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asm.cpp
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/*
根据四元式和符号表信息生成汇编代码
*/
#include "global.h"
#include "asm.h"
#include <map>
#include <cstdio>
#include <stack>
#pragma warning(disable:4996)
enum Reg
{
EAX = 0, EBX, ECX, EDX
};
void getIR(char *Q_ins, std::string &op, std::string &res, std::string &op1, std::string &op2)
{
int i = 0;
if (Q_ins[0] == '\n')
return;
for (; Q_ins[i] != ',' && Q_ins[i] != '\n'; i++)
{
op.append(sizeof(char), Q_ins[i]);
}
if (Q_ins[i] == '\n')
return;
for (i++; Q_ins[i] != ',' && Q_ins[i] != '\n'; i++)
{
res.append(sizeof(char), Q_ins[i]);
}
if (Q_ins[i] == '\n')
return;
for (i++; Q_ins[i] != ',' && Q_ins[i] != '\n'; i++)
{
op1.append(sizeof(char), Q_ins[i]);
}
if (Q_ins[i] == '\n')
return;
for (i++; Q_ins[i] != '\n'; i++)
{
op2.append(sizeof(char), Q_ins[i]);
}
return;
}
/*
将语法树中语法类型为fundef和prodef的节点存起来，以便后续使用相关的符号表
*/
void storeNode(AST_node t, std::vector<AST_node> &prosAndFuns)
{
if (t == NULL)
{
return;
}
if (t->ast_type == FUNDEF || t->ast_type == PRODEF)
{
prosAndFuns.push_back(t);
return;
}
for (std::vector<AST_node>::iterator i = t->children->begin();
i != t->children->end(); i++)
{
storeNode(*i, prosAndFuns);
}
return;
}
/*
引用时的地址计算函数
cnt:表示需要回溯静态链的次数
*/
void calcOffset(tableItem *item, std::string &pos, int cnt)
{
if (cnt == 0)
{
//访问的是局部变量
char _s[5], *s;
s = itoa(item->offset, _s, 10);
pos = *(new std::string(s));
emitASM(new std::string("mov"), new std::string("eax"), new std::string("ebp"));
emitASM(new std::string("sub"), new std::string("eax"), &pos);
pos = "eax";
return;
}
else
{
//访问的是非局部变量，需要通过静态链回溯
std::string reg = "eax";
emitASM(new std::string("mov"), ®, new std::string("[ebp+8]"));
cnt--;
while (cnt > 0)
{
emitASM(new std::string("mov"), ®, new std::string("[" + reg + "+8]"));
cnt--;
}
char _s[5], *s;
s = itoa(item->offset, _s, 10);
pos = *(new std::string(s));
emitASM(new std::string("sub"), ®, &pos);
pos = reg;
}
}
/*
实现了静态链时的地址计算函数
cnt:表示需要回溯静态链的次数
*/
void calcOffset(tableItem *item, std::string &pos, int cnt, int ®use)
{
if (cnt == 0)
{
//访问的是局部变量
char _s[5], *s;
s = itoa(item->offset, _s, 10);
pos = *(new std::string(s));
pos = "[ebp-" + pos + "]";
return;
}
else
{
//访问的是非局部变量，需要通过静态链回溯
std::string reg;
switch (reguse)
{
case EAX:reg = "eax"; reguse++; break;
case EBX:reg = "ebx"; reguse++; break;
case ECX:reg = "ecx"; reguse++; break;
case EDX:reg = "edx"; reguse = EAX; break;
default:
break;
}
emitASM(new std::string("mov"), ®, new std::string("[ebp+8]"));
cnt--;
while (cnt > 0)
{
emitASM(new std::string("mov"), ®, new std::string("[" + reg + "+8]"));
cnt--;
}
char _s[5], *s;
s = itoa(item->offset, _s, 10);
pos = *(new std::string(s));
pos = "["+ reg + "-" + pos + "]";
return;
}
}
/*
生成字符串的标号
*/
std::string *genStringLable()
{
static int StringLab = 0;
char _s[5], *s;
s = itoa(StringLab, _s, 10);
std::string *ret = new std::string(s);
*ret = "_string" + *ret;
StringLab++;
return ret;
}
/*
在寄存器中查找target，若target在寄存器中，则将target置为寄存器名字
*/
bool findInRegs(std::string &target, std::string regs[])
{
int i = 0;
for (i = 0; i < 4; i++)
{
if (regs[i] == target)
{
switch (i)
{
case EAX:target = "eax"; return true;
case EBX:target = "ebx"; return true;
case ECX:target = "ecx"; return true;
case EDX:target = "edx"; return true;
default:
break;
}
}
}
return false;
}
/*
在常量池中查找target，若target在寄存器中，则将target置为寄存器名字
*/
bool findInConst(std::string &target, std::map<std::string,int> &constPool)
{
if(constPool.find(target) == constPool.end())
return false;
else
{
char s[5];
target = *new std::string(itoa(constPool.find(target)->second,s,10));
return true;
}
}
/*
将target中的内容移至寄存器中
target:变量的地址
*/
void moveToRegs(std::string &target, std::string regs[], int ®use)
{
if (reguse == EAX)
{
emitASM(new std::string("mov"), new std::string("eax"), new std::string(target));
regs[reguse] = target;
target = "eax";
}
else if (reguse == EBX)
{
emitASM(new std::string("mov"), new std::string("ebx"), new std::string(target));
regs[reguse] = target;
target = "ebx";
}
else if (reguse == ECX)
{
emitASM(new std::string("mov"), new std::string("ecx"), new std::string(target));
regs[reguse] = target;
target = "ecx";
}
else if (reguse == EDX)
{
emitASM(new std::string("mov"), new std::string("edx"), new std::string(target));
regs[reguse] = target;
target = "edx";
}
reguse = (reguse + 1) % 4;
return;
}
FILE *offsetTable = fopen("offsetTable.txt", "w");
FILE *data = fopen("data.txt", "w");
int insNo = 0;
/*
根据语法树中的符号表信息和四元式生成相应的汇编代码
*/
int asmMaker(AST_node cur, AST_node parent, int level)
{
std::vector<AST_node> prosAndFuns; //用于存放函数和过程的节点以便使用符号表
Table *table = cur->symTable;
std::vector<AST_node>::iterator i = cur->children->begin();
for (; i != cur->children->end() && (*i)->ast_type != PROGRAM; i++)
{
//跳过不是program的节点
}
if(i != cur->children->end())
storeNode(*i, prosAndFuns);
char Q_ins[100];
int offset = 8;
std::string *ins = NULL;
std::string op, res, op1, op2;
std::map<std::string, int> constPool; //用于存放常量
std::map<std::string, std::vector<int>> varPosRecord; //用于记录变量当前所在的位置
std::string regs[4]; //用于记录当前寄存器中保存的临时变量名
int reguse = 0; //用于记录当前可用的寄存器
std::stack<int> regStack; //用于在保存寄存器时同时保存reguse
bool saved = false; //用于记录函数过程调用时寄存器是否被保存
while (fgets(Q_ins, 1000, stdin) != NULL)
{
getIR(Q_ins, op, res, op1, op2);
insNo++;
// printf("-------------%s %s %s %s\n", op.c_str(), res.c_str(), op1.c_str(), op2.c_str());
if (op == "int" || op == "char")
{
//int或者char类型的声明
if (op1 != "")
{
//常量声明
if (op == "int")
{
//整型声明
constPool.insert(std::pair<std::string, int>(res, atoi(op1.c_str())));
}
else
{
constPool.insert(std::pair<std::string, int>(res, op1.c_str()[0]));
}
}
else
{
//变量声明
tableItem* item = tableFind(*table, res, parent);
std::vector<int> *pos = new std::vector<int>();
pos->push_back(offset);
item->offset = offset;
offset += 4;
//std::cout << res << ":" << item->offset;
fprintf(offsetTable, "%s:%d\n", res.c_str(), item->offset);
varPosRecord.insert(std::pair<std::string, std::vector<int>>(res, *pos));
}
}
else if (op == "arraydef")
{
//数组声明
std::vector<int> *pos = new std::vector<int>();
pos->push_back(offset);
tableFind(*table, res, parent)->offset = offset;
fprintf(offsetTable, "%s:%d\n", res.c_str(), offset);
offset += (4 * atoi(op2.c_str()));
varPosRecord.insert(std::pair<std::string, std::vector<int>>(res, *pos));
}
else if (op == "procedure" || op == "function")
{
tableItem *item = tableFind(*table, res, parent);
if(op == "function")
{
item->offset = offset;
offset += 4;
}
fprintf(offsetTable, "\n%s:%d\n", res.c_str(),item->offset);
for (int i = 0; i < prosAndFuns.size(); i++)
{
if (*(prosAndFuns[i]->children->at(0)->children->at(1)->val.ident) == res)
{
asmMaker(prosAndFuns[i], cur, level+1);
break;
}
}
}
else if (op == "+" || op == "-" || op == "*" || op == "/")
{
//算术运算
//res = op1 op op2;
//若op1不在寄存器中,则将其移至寄存器中
tableItem* item = tableFind(*table, op1, parent);
if ('0' <= op1.c_str()[0] && op1.c_str()[0] <= '9' || item != NULL)
{
//不是临时变量
std::string *pos = NULL;
if ('0' <= op1.c_str()[0] && op1.c_str()[0] <= '9')
{
//op1是立即数
}
else if (!findInConst(op1, constPool))
{
//op1是变量
pos = new std::string();
calcOffset(item, *pos, level - item->level, reguse);
if (reguse == EAX)
{
emitASM(new std::string("mov"), new std::string("eax"), new std::string(*pos));
regs[reguse] = op1;
op1 = "eax";
}else if (reguse == EBX)
{
emitASM(new std::string("mov"), new std::string("ebx"), new std::string(*pos));
regs[reguse] = op1;
op1 = "ebx";
}
else if (reguse == ECX)
{
emitASM(new std::string("mov"), new std::string("ecx"), new std::string(*pos));
regs[reguse] = op1;
op1 = "ecx";
}
else if (reguse == EDX)
{
emitASM(new std::string("mov"), new std::string("edx"), new std::string(*pos));
regs[reguse] = op1;
op1 = "edx";
}
else
{
printf("Can not find the temp value %s\n", op1.c_str());
}
reguse = (reguse + 1) % 4;
if(item->type == REFERENCE)
{
//op1是引用
emitASM(new std::string("mov"), &op1, new std::string("[" + op1 + "]"));
}
}
}
else
{
//op1是临时变量
int j = 0;
for (; j < 4; j++)
{
if (regs[j] == op1)
break;
}
switch (j)
{
case EAX:op1 = "eax"; break;
case EBX:op1 = "ebx"; break;
case ECX:op1 = "ecx"; break;
case EDX:op1 = "edx"; break;
default:
break;
}
}
item = tableFind(*table, op2, parent);
if (item == NULL)
{
//op2是临时变量或立即数
if (op2.c_str()[0] >= '0' && op2.c_str()[0] <= '9')
{
//op2是个立即数
}
int j = 0;
for (; j < 4; j++)
{
if (regs[j] == op2)
break;
}
switch (j)
{
case EAX:op2 = "eax"; break;
case EBX:op2 = "ebx"; break;
case ECX:op2 = "ecx"; break;
case EDX:op2 = "edx"; break;
default:
break;
}
}
else if(!findInConst(op2,constPool))
{
//op2是变量
std::string name = op2;
calcOffset(item, op2, level - item->level, reguse);
if(item->type == REFERENCE)
{
//op2是引用
regs[reguse] = name;
moveToRegs(op2, regs, reguse);
emitASM(new std::string("mov"), &op2, new std::string("[" + op2 + "]"));
}else
{
op2 = "DWORD PTR " + op2;
}
}
if(op == "+")
{
if (op1.c_str()[0] >= '0' && op1.c_str()[0] <= '9')
{
//op1是个立即数
if(op2.c_str()[0] >= '0' && op2.c_str()[0] <= '9')
{
//op2也是个立即数
moveToRegs(op1, regs, reguse);
emitASM(new std::string("add"), new std::string(op1), new std::string(op2));
}else
{
emitASM(new std::string("add"), new std::string(op2), new std::string(op1));
}
}
else
{
emitASM(new std::string("add"), new std::string(op1), new std::string(op2));
}
}
else if (op == "-")
{
if (op1.c_str()[0] >= '0' && op1.c_str()[0] <= '9')
{
emitASM(new std::string("sub"), new std::string(op2), new std::string(op1));
}
else
{
emitASM(new std::string("sub"), new std::string(op1), new std::string(op2));
}
}
else if (op == "*" || op == "/")
{
//imull S
//mull S
//有符号 / 无符号乘法：R[%edx]:R[%eax] <-S * R[%eax]
//idivl S
//divl S
//有符号 / 无符号除法：R[%eax] <-R[%edx]:R[%eax] / S;
emitASM(new std::string("push"), new std::string("eax"), NULL);
emitASM(new std::string("push"), new std::string("ebx"), NULL);
emitASM(new std::string("push"), new std::string("ecx"), NULL);
emitASM(new std::string("push"), new std::string("edx"), NULL);
if (op2.c_str()[0] >= '0' && op2.c_str()[0] <= '9' || op2 != "ebx" && op2 != "ecx")
{
//将op2移至ecx
if (op1 == "ecx")
{
emitASM(new std::string("mov"), new std::string("eax"), &op1);
}
emitASM(new std::string("mov"), new std::string("ecx"), &op2);
op2 = "ecx";
}
if (op1 != "eax")
{
emitASM(new std::string("mov"), new std::string("eax"), new std::string(op1));
}
if (op == "*")
{
emitASM(new std::string("imul"), new std::string(op2), NULL);
}
else
{
emitASM(new std::string("mov"), new std::string("edx"), new std::string("0"));
emitASM(new std::string("idiv"), new std::string(op2), NULL);
}
}
if (op == "+" || op == "-")
{
item = tableFind(*table, res, parent);
if (item == NULL)
{
//res是临时变量
if (op1.c_str()[0] > '9' || op1.c_str()[0] < '0')
{
if (op1 == "eax")
{
regs[EAX] = res;
//避免结果被下一次计算结果覆盖
if(reguse == EAX)
{
reguse++;
}
}else if (op1 == "ebx")
{
regs[EBX] = res;
if (reguse == EBX)
{
reguse++;
}
}
else if (op1 == "ecx")
{
regs[ECX] = res;
if (reguse == ECX)
{
reguse++;
}
}
else if (op1 == "edx")
{
regs[EDX] = res;
if (reguse == EDX)
{
reguse = EAX;
}
}
}
else
{
if (op2 == "eax")
{
regs[EAX] = res;
if (reguse == EAX)
{
reguse++;
}
}
else if (op2 == "ebx")
{
regs[EBX] = res;
if (reguse == EBX)
{
reguse++;
}
}
else if (op2 == "ecx")
{
regs[ECX] = res;
if (reguse == ECX)
{
reguse++;
}
}
else if (op2 == "edx")
{
regs[EDX] = res;
if (reguse == EDX)
{
reguse = EAX;
}
}
}
}
else
{
//res不是临时变量
calcOffset(item, res, level - item->level, reguse);
emitASM(new std::string("mov"), new std::string(res), new std::string(op1));
}
}
else if(op == "*" || "/")
{
item = tableFind(*table, res, parent);
if (item == NULL)
{
//res是临时变量
switch (reguse)
{
case EAX:
//将eax的旧值留在栈中
regs[EAX] = res;
if (reguse == EAX)
{
reguse++;
}
emitASM(new std::string("pop"), new std::string("edx"), NULL);
emitASM(new std::string("pop"), new std::string("ecx"), NULL);
emitASM(new std::string("pop"), new std::string("ebx"), NULL);
break;
case EBX:
emitASM(new std::string("mov"), new std::string("ebx"), new std::string("eax"));
regs[EBX] = res;
if (reguse == EBX)
{
reguse++;
}
emitASM(new std::string("pop"), new std::string("edx"), NULL);
emitASM(new std::string("pop"), new std::string("ecx"), NULL);
emitASM(new std::string("pop"), new std::string("eax"), NULL); //将ebx的旧值存入eax以便覆盖掉
emitASM(new std::string("pop"), new std::string("eax"), NULL);
break;
case ECX:
emitASM(new std::string("mov"), new std::string("ecx"), new std::string("eax"));
regs[ECX] = res;
if (reguse == ECX)
{
reguse++;
}
emitASM(new std::string("pop"), new std::string("edx"), NULL);
emitASM(new std::string("pop"), new std::string("ebx"), NULL); //将ecx的旧值存入ebx以便覆盖掉
emitASM(new std::string("pop"), new std::string("ebx"), NULL);
emitASM(new std::string("pop"), new std::string("eax"), NULL);
break;
case EDX:
emitASM(new std::string("mov"), new std::string("edx"), new std::string("eax"));
regs[EDX] = res;
if (reguse == EDX)
{
reguse = EAX;
}
emitASM(new std::string("pop"), new std::string("ecx"), NULL); //将edx的旧值存入ecx以便覆盖掉
emitASM(new std::string("pop"), new std::string("ecx"), NULL);
emitASM(new std::string("pop"), new std::string("ebx"), NULL);
emitASM(new std::string("pop"), new std::string("eax"), NULL);
break;
default:
break;
}
}
else
{
//res不是临时变量
calcOffset(item, res, level - item->level, reguse);
emitASM(new std::string("mov"), new std::string(res), new std::string("eax"));
emitASM(new std::string("pop"), new std::string("edx"), NULL);
emitASM(new std::string("pop"), new std::string("ecx"), NULL);
emitASM(new std::string("pop"), new std::string("ebx"), NULL);
emitASM(new std::string("pop"), new std::string("eax"), NULL);
}
}
}
else if (op == ":=")
{
//根据op2来取得res的表示
if (op2 == "")
{
//res := op1
tableItem *item = tableFind(*table, res, parent);
calcOffset(item, res, level - item->level, reguse);
if(item->type == REFERENCE)
{
//当前是引用
moveToRegs(res, regs, reguse);
res = "[" + res + "]";
}
}
else
{
//:=,res,op1, op2，其中res是数组名，含义：res[op2] := op1
if (op2.c_str()[0] >= '0' && op2.c_str()[0] <= '9')
{
//op2是个立即数
char _s[5],*s;
tableItem *item = tableFind(*table, res, parent);
calcOffset(item, res, level - item->level, reguse);
moveToRegs(res, regs, reguse);
int _offset = item->offset + atoi(op2.c_str()) * 4; //获得数组元素的偏移
s = itoa(_offset, _s, 10);
res = "[" + res + "-" + *new std::string(s) + "]";
}
else
{
//op2是变量、常量或者寄存器
if (!findInConst(op2, constPool) && !findInRegs(op2, regs))
{
//op2是变量
tableItem *item = tableFind(*table, op2, parent);
if (item == NULL)
calcOffset(item, op2, level - item->level, reguse);
moveToRegs(op2, regs, reguse);
}
emitASM(new std::string("shl"), &op2, new std::string("2"));
char _s[5], *s;
s = itoa(tableFind(*table, res, parent)->offset, _s, 10);
emitASM(new std::string("add"), &op2, new std::string(s));
emitASM(new std::string("neg"), &op2, NULL);
res = "[ebp+" + op2 + "]";
}
}
//取得op1的表示
if (!findInRegs(op1, regs))
{
//op1不在寄存器中
if (op1.c_str()[0] >= '0' && op1.c_str()[0] <= '9' || findInConst(op1,constPool))
{
//op1是立即数
res = "DWORD PTR " + res;
}
else
{
//op1是变量
tableItem *item = tableFind(*table, op1, parent);
if(item == NULL)
{
FILE *fstdout = fopen("CON", "w");
fprintf(fstdout, "Can not find the temp %s\n", op1.c_str());
return 1;
}
calcOffset(item, op1, level - item->level, reguse);
moveToRegs(op1, regs, reguse);
if (item->type == REFERENCE)
{
//op1是引用
emitASM(new std::string("mov"), &op1, new std::string("[" + op1 + "]"));
}
}
}
emitASM(new std::string("mov"), &res, &op1);
}
else if (op == "array")
{
//访问数组元素
//res := op1[op2]
if (op2.c_str()[0] >= '0' && op2.c_str()[0] <= '9' || findInConst(op2, constPool))
{
//op2是个立即数或者常量
char _s[5], *s;
tableItem *item = tableFind(*table, op1, parent);
int _offset = item->offset + atoi(op2.c_str()) * 4; //获得数组元素的偏移
s = itoa(-_offset, _s, 10);
op2 = *new std::string(s);
}
else
{
//op2是变量
tableItem *item = NULL;
if (!findInRegs(op2, regs))
{
//op2不是临时变量
item = tableFind(*table, op2, parent);
calcOffset(item, op2, level - item->level, reguse);
moveToRegs(op2, regs, reguse);
if(item->type == REFERENCE)
{
//op2是引用
emitASM(new std::string("mov"), &op2, new std::string("[" + op2 + "]"));
}
}
emitASM(new std::string("shl"), &op2, new std::string("2"));
char _s[5], *s;
item = tableFind(*table, op1, parent);
s = itoa(item->offset, _s, 10);
emitASM(new std::string("add"), &op2, new std::string(s));
emitASM(new std::string("neg"), &op2, NULL);
}
tableItem *item = tableFind(*table, op1, parent);
if (level == item->level)
{
//数组为本层的局部变量
op1 = "[ebp+" + op2 + "]";
}
else
{
//数组为非局部变量
int cnt = level - item->level;
std::string reg;
switch (reguse)
{
case EAX:reg = "eax"; break;
case EBX:reg = "ebx"; break;
case ECX:reg = "ecx"; break;
case EDX:reg = "edx"; break;
default:
break;
}
emitASM(new std::string("mov"), ®, new std::string("[ebp+8]"));
cnt--;
while (cnt > 0)
{
emitASM(new std::string("mov"), ®, new std::string("[" + reg + "+8]"));
cnt--;
}
op1 = "[" + reg + "+" + op2 + "]";
}
moveToRegs(op1, regs, reguse);
item = tableFind(*table, res, parent);
if (item == NULL)
{
//res是临时变量
regs[(reguse+3)%4] = res;
}
else
{
calcOffset(item, res, level - item->level, reguse);
if(item->type == REFERENCE)
{
//res是引用
moveToRegs(res, regs, reguse);
res = "[" + res + "]";
}
emitASM(new std::string("mov"), &res, &op1);
}
}
else if (op == "cmp")
{
if (res.c_str()[0] < '0' || res.c_str()[0] > '9')
{
//res不是立即数
if (!findInConst(res, constPool) && !findInRegs(res, regs))
{
//res不在寄存器中且res不在常量池中
tableItem *item = tableFind(*table, res, parent);
calcOffset(item, res, level - item->level, reguse);
moveToRegs(res, regs, reguse);
if(item->type == REFERENCE)
{
//res是引用
res = "[" + res + "]";
}
}
}
if (op1.c_str()[0] < '0' || op1.c_str()[0] > '9')
{
//op1不是立即数
if (!findInRegs(op1, regs) && !findInConst(op1,constPool))
{
//op1不在寄存器中且op1不在常量池中
tableItem *item = tableFind(*table, op1, parent);
calcOffset(item, op1, level - item->level, reguse);
if(item->type == REFERENCE)
{
//op1是引用
moveToRegs(op1, regs, reguse);
op1 = "[" + op1 + "]";
}
}
}
emitASM(new std::string("cmp"), &res, &op1);
}
else if (op == "param")
{
if (!saved)
{
emitASM(new std::string("push"), new std::string("eax"), NULL);
emitASM(new std::string("push"), new std::string("ebx"), NULL);
emitASM(new std::string("push"), new std::string("ecx"), NULL);
emitASM(new std::string("push"), new std::string("edx"), NULL);
saved = true;
}
if (res.c_str()[0] >= '0' && res.c_str()[0] <= '9' || findInConst(res,constPool))
{
//res是个立即数
}
else
{
//res是个标识符
if(op1 != "")
{
//传引用
tableItem *item = tableFind(*table, res, parent);
if(item->type == REFERENCE)
{
//res本身就是引用
calcOffset(item, res, level - item->level, reguse);
}else
{
//计算res的地址
calcOffset(item, res, level - item->level);
}
}else
{
//传值
if (!findInRegs(res, regs) && !findInConst(res,constPool))
{
//res不在寄存器中
tableItem *item = tableFind(*table, res, parent);
calcOffset(item, res, level - item->level, reguse);
}
}
}
emitASM(new std::string("push"), &res, NULL);
}
else if (op == "call")
{
//call,retVal,name,args,
//retVal = name(arg1, arg2...)
//其中retVal为存放返回值的变量地址(过程调用则为NULL)
//name为过程(函数)名，args为参数个数
if (!saved)
{
emitASM(new std::string("push"), new std::string("eax"), NULL);
emitASM(new std::string("push"), new std::string("ebx"), NULL);
emitASM(new std::string("push"), new std::string("ecx"), NULL);
emitASM(new std::string("push"), new std::string("edx"), NULL);
regStack.push(reguse);
saved = true;
}
tableItem *item = tableFind(*table, op1, parent);
if (item != NULL)
{
if (item->level > level-1)
{
//上层调用下层
printf(";静态链\n");
emitASM(new std::string("push"), new std::string("ebp"), NULL);
}
else if (item->level == level-1)
{
//同层调用
printf(";静态链\n");
emitASM(new std::string("push"), new std::string("[ebp+8]"), NULL);
}
else
{
//下层调用上层
printf(";静态链\n");
int cnt = item->level - level;
std::string SL = "";
switch (reguse)
{
case EAX:
emitASM(new std::string("mov"), new std::string("eax"), new std::string("ebp"));
SL = "eax";
reguse++;
break;
case EBX:
emitASM(new std::string("mov"), new std::string("ebx"), new std::string("ebp"));
SL = "ebx";
reguse++;
break;
case ECX:
emitASM(new std::string("mov"), new std::string("ecx"), new std::string("ebp"));
SL = "ecx";
reguse++;
break;
case EDX:
emitASM(new std::string("mov"), new std::string("edx"), new std::string("ebp"));
SL = "edx";
reguse = EAX;
break;
default:
break;
}
while (cnt > 0)
{
emitASM(new std::string("mov"), &SL, new std::string("[" + SL + "+8]"));
}
emitASM(new std::string("push"), &SL, NULL);
}
}
op1 = "__" + op1;
emitASM(new std::string("call"), &op1, NULL);
if (res != "")
{
//函数调用
tableItem *item = tableFind(*table, res, parent);
if (item == NULL)
{
//res是个临时变量
regs[EAX] = res;
//避免计算结果被覆盖
if (reguse == EAX)
{
reguse++;
}
}
else
{
//res不是临时变量