Testing some LLVM optimization passes

evmjit/CMakeLists.txt

@@ -22,7 +22,7 @@ if(LLVM_DIR OR APPLE)	# local LLVM build
 	message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")
 	add_definitions(${LLVM_DEFINITIONS})
 	# TODO: bitwriter is needed only for evmcc
-	llvm_map_components_to_libnames(LLVM_LIBS core support mcjit x86asmparser x86codegen bitwriter)
+	llvm_map_components_to_libnames(LLVM_LIBS core support mcjit x86asmparser x86codegen bitwriter ipo)
 else()
 	# Workaround for Ubuntu broken LLVM package
 	message(STATUS "Using llvm-3.5-dev package from Ubuntu. If does not work, build LLVM and set -DLLVM_DIR=llvm-build/share/llvm/cmake")

evmjit/libevmjit/Optimizer.cpp

@@ -3,6 +3,7 @@
 #include "preprocessor/llvm_includes_start.h"
 #include <llvm/PassManager.h>
 #include <llvm/Transforms/Scalar.h>
+#include <llvm/Transforms/IPO.h>
 #include "preprocessor/llvm_includes_end.h"
 
 namespace dev
@@ -15,6 +16,10 @@ namespace jit
 bool optimize(llvm::Module& _module)
 {
 	auto pm = llvm::PassManager{};
+	//pm.add(llvm::createFunctionInliningPass(2, 2)); // Produces invalid IR
+	pm.add(llvm::createCFGSimplificationPass());
+	//pm.add(llvm::createInstructionCombiningPass()); // Produces invalid runtime results
+	pm.add(llvm::createAggressiveDCEPass());
 	pm.add(llvm::createLowerSwitchPass());
 	return pm.run(_module);
 }