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regs.c
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regs.c
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/* $VER: vbcc (regs.c) V0.8 */
/* Registerzuteilung */
#include "opt.h"
static char FILE_[]=__FILE__;
#ifndef NO_OPTIMIZER
int (*savings)[MAXR+1],regu[MAXR+1];
int *rvlist;
static int const_vars;
struct regp {int treg;struct Var *tvar,*tmp;};
void do_load_parms(struct regp [],struct flowgraph *);
void load_one_parm(int,int,struct Var *,struct Var *,struct flowgraph *);
static void insert_cobj(struct obj *o,struct obj *co);
#ifndef HAVE_TARGET_RALLOC
int reg_prio[MAXR+1];
#define cost_move_reg(x,y) 1
#define cost_load_reg(x,y) 2
#define cost_save_reg(x,y) 2
#define cost_pushpop_reg(x) 4
int cost_savings(struct IC *p,int r,struct obj *o)
{
int c=p->code;
if(o->flags&VKONST) return 0;
if(o->flags&DREFOBJ){
int t;
if(o==&p->q1){
t=q1typ(p);
}else if(o==&p->q2){
t=q2typ(p);
}else{
t=ztyp(p);
}
if(regok(r,o->v->vtyp->flags,t)) return 4;
}
if(c==SETRETURN&&r==p->z.reg&&!(o->flags&DREFOBJ)) return 3;
if(c==GETRETURN&&r==p->q1.reg&&!(o->flags&DREFOBJ)) return 3;
return 2;
}
#endif
int cmp_savings(const void *v1,const void *v2)
/* Vergleichsfkt, um rvlist nach savings zu sortieren */
{
return savings[*(int *)v2][0]-savings[*(int *)v1][0];
}
int entry_load(struct flowgraph *fg,int i)
/* Testet, ob die Variable in Register i am Anfang von Block fg geladen */
/* werden muss, d.h. ein Vorgaenger sie nicht im selben Register hat. */
{
struct flowlist *lp;
lp=fg->in;
while(lp){
if(lp->graph&&lp->graph->regv[i]!=fg->regv[i]&&(fg->regv[i]->index>=vcount-rcount||BTST(lp->graph->av_out,fg->regv[i]->index))) return 1;
lp=lp->next;
}
return 0;
}
/* checks if variable i can be held in a register in loop start-end */
/* currently we check whether an IC uses/modifies the variable and */
/* has a corresponding drefobj which might alias the variable */
int check_cacheable(int i,struct flowgraph *start,struct flowgraph *end)
{
int j,k;
struct IC *p;struct Var *v;
struct flowgraph *g;
/* constants are always cacheable */
if(vilist[i]->identifier[0]==' ')
return 1;
if(i<vcount-rcount){
/* simple local variables are also easy */
v=vilist[i];
if(v->storage_class!=STATIC&&v->storage_class!=EXTERN&&!(v->flags&USEDASADR))
return 1;
}
if(disable&16384) return 0;
for(g=start;g;g=g->normalout){
for(p=g->start;p;p=p->next){
for(j=0;j<p->use_cnt;j++){
k=p->use_list[j].v->index;
if(p->use_list[j].flags&DREFOBJ)
k+=vcount-rcount;
if(k==i&&(p->code==CALL||(p->q1.flags&DREFOBJ)||(p->q2.flags&DREFOBJ)))
return 0;
}
for(j=0;j<p->change_cnt;j++){
k=p->change_list[j].v->index;
if(p->change_list[j].flags&DREFOBJ)
k+=vcount-rcount;
if(k==i&&(p->code==CALL||(p->z.flags&DREFOBJ)))
return 0;
}
if(p==g->end) break;
}
if(g==end) break;
}
/*printf("assigned static %s to reg\n",vilist[i]->identifier);*/
return 1;
}
int exit_save(struct flowgraph *fg,int i)
/* Testet, ob die Variable in Register i am Ende von Block fg gespeichert */
/* werden muss, d.h. der Vorgaenger eines Nachfolgers nicht dieselbe */
/* Variable im selben Register hat. */
{
struct flowlist *lp;
/* Konstanten muessen nie gespeichert werden */
if(fg->regv[i]->index>=vcount-rcount) return 0;
if(!fg->normalout){
/* letzter Block, statische Variablen und drefobjs aktiv */
int sc=fg->regv[i]->storage_class;
return sc==STATIC||sc==EXTERN;
}
if((fg->normalout&&(!fg->end||fg->end->code!=BRA))&&BTST(fg->normalout->av_in,fg->regv[i]->index)){
if(fg->normalout->regv[i]!=fg->regv[i]) return 1;
lp=fg->normalout->in;
while(lp){
if(lp->graph&&lp->graph->regv[i]!=fg->regv[i]) return 1;
lp=lp->next;
}
}
if(fg->branchout&&BTST(fg->branchout->av_in,fg->regv[i]->index)){
if(fg->branchout->regv[i]!=fg->regv[i]) return 1;
lp=fg->branchout->in;
while(lp){
if(lp->graph&&lp->graph->regv[i]!=fg->regv[i]) return 1;
lp=lp->next;
}
}
return 0;
}
void load_reg_parms(struct flowgraph *fg)
/* Laedt Registerparameter, falls noetig. */
{
int i,j; struct Var *v;
struct regp regp[MAXR+1]={0};
/* for(i=1;i<=MAXR;i++){ regp[i].treg=0;regp[i].tvar=0;} */
for(i=0;i<vcount-rcount;i++){
v=vilist[i];
if((v->flags®PARM)&&(fg->regv[abs(v->reg)]!=v||(v->flags&CONVPARAMETER))&&(BTST(fg->av_in,i)||(v->flags&USEDASADR))){
regp[abs(v->reg)].tvar=v;
for(j=1;j<=MAXR;j++)
if(fg->regv[j]==v) regp[abs(v->reg)].treg=j;
}
}
do_load_parms(regp,fg);
}
void insert_regs(struct flowgraph *fg1)
/* Fuegt Registervariablen in die ICs ein. */
{
int i;struct IC *p,*lic=0,*new;struct flowgraph *lfg=0,*fg;
if(DEBUG&9216) printf("inserting register variables\n");
fg=fg1;
while(fg){
if(DEBUG&8192) printf("block %d:\n",fg->index);
p=fg->start;
while(p){
for(i=1;i<=MAXR;i++){
if(!fg->regv[i]) continue;
if(p->code==ALLOCREG&&p->q1.reg==i) ierror(0);
if((p->q1.flags&(VAR|REG|DONTREGISTERIZE))==VAR&&p->q1.v==fg->regv[i]){
if(p->q1.v->index>=vcount-rcount)
p->q1.flags&=~(KONST|VAR|VARADR);
p->q1.flags|=REG;
p->q1.reg=i;
}
if((p->q2.flags&(VAR|REG|DONTREGISTERIZE))==VAR&&p->q2.v==fg->regv[i]){
if(p->q2.v->index>=vcount-rcount)
p->q2.flags&=~(KONST|VAR|VARADR);
p->q2.flags|=REG;
p->q2.reg=i;
}
if((p->z.flags&(VAR|REG|DONTREGISTERIZE))==VAR&&p->z.v==fg->regv[i]){
if(p->z.v->index>=vcount-rcount)
p->z.flags&=~(KONST|VAR|VARADR);
p->z.flags|=REG;
p->z.reg=i;
}
}
/* evtl. const-Variablen ruecksubstituieren */
if((p->q1.flags&VAR)&&p->q1.v->index>=vcount-rcount){
insert_cobj(&p->q1,&p->q1.v->cobj);
}
if((p->q2.flags&VAR)&&p->q2.v->index>=vcount-rcount){
insert_cobj(&p->q2,&p->q2.v->cobj);
}
if((p->z.flags&VAR)&&p->z.v->index>=vcount-rcount){
insert_cobj(&p->z,&p->z.v->cobj);
}
if(DEBUG&8192) pric2(stdout,p);
if(p==fg->end) break;
p=p->next;
}
if(fg->start&&fg->start->code==LABEL) lic=fg->start;
for(i=1;i<=MAXR;i++){
if(fg->regv[i]){
if(DEBUG&8192){
printf("(%s),%ld(%p) assigned to %s\n",fg->regv[i]->identifier,zm2l(fg->regv[i]->offset),(void *)fg->regv[i],regnames[i]);
if(fg->regv[i]->index>=vcount-rcount||BTST(fg->av_in,fg->regv[i]->index)) printf("active at the start of block\n");
if(fg->regv[i]->index<vcount-rcount&&BTST(fg->av_out,fg->regv[i]->index)) printf("active at the end of block\n");
}
if(fg->regv[i]->index<vcount-rcount&&BTST(fg->av_out,fg->regv[i]->index)){
/* Variable beim Austritt aktiv? */
if(exit_save(fg,i)){
struct IC *tp;
if(DEBUG&8192) printf("\thave to save it at end of block\n");
new=new_IC();
new->line=0;
new->file=0;
new->code=ASSIGN;
new->typf=fg->regv[i]->vtyp->flags;
/* vla */
if(ISARRAY(new->typf))
new->typf=POINTER_TYPE(fg->regv[i]->vtyp->next);
/* cc */
if(new->typf==0) ierror(0);
new->q1.flags=VAR|REG;
new->q1.val.vmax=l2zm(0L);
new->q1.v=fg->regv[i];
new->q1.reg=i;
new->q2.flags=0;
new->q2.val.vmax=szof(fg->regv[i]->vtyp);
new->z.flags=VAR|DONTREGISTERIZE;
new->z.val.vmax=l2zm(0L);
new->z.v=fg->regv[i];
new->q1.am=new->q2.am=new->z.am=0;
new->use_cnt=new->change_cnt=0;
new->use_list=new->change_list=0;
/* Vor FREEREGs und evtl. Branch+COMPARE/TEST setzen */
if(fg->end){
tp=fg->end;
while(tp!=fg->start&&(tp->code==FREEREG||tp->code==SETRETURN))
tp=tp->prev;
if(tp&&tp->code>=BEQ&&tp->code<=BRA){
if(tp->code<BRA){
int c;
do{
tp=tp->prev;
c=tp->code;
if(c!=FREEREG&&c!=COMPARE&&c!=TEST) ierror(0);
}while(c!=COMPARE&&c!=TEST);
}
tp=tp->prev;
}
}else tp=lic;
insert_IC_fg(fg,tp,new);
}
}
if(fg->regv[i]->index>=vcount-rcount||BTST(fg->av_in,fg->regv[i]->index)){
if((fg==fg1||entry_load(fg,i))&&(fg!=fg1||!(fg->regv[i]->flags®PARM))){
if(DEBUG&8192) printf("\thave to load it at start of block\n");
new=new_IC();
new->line=0;
new->file=0;
new->code=ASSIGN;
new->typf=fg->regv[i]->vtyp->flags;
/* vla */
if(ISARRAY(new->typf))
new->typf=POINTER_TYPE(fg->regv[i]->vtyp->next);
/* cc */
if(new->typf==0) ierror(0);
if(fg->regv[i]->index>=vcount-rcount){
insert_cobj(&new->q1,&fg->regv[i]->cobj);
}else{
new->q1.flags=VAR|DONTREGISTERIZE;
new->q1.val.vmax=l2zm(0L);
new->q1.v=fg->regv[i];
}
new->q2.flags=0;
new->q2.val.vmax=szof(fg->regv[i]->vtyp);
if(fg->regv[i]->index>=vcount-rcount)
new->z.flags=REG;
else
new->z.flags=VAR|REG;
new->z.val.vmax=l2zm(0L);
new->z.v=fg->regv[i];
new->z.reg=i;
new->q1.am=new->q2.am=new->z.am=0;
new->use_cnt=new->change_cnt=0;
new->use_list=new->change_list=0;
insert_IC_fg(fg,lic,new);
}
}
if(!lfg||!lfg->regv[i]) insert_allocreg(fg,lic,ALLOCREG,i);
if(!fg->normalout||!fg->normalout->regv[i])
insert_allocreg(fg,fg->end?fg->end:lic,FREEREG,i);
}
}
if(fg->end) lic=fg->end;
lfg=fg;
fg=fg->normalout;
}
load_reg_parms(fg1);
}
void do_loop_regs(struct flowgraph *start,struct flowgraph *end,int intask)
/* Macht die Variablenzuweisung in Schleife start-end. */
/* Wenn end==0 Registerzuweisung fuer die ganze Funktion, ansonsten */
/* fuer die Schleife, die zum Header start gehoert. */
{
struct flowgraph *g,*lend;
int i,r,iterations;
struct Var *lregs[MAXR+1]={0};
unsigned char regu[MAXR+1]={0};
bvtype *isused=mymalloc(vsize);
/* Berechnen, wieviel ungefaehr eingespart wird, wenn eine Variable */
/* fuer diese Schleife in einem best. Register gehalten wird. */
/* Die savings in einer Schleife werden multipliziert, um das */
/* Laden/Speichern ausserhalb der Schleife geringer zu wichten. */
/* if(end&&(!g->normalout||!g->normalout->loopend||g->normalout->loopend->normalout->index!=-2)) ierror(0);*/
/* alle auf 0 */
for(i=0;i<vcount-rcount+const_vars;i++){
if(i<vcount-rcount&&(vilist[i]->vtyp->flags&VOLATILE)){
for(r=1;r<=MAXR;r++){
savings[i][r]=INT_MIN;
}
}else{
for(r=1;r<=MAXR;r++){
savings[i][r]=0;
}
}
}
if(end){
struct Var *v;
/* estimated number of iterations, avoid too big values */
if(optsize)
iterations=1;
else
iterations=4;
/* Evtl. Kosten fuers Laden/Speichern beim Ein-/Austritt in die */
/* Schleife. */
end=start->normalout->loopend;
g=end->normalout;
if(DEBUG&9216) printf("assigning regs to blocks %d to %d\n",start->normalout->index,end->index);
/* Werte modifizieren, falls Variable am Anfang/Ende der Schleife */
/* geladen/gespeichert werden muss. */
/* FIXME: Evtl. noetige stores/loads in anderen Bloecken! */
for(i=0;i<vcount-rcount+const_vars;i++){
v=vilist[i];
if(i>=vcount-rcount||BTST(start->av_in,i)){
for(r=1;r<=MAXR;r++)
if(start->regv[r]!=v&&savings[i][r]!=INT_MIN)
savings[i][r]-=cost_load_reg(r,v);
}
if(i<vcount-rcount&&BTST(g->av_out,i)){
for(r=1;r<=MAXR;r++)
if(g->regv[r]!=v&&savings[i][r]!=INT_MIN)
savings[i][r]-=cost_save_reg(r,v);
}
}
/* Werte modifizieren, falls eine andere Variable gespeichert oder */
/* geladen werden muss. Hmm..stimmt das so? */
for(r=1;r<=MAXR;r++){
v=start->regv[r];
if(v&&v->index<vcount-rcount&&BTST(start->av_in,v->index)){
for(i=0;i<vcount-rcount;i++)
if(v->index!=i&&savings[i][r]!=INT_MIN)
savings[i][r]-=cost_load_reg(r,vilist[i]);
}
if(v&&v->index<vcount-rcount&&BTST(g->av_out,v->index)){
for(i=0;i<vcount-rcount;i++)
if(v->index!=i&&savings[i][r]!=INT_MIN)
savings[i][r]-=cost_save_reg(r,vilist[i]);
}
}
g=start->normalout;
}else{
iterations=1;
/* Bei Registervergabe fuer die ganze Funktion muessen alle beim */
/* Eintritt der Funktion aktiven Variablen geladen werden. */
/* statics have to be saved at the end */
if(DEBUG&9216) printf("assigning regs to whole function\n");
for(i=0;i<vcount-rcount+const_vars;i++){
if(i<vcount-rcount&&(vilist[i]->storage_class==STATIC||vilist[i]->storage_class==EXTERN)){
for(r=1;r<=MAXR;r++)
if(savings[i][r]!=INT_MIN)
savings[i][r]-=cost_save_reg(r,vilist[i]);
}
if(i>=vcount-rcount||BTST(start->av_in,i)){
int pr=abs(vilist[i]->reg);
for(r=1;r<=MAXR;r++){
if(savings[i][r]!=INT_MIN){
if(pr==0){
savings[i][r]-=cost_load_reg(r,vilist[i]);
}else if(!regsa[r]){
if(r==pr)
savings[i][r]+=cost_save_reg(r,vilist[i]);
else
savings[i][r]+=(cost_save_reg(r,vilist[i])-cost_move_reg(pr,r));
}
}
}
}
}
/* Nonscratchregister muessen geladen/gesichert werden. */
/*FIXME: einige unschoene Effekte(?) */
if(!intask){
for(r=1;r<=MAXR;r++){
if(!regscratch[r]&&!regsa[r]){
for(i=0;i<vcount-rcount+const_vars;i++)
if(savings[i][r]!=INT_MIN)
savings[i][r]-=cost_pushpop_reg(r);
}
}
}
g=start;
}
if(DEBUG&9216) printf("calculating approximate savings\n");
lend=0;
for(;g;g=g->normalout){
struct IC *p;struct Var *v;
int t,vt;
if(!end&&!lend){
lend=g->loopend;
if(lend&&iterations==1&&!optsize) iterations=4;
}
/* Wenn das Register in dem Block benutzt wird, muss man es retten */
for(r=1;r<=MAXR;r++){
if(BTST(g->regused,r)||(reg_pair(r,&rp)&&(BTST(g->regused,rp.r1)||BTST(g->regused,rp.r2)))){
int vi;
if(g->regv[r]) vi=g->regv[r]->index; else vi=-1;
for(i=0;i<vcount-rcount+const_vars;i++){
if(i>=vcount-rcount||BTST(g->av_out,i)||BTST(g->av_gen,i))
if(vi!=i&&savings[i][r]!=INT_MIN)
savings[i][r]-=iterations*cost_load_reg(r,vilist[i])+cost_save_reg(r,vilist[i]);
}
}
}
memcpy(isused,g->av_out,vsize);
p=g->end;
while(p){
if((p->q1.flags&(VAR|VARADR|REG))==VAR){
v=p->q1.v;vt=v->vtyp->flags;
/* vla */
if(ISARRAY(vt)&&is_vlength(v->vtyp))
vt=POINTER_TYPE(v->vtyp->next);
if((optflags&1024)||((v->storage_class==AUTO||v->storage_class==REGISTER)&&!(v->flags&USEDASADR))){
i=v->index;
if(p->code==ADDRESS||((p->code==ASSIGN||p->code==PUSH)&&(q1typ(p)&NQ)==(CHAR)&&!zmeqto(p->q2.val.vmax,l2zm(1L)))){
for(r=1;r<=MAXR;r++)
savings[i][r]=INT_MIN;
}else{
for(r=1;r<=MAXR;r++){
if(!regsa[r]&&!BTST(g->regused,r)&&savings[i][r]!=INT_MIN&®ok(r,vt,-1)&&(!reg_pair(r,&rp)||(!regsa[rp.r1]&&!regsa[rp.r2]&&!BTST(g->regused,rp.r1)&&!BTST(g->regused,rp.r2)))){
int s=cost_savings(p,r,&p->q1);
if(s==INT_MIN)
savings[i][r]=INT_MIN;
else
savings[i][r]+=iterations*s;
}
}
}
}
}
if((p->q2.flags&(VAR|VARADR|REG))==VAR){
v=p->q2.v;vt=v->vtyp->flags;
/* vla */
if(ISARRAY(vt)&&is_vlength(v->vtyp))
vt=POINTER_TYPE(v->vtyp->next);
if((optflags&1024)||((v->storage_class==AUTO||v->storage_class==REGISTER)&&!(v->flags&USEDASADR))){
i=v->index;
for(r=1;r<=MAXR;r++){
if(!regsa[r]&&!BTST(g->regused,r)&&savings[i][r]!=INT_MIN&®ok(r,vt,-1)&&(!reg_pair(r,&rp)||(!regsa[rp.r1]&&!regsa[rp.r2]&&!BTST(g->regused,rp.r1)&&!BTST(g->regused,rp.r2)))){
int s=cost_savings(p,r,&p->q2);
if(s==INT_MIN)
savings[i][r]=INT_MIN;
else
savings[i][r]+=iterations*s;
}
}
}
}
if((p->z.flags&(VAR|VARADR|REG))==VAR){
v=p->z.v;vt=v->vtyp->flags;
if(ISARRAY(vt)&&is_vlength(v->vtyp))
vt=POINTER_TYPE(v->vtyp->next);
if((optflags&1024)||((v->storage_class==AUTO||v->storage_class==REGISTER)&&!(v->flags&USEDASADR))){
i=v->index;
if(p->code==ASSIGN&&(ztyp(p)&NQ)==(CHAR)&&!zmeqto(p->q2.val.vmax,l2zm(1L))){
for(r=1;r<=MAXR;r++)
savings[i][r]=INT_MIN;
}
for(r=1;r<=MAXR;r++){
if(!regsa[r]&&!BTST(g->regused,r)&&savings[i][r]!=INT_MIN&®ok(r,vt,-1)&&(!reg_pair(r,&rp)||(!regsa[rp.r1]&&!regsa[rp.r2]&&!BTST(g->regused,rp.r1)&&!BTST(g->regused,rp.r2)))){
int s=cost_savings(p,r,&p->z);
if(s==INT_MIN)
savings[i][r]=INT_MIN;
else
savings[i][r]+=iterations*s;
}
}
}
}
/* bei Funktionsaufruf zerstoert... */
if(p->code==CALL){
if((p->q1.flags&(VAR|DREFOBJ))==VAR&&p->q1.v->fi&&(p->q1.v->fi->flags&ALL_REGS)&&!(disable&2048)){
for(i=0;i<vcount-rcount+const_vars;i++){
if(i>=vcount-rcount||BTST(isused,i)){
for(r=1;r<=MAXR;r++){
if(savings[i][r]!=INT_MIN&&BTST(p->q1.v->fi->regs_modified,r))
savings[i][r]-=iterations*(cost_load_reg(r,vilist[i])+cost_load_reg(r,vilist[i]));
}
}
}
}else{
for(i=0;i<vcount-rcount+const_vars;i++){
if(i>=vcount-rcount||BTST(isused,i)){
for(r=1;r<=MAXR;r++){
if(regscratch[r]&&savings[i][r]!=INT_MIN)
savings[i][r]-=iterations*(cost_load_reg(r,vilist[i])+cost_load_reg(r,vilist[i]));
}
}
}
}
}
if(p==g->start) break;
if(p->change_cnt!=0||p->use_cnt!=0)
av_update(p,isused);
p=p->prev;
}
if(g==end) break;
if(!end){
if(g==lend) {lend=0;iterations=1;}
}
}
/* Maximum ermitteln */
for(i=0;i<vcount-rcount+const_vars;i++){
int m=0,t;struct Var *v;
v=vilist[i];t=v->vtyp->flags;
if(ISARRAY(t)&&is_vlength(v->vtyp))
t=POINTER_TYPE(v->vtyp->next);
if(!(optflags&1024)&&((v->storage_class!=AUTO&&v->storage_class!=REGISTER)||(v->flags&USEDASADR))){
for(r=0;r<=MAXR;r++)
savings[i][r]=INT_MIN;
}else{
for(r=1;r<=MAXR;r++){
/* Falls Variable in best. Register muss. */
if(r==abs(v->reg)&&!(v->flags®PARM)) savings[i][r]=INT_MAX;
if(regsa[r]||!regok(r,t,-1)) savings[i][r]=INT_MIN;
if(savings[i][r]>m) m=savings[i][r];
}
savings[i][0]=m;
}
}
if(DEBUG&8192){
for(i=0;i<vcount-rcount+const_vars;i++){
printf("(%s),%ld(best=%d):\n",vilist[i]->identifier,zm2l(vilist[i]->offset),savings[i][0]);
for(r=1;r<=MAXR;r++)
printf("%s=%d ",regnames[r],savings[i][r]);
printf("\n");
}
}
/* Suchen, welche Variablen/Registerkombination das beste Ergebnis */
/* liefert. Nur angenaehert, da sonst wohl zu aufwendig. Simplex? */
for(i=0;i<vcount-rcount+const_vars;i++) rvlist[i]=i;
vqsort(rvlist,vcount-rcount+const_vars,sizeof(*rvlist),cmp_savings);
for(i=0;i<vcount-rcount+const_vars;i++){
int use,m=0,prio=0,vi;
vi=rvlist[i];
/*if(vilist[vi]->flags&USEDASADR) continue;*/
if(DEBUG&8192) printf("%d: (%s),%ld(best=%d)\n",i,vilist[vi]->identifier,zm2l(vilist[vi]->offset),savings[vi][0]);
for(r=1;r<=MAXR;r++){
if(!lregs[r]&&!regu[r]&&savings[vi][r]>=m&&(!reg_pair(r,&rp)||(!regu[rp.r1]&&!regu[rp.r2]))){
if(savings[vi][r]>m||reg_prio[r]>prio){
m=savings[vi][r];prio=reg_prio[r];
use=r;
}
}
}
if(m>0&&check_cacheable(vi,start,end)){
if(DEBUG&9216) printf("assigned (%s),%ld(%p) to %s, saving=%d\n",vilist[vi]->identifier,zm2l(vilist[vi]->offset),(void *)vilist[vi],regnames[use],m);
lregs[use]=vilist[vi];
regu[use]=1;
if(reg_pair(use,&rp))
regu[rp.r1]=regu[rp.r2]=1;
}
}
/* Registervariablen in alle Bloecke der Schleife eintragen */
/* dabei beruecksichtigen, dass sie in manchen Bloecken nicht */
/* in Register kommen koennen, wenn das Register da schon von */
/* local_regs benutzt wird */
/* Gegebenenfalls auch in Header/Footer einer Schleife */
/* eintragen. */
if(DEBUG&9216) printf("propagate register vars\n");
for(g=start;g;g=g->normalout){
for(r=1;r<=MAXR;r++){
if(lregs[r]&&!BTST(g->regused,r)&&(!reg_pair(r,&rp)||(!BTST(g->regused,rp.r1)&&!BTST(g->regused,rp.r2)))){
/* Falls Variable schon in anderem Register, loeschen */
for(i=1;i<=MAXR;i++){
if(g->regv[i]==lregs[r]) g->regv[i]=0;
if(reg_pair(i,&rp)){
if(rp.r1==r||rp.r2==r) g->regv[i]=0;
}
}
g->regv[r]=lregs[r];
if(reg_pair(r,&rp)) g->regv[rp.r1]=g->regv[rp.r2]=0;
}
}
if(end&&g==end->normalout) break;
}
}
void block_regs(struct flowgraph *fg)
/* macht die Variablenzuweisung fuer einzelne Bloecke */
{
struct flowgraph *g,**fgp;
int i,r,changed,fgz;
if(DEBUG&9216) printf("block_regs\n");
savings=mymalloc((vcount-rcount)*sizeof(*savings));
rvlist=mymalloc((vcount-rcount)*sizeof(*rvlist));
/* Array auf Bloecke im Flussgraphen mangels doppelter Verkettung */
fgp=mymalloc(basic_blocks*sizeof(*fgp));
g=fg;fgz=0;
while(g){
fgp[fgz]=g;fgz++;
g=g->normalout;
}
if(fgz>basic_blocks) ierror(0); else basic_blocks=fgz;
/* alle auf 0 */
do{
changed=0;
if(DEBUG&9216) printf("block_regs pass\n");
for(fgz=basic_blocks-1;fgz>=0;fgz--){
struct IC *p;struct Var *v;struct flowlist *lp;
int t,vt;
g=fgp[fgz];
if(DEBUG&8192) printf("assigning regs to block %d\n",g->index);
/* berechnen, wieviel ungefaehr eingespart wird, wenn eine Variable */
/* fuer diesen Block in einem best. Register gehalten wird */
if(DEBUG&8192) printf("calculating approximate savings\n");
for(i=0;i<vcount-rcount;i++){
for(r=1;r<=MAXR;r++){
if(!g->regv[r]||g->regv[r]->index!=i){
int w=0;
/* Variable muss evtl. geladen/gespeichert werden */
if(BTST(g->av_in,i)) w--;
if(BTST(g->av_out,i)) w--;
savings[i][r]=w;
}
}
}
if(g->calls>0){
/* bei Funktionsaufrufen muessen Scratchregister gespeichert werden */
for(r=1;r<=MAXR;r++)
if(regscratch[r])
for(i=0;i<vcount-rcount;i++) savings[i][r]-=g->calls*2;
}
/* Wenn Vorgaenger/Nachfolger selbe Variable im selben */
/* Register hat, entfaellt Laden/Speichern in diesem */
/* Block und vermutlich auch im Vorgaenger/Nachfolger */
/* nicht immer, aber naeherungsweise... */
lp=g->in;
while(lp){
if(lp->graph){
for(r=1;r<=MAXR;r++){
if(lp->graph->regv[r]&&BTST(g->av_in,lp->graph->regv[r]->index)) savings[lp->graph->regv[r]->index][r]+=2;
}
}
lp=lp->next;
}
if(g->branchout){
for(r=1;r<=MAXR;r++){
if(g->branchout->regv[r]&&BTST(g->av_out,g->branchout->regv[r]->index)) savings[g->branchout->regv[r]->index][r]+=2;
}
}
if(g->normalout&&(!g->normalout->end||g->normalout->end->code!=BRA)){
for(r=1;r<=MAXR;r++){
if(g->normalout->regv[r]&&BTST(g->av_out,g->normalout->regv[r]->index)) savings[g->normalout->regv[r]->index][r]+=2;
}
}
p=g->start;
while(p){
if((p->q1.flags&(VAR|VARADR|REG))==VAR){
v=p->q1.v;
if((v->storage_class==AUTO||v->storage_class==REGISTER)&&!(v->flags&USEDASADR)){
vt=v->vtyp->flags&NU;
i=v->index;
if(p->q1.flags&DREFOBJ) t=p->typf&NU; else t=0;
for(r=1;r<=MAXR;r++){
if(!regsa[r]&&!BTST(g->regused,r)){
/* extra saving, falls passendes Reg fuer DREF */
if(t&®ok(r,vt,t)) savings[i][r]++;
if(regok(r,vt,0)) savings[i][r]++;
}
}
}
}
if((p->q2.flags&(VAR|VARADR|REG))==VAR){
v=p->q2.v;
if((v->storage_class==AUTO||v->storage_class==REGISTER)&&!(v->flags&USEDASADR)){
vt=v->vtyp->flags&NU;
i=v->index;
if(p->q2.flags&DREFOBJ) t=p->typf&NU; else t=0;
for(r=1;r<=MAXR;r++){
if(!regsa[r]&&!BTST(g->regused,r)){
/* extra saving, falls passendes Reg fuer DREF */
if(t&®ok(r,vt,t)) savings[i][r]++;
if(regok(r,vt,0)) savings[i][r]++;
}
}
}
}
if((p->z.flags&(VAR|VARADR|REG))==VAR){
v=p->z.v;
if((v->storage_class==AUTO||v->storage_class==REGISTER)&&!(v->flags&USEDASADR)){
vt=v->vtyp->flags&NU;
i=v->index;
if(p->z.flags&DREFOBJ) t=p->typf&NU; else t=0;
for(r=1;r<=MAXR;r++){
if(!regsa[r]&&!BTST(g->regused,r)){
/* extra saving, falls passendes Reg fuer DREF */
if(t&®ok(r,vt,t)) savings[i][r]++;
if(regok(r,vt,0)) savings[i][r]++;
}
}
}
}
if(p==g->end) break;
p=p->next;
}
/* moegliche Kandidaten suchen; muss nicht immer die beste */
/* Kombination finden, sollte aber bei lokaler Vergabe */
/* selten einen Unterschied machen */
for(r=1;r<=MAXR;r++){
if(g->regv[r]||BTST(g->regused,r)) continue;
for(i=0;i<vcount-rcount;i++){
if(savings[i][r]>0){
int flag;struct Var *v=vilist[i];
/* Variable schon in anderem Register? */
for(flag=1;flag<=MAXR;flag++)
if(g->regv[flag]==v){flag=-1;break;}
if(flag>0){
if(DEBUG&9216) printf("assigned (%s),%ld(%p) to %s; saving=%d\n",vilist[i]->identifier,zm2l(vilist[i]->offset),(void *)vilist[i],regnames[r],savings[i][r]);
if(vilist[i]&&!vilist[i]->vtyp->flags) ierror(0);
g->regv[r]=vilist[i];
changed=1;
break;
}
}
}
}
}
}while(changed);
/* jetzt nochmal globale Register vergeben */
/* do_loop_regs(fgp[0],fgp[basic_blocks-1]);*/
free(fgp);
free(rvlist);
free(savings);
}
void loop_regs(struct flowgraph *fg,int intask)
/* weist Variablen in Schleifen Register zu */
{
struct flowgraph *g;
if(disable&4096) return;
if(DEBUG&9216) printf("assigning regs to function\n");
savings=mymalloc((vcount-rcount+const_vars)*sizeof(*savings));
rvlist=mymalloc((vcount-rcount+const_vars)*sizeof(*rvlist));
do_loop_regs(fg,0,intask);
if(DEBUG&9216) printf("assigning regs in loops\n");
for(g=fg;g;g=g->normalout){
if(g->index==-1&&!(disable&32768)) do_loop_regs(g,g,0);
}
free(rvlist);
free(savings);
}
void insert_allocreg(struct flowgraph *fg,struct IC *p,int code,int reg)
/* Fuegt ein ALLOCREG/FREEREG (in code) hinter p ein - bei p==0 in */
/* first_ic. */
{
struct IC *new=new_IC();
/* printf("%s %s",code==FREEREG?"freereg":"allocreg",regnames[reg]);pric2(stdout,p);*/
new->line=0;
new->file=0;
BSET(fg->regused,reg);
if(reg_pair(reg,&rp)){
BSET(fg->regused,rp.r1);
BSET(fg->regused,rp.r2);
regused[rp.r1]=regused[rp.r2]=1;
}
regused[reg]=1;
new->code=code;
new->typf=0;
new->q1.am=new->q2.am=new->z.am=0;
new->q1.flags=REG;
new->q1.reg=reg;
new->q2.flags=new->z.flags=0;
new->use_cnt=new->change_cnt=0;
new->use_list=new->change_list=0;
insert_IC_fg(fg,p,new);
}
struct Var *lregv[MAXR+1],*first_const,*last_const;
struct flowgraph *lfg;
/* re-inserts a cobj into an obj */
static void insert_cobj(struct obj *o,struct obj *co)
{
int dt=o->dtyp,df=o->flags&DREFOBJ;
*o=*co;
o->flags|=df;
o->dtyp=dt;
}
static struct Var *find_const_var(struct obj *o,int t)
{
struct Var *v;
for(v=first_const;v;v=v->next){
if((v->ctyp&NQ)==(t&NQ)&&!compare_objs(o,&v->cobj,t))
return v;
}
return 0;
}
static long cidx;
static struct Var *add_const_var(struct obj *o,int t)
{
struct Var *v;
static struct Typ vt={VOID},tt;
int m=o->flags;
if(o->flags&DREFOBJ){
t=o->dtyp;
o->flags&=~DREFOBJ;
}
if(v=find_const_var(o,t)){
o->flags=m;
return v;
}
v=mymalloc(sizeof(*v));
v->storage_class=AUTO;
v->cobj=*o;
v->ctyp=t;
tt.flags=t;
if(ISPOINTER(t)) tt.next=&vt;
v->vtyp=clone_typ(&tt);
v->next=0;
v->identifier=" constant";
v->flags=0;
v->reg=0;
cidx++;
v->offset=l2zm(cidx);
if(last_const){
last_const->next=v;
}else{
first_const=v;
const_vars=0;
}
last_const=v;
v->index=vcount-rcount+const_vars;
const_vars++;
/* Wir ueberschreiben die Eintraege von vcount-rcount bis vcount. */
/* Da sie nicht mehr benutzt werden, sollte das ok sein. */
vilist=myrealloc(vilist,sizeof(*vilist)*(vcount-rcount+const_vars));
vilist[vcount-rcount+const_vars-1]=v;
o->flags=m;
return v;
}
void create_const_vars(struct flowgraph *fg)
{
struct IC *p;int t;
struct Var *v;
if(DEBUG&1024) printf("creating const-vars\n");
cidx=0;
const_vars=0;
first_const=last_const=0;
for(;fg;fg=fg->normalout){
for(p=fg->start;p;p=p->next){
if(p->q1.flags&(KONST|VARADR)){
t=q1typ(p);
v=add_const_var(&p->q1,t);
p->q1.flags&=~(KONST|VARADR);
p->q1.flags|=(VAR|VKONST);
p->q1.v=v;
p->q1.val.vmax=l2zm(0L);
}
if(p->q2.flags&(KONST|VARADR)){
t=q2typ(p);
v=add_const_var(&p->q2,t);
p->q2.flags&=~(KONST|VARADR);
p->q2.flags|=(VAR|VKONST);
p->q2.v=v;
p->q2.val.vmax=l2zm(0L);
}
if(p->z.flags&(KONST|VARADR)){
t=ztyp(p);
v=add_const_var(&p->z,t);
p->z.flags&=~(KONST|VARADR);
p->z.flags|=(VAR|VKONST);
p->z.v=v;
p->z.val.vmax=l2zm(0L);
}
if(p==fg->end) break;
}
}
if(DEBUG&1024){
struct Var *v;
printf("const-vars:\n");
for(v=first_const;v;v=v->next){
printf("%d: ",v->index);
probj(stdout,&v->cobj,v->ctyp);
printf(" (t=%d)\n",v->ctyp);
}
}
}
void free_const_vars(void)
{
struct Var *v,*m;
if(DEBUG&1024) printf("free_const_vars()\n");
for(v=first_const;v;){
m=v->next;
free(v);
v=m;
}
}
#if 0
int free_hreg(struct flowgraph *fg,struct IC *p,int reg,int mustr)
/* Macht das Register reg frei, damit es als lokale Variable im IC p */
/* zur Verfuegung steht. Wenn mustr!=0, muss das Register unbedingt */
/* freigemacht werden, ansonsten kann davon abgesehen werden. */
{
struct IC *m,*first;struct Var *v;
int preg[MAXR+1]={0},calls[MAXR+1]={0},rreg,i;
first=0;
v=lregv[reg];
if(!v)
ierror(0);
if(DEBUG&8192) printf("free_hreg %s,%s,%d\n",regnames[reg],v->identifier,mustr);
if(v->reg&&!*v->identifier) ierror(0);
for(m=p;m;m=m->next){
if(m->code==CALL){
if((m->q1.flags&(VAR|DREFOBJ))==VAR&&m->q1.v->fi&&(m->q1.v->fi->flags&ALL_REGS)){
for(i=1;i<=MAXR;i++)
if(BTST(m->q1.v->fi->regs_modified,i)) calls[i]++;
}else{
for(i=1;i<=MAXR;i++)
if(regscratch[i]) calls[i]++;
}
}
if(m->code==ALLOCREG){
preg[m->q1.reg]=1;
if(m->q1.reg==reg) ierror(0);
}
if(m->code==FREEREG){
preg[m->q1.reg]=1;
if(m->q1.reg==reg) break;
}
if(!USEQ2ASZ){
if((m->q2.flags&VAR)&&m->q2.v==v&&(m->z.flags&(REG|DREFOBJ))==REG&&
(!(m->z.flags&VAR)||m->z.v!=v))
preg[m->z.reg]=1;
}
if(((m->q1.flags&VAR)&&m->q1.v==v)||
((m->q2.flags&VAR)&&m->q2.v==v)||
((m->z.flags&(VAR|DREFOBJ))==(VAR|DREFOBJ)&&m->z.v==v))
first=m;
/* if((m->z.flags&(REG|DREFOBJ))==REG&&m->z.reg==reg) break;*/
}
if(!first) {pric(stdout,p);ierror(0);}
rp.r1=rp.r2=0;
for(rreg=0,i=1;i<=MAXR;i++){
if(preg[i]||regu[i]||regsa[i]||!regok(i,v->vtyp->flags,0)) continue;
if(reg_pair(i,&rp)&&(preg[rp.r1]||preg[rp.r2]||regu[rp.r1]||regu[rp.r2]||regsa[rp.r1]||regsa[rp.r2])) continue;
if(calls[i]==0&®scratch[i]){rreg=i;break;}
if(calls[i]==0) rreg=i;
}
if(!rreg&&!mustr) return 0;
for(m=p;m!=first->next;m=m->next){
if((m->q1.flags&VAR)&&m->q1.v==v)
{if(!rreg) m->q1.flags&=~REG; else m->q1.reg=rreg;}
if((m->q2.flags&VAR)&&m->q2.v==v)
{if(!rreg) m->q2.flags&=~REG; else m->q2.reg=rreg;}
if((m->z.flags&VAR)&&m->z.v==v)
{if(!rreg) m->z.flags&=~REG; else m->z.reg=rreg;}
#if 0
if((m->z.flags&(VAR|DREFOBJ))==VAR&&m->z.v==v)
break;
#endif
}
if(rreg){
lregv[rreg]=lregv[reg];
regused[rreg]=1;regu[rreg]=1;BSET(fg->regused,rreg);