From 5950ec306bcb52acf78759025eb364f751382bd1 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Thu, 10 Nov 2022 16:43:58 +0100
Subject: [PATCH] Code to output performance metrics for optimizer steps.

---
 CMakeLists.txt             |  6 ++++
 libyul/optimiser/Suite.cpp | 58 +++++++++++++++++++++++++++++++++++++-
 libyul/optimiser/Suite.h   |  3 ++
 3 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 81c5f96c2..c82ad7e48 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,7 @@ option(SOLC_LINK_STATIC "Link solc executable statically on supported platforms"
 option(SOLC_STATIC_STDLIBS "Link solc against static versions of libgcc and libstdc++ on supported platforms" OFF)
 option(STRICT_Z3_VERSION "Use the latest version of Z3" ON)
 option(PEDANTIC "Enable extra warnings and pedantic build flags. Treat all warnings as errors." ON)
+option(PROFILE_OPTIMIZER_STEPS "Output performance metrics for the optimiser steps." OFF)
 
 # Setup cccache.
 include(EthCcache)
@@ -52,6 +53,11 @@ find_package(Threads)
 if(NOT PEDANTIC)
   message(WARNING "-- Pedantic build flags turned off. Warnings will not make compilation fail. This is NOT recommended in development builds.")
 endif()
+
+if (PROFILE_OPTIMIZER_STEPS)
+    add_definitions(-DPROFILE_OPTIMIZER_STEPS)
+endif()
+
 # Figure out what compiler and system are we using
 include(EthCompilerSettings)
 
diff --git a/libyul/optimiser/Suite.cpp b/libyul/optimiser/Suite.cpp
index c71a44001..0641328f1 100644
--- a/libyul/optimiser/Suite.cpp
+++ b/libyul/optimiser/Suite.cpp
@@ -83,9 +83,55 @@
 #include <limits>
 #include <tuple>
 
+#ifdef PROFILE_OPTIMIZER_STEPS
+#include <chrono>
+#include <fmt/format.h>
+#endif
+
 using namespace std;
 using namespace solidity;
 using namespace solidity::yul;
+#ifdef PROFILE_OPTIMIZER_STEPS
+using namespace std::chrono;
+#endif
+
+namespace
+{
+
+#ifdef PROFILE_OPTIMIZER_STEPS
+void outputPerformanceMetrics(map<string, int64_t> const& _metrics)
+{
+	vector<pair<string, int64_t>> durations(_metrics.begin(), _metrics.end());
+	sort(
+		durations.begin(),
+		durations.end(),
+		[](pair<string, int64_t> const& _lhs, pair<string, int64_t> const& _rhs) -> bool
+		{
+			return _lhs.second < _rhs.second;
+		}
+	);
+
+	int64_t totalDurationInMicroseconds = 0;
+	for (auto&& [step, durationInMicroseconds]: durations)
+		totalDurationInMicroseconds += durationInMicroseconds;
+
+	cerr << "Performance metrics of optimizer steps" << endl;
+	cerr << "======================================" << endl;
+	constexpr double microsecondsInSecond = 1000000;
+	for (auto&& [step, durationInMicroseconds]: durations)
+	{
+		double percentage = 100.0 * static_cast<double>(durationInMicroseconds) / static_cast<double>(totalDurationInMicroseconds);
+		double sec = static_cast<double>(durationInMicroseconds) / microsecondsInSecond;
+		cerr << fmt::format("{:>7.3f}% ({} s): {}", percentage, sec, step) << endl;
+	}
+	double totalDurationInSeconds = static_cast<double>(totalDurationInMicroseconds) / microsecondsInSecond;
+	cerr << "--------------------------------------" << endl;
+	cerr << fmt::format("{:>7}% ({:.3f} s)", 100, totalDurationInSeconds) << endl;
+}
+#endif
+
+}
+
 
 void OptimiserSuite::run(
 	Dialect const& _dialect,
@@ -178,13 +224,16 @@ void OptimiserSuite::run(
 	NameSimplifier::run(suite.m_context, ast);
 	VarNameCleaner::run(suite.m_context, ast);
 
+#ifdef PROFILE_OPTIMIZER_STEPS
+	outputPerformanceMetrics(suite.m_durationPerStepInMicroseconds);
+#endif
+
 	*_object.analysisInfo = AsmAnalyzer::analyzeStrictAssertCorrect(_dialect, _object);
 }
 
 namespace
 {
 
-
 template <class... Step>
 map<string, unique_ptr<OptimiserStep>> optimiserStepCollection()
 {
@@ -445,7 +494,14 @@ void OptimiserSuite::runSequence(std::vector<string> const& _steps, Block& _ast)
 	{
 		if (m_debug == Debug::PrintStep)
 			cout << "Running " << step << endl;
+#ifdef PROFILE_OPTIMIZER_STEPS
+		steady_clock::time_point startTime = steady_clock::now();
+#endif
 		allSteps().at(step)->run(m_context, _ast);
+#ifdef PROFILE_OPTIMIZER_STEPS
+		steady_clock::time_point endTime = steady_clock::now();
+		m_durationPerStepInMicroseconds[step] += duration_cast<microseconds>(endTime - startTime).count();
+#endif
 		if (m_debug == Debug::PrintChanges)
 		{
 			// TODO should add switch to also compare variable names!
diff --git a/libyul/optimiser/Suite.h b/libyul/optimiser/Suite.h
index 2db6288c0..abed2720e 100644
--- a/libyul/optimiser/Suite.h
+++ b/libyul/optimiser/Suite.h
@@ -87,6 +87,9 @@ public:
 private:
 	OptimiserStepContext& m_context;
 	Debug m_debug;
+#ifdef PROFILE_OPTIMIZER_STEPS
+	std::map<std::string, int64_t> m_durationPerStepInMicroseconds;
+#endif
 };
 
 }