Add perf benchmark utility. (#2977)

* Add perf benchmark utility.

* Update documentation.

* Fix.

* Fix doc.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

2 files changed, 94 insertions, 0 deletions

diff --git a/source/core/slang-performance-profiler.cpp b/source/core/slang-performance-profiler.cpp
new file mode 100644
index 000000000..f5f74f99d
--- /dev/null
+++ b/source/core/slang-performance-profiler.cpp
@@ -0,0 +1,52 @@
+#include "slang-performance-profiler.h"
+#include "slang-dictionary.h"
+
+namespace Slang
+{
+    struct FuncProfileInfo
+    {
+        int invocationCount = 0;
+        std::chrono::nanoseconds duration = std::chrono::nanoseconds::zero();
+    };
+    class PerformanceProfilerImpl : public PerformanceProfiler
+    {
+    public:
+        OrderedDictionary<const char*, FuncProfileInfo> data;
+
+        virtual FuncProfileContext enterFunction(const char* funcName) override
+        {
+            auto entry = data.tryGetValue(funcName);
+            if (!entry)
+            {
+                data.add(funcName, FuncProfileInfo());
+                entry = data.tryGetValue(funcName);
+            }
+            entry->invocationCount++;
+            FuncProfileContext ctx;
+            ctx.funcName = funcName;
+            ctx.startTime = std::chrono::high_resolution_clock::now();
+            return ctx;
+        }
+        virtual void exitFunction(FuncProfileContext ctx) override
+        {
+            auto endTime = std::chrono::high_resolution_clock::now();
+            auto duration = endTime - ctx.startTime;
+            auto entry = data.tryGetValue(ctx.funcName);
+            entry->duration += duration;
+        }
+        virtual void getResult(StringBuilder& out) override
+        {
+            for (auto func : data)
+            {
+                out << func.key << ": \t";
+                out << func.value.invocationCount << "\t" << func.value.duration.count()/1000000 << "\n";
+            }
+        }
+    };
+
+    PerformanceProfiler* Slang::PerformanceProfiler::getProfiler()
+    {
+        static PerformanceProfilerImpl profiler = PerformanceProfilerImpl();
+        return &profiler;
+    }
+}
diff --git a/source/core/slang-performance-profiler.h b/source/core/slang-performance-profiler.h
new file mode 100644
index 000000000..323940ade
--- /dev/null
+++ b/source/core/slang-performance-profiler.h
@@ -0,0 +1,42 @@
+#ifndef SLANG_CORE_PERFORMANCE_PROFILER_H
+#define SLANG_CORE_PERFORMANCE_PROFILER_H
+
+#include "slang-string.h"
+#include <chrono>
+
+namespace Slang
+{
+
+struct FuncProfileContext
+{
+    const char* funcName = nullptr;
+    std::chrono::time_point<std::chrono::high_resolution_clock> startTime;
+};
+
+class PerformanceProfiler
+{
+public:
+    virtual FuncProfileContext enterFunction(const char* funcName) = 0;
+    virtual void exitFunction(FuncProfileContext context) = 0;
+    virtual void getResult(StringBuilder& out) = 0;
+public:
+    static PerformanceProfiler* getProfiler();
+};
+
+struct PerformanceProfilerFuncRAIIContext
+{
+    FuncProfileContext context;
+    PerformanceProfilerFuncRAIIContext(const char* funcName)
+    {
+        context = PerformanceProfiler::getProfiler()->enterFunction(funcName);
+    }
+    ~PerformanceProfilerFuncRAIIContext()
+    {
+        PerformanceProfiler::getProfiler()->exitFunction(context);
+    }
+};
+
+#define SLANG_PROFILE PerformanceProfilerFuncRAIIContext _profileContext(__func__)
+}
+
+#endif