[midend-BuildCFG]修复逻辑
This commit is contained in:
rain2133
@@ -1,121 +1,79 @@
|
||||
#include "BuildCFG.h"
|
||||
#include "Instruction.h"
|
||||
#include "IR.h"
|
||||
#include "Liveness.h" // 包含活跃性分析的头文件以引用其ID
|
||||
#include "Dom.h" // 包含支配树分析的头文件以引用其ID
|
||||
#include "Dom.h"
|
||||
#include "Liveness.h"
|
||||
#include <iostream>
|
||||
#include <queue>
|
||||
#include <set>
|
||||
|
||||
namespace sysy {
|
||||
|
||||
char BuildCFG::ID = 0;
|
||||
void *BuildCFG::ID = (void *)&BuildCFG::ID; // 定义唯一的 Pass ID
|
||||
|
||||
// 声明Pass的分析使用
|
||||
void BuildCFG::getAnalysisUsage(std::set<void *> &analysisDependencies,
|
||||
std::set<void *> &analysisInvalidations) {
|
||||
// BuildCFG不依赖其他分析
|
||||
// analysisDependencies.insert(&DominatorTreeAnalysisPass::ID); // 错误的例子
|
||||
void BuildCFG::getAnalysisUsage(std::set<void *> &analysisDependencies, std::set<void *> &analysisInvalidations) const {
|
||||
// BuildCFG不依赖其他分析
|
||||
// analysisDependencies.insert(&DominatorTreeAnalysisPass::ID); // 错误的例子
|
||||
|
||||
// BuildCFG会使所有依赖于CFG的分析结果失效，所以它必须声明这些失效
|
||||
analysisInvalidations.insert(&DominatorTreeAnalysisPass::ID);
|
||||
analysisInvalidations.insert(&LivenessAnalysisPass::ID);
|
||||
// BuildCFG会使所有依赖于CFG的分析结果失效，所以它必须声明这些失效
|
||||
analysisInvalidations.insert(&DominatorTreeAnalysisPass::ID);
|
||||
analysisInvalidations.insert(&LivenessAnalysisPass::ID);
|
||||
}
|
||||
|
||||
bool BuildCFG::runOnFunction(Function *F, AnalysisManager& AM) {
|
||||
if (DEBUG) {
|
||||
std::cout << "Running BuildCFG pass on function: " << F->getName() << std::endl;
|
||||
bool BuildCFG::runOnFunction(Function *F, AnalysisManager &AM) {
|
||||
if (DEBUG) {
|
||||
std::cout << "Running BuildCFG pass on function: " << F->getName() << std::endl;
|
||||
}
|
||||
|
||||
bool changed = false;
|
||||
|
||||
// 1. 清空所有基本块的前驱和后继列表
|
||||
for (auto &bb : F->getBasicBlocks()) {
|
||||
bb->clearPredecessors();
|
||||
bb->clearSuccessors();
|
||||
}
|
||||
|
||||
// 2. 遍历每个基本块，重建CFG
|
||||
for (auto &bb : F->getBasicBlocks()) {
|
||||
// 获取基本块的最后一条指令
|
||||
auto &inst = *bb->terminator();
|
||||
Instruction *termInst = inst.get();
|
||||
// 确保基本块有终结指令
|
||||
if (!termInst) {
|
||||
continue;
|
||||
}
|
||||
|
||||
bool changed = false;
|
||||
// 根据终结指令类型，建立前驱后继关系
|
||||
if (termInst->isBranch()) {
|
||||
// 无条件跳转
|
||||
if (termInst->isUnconditional()) {
|
||||
auto brInst = dynamic_cast<UncondBrInst *>(termInst);
|
||||
BasicBlock *succ = dynamic_cast<BasicBlock *>(brInst->getBlock());
|
||||
assert(succ && "Branch instruction's target must be a BasicBlock");
|
||||
bb->addSuccessor(succ);
|
||||
succ->addPredecessor(bb.get());
|
||||
changed = true;
|
||||
|
||||
// 1. 清空所有基本块的前驱和后继列表
|
||||
for (auto &bb : *F) {
|
||||
bb->predecessors.clear();
|
||||
bb->successors.clear();
|
||||
// 条件跳转
|
||||
} else if (termInst->isConditional()) {
|
||||
auto brInst = dynamic_cast<CondBrInst *>(termInst);
|
||||
BasicBlock *trueSucc = dynamic_cast<BasicBlock *>(brInst->getThenBlock());
|
||||
BasicBlock *falseSucc = dynamic_cast<BasicBlock *>(brInst->getElseBlock());
|
||||
|
||||
assert(trueSucc && falseSucc && "Branch instruction's targets must be BasicBlocks");
|
||||
|
||||
bb->addSuccessor(trueSucc);
|
||||
trueSucc->addPredecessor(bb.get());
|
||||
bb->addSuccessor(falseSucc);
|
||||
falseSucc->addPredecessor(bb.get());
|
||||
changed = true;
|
||||
}
|
||||
} else if (auto retInst = dynamic_cast<ReturnInst *>(termInst)) {
|
||||
// RetInst没有后继，无需处理
|
||||
// ...
|
||||
}
|
||||
}
|
||||
|
||||
// 2. 遍历每个基本块，重建CFG
|
||||
for (auto &bb : *F) {
|
||||
// 获取基本块的最后一条指令
|
||||
Instruction *termInst = bb->getTerminator();
|
||||
|
||||
// 确保基本块有终结指令
|
||||
if (!termInst) {
|
||||
continue;
|
||||
}
|
||||
|
||||
// 根据终结指令类型，建立前驱后继关系
|
||||
if (auto brInst = dynamic_cast<BrInst *>(termInst)) {
|
||||
// 无条件跳转
|
||||
if (brInst->getNumOperands() == 1) {
|
||||
BasicBlock *succ = dynamic_cast<BasicBlock *>(brInst->getOperand(0));
|
||||
assert(succ && "Branch instruction's target must be a BasicBlock");
|
||||
|
||||
bb->successors.push_back(succ);
|
||||
succ->predecessors.push_back(bb.get());
|
||||
changed = true;
|
||||
|
||||
// 条件跳转
|
||||
} else if (brInst->getNumOperands() == 3) {
|
||||
BasicBlock *trueSucc = dynamic_cast<BasicBlock *>(brInst->getOperand(1));
|
||||
BasicBlock *falseSucc = dynamic_cast<BasicBlock *>(brInst->getOperand(2));
|
||||
|
||||
assert(trueSucc && falseSucc && "Branch instruction's targets must be BasicBlocks");
|
||||
|
||||
bb->successors.push_back(trueSucc);
|
||||
trueSucc->predecessors.push_back(bb.get());
|
||||
|
||||
bb->successors.push_back(falseSucc);
|
||||
falseSucc->predecessors.push_back(bb.get());
|
||||
changed = true;
|
||||
}
|
||||
} else if (auto retInst = dynamic_cast<RetInst *>(termInst)) {
|
||||
// RetInst没有后继，无需处理
|
||||
// ...
|
||||
}
|
||||
}
|
||||
|
||||
// 3. 额外处理：可达性分析，标记不可达基本块
|
||||
std::queue<BasicBlock*> q;
|
||||
std::set<BasicBlock*> visited;
|
||||
|
||||
// 默认所有块不可达
|
||||
for (auto &bb : *F) {
|
||||
bb->setreachableFalse();
|
||||
}
|
||||
|
||||
// 从函数入口基本块开始
|
||||
BasicBlock* entryBB = F->getEntryBlock();
|
||||
if (entryBB) {
|
||||
q.push(entryBB);
|
||||
visited.insert(entryBB);
|
||||
entryBB->setreachableTrue();
|
||||
}
|
||||
|
||||
// 广度优先搜索 (BFS) 遍历所有可达的基本块
|
||||
while (!q.empty()) {
|
||||
BasicBlock* currentBB = q.front();
|
||||
q.pop();
|
||||
|
||||
for (auto& succ : currentBB->successors) {
|
||||
if (visited.find(succ) == visited.end()) {
|
||||
q.push(succ);
|
||||
visited.insert(succ);
|
||||
succ->setreachableTrue();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// 将未访问到的基本块标记为不可达
|
||||
for (auto& bb : *F) {
|
||||
if (visited.find(bb.get()) == visited.end()) {
|
||||
bb->setreachableFalse();
|
||||
changed = true; // 发现不可达块，视为改变
|
||||
}
|
||||
}
|
||||
|
||||
return changed;
|
||||
return changed;
|
||||
}
|
||||
|
||||
} // namespace sysy
|
||||
Reference in New Issue
Block a user