[backend-LAG]添加新的LargeArrayToGlobal中端Pass，以及栈保护逻辑

src/midend/Pass/Optimize/LargeArrayToGlobal.cpp

@@ -0,0 +1,143 @@
+#include "../../include/midend/Pass/Optimize/LargeArrayToGlobal.h"
+#include "../../IR.h"
+#include <unordered_map>
+#include <sstream>
+#include <string>
+
+namespace sysy {
+
+// Helper function to convert type to string
+static std::string typeToString(Type *type) {
+    if (!type) return "null";
+    
+    switch (type->getKind()) {
+        case Type::kInt:
+            return "int";
+        case Type::kFloat:
+            return "float";
+        case Type::kPointer:
+            return "ptr";
+        case Type::kArray: {
+            auto *arrayType = type->as<ArrayType>();
+            return "[" + std::to_string(arrayType->getNumElements()) + " x " + 
+                   typeToString(arrayType->getElementType()) + "]";
+        }
+        default:
+            return "unknown";
+    }
+}
+
+void *LargeArrayToGlobalPass::ID = &LargeArrayToGlobalPass::ID;
+
+bool LargeArrayToGlobalPass::runOnModule(Module *M, AnalysisManager &AM) {
+        bool changed = false;
+        
+        if (!M) {
+            return false;
+        }
+
+        // Collect all alloca instructions from all functions
+        std::vector<std::pair<AllocaInst*, Function*>> allocasToConvert;
+        
+        for (auto &funcPair : M->getFunctions()) {
+            Function *F = funcPair.second.get();
+            if (!F || F->getBasicBlocks().begin() == F->getBasicBlocks().end()) {
+                continue;
+            }
+            
+            for (auto &BB : F->getBasicBlocks()) {
+                for (auto &inst : BB->getInstructions()) {
+                    if (auto *alloca = dynamic_cast<AllocaInst*>(inst.get())) {
+                        Type *allocatedType = alloca->getAllocatedType();
+                        
+                        // Calculate the size of the allocated type
+                        unsigned size = calculateTypeSize(allocatedType);
+                        
+                        // Debug: print size information
+                        std::cout << "LargeArrayToGlobalPass: Found alloca with size " << size 
+                                  << " for type " << typeToString(allocatedType) << std::endl;
+                        
+                        // Convert arrays of 1KB (1024 bytes) or larger to global variables
+                        if (size >= 1024) {
+                            std::cout << "LargeArrayToGlobalPass: Converting array of size " << size << " to global" << std::endl;
+                            allocasToConvert.emplace_back(alloca, F);
+                        }
+                    }
+                }
+            }
+        }
+
+        // Convert the collected alloca instructions to global variables
+        for (auto [alloca, F] : allocasToConvert) {
+            convertAllocaToGlobal(alloca, F, M);
+            changed = true;
+        }
+
+return changed;
+    }
+
+unsigned LargeArrayToGlobalPass::calculateTypeSize(Type *type) {
+    if (!type) return 0;
+
+    switch (type->getKind()) {
+        case Type::kInt:
+        case Type::kFloat:
+            return 4;
+        case Type::kPointer:
+            return 8;
+        case Type::kArray: {
+            auto *arrayType = type->as<ArrayType>();
+            return arrayType->getNumElements() * calculateTypeSize(arrayType->getElementType());
+        }
+        default:
+            return 0;
+    }
+}
+
+void LargeArrayToGlobalPass::convertAllocaToGlobal(AllocaInst *alloca, Function *F, Module *M) {
+    Type *allocatedType = alloca->getAllocatedType();
+    
+    // Create a unique name for the global variable
+    std::string globalName = generateUniqueGlobalName(alloca, F);
+    
+    // Create the global variable - GlobalValue expects pointer type
+    Type *pointerType = Type::getPointerType(allocatedType);
+    GlobalValue *globalVar = M->createGlobalValue(globalName, pointerType);
+    
+    if (!globalVar) {
+        return;
+    }
+    
+    // Replace all uses of the alloca with the global variable
+    alloca->replaceAllUsesWith(globalVar);
+    
+    // Remove the alloca instruction from its basic block
+    for (auto &BB : F->getBasicBlocks()) {
+        auto &instructions = BB->getInstructions();
+        for (auto it = instructions.begin(); it != instructions.end(); ++it) {
+            if (it->get() == alloca) {
+                instructions.erase(it);
+                break;
+            }
+        }
+    }
+}
+
+std::string LargeArrayToGlobalPass::generateUniqueGlobalName(AllocaInst *alloca, Function *F) {
+    std::string baseName = alloca->getName();
+    if (baseName.empty()) {
+        baseName = "array";
+    }
+    
+    // Ensure uniqueness by appending function name and counter
+    static std::unordered_map<std::string, int> nameCounter;
+    std::string key = F->getName() + "." + baseName;
+    
+    int counter = nameCounter[key]++;
+    std::ostringstream oss;
+    oss << key << "." << counter;
+    
+    return oss.str();
+}
+
+} // namespace sysy