GlobalDepsAnalyzer Optimizations

llvm/include/llvm/Cheerp/GlobalDepsAnalyzer.h

@@ -73,22 +73,22 @@ class GlobalDepsAnalyzer
 	/**
 	 * Get a list of the classes which require bases info
 	 */
-	const std::unordered_set<llvm::StructType*> & classesWithBaseInfo() const { return classesWithBaseInfoNeeded; }
+	const llvm::DenseSet<llvm::StructType*> & classesWithBaseInfo() const { return classesWithBaseInfoNeeded; }
 
 	/**
 	 * Get a list of the classes which are allocated in the code
 	 */
-	const std::unordered_set<llvm::StructType*> & classesUsed() const { return classesNeeded; }
+	const llvm::DenseSet<llvm::StructType*> & classesUsed() const { return classesNeeded; }
 
 	/**
 	 * Get a list of the arrays which are dynamically allocated with unknown size
 	 */
-	const std::unordered_set<llvm::Type*> & dynAllocArrays() const { return arraysNeeded; }
+	const llvm::DenseSet<llvm::Type*> & dynAllocArrays() const { return arraysNeeded; }
 
 	/**
 	 * Get a list of the arrays which are dynamically resized
 	 */
-	const std::unordered_set<llvm::Type*> & dynResizeArrays() const { return arrayResizesNeeded; }
+	const llvm::DenseSet<llvm::Type*> & dynResizeArrays() const { return arrayResizesNeeded; }
 
 	/**
 	 * Get a list of the asm.js functions called from genericjs
@@ -244,13 +244,13 @@ class GlobalDepsAnalyzer
 	//Determine whether an instruction is atomic.
 	bool isAtomicInstruction(const llvm::Instruction& I);
 
-	std::unordered_set< const llvm::GlobalValue * > reachableGlobals; // Set of all the reachable globals
+	llvm::DenseSet< const llvm::GlobalValue * > reachableGlobals; // Set of all the reachable globals
 
 	FixupMap varsFixups;
-	std::unordered_set<llvm::StructType* > classesWithBaseInfoNeeded;
-	std::unordered_set<llvm::StructType* > classesNeeded;
-	std::unordered_set<llvm::Type* > arraysNeeded;
-	std::unordered_set<llvm::Type* > arrayResizesNeeded;
+	llvm::DenseSet<llvm::StructType* > classesWithBaseInfoNeeded;
+	llvm::DenseSet<llvm::StructType* > classesNeeded;
+	llvm::DenseSet<llvm::Type* > arraysNeeded;
+	llvm::DenseSet<llvm::Type* > arrayResizesNeeded;
 	DeterministicFunctionSet asmJSExportedFunctions;
 	DeterministicAliasSet asmJSExportedAliases;
 	DeterministicFunctionSet asmJSImportedFunctions;
@@ -259,7 +259,7 @@ class GlobalDepsAnalyzer
 	std::vector< llvm::GlobalValue * > externals;
 	std::vector< const llvm::Function* > functionsQueue;
 
-	std::unordered_map<llvm::StructType*, uint32_t> basesInfo;
+	llvm::DenseMap<llvm::StructType*, uint32_t> basesInfo;
 
 	std::array<bool, BuiltinInstr::numGenericBuiltins()> hasBuiltin;
 

llvm/lib/CheerpUtils/GlobalDepsAnalyzer.cpp

@@ -188,12 +188,15 @@ bool GlobalDepsAnalyzer::runOnModule( llvm::Module & module )
 
 	simplifyCalls(module);
 
-	if (!llcPass)
-	{
-		for (Function& F : module.getFunctionList())
+	bool anyWasmFuncAddrTaken = false;
+	// Replace calls like 'printf("Hello!")' with 'puts("Hello!")'.
+	for (Function& F : module.getFunctionList()) {
+		bool asmjs = F.getSection() == StringRef("asmjs");
+		if (asmjs) {
+			anyWasmFuncAddrTaken |= F.hasAddressTaken();
+		}
+		if (!llcPass)
 		{
-			//Those intrinsics may come back as result of other optimizations
-			//And we may need the actual functions to lower the intrinsics
 			const auto builtinID = BuiltinInstr::getMathBuiltin(F);
 			const auto typedBuiltinID = TypedBuiltinInstr::getMathTypedBuiltin(F);
 
@@ -204,20 +207,10 @@ bool GlobalDepsAnalyzer::runOnModule( llvm::Module & module )
 				|| F.getName() == "memset"
 				|| F.getName() == "memmove")
 			{
-				if (TypedBuiltinInstr::isAlwaysExactNatively(typedBuiltinID))
-					continue;
-				extendLifetime(&F);
+				if (!TypedBuiltinInstr::isAlwaysExactNatively(typedBuiltinID))
+					extendLifetime(&F);
 			}
 		}
-	}
-
-	bool anyWasmFuncAddrTaken = false;
-	// Replace calls like 'printf("Hello!")' with 'puts("Hello!")'.
-	for (Function& F : module.getFunctionList()) {
-		bool asmjs = F.getSection() == StringRef("asmjs");
-		if (asmjs) {
-			anyWasmFuncAddrTaken |= F.hasAddressTaken();
-		}
 		for (BasicBlock& bb : F)
 		{
 			bool advance = false;	//Do not advance at the start
@@ -835,7 +828,7 @@ bool GlobalDepsAnalyzer::runOnModule( llvm::Module & module )
 			uint32_t firstBase = cast<ConstantInt>(cast<ConstantAsMetadata>(basesMeta->getOperand(0))->getValue())->getZExtValue();
 			StructType * t = StructType::getTypeByName(module.getContext(), name.drop_back(6));
 			if (t)
-				basesInfo.emplace(t, firstBase);
+				basesInfo.try_emplace(t, firstBase);
 		}
 	}
 
@@ -886,8 +879,6 @@ bool GlobalDepsAnalyzer::runOnModule( llvm::Module & module )
 			llvm::errs() << "warning: _startPreThread function point not found, and -pthread is linked\n";
 	}
 
-	processEnqueuedFunctions();
-
 	// Flush out all functions
 	processEnqueuedFunctions();
 
@@ -1064,7 +1055,6 @@ bool GlobalDepsAnalyzer::runOnModule( llvm::Module & module )
 
 	//Check agains the previous set what CallInstruction are actually impossible (and remove them)
 	std::vector<llvm::CallBase*> unreachList;
-	std::vector<std::pair<llvm::CallBase*, llvm::Function*> > devirtualizedCalls;
 
 	//Fixing function casts implies that new functions types will be created
 	//Exporting the table implies that functions can be added outside of our control
@@ -1106,7 +1096,6 @@ bool GlobalDepsAnalyzer::runOnModule( llvm::Module & module )
 						// Always an asmjs functions, thus it is ok to perform ptr to int conversions
 						replaceCallOfBitCastWithBitCastOfCall(*ci, false, true);
 
-						devirtualizedCalls.push_back({ci, toBeCalledFunc});
 					}
 					else
 					{
@@ -1235,7 +1224,7 @@ bool GlobalDepsAnalyzer::runOnModule( llvm::Module & module )
 		}
 	}
 
-	std::unordered_set<llvm::Function*> modifiedFunctions;
+	llvm::DenseSet<llvm::Function*> modifiedFunctions;
 
 	//Processing has to be done in reverse, so that multiple unreachable callInst in the same BasicBlock are processed from the last to the first
 	//This avoid erasing the latter ones while processing the first