ringct: a few minor optimizations from review

1 files changed, 15 insertions, 18 deletions

diff --git a/src/ringct/bulletproofs_plus.cc b/src/ringct/bulletproofs_plus.cc
index 589e58525..5aebba450 100644
--- a/src/ringct/bulletproofs_plus.cc
+++ b/src/ringct/bulletproofs_plus.cc
@@ -68,17 +68,16 @@ namespace rct
     static constexpr size_t maxM = BULLETPROOF_PLUS_MAX_OUTPUTS; // maximum number of outputs to aggregate into a single proof
 
     // Cached public generators
-    static rct::key Hi[maxN*maxM], Gi[maxN*maxM];
     static ge_p3 Hi_p3[maxN*maxM], Gi_p3[maxN*maxM];
     static std::shared_ptr<straus_cached_data> straus_HiGi_cache;
     static std::shared_ptr<pippenger_cached_data> pippenger_HiGi_cache;
 
     // Useful scalar constants
-    static const rct::key ZERO = { {0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } }; // 0
-    static const rct::key ONE = { {0x01, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } }; // 1
-    static const rct::key TWO = { {0x02, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } }; // 2
-    static const rct::key MINUS_ONE = { { 0xec, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10 } }; // -1
-    static const rct::key MINUS_INV_EIGHT = { { 0x74, 0xa4, 0x19, 0x7a, 0xf0, 0x7d, 0x0b, 0xf7, 0x05, 0xc2, 0xda, 0x25, 0x2b, 0x5c, 0x0b, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a } }; // -(8**(-1))
+    static const constexpr rct::key ZERO = { {0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } }; // 0
+    static const constexpr rct::key ONE = { {0x01, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } }; // 1
+    static const constexpr rct::key TWO = { {0x02, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } }; // 2
+    static const constexpr rct::key MINUS_ONE = { { 0xec, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10 } }; // -1
+    static const constexpr rct::key MINUS_INV_EIGHT = { { 0x74, 0xa4, 0x19, 0x7a, 0xf0, 0x7d, 0x0b, 0xf7, 0x05, 0xc2, 0xda, 0x25, 0x2b, 0x5c, 0x0b, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a } }; // -(8**(-1))
     static rct::key TWO_SIXTY_FOUR_MINUS_ONE; // 2**64 - 1
 
     // Initial transcript hash
@@ -107,16 +106,15 @@ namespace rct
     }
 
     // Use hashed values to produce indexed public generators
-    static rct::key get_exponent(const rct::key &base, size_t idx)
+    static ge_p3 get_exponent(const rct::key &base, size_t idx)
     {
-        static const std::string domain_separator(config::HASH_KEY_BULLETPROOF_PLUS_EXPONENT);
-        std::string hashed = std::string((const char*)base.bytes, sizeof(base)) + domain_separator + tools::get_varint_data(idx);
+        std::string hashed = std::string((const char*)base.bytes, sizeof(base)) + config::HASH_KEY_BULLETPROOF_PLUS_EXPONENT + tools::get_varint_data(idx);
         rct::key generator;
         ge_p3 generator_p3;
         rct::hash_to_p3(generator_p3, rct::hash2rct(crypto::cn_fast_hash(hashed.data(), hashed.size())));
         ge_p3_tobytes(generator.bytes, &generator_p3);
         CHECK_AND_ASSERT_THROW_MES(!(generator == rct::identity()), "Exponent is point at infinity");
-        return generator;
+        return generator_p3;
     }
 
     // Construct public generators
@@ -133,10 +131,8 @@ namespace rct
         data.reserve(maxN*maxM*2);
         for (size_t i = 0; i < maxN*maxM; ++i)
         {
-            Hi[i] = get_exponent(rct::H, i * 2);
-            CHECK_AND_ASSERT_THROW_MES(ge_frombytes_vartime(&Hi_p3[i], Hi[i].bytes) == 0, "ge_frombytes_vartime failed");
-            Gi[i] = get_exponent(rct::H, i * 2 + 1);
-            CHECK_AND_ASSERT_THROW_MES(ge_frombytes_vartime(&Gi_p3[i], Gi[i].bytes) == 0, "ge_frombytes_vartime failed");
+            Hi_p3[i] = get_exponent(rct::H, i * 2);
+            Gi_p3[i] = get_exponent(rct::H, i * 2 + 1);
 
             data.push_back({rct::zero(), Gi_p3[i]});
             data.push_back({rct::zero(), Hi_p3[i]});
@@ -154,7 +150,7 @@ namespace rct
         sc_sub(TWO_SIXTY_FOUR_MINUS_ONE.bytes, TWO_SIXTY_FOUR_MINUS_ONE.bytes, ONE.bytes);
 
         // Generate the initial Fiat-Shamir transcript hash, which is constant across all proofs
-        static const std::string domain_separator(config::HASH_KEY_BULLETPROOF_PLUS_TRANSCRIPT);
+        const std::string domain_separator(config::HASH_KEY_BULLETPROOF_PLUS_TRANSCRIPT);
         ge_p3 initial_transcript_p3;
         rct::hash_to_p3(initial_transcript_p3, rct::hash2rct(crypto::cn_fast_hash(domain_separator.data(), domain_separator.size())));
         ge_p3_tobytes(initial_transcript.bytes, &initial_transcript_p3);
@@ -846,7 +842,8 @@ try_again:
             max_length = std::max(max_length, proof.L.size());
             nV += proof.V.size();
 
-            bp_plus_proof_data_t pd;
+            proof_data.push_back({});
+            bp_plus_proof_data_t &pd = proof_data.back();
 
             // Reconstruct the challenges
             rct::key transcript = copy(initial_transcript);
@@ -883,7 +880,6 @@ try_again:
                 to_invert.push_back(pd.challenges[j]);
             to_invert.push_back(pd.y);
             inv_offset += rounds + 1;
-            proof_data.push_back(pd);
         }
         CHECK_AND_ASSERT_MES(max_length < 32, false, "At least one proof is too large");
         size_t maxMN = 1u << max_length;
@@ -896,7 +892,8 @@ try_again:
         multiexp_data.reserve(nV + (2 * (max_logM + logN) + 3) * proofs.size() + 2 * maxMN);
         multiexp_data.resize(2 * maxMN);
 
-        const std::vector<rct::key> inverses = invert(to_invert);
+        const std::vector<rct::key> inverses = invert(std::move(to_invert));
+        to_invert.clear();
 
         // Weights and aggregates
         //