent, *get<2>(J), get<0>(J), pool);
+                            });
+                    });
                 }
                 else
                 {
                     // Every coeff_modulus prime is larger than plain_modulus, so there is no need to adjust the
                     // monomial. Instead, just do an RNS multiplication.
-                    rns_monomial_multiply(encrypted, plain.data());
+                    for_each_n(PolyIter(encrypted), encrypted_size, [&](auto I) {
+                        for_each_n(
+                            IterTuple<RNSIter, PtrIter<const Modulus *>>(I, coeff_modulus), coeff_modulus_size,
+                            [&](auto J) {
+                                negacyclic_multiply_poly_mono_coeffmod(
+                                    get<0>(J), coeff_count, plain[mono_exponent], mono_exponent, *get<1>(J), get<0>(J),
+                                    pool);
+                            });
+                    });
                 }
             }
             else