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 genif(SNODE *stmt)
/*
* generate code to evaluate an if statement.
*/
{
int lab1, lab2;
int areg, sreg;
lab1 = nextlabel++; /* else label */
lab2 = nextlabel++; /* exit label */
InitRegs(); /* clear temps */
ChooseRegs(&areg, &sreg);
falsejp(stmt->exp, areg, sreg, lab1);
genstmt(stmt->s1);
if (stmt->s2 != 0)
/* else part exists */
{
gen_codes(op_jmp, 0, make_label(lab2), 0);
gen_label(lab1);
genstmt(stmt->s2);
gen_label(lab2);
}
else
/* no else code */
gen_label(lab1);
}
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 genif(SNODE *stmt)
/*
* generate code to evaluate an if statement.
*/
{ int lab1, lab2;
lab1 = nextlabel++; /* else label */
lab2 = nextlabel++; /* exit label */
initstack(); /* clear temps */
falsejp(stmt->exp,lab1);
genstmt(stmt->s1);
if( stmt->s2 != 0 ) /* else part exists */
{
gen_code(op_jmp,0,make_label(lab2),0);
gen_label(lab1);
genstmt(stmt->s2);
gen_label(lab2);
}
else /* no else code */
gen_label(lab1);
}
void genASM(STATEMENT *st)
{
cseg();
contlab = breaklab = - 1;
structret_imode = 0 ;
tempCount = 0;
blockCount = 0;
blockMax = 0;
exitBlock = 0;
genstmt(st, NULL);
rewrite_icode(); /* Translate to machine code & dump */
}
void gencase(SNODE *stmt)
/*
* generate all cases for a switch statement.
*/
{ while( stmt != 0 )
{
gen_label((int)stmt->label);
if( stmt->s1 != 0 )
{
genstmt(stmt->s1);
}
stmt = stmt->next;
}
}
/*-------------------------------------------------------------------------*/
static void gen_try(SYMBOL *funcsp, STATEMENT *stmt, int startLab, int endLab, int transferLab, STATEMENT *lower)
{
gen_label(startLab);
stmt->tryStart = ++consIndex;
xcexp->right->v.i = consIndex;
gen_expr(funcsp, xcexp, F_NOVALUE, ISZ_ADDR);
genstmt(lower, funcsp);
stmt->tryEnd = ++consIndex;
xcexp->right->v.i = consIndex;
gen_expr(funcsp, xcexp, F_NOVALUE, ISZ_ADDR);
gen_label(endLab);
/* not using gen_igoto because it will make a new block */
gen_icode(i_goto, NULL, NULL, NULL);
intermed_tail->dc.v.label = transferLab;
tryStart = stmt->tryStart;
tryEnd = stmt->tryEnd;
}
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;
}
static void gen_catch(SYMBOL *funcsp, STATEMENT *stmt, int startLab, int transferLab, STATEMENT *lower)
{
int oldtryStart = tryStart;
int oldtryEnd = tryEnd;
gen_label(startLab);
currentBlock->alwayslive = TRUE;
intermed_tail->alwayslive = TRUE;
catchLevel++;
genstmt(lower, funcsp);
catchLevel--;
/* not using gen_igoto because it will make a new block */
gen_icode(i_goto, NULL, NULL, NULL);
intermed_tail->dc.v.label = transferLab;
tryStart = oldtryStart;
tryEnd = oldtryEnd;
stmt->tryStart = tryStart;
stmt->tryEnd = tryEnd;
}
void genfunc(SNODE *stmt)
/*
* generate a function body.
*/
{ retlab = contlab = breaklab = -1;
funcfloat = 0;
init_muldivval();
stackdepth = 0;
if (stmt->stype == st_line) {
gen_line(stmt);
stmt = stmt->next;
}
gen_codelab(currentfunc); /* name of function */
opt1(stmt); /* push args & also subtracts SP */
#ifdef CPLUSPLUS
if (prm_cplusplus)
scppinit();
#endif
genstmt(stmt);
genreturn(0,1);
}
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;
}
void
genstmt(NODE *n)
{
VREG *muuo_ac;
if (n == NULL) return;
switch (n->Nop) {
case N_STATEMENT:
{ NODE *beg, *next;
if (n->Nleft && n->Nleft->Nop == N_DATA) { /* Check for auto inits */
genadata(n->Nleft); /* Yep, do them */
n = n->Nright; /* then move on to real statements */
}
for(beg = n; n != NULL; n = n->Nright) {
if(n->Nop != N_STATEMENT)
int_error("genstmt: bad stmt %N", n);
if(n->Nleft == NULL) continue;
/* Check out following stmt for possible optimizations */
if(n->Nright && (next = n->Nright->Nleft) != NULL && optgen) {
switch(next->Nop) {
/* Hack to encourage tail recursion */
case Q_RETURN: /* If next will be RETURN */
if(next->Nright == NULL) { /* and has no return val */
NODE *v; /* Then try to optimize */
if((v = laststmt(n->Nleft)) != NULL && v->Nop == N_FNCALL)
v->Nflag |= NF_RETEXPR;
}
break;
/* If next stmt is a GOTO, ensure that any jumps
* within current stmt to end of stmt will
* instead go directly to object of the GOTO.
* Avoids jumping to jumps...
* We do a similar hack for BREAK and CONTINUE,
* which are similar to GOTOs except that their
* destination is kept in variables global to the
* code generation routines.
*/
case Q_CASE: /* Not sure about this one yet */
case N_LABEL:
case Q_GOTO:
n->Nleft->Nendlab = next->Nxfsym;
break;
case Q_BREAK:
n->Nleft->Nendlab = brklabel;
break;
case Q_CONTINUE:
n->Nleft->Nendlab = looplabel;
break;
default:
; /* do nothing */
} /* end of Nop switch */
} /* end of next-stmt check */
/* Optimize label usage */
if(n->Nright == NULL /* If this is last stmt in list */
&& optgen)
n->Nleft->Nendlab = beg->Nendlab; /* Copy from 1st */
genstmt(n->Nleft);
}
break;
} /* end of N_STATEMENT case block */
case Q_CASE:
codlabel(n->Nxfsym); /* send forward label */
n->Nleft->Nendlab = n->Nendlab; /* propagate end label */
genstmt (n->Nleft); /* finish rest of body */
break;
case N_LABEL:
if (n->Nxfsym->Sname[0] == '%' && isdigit(n->Nxfsym->Sname[1]))
code_debugcall(n);
else
codgolab(n->Nxfsym); /* send goto label */
n->Nleft->Nendlab = n->Nendlab; /* propagate end label */
genstmt(n->Nleft); /* finish rest of body */
break;
case Q_BREAK: code6(P_JRST, NULL, brklabel); break;
case Q_GOTO: code6(P_JRST, NULL, n->Nxfsym); break;
case Q_CONTINUE: code6(P_JRST, NULL, looplabel); break;
case Q_DO: gdo(n); break;
case Q_FOR: gfor(n); break;
case Q_IF: gif(n); break;
case Q_RETURN: greturn(n); break;
case Q_SWITCH: gswitch(n); break;
case Q_WHILE: gwhile(n); break;
#if SYS_CSI /* Added 1/91 for in-line monitor calls; KAR */
case Q_MUUO:
muuo_ac = gmuuo(n);
vrfree(muuo_ac);
break;
#endif
case N_EXPRLIST: /* Same as expression stmt */
default: /* None of above, assume expression stmt */
genxrelease(n); /* Generate it and flush any result */
break;
}
}
void genfunc(SYMBOL *funcsp)
/*
* generate a function body and dump the icode
*/
{
IMODE *allocaAP = NULL;
SYMBOL *oldCurrentFunc;
EXPRESSION *funcexp = varNode(en_global, funcsp);
if (total_errors)
return;
// //printf("%s\n", funcsp->name);
contlab = breaklab = - 1;
structret_imode = 0 ;
tempCount = 0;
blockCount = 0;
blockMax = 0;
exitBlock = 0;
oldCurrentFunc = theCurrentFunc;
theCurrentFunc = funcsp;
iexpr_func_init();
/* firstlabel = nextLabel;*/
cseg();
gen_line(funcsp->linedata);
gen_func(funcexp, 1);
/* in C99 inlines can clash if declared 'extern' in multiple modules */
/* in C++ we introduce virtual functions that get coalesced at link time */
if (cparams.prm_cplusplus && funcsp->linkage == lk_inline)
gen_virtual(funcsp, FALSE);
else
{
if (funcsp->storage_class == sc_global)
globaldef(funcsp);
else
localdef(funcsp);
gen_strlab(funcsp); /* name of function */
}
addblock( - 1);
if (funcsp->linkage == lk_interrupt || funcsp->linkage == lk_fault) {
gen_icode(i_pushcontext, 0,0,0);
/* if (funcsp->loadds) */
/* gen_icode(i_loadcontext, 0,0,0); */
}
gen_icode(i_prologue,0,0,0);
gen_label(startlab);
/* if (funcsp->loadds && funcsp->farproc) */
/* gen_icode(i_loadcontext, 0,0,0); */
AllocateLocalContext(NULL, funcsp);
if (funcsp->allocaUsed)
{
EXPRESSION *allocaExp = varNode(en_auto, anonymousVar(sc_auto, &stdpointer));
allocaAP = gen_expr(funcsp, allocaExp, 0, ISZ_ADDR);
gen_icode(i_savestack, 0, allocaAP, 0);
}
/* Generate the icode */
/* LCSE is done while code is generated */
genstmt(funcsp->inlineFunc.stmt->lower, funcsp);
if (funcsp->inlineFunc.stmt->blockTail)
{
gen_icode(i_functailstart, 0, 0, 0);
genstmt(funcsp->inlineFunc.stmt->blockTail, funcsp);
gen_icode(i_functailend, 0, 0, 0);
}
genreturn(0, funcsp, 1, 0, allocaAP);
gen_func(funcexp, 0);
tFree();
InsertParameterThunks(funcsp, blockArray[1]);
optimize(funcsp);
FreeLocalContext(NULL, funcsp);
AllocateStackSpace(funcsp);
FillInPrologue(intermed_head, funcsp);
/* Code gen from icode */
rewrite_icode(); /* Translate to machine code & dump */
if (chosenAssembler->gen->post_function_gen)
chosenAssembler->gen->post_function_gen(funcsp, intermed_head);
if (cparams.prm_cplusplus && funcsp->linkage == lk_inline)
gen_endvirtual(funcsp);
intermed_head = NULL;
dag_rundown();
oFree();
theCurrentFunc = oldCurrentFunc;
if (blockCount > maxBlocks)
maxBlocks = blockCount;
if (tempCount > maxTemps)
maxTemps = tempCount;
}
void genstmt(STATEMENT *stmt, SYMBOL *funcsp)
/*
* genstmt will generate a statement and follow the next pointer
* until the block is generated.
*/
{
while (stmt != 0)
{
switch (stmt->type)
{
case st_varstart:
gen_varstart(stmt->select);
break;
case st_dbgblock:
gen_dbgblock(stmt->label);
break;
case st_tryblock:
/* gen_tryblock(stmt->label); */
break;
case st_block:
genstmt(stmt->lower, funcsp);
genstmt(stmt->blockTail, funcsp);
break;
case st_label:
gen_label((int)stmt->label);
break;
case st_goto:
gen_igoto(i_goto, (int)stmt->label);
break;
case st_asmgoto:
gen_igoto(i_asmgoto, (int)stmt->label);
break;
case st_asmcond:
gen_igoto(i_asmcond, (int)stmt->label);
break;
case st_throw:
/* gen_throw((TYPE *)stmt->lst, stmt->select);*/
break;
/* case st_functailexpr:
gen_icode(i_functailstart, 0, 0, 0);
gen_expr(funcsp, stmt->select, F_NOVALUE, natural_size(stmt->select)); *
gen_icode(i_functailend, 0, 0, 0);
break;
*/
case st_expr:
case st_declare:
gen_expr(funcsp, stmt->select, F_NOVALUE, natural_size(stmt->select));
break;
case st_return:
genreturn(stmt, funcsp, 0, 0, NULL);
break;
case st_line:
gen_line(stmt->lineData);
break;
case st_select:
genselect(stmt, funcsp, TRUE);
break;
case st_notselect:
genselect(stmt, funcsp, FALSE);
break;
case st_switch:
genxswitch(stmt, funcsp);
break;
case st__genword:
gen_genword(stmt, funcsp);
break;
case st_passthrough:
gen_asm(stmt);
break;
case st_datapassthrough:
gen_asmdata(stmt);
break;
default:
diag("unknown statement.");
break;
}
stmt = stmt->next;
}
}
void genstmt(SNODE *stmt)
/*
* genstmt will generate a statement and follow the next pointer
* until the block is generated.
*/
{
while( stmt != 0 )
{
switch( stmt->stype )
{
case st_block:
genstmt(stmt->exp);
break;
case st_label:
gen_label((int)stmt->label);
break;
case st_goto:
gen_code(op_jmp,0,make_label((int)stmt->label),0);
break;
case st_expr:
initstack();
gen_expr(stmt->exp,F_ALL | F_NOVALUE,
natural_size(stmt->exp));
break;
case st_return:
genreturn(stmt,0);
break;
case st_if:
genif(stmt);
break;
case st_while:
genwhile(stmt);
break;
case st_do:
gendo(stmt);
break;
case st_for:
gen_for(stmt);
break;
case st_continue:
gen_code(op_jmp,0,make_label(contlab),0);
break;
case st_break:
gen_code(op_jmp,0,make_label(breaklab),0);
break;
case st_switch:
genxswitch(stmt);
break;
case st_line:
gen_line(stmt);
break;
case st_asm:
if (stmt->exp)
add_peep(stmt->exp);
break;
case st__genword:
gen_code(op_genword,0,make_immed((int)stmt->exp),0);
break;
default:
diag("unknown statement.");
break;
}
stmt = stmt->next;
}
}
IMODE *genstmt(STATEMENT *stmt, SYMBOL *funcsp)
/*
* genstmt will generate a statement and follow the next pointer
* until the block is generated.
*/
{
IMODE *rv = NULL;
while (stmt != 0)
{
STATEMENT *last = stmt;
switch (stmt->type)
{
case st_varstart:
gen_varstart(stmt->select);
break;
case st_dbgblock:
gen_dbgblock(stmt->label);
break;
break;
case st_block:
rv = genstmt(stmt->lower, funcsp);
genstmt(stmt->blockTail, funcsp);
break;
case st_label:
gen_label((int)stmt->label);
break;
case st_goto:
gen_igoto(i_goto, (int)stmt->label);
break;
case st_asmgoto:
gen_igoto(i_asmgoto, (int)stmt->label);
break;
case st_asmcond:
gen_igoto(i_asmcond, (int)stmt->label);
break;
case st_try:
gen_try(funcsp, stmt, stmt->label, stmt->endlabel, stmt->breaklabel, stmt->lower);
break;
case st_catch:
{
STATEMENT *last;
while (stmt && stmt->type == st_catch)
{
gen_catch(funcsp, stmt, stmt->altlabel, stmt->breaklabel, stmt->lower);
last = stmt;
stmt = stmt->next;
}
stmt = last;
gen_label(stmt->breaklabel);
}
break;
case st_expr:
case st_declare:
if (stmt->select)
rv = gen_expr(funcsp, stmt->select, F_NOVALUE, natural_size(stmt->select));
break;
case st_return:
genreturn(stmt, funcsp, 0, 0, NULL);
break;
case st_line:
gen_line(stmt->lineData);
break;
case st_select:
genselect(stmt, funcsp, TRUE);
break;
case st_notselect:
genselect(stmt, funcsp, FALSE);
break;
case st_switch:
genxswitch(stmt, funcsp);
break;
case st__genword:
gen_genword(stmt, funcsp);
break;
case st_passthrough:
gen_asm(stmt);
break;
case st_datapassthrough:
gen_asmdata(stmt);
break;
default:
diag("unknown statement.");
break;
}
if (last->type != st_return && last->destexp)
{
gen_expr(funcsp, last->destexp, F_NOVALUE, ISZ_ADDR);
}
stmt = stmt->next;
}
return rv;
}
