Split jumpdest map into 2 vectors of int16_t

Author: chfast

lib/evmone/analysis.cpp

@@ -65,7 +65,10 @@ code_analysis analyze(
             beginblock_instr.arg.p.number = static_cast<int>(analysis.blocks.size() - 1);
 
             if (jumpdest)  // Add the jumpdest to the map.
-                analysis.jumpdest_map.emplace_back(static_cast<int>(i), instr_index);
+            {
+                analysis.jumpdest_offsets.emplace_back(static_cast<int16_t>(i));
+                analysis.jumpdest_targets.emplace_back(static_cast<int16_t>(instr_index));
+            }
             else  // Increase instruction count because additional BEGINBLOCK was injected.
                 ++instr_index;
         }

lib/evmone/analysis.hpp

@@ -152,15 +152,23 @@ struct code_analysis
     /// invalidated when the container grows.
     std::deque<bytes32> args_storage;
 
-    std::vector<std::pair<int, int>> jumpdest_map;
+    /// The offsets of JUMPDESTs in the original code.
+    /// These are values that JUMP/JUMPI receives as an argument.
+    /// The elements are sorted.
+    std::vector<int16_t> jumpdest_offsets;
+
+    /// The indexes of the instructions in the generated instruction table
+    /// matching the elements from jumdest_offsets.
+    /// This is value to which the next instruction pointer must be set in JUMP/JUMPI.
+    std::vector<int16_t> jumpdest_targets;
 };
 
 inline int find_jumpdest(const code_analysis& analysis, int offset) noexcept
 {
-    const auto& m = analysis.jumpdest_map;
-    const auto it = std::lower_bound(std::begin(m), std::end(m), offset,
-        [](std::pair<int, int> p, int v) noexcept { return p.first < v; });
-    return (it != std::end(m) && it->first == offset) ? it->second : -1;
+    const auto begin = std::begin(analysis.jumpdest_offsets);
+    const auto end = std::end(analysis.jumpdest_offsets);
+    const auto it = std::lower_bound(begin, end, offset);
+    return (it != end && *it == offset) ? analysis.jumpdest_targets[it - begin] : -1;
 }
 
 EVMC_EXPORT code_analysis analyze(

test/unittests/analysis_test.cpp

@@ -86,8 +86,10 @@ TEST(analysis, jump1)
     const auto analysis = analyze(fake_fn_table, rev, &code[0], code.size());
 
     ASSERT_EQ(analysis.blocks.size(), 3);
-    ASSERT_EQ(analysis.jumpdest_map.size(), 1);
-    EXPECT_EQ(analysis.jumpdest_map[0], std::pair(6, 5));
+    ASSERT_EQ(analysis.jumpdest_offsets.size(), 1);
+    ASSERT_EQ(analysis.jumpdest_targets.size(), 1);
+    EXPECT_EQ(analysis.jumpdest_offsets[0], 6);
+    EXPECT_EQ(analysis.jumpdest_targets[0], 5);
     EXPECT_EQ(find_jumpdest(analysis, 6), 5);
     EXPECT_EQ(find_jumpdest(analysis, 0), -1);
     EXPECT_EQ(find_jumpdest(analysis, 7), -1);
@@ -109,8 +111,10 @@ TEST(analysis, only_jumpdest)
     auto analysis = evmone::analyze(fake_fn_table, rev, &code[0], code.size());
 
     ASSERT_EQ(analysis.blocks.size(), 1);
-    ASSERT_EQ(analysis.jumpdest_map.size(), 1);
-    EXPECT_EQ(analysis.jumpdest_map[0], std::pair(0, 0));
+    ASSERT_EQ(analysis.jumpdest_offsets.size(), 1);
+    ASSERT_EQ(analysis.jumpdest_targets.size(), 1);
+    EXPECT_EQ(analysis.jumpdest_offsets[0], 0);
+    EXPECT_EQ(analysis.jumpdest_targets[0], 0);
 }
 
 TEST(analysis, jumpi_at_the_end)

test/utils/dump.cpp

@@ -32,12 +32,13 @@ void dump_analysis(const evmone::code_analysis& analysis)
 
             auto get_jumpdest_offset = [&analysis](size_t index) noexcept
             {
-                for (const auto& d : analysis.jumpdest_map)
+                for (auto it = analysis.jumpdest_targets.begin();
+                     it != analysis.jumpdest_targets.end(); ++it)
                 {
-                    if (d.second == static_cast<int>(index))
-                        return d.first;
+                    if (*it == static_cast<int>(index))
+                        return analysis.jumpdest_offsets[it - analysis.jumpdest_targets.begin()];
                 }
-                return -1;
+                return int16_t{-1};
             };
 
             std::cout << "┌ ";