void Add()
{
Match('+');
Term();
EmitLn("addl (%esp), %eax");
EmitLn("addl $4, %esp");
}
void DoFor() {
char L1[100];
char L2[100];
Match('f');
strcpy(L1, NewLabel());
strcpy(L2, NewLabel());
char Name = GetName();
Match('=');
Expression();
EmitLn("dec rax");
sprintf(tmp, "mov qword [%c], rax", Name);
EmitLn(tmp);
Expression();
EmitLn("push rax");
PostLabel(L1);
sprintf(tmp, "mov rax, qword [%c]", Name);
EmitLn(tmp);
EmitLn("inc rax");
sprintf(tmp, "mov qword [%c], rax", Name);
EmitLn(tmp);
EmitLn("cmp rax, qword [rsp]");
sprintf(tmp, "jg %s", L2);
EmitLn(tmp);
Block();
Match('e');
sprintf(tmp, "jmp %s", L1);
EmitLn(tmp);
PostLabel(L2);
EmitLn("add rsp, 8");
}
void DoWhile(void)
{
char code[MAXMSG];
char l1[MAXLBL];
char l2[MAXLBL];
Match('w');
NewLabel();
strncpy(l1, label, MAXLBL);
NewLabel();
strncpy(l2, label, MAXLBL);
PostLabel(l1);
BoolExpression();
snprintf(code, MAXMSG, "je .%s", l2);
EmitLn(code);
Block(l2);
Match('e'); // ENDWHILE
printf("#ENDWHILE\n");
snprintf(code, MAXMSG, "jmp .%s", l1);
EmitLn(code);
PostLabel(l2);
}
void DoIf()
{
Condition();
char L1[MAX_BUF];
char L2[MAX_BUF];
strcpy(L1, NewLabel());
strcpy(L2, L1);
sprintf(tmp, "jz %s", L1);
EmitLn(tmp);
Block();
if (Token == 'l') {
/* match *else* statement */
strcpy(L2, NewLabel());
sprintf(tmp, "jmp %s", L2);
EmitLn(tmp);
PostLabel(L1);
Block();
}
PostLabel(L2);
MatchString("ENDIF");
}
void Subtract() {
Match('-');
Term();
EmitLn("pop rbx");
EmitLn("sub rax, rbx");
EmitLn("neg rax");
}
void BoolXor()
{
Match('~');
BoolTerm();
EmitLn("xor (%esp), %eax");
EmitLn("addl $4, %esp"); /* recover the stack */
}
void DoIf(char *L)
{
char L1[MAX_BUF];
char L2[MAX_BUF];
strcpy(L1, NewLabel());
strcpy(L2, L1);
Match('i');
BoolExpression();
sprintf(tmp, "jz %s", L1);
EmitLn(tmp);
Block(L);
dprint("DoIf: Got Look = %c\n", Look);
if (Look == 'l') {
/* match *else* statement */
Match('l');
strcpy(L2, NewLabel());
sprintf(tmp, "jmp %s", L2);
EmitLn(tmp);
PostLabel(L1);
Block(L);
}
Match('e');
PostLabel(L2);
}
void DoDo(void)
{
char code[MAXMSG];
char l1[MAXLBL];
char l2[MAXLBL];
Match('d');
NewLabel();
strncpy(l1, label, MAXLBL);
NewLabel();
strncpy(l2, label, MAXLBL); // exit point
printf("# DO\n");
Expression(); // expr1 = repeat count
EmitLn("pushl %eax\t\t# repeat count");
PostLabel(l1);
Block(l2);
EmitLn("popl %ecx");
EmitLn("dec %ecx");
EmitLn("pushl %ecx");
// test
snprintf(code, MAXMSG, "jnz .%s", l1);
EmitLn(code);
Match('e'); // ENDWHILE
printf("#ENDDO\n");
PostLabel(l2);
}
void Greater() {
Match('>');
Expression();
EmitLn("cmp rax, [rsp]");
EmitLn("setle al");
}
void DoIf(char *exit_label)
{
char code[MAXMSG];
char l1[MAXLBL];
char l2[MAXLBL];
Match('i');
printf("# IF\n");
NewLabel();
strncpy(l1, label, MAXLBL);
strncpy(l2, label, MAXLBL);
BoolExpression();
snprintf(code, MAXMSG, "je .%s", l1);
EmitLn(code);
printf("# TRUE\n");
// here, tutorial 05 only matches 'e' once, after the if statement
// this doesn't seem to work unless i add Look=='l' to the test in
// Blocks().
Block(exit_label);
if (Look=='l') {
Match('l');
printf("#ELSE\n");
NewLabel();
strncpy(l2, label, MAXLBL);
snprintf(code, MAXMSG, "jmp .%s", l2);
EmitLn(code);
PostLabel(l1);
Block(exit_label);
}
Match('e'); // ENDIF
printf("#ENDIF\n");
PostLabel(l2);
}
void Subtract()
{
Match('-');
Term();
EmitLn("subl (%esp), %eax");
EmitLn("negl %eax");
EmitLn("addl $4, %esp");
}
void Multiply()
{
Match('*');
Factor();
EmitLn("imull (%esp), %eax");
/* push of the stack */
EmitLn("addl $4, %esp");
}
void Greater()
{
Match('>');
Expression();
EmitLn("cmp %eax, (%esp)");
EmitLn("setg %al");
EmitLn("addl $4, %esp"); /* recover the stack */
}
void NotEquals()
{
Match('#');
Expression();
EmitLn("cmp (%esp), %eax");
EmitLn("setne %al");
EmitLn("addl $4, %esp"); /* recover the stack */
}
void Divide() {
Match('/');
Factor();
EmitLn("mov rbx, rax");
EmitLn("pop rax");
EmitLn("cqo");
EmitLn("idiv rbx");
}
void Less()
{
Match('<');
Expression();
EmitLn("cmp %eax, (%esp)");
EmitLn("setl %al");
EmitLn("addl $4, %esp"); /* recover the stack */
}
void Header() {
EmitLn("extern printf");
EmitLn("extern scanf");
EmitLn("section .data");
printf("fmt: db \"%%d\", 10, 0\n");
printf("fmtin: db \"%%d\", 0\n");
}
void Assignment()
{
char c = GetName();
Match('=');
BoolExpression();
sprintf(tmp, "lea %c, %%ebx", c);
EmitLn(tmp);
EmitLn("movl %eax, (%ebx)");
}
void Equals()
{
Match('=');
Expression();
EmitLn("cmp (%esp), %eax");
/* Note that 80386 has setcc corresponds to 86000's SETCC
* However, it only takes 8-bit registers */
EmitLn("sete %al");
EmitLn("addl $4, %esp"); /* recover the stack */
}
void Assignment()
{
char name[MAX_BUF];
strcpy(name, Value);
Match('=');
Expression();
sprintf(tmp, "lea %s, %%ebx", name);
EmitLn(tmp);
EmitLn("movl %eax, (%ebx)");
}
void BoolTerm() {
NotFactor();
while (Look == '&') {
EmitLn("push rax");
Match('&');
NotFactor();
EmitLn("and rax, [rsp]");
EmitLn("add rsp, 8");
}
}
void BoolTerm()
{
NotFactor();
while(Look == '&') {
EmitLn("pushl %eax");
Match('&');
NotFactor();
EmitLn("and (%esp), %eax");
EmitLn("addl $4, %esp");
}
}
void BoolFactor()
{
if (IsBoolean(Look)) {
if (GetBoolean()) {
EmitLn("movl $-1, %eax");
} else {
EmitLn("xor %eax, %eax");
}
} else {
Relation();
}
}
void Ident() {
char Name = GetName();
if(Look == ('(')) {
Match('(');
Match(')');
sprintf(tmp, "call %c", Name);
EmitLn(tmp);
} else {
sprintf(tmp, "mov rax, [%c]", Name);
EmitLn(tmp);
}
}
void Ident()
{
GetName();
if (Look == '(') {
Match('(');
Match(')');
sprintf(tmp, "call %s", Value);
EmitLn(tmp);
} else {
sprintf(tmp, "movl %s, %%eax", Value);
EmitLn(tmp);
}
}
void Ident()
{
char c = GetName();
if (Look == '(') {
Match('(');
Match(')');
sprintf(tmp, "call %c", c);
EmitLn(tmp);
} else {
sprintf(tmp, "movl %c, %%eax", c);
EmitLn(tmp);
}
}
void BoolFactor() {
if(IsBoolean(Look)) {
if(GetBoolean()) {
EmitLn("mov rax, -1");
}
else {
EmitLn("xor rax, rax");
}
}
else {
Relation();
}
}
void Relation() {
Expression();
if (IsRelop(Look)) {
EmitLn("push rax");
switch(Look) {
case '=': Equals(); break;
case '#': NotEquals(); break;
case '<': Less(); break;
case '>': Greater(); break;
}
EmitLn("add rsp, 8");
EmitLn("cmp rax, 0");
}
}
/* Adjust the stack pointer upwards by n bytes */
void CleanStack(int bytes)
{
if (bytes > 0) {
sprintf(tmp, "addl $%d, %%esp", bytes);
EmitLn(tmp);
}
}
void Assignment() {
char Name = GetName();
Match('=');
BoolExpression();
sprintf(tmp, "mov [%c], rax", Name);
EmitLn(tmp);
}