From 0f014554556cf4ae39e1b5b1829f7b8c48ce1e84 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel@hepcolgum.band>
Date: Fri, 19 Aug 2022 19:15:48 +0200
Subject: [PATCH] Add option to disable "computed goto" dispatch

Add EVMC option cgoto=no to disable the "computed goto" dispatch
in Baseline.
---
 lib/evmone/baseline.cpp        |  7 ++++---
 lib/evmone/vm.cpp              | 13 +++++++++++++
 lib/evmone/vm.hpp              |  4 ++++
 test/bench/bench.cpp           | 12 ++++++++++++
 test/unittests/evm_fixture.cpp |  6 +++++-
 5 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/lib/evmone/baseline.cpp b/lib/evmone/baseline.cpp
index d67bdc8344..984697497a 100644
--- a/lib/evmone/baseline.cpp
+++ b/lib/evmone/baseline.cpp
@@ -325,10 +325,11 @@ evmc_result execute(const VM& vm, ExecutionState& state, const CodeAnalysis& ana
     else
     {
 #if EVMONE_CGOTO_SUPPORTED
-        dispatch_cgoto(cost_table, state);
-#else
-        dispatch<false>(cost_table, state, tracer);
+        if (vm.cgoto)
+            dispatch_cgoto(cost_table, state);
+        else
 #endif
+            dispatch<false>(cost_table, state, tracer);
     }
 
     const auto gas_left =
diff --git a/lib/evmone/vm.cpp b/lib/evmone/vm.cpp
index f18782f5b0..3903d0e57d 100644
--- a/lib/evmone/vm.cpp
+++ b/lib/evmone/vm.cpp
@@ -47,6 +47,19 @@ evmc_set_option_result set_option(evmc_vm* c_vm, char const* c_name, char const*
         }
         return EVMC_SET_OPTION_INVALID_VALUE;
     }
+    else if (name == "cgoto")
+    {
+#if EVMONE_CGOTO_SUPPORTED
+        if (value == "no")
+        {
+            vm.cgoto = false;
+            return EVMC_SET_OPTION_SUCCESS;
+        }
+        return EVMC_SET_OPTION_INVALID_VALUE;
+#else
+        return EVMC_SET_OPTION_INVALID_NAME;
+#endif
+    }
     else if (name == "trace")
     {
         vm.add_tracer(create_instruction_tracer(std::cerr));
diff --git a/lib/evmone/vm.hpp b/lib/evmone/vm.hpp
index 9b221d27eb..98c8d39105 100644
--- a/lib/evmone/vm.hpp
+++ b/lib/evmone/vm.hpp
@@ -17,6 +17,10 @@ namespace evmone
 /// The evmone EVMC instance.
 class VM : public evmc_vm
 {
+public:
+    bool cgoto = EVMONE_CGOTO_SUPPORTED;
+
+private:
     std::unique_ptr<Tracer> m_first_tracer;
 
 public:
diff --git a/test/bench/bench.cpp b/test/bench/bench.cpp
index 9125034d79..b92954b10e 100644
--- a/test/bench/bench.cpp
+++ b/test/bench/bench.cpp
@@ -150,10 +150,13 @@ void register_benchmarks(const std::vector<BenchmarkCase>& benchmark_cases)
 {
     evmc::VM* advanced_vm = nullptr;
     evmc::VM* baseline_vm = nullptr;
+    evmc::VM* basel_cg_vm = nullptr;
     if (const auto it = registered_vms.find("advanced"); it != registered_vms.end())
         advanced_vm = &it->second;
     if (const auto it = registered_vms.find("baseline"); it != registered_vms.end())
         baseline_vm = &it->second;
+    if (const auto it = registered_vms.find("bnocgoto"); it != registered_vms.end())
+        basel_cg_vm = &it->second;
 
     for (const auto& b : benchmark_cases)
     {
@@ -193,6 +196,14 @@ void register_benchmarks(const std::vector<BenchmarkCase>& benchmark_cases)
                 })->Unit(kMicrosecond);
             }
 
+            if (basel_cg_vm != nullptr)
+            {
+                const auto name = "bnocgoto/execute/" + case_name;
+                RegisterBenchmark(name.c_str(), [&vm = *basel_cg_vm, &b, &input](State& state) {
+                    bench_baseline_execute(state, vm, b.code, input.input, input.expected_output);
+                })->Unit(kMicrosecond);
+            }
+
             for (auto& [vm_name, vm] : registered_vms)
             {
                 const auto name = std::string{vm_name} + "/total/" + case_name;
@@ -308,6 +319,7 @@ int main(int argc, char** argv)
 
         registered_vms["advanced"] = evmc::VM{evmc_create_evmone(), {{"O", "2"}}};
         registered_vms["baseline"] = evmc::VM{evmc_create_evmone(), {{"O", "0"}}};
+        registered_vms["bnocgoto"] = evmc::VM{evmc_create_evmone(), {{"O", "0"}, {"cgoto", "no"}}};
         register_benchmarks(benchmark_cases);
         register_synthetic_benchmarks();
         RunSpecifiedBenchmarks();
diff --git a/test/unittests/evm_fixture.cpp b/test/unittests/evm_fixture.cpp
index c166583460..f439491f77 100644
--- a/test/unittests/evm_fixture.cpp
+++ b/test/unittests/evm_fixture.cpp
@@ -11,6 +11,7 @@ namespace
 {
 evmc::VM advanced_vm{evmc_create_evmone(), {{"O", "2"}}};
 evmc::VM baseline_vm{evmc_create_evmone(), {{"O", "0"}}};
+evmc::VM bnocgoto_vm{evmc_create_evmone(), {{"O", "0"}, {"cgoto", "no"}}};
 
 const char* print_vm_name(const testing::TestParamInfo<evmc::VM*>& info) noexcept
 {
@@ -18,9 +19,12 @@ const char* print_vm_name(const testing::TestParamInfo<evmc::VM*>& info) noexcep
         return "advanced";
     if (info.param == &baseline_vm)
         return "baseline";
+    if (info.param == &bnocgoto_vm)
+        return "bnocgoto";
     return "unknown";
 }
 }  // namespace
 
-INSTANTIATE_TEST_SUITE_P(evmone, evm, testing::Values(&advanced_vm, &baseline_vm), print_vm_name);
+INSTANTIATE_TEST_SUITE_P(
+    evmone, evm, testing::Values(&advanced_vm, &baseline_vm, &bnocgoto_vm), print_vm_name);
 }  // namespace evmone::test