void genwhile(SNODE *stmt)
/*
* generate code to evaluate a while statement.
*/
{ int lab1, lab2, lab3;
initstack(); /* initialize temp registers */
lab1 = contlab; /* save old continue label */
contlab = nextlabel++; /* new continue label */
if( stmt->s1 != 0 ) /* has block */
{
lab2 = breaklab; /* save old break label */
breaklab = nextlabel++;
gen_code(op_jmp,0,make_label(contlab),0);
lab3 = nextlabel++;
gen_label(lab3);
genstmt(stmt->s1);
gen_label(contlab);
if (stmt->lst)
gen_line(stmt->lst);
initstack();
truejp(stmt->exp,lab3);
gen_label(breaklab);
breaklab = lab2; /* restore old break label */
}
else /* no loop code */
{
if (stmt->lst)
gen_line(stmt->lst);
gen_label(contlab);
initstack();
truejp(stmt->exp,contlab);
}
contlab = lab1; /* restore old continue label */
}
void gendo(SNODE *stmt)
/*
* generate code for a do - while loop.
*/
{ int oldcont, oldbreak;
oldcont = contlab;
oldbreak = breaklab;
contlab = nextlabel++;
gen_label(contlab);
if( stmt->s1 != 0 && stmt->s1->next != 0 )
{
breaklab = nextlabel++;
genstmt(stmt->s1); /* generate body */
initstack();
truejp(stmt->exp,contlab);
gen_label(breaklab);
}
else
{
genstmt(stmt->s1);
initstack();
truejp(stmt->exp,contlab);
}
breaklab = oldbreak;
contlab = oldcont;
}
void genselect(STATEMENT *stmt, SYMBOL *funcsp, BOOL jmptrue)
{
if (stmt->altlabel)
{
// gen_label(stmt->altlabel);
// intermed_tail->dc.opcode = i_skipcompare;
}
if (jmptrue)
truejp(stmt->select, funcsp, stmt->label);
else
falsejp(stmt->select, funcsp, stmt->label);
if (stmt->altlabel)
{
// gen_label(stmt->altlabel);
// intermed_tail->dc.opcode = i_skipcompare;
}
}
void gen_for(SNODE *stmt)
/*
* generate code to evaluate a for loop
*/
{
int old_break, old_cont, exit_label, loop_label, start_label;
int areg, sreg;
old_break = breaklab;
old_cont = contlab;
loop_label = nextlabel++;
contlab = nextlabel++;
start_label = nextlabel++;
exit_label = nextlabel++;
InitRegs();
if (stmt->label != 0)
{
gen_void_external(stmt->label);
}
gen_codes(op_jmp, 0, make_label(start_label), 0);
gen_label(loop_label);
if (stmt->s1 != 0)
{
breaklab = exit_label;
genstmt(stmt->s1);
}
if (stmt->lst)
gen_line(stmt->lst);
gen_label(contlab);
InitRegs();
if (stmt->s2 != 0)
{
gen_void_external(stmt->s2);
}
gen_label(start_label);
InitRegs();
ChooseRegs(&areg, &sreg);
if (stmt->exp != 0)
truejp(stmt->exp, areg, sreg, loop_label);
else
gen_codes(op_jmp, 0, make_label(loop_label), 0);
gen_label(exit_label);
breaklab = old_break;
contlab = old_cont;
}
void gendo(SNODE *stmt)
/*
* generate code for a do - while loop.
*/
{
int oldcont, oldbreak, looplab;
int areg, sreg;
oldcont = contlab;
oldbreak = breaklab;
looplab = nextlabel++;
contlab = nextlabel++;
breaklab = nextlabel++;
gen_label(looplab);
genstmt(stmt->s1); /* generate body */
gen_label(contlab);
InitRegs();
ChooseRegs(&areg, &sreg);
truejp(stmt->exp, areg, sreg, looplab);
gen_label(breaklab);
breaklab = oldbreak;
contlab = oldcont;
}
void gen_for(SNODE *stmt)
/*
* generate code to evaluate a for loop
*/
{ int old_break, old_cont, exit_label, loop_label;
old_break = breaklab;
old_cont = contlab;
loop_label = nextlabel++;
exit_label = nextlabel++;
contlab = nextlabel++;
initstack();
if( stmt->label != 0 )
gen_expr(stmt->label,F_ALL | F_NOVALUE
,natural_size(stmt->label));
gen_code(op_jmp,0,make_label(contlab),0);
gen_label(loop_label);
if( stmt->s1 != 0 ) {
breaklab = exit_label;
genstmt(stmt->s1);
}
initstack();
if( stmt->s2 != 0 )
gen_expr(stmt->s2,F_ALL | F_NOVALUE,natural_size(stmt->s2));
gen_label(contlab);
if (stmt->lst)
gen_line(stmt->lst);
initstack();
if( stmt->exp != 0 )
truejp(stmt->exp,loop_label);
else
gen_code(op_jmp,0,make_label(loop_label),0);
gen_label(exit_label);
breaklab = old_break;
contlab = old_cont;
}