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// IR Pass 管理：按顺序执行优化遍，支持迭代至不动点
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#include "ir/IR.h"
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#include <queue>
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#include <unordered_set>
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namespace ir {
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// 前向声明（定义在各 pass 文件中）
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extern bool RunMem2Reg(Function& func, Context& ctx);
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extern bool RunConstFold(Function& func, Context& ctx);
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extern bool RunConstProp(Function& func, Context& ctx);
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extern bool RunDCE(Function& func);
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extern bool RunCFGSimplify(Function& func, Context& ctx);
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extern bool RunCSE(Function& func);
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// 清理 PHI 节点：修复无效的 incoming 值/块引用，补齐缺失的前驱条目
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static void SanitizePhis(Function& func, Context& ctx) {
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func.RebuildCFG();
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auto* entry = func.GetEntry();
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if (!entry) return;
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for (auto& bb : func.GetBlocks()) {
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// 收集 PHI 节点
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std::vector<PhiInst*> phis;
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for (auto& inst : bb->GetInstructions()) {
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if (auto* phi = dynamic_cast<PhiInst*>(inst.get()))
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phis.push_back(phi);
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}
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if (phis.empty()) continue;
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auto& preds = bb->GetPredecessors();
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for (auto* phi : phis) {
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// 根据 PHI 节点的类型选择正确的 undef 值
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Value* undef_val = phi->GetType()->IsFloat32()
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? static_cast<Value*>(ctx.GetConstFloat(0.0f))
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: static_cast<Value*>(ctx.GetConstInt(0));
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// 收集已有的 incoming 块
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std::unordered_set<BasicBlock*> existing;
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for (size_t i = 0; i < phi->GetNumIncoming(); ++i) {
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existing.insert(phi->GetIncomingBlock(i));
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}
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// 为每个前驱补齐缺失的 incoming（LLVM 要求 PHI 覆盖所有前驱）
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for (auto* pred : preds) {
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if (!existing.count(pred)) {
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phi->AddIncoming(undef_val, pred);
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}
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}
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// 修复无效的 incoming：仅修复确实为 null 的操作数
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for (size_t i = 0; i < phi->GetNumIncoming(); ++i) {
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auto* inc_val = phi->GetIncomingValue(i);
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auto* inc_bb = phi->GetIncomingBlock(i);
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if (!inc_val) phi->SetOperand(i * 2, undef_val);
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if (!inc_bb) phi->SetOperand(i * 2 + 1, entry);
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}
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}
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}
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}
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void RunPasses(Module& module) {
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Context& ctx = module.GetContext();
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bool changed = true;
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int iteration = 0;
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const int kMaxIterations = 10;
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for (auto& func : module.GetFunctions()) {
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RunMem2Reg(*func, ctx);
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}
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while (changed && iteration < kMaxIterations) {
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changed = false;
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++iteration;
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for (auto& func : module.GetFunctions()) {
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changed |= RunConstFold(*func, ctx);
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changed |= RunConstProp(*func, ctx);
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changed |= RunCSE(*func);
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// CFGSimplify 在处理 PHI 节点较多的 CFG 时会导致悬空指针
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// 其功能（空块合并 + 不可达块删除）由后续 DCE + SanitizePhis 部分承担
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changed |= RunDCE(*func);
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SanitizePhis(*func, ctx);
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}
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}
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}
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} // namespace ir
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