/* $VER: vbcc (alias.c) V0.8 */ /* Listen benutzter/veraenderter Variablen und Behandlung von Decknamen. */ #include "opt.h" static char FILE_[]=__FILE__; static bvtype **gpt; static unsigned long ptsize; #define is_restrict(i) ((i)<=vcount-rcount&&(vilist[i]->vtyp->flags&RESTRICT)) /* sets points-to-info for var i to undefined */ void undef_pt(bvtype **pt,int i) { if(i<0||i>=vcount) ierror(0); if(pt[i]) ptsize-=vsize; free(pt[i]); pt[i]=0; if(iflags)){ for(sz=l2zm(0L);!zmleq(t->size,sz)&&cl;sz=zmadd(sz,l2zm(1L)),cl=cl->next){ if(!cl->other){ierror(0);return;} add_clist_refs(bv,t->next,cl->other); } return; } if(ISUNION(t->flags)){ add_clist_refs(bv,(*t->exact->sl)[0].styp,cl); return; } if(ISSTRUCT(t->flags)){ struct Typ *st; for(i=0;iexact->count&&cl;i++){ if(!cl->other){ierror(0);return;} st=(*t->exact->sl)[i].styp; if(!(*t->exact->sl)[i].identifier) ierror(0); if((*t->exact->sl)[i].identifier[0]){ add_clist_refs(bv,st,cl->other); cl=cl->next; } } return; } if(cl->tree&&(cl->tree->o.flags&VARADR)){ /* careful: variable might not have a valid index if it is not used within the function optimized */ i=cl->tree->o.v->index; if(i>=0&&itree->o.v){ /*printf("add %s\n",vilist[i]->identifier);*/ BSET(bv,i); } } } /* copies points-to-info for one var to another */ void copy_pt(bvtype **pt,int to,int from) { if(to<0||to>=vcount) ierror(0); if(from<0||from>=vcount) ierror(0); if(!pt[from]){ if(from>=vcount-rcount&&pt[from-(vcount-rcount)]){ /* if dref check, whether from only points to initialized const */ int i;bvtype *new; for(i=0;ivtyp)||!v->clist) break; } } if(i==vcount){ /* yes, take the points-to-info from clist */ if(!pt[to]||to+vcount-rcount==from){ new=mymalloc(vsize); ptsize+=vsize; }else new=pt[to]; memset(new,0,vsize); for(i=0;ivtyp,vilist[i]->clist); } if(to+vcount-rcount==from){ ptsize-=vsize; free(pt[to]); } pt[to]=new; return; } } undef_pt(pt,to); }else{ if(!pt[to]){ pt[to]=mymalloc(vsize); ptsize+=vsize; } memcpy(pt[to],pt[from],vsize); } } /* set var i points only to j in points-to-info */ void set_pt(bvtype **pt,int i,int j) { if(i<0||i>=vcount) ierror(0); if(j<0||j>=vcount) ierror(0); if(!pt[i]){ pt[i]=mymalloc(vsize); ptsize+=vsize; } memset(pt[i],0,vsize); BSET(pt[i],j); } void print_single_pt(bvtype *pt) { int j; if(pt){ for(j=0;j(%p)\n",(j>=vcount-rcount)?"*":"",vilist[j]->identifier,(void*)vilist[j]); } }else{ printf(" (undefined)\n"); } } void print_pt(bvtype **pt) { int i,j; if(!pt) return; printf("points-to:\n"); for(i=0;i(%p):\n",(i>=vcount-rcount)?"*":"",vilist[i]->identifier,(void*)vilist[i]); print_single_pt(pt[i]); } } /* creates new points-to-info; every var set to undefined */ bvtype **new_pt(void) { bvtype **pt; int i; pt=mymalloc(vcount*sizeof(*pt)); ptsize+=vcount*sizeof(*pt); for(i=0;ivtyp->flags&RESTRICT)){ pt[i]=mymalloc(vsize); ptsize+=vsize; memset(pt[i],0,vsize); BSET(pt[i],i+vcount-rcount); }else pt[i]=0; } return pt; } void free_pt(bvtype **pt) { int i; if(pt){ for(i=0;i=rcount) ierror(0); d=i+vcount-rcount; if(!pt[i]){ undef_pt(pt,d); return; } if(!pt[d]){ pt[d]=mymalloc(vsize); ptsize+=vsize; } memset(pt[d],0,vsize); for(j=0;jclist&&is_const(v->vtyp)){ add_clist_refs(pt[d],v->vtyp,v->clist); }else if(!pt[j]){ undef_pt(pt,d); return; }else bvunite(pt[d],pt[j],vsize); } } } void trans_pt(bvtype **pt,struct IC *p) { int i,j,newset=-1,sv,cp; if((p->code==ADDI2P||p->code==SUBIFP)&&!compare_objs(&p->q1,&p->z,ztyp(p))) return; if((p->z.flags&VAR)&&ISSCALAR(p->z.v->vtyp->flags)){ i=p->z.v->index; if(i<0||i>=vcount) ierror(0); if(p->z.flags&DREFOBJ){ if(i>=rcount) ierror(0); i+=vcount-rcount; } if(!is_restrict(i)){ if(p->code==ASSIGN){ newset=i;sv=-1;cp=-1; if(p->q1.flags&VARADR){ sv=p->q1.v->index; set_pt(pt,i,p->q1.v->index); }else if(p->q1.flags&VAR){ j=p->q1.v->index; if(j<0||j>=vcount) ierror(0); if(p->q1.flags&DREFOBJ){ if(j>=rcount) ierror(0); j+=vcount-rcount; } cp=j; copy_pt(pt,i,j); }else{ if(!pt[i]){ pt[i]=mymalloc(vsize); ptsize+=vsize; } memset(pt[i],0,vsize); } } if(p->code==ADDRESS){ newset=i;sv=p->q1.v->index;cp=-1; set_pt(pt,i,p->q1.v->index); } if((p->code==ADDI2P||p->code==SUBIFP)&&(p->q1.flags&VAR)){ newset=i;sv=-1;cp=-1; if(p->q1.flags&VARADR){ sv=p->q1.v->index; set_pt(pt,i,p->q1.v->index); }else{ j=p->q1.v->index; if(j<0||j>=vcount) ierror(0); if(p->q1.flags&DREFOBJ){ if(j>=rcount) ierror(0); j+=vcount-rcount; } cp=j; copy_pt(pt,i,j); } } } } if(newset>=0&&newsetchange_cnt;i++){ j=p->change_list[i].v->index; if(j<0||j>=vcount) ierror(0); if(p->change_list[i].flags&DREFOBJ){ if(j>=rcount) ierror(0); j+=vcount-rcount; } if(j!=newset&&!is_restrict(j)){ if(newset>=0&&pt[j]){ if(sv>=0){ if(sv>=vcount) ierror(0); BSET(pt[j],sv); } if(cp>=0&&pt[cp]){ if(cp<0||cp>=vcount) ierror(0); bvunite(pt[j],pt[cp],vsize); } }else undef_pt(pt,j); } } } bvtype **clone_pt(bvtype **pt) { int i; bvtype **new; if(!pt) return new_pt(); new=mymalloc(vcount*sizeof(*new)); ptsize+=vcount*sizeof(*new); for(i=0;inormalout){ /* do all predecessors already have points-to-info? */ all_preds=1; for(in=g->in;in;in=in->next){ if(!in->graph->pt){ all_preds=0; break; } } if(all_preds&&g->in){ /* calc union of all predecessors */ pt=clone_pt(g->in->graph->pt); for(in=g->in->next;in;in=in->next){ ppt=in->graph->pt; for(i=0;istart;p;p=p->next){ trans_pt(pt,p); if(p==g->end) break; } if(pt==g->pt) ierror(0); if(!changed){ if(!equal_pt(pt,g->pt)){ changed=1; free_pt(g->pt); g->pt=pt; }else{ free_pt(pt); } }else{ free_pt(g->pt); g->pt=pt; } } } } #endif int p_typ(struct Var *v) /* Liefert den Typ, auf den Variable zeigen kann. Falls nicht eindeutig */ /* wird CHAR zurueckgegeben, da ein char * auf alles zeigen kann. */ { struct Typ *t=v->vtyp;int f; /* Kein Zeiger? Dann moeglicherweise Struktur, die verschiedene Zeiger */ /* enthalten koennte. Koennte man evtl. noch genauer pruefen. */ if(!ISPOINTER(t->flags)||!t->next||(v->flags&DNOTTYPESAFE)) return CHAR; f=t->next->flags&NQ; if(f==VOID) f=CHAR; return f; } /* propagates information if a variable whose address may have been taken is modified */ static void propagate_pointers(bvtype *set,struct Var *v,int t,int i) { int j,t2; if(v->nesting==0||v->storage_class==EXTERN||(v->flags&USEDASADR)){ if(noaliasopt){ bvunite(set,av_drefs,vsize); }else{ for(j=0;j=0&&BTST(gpt[j],i))) BSET(set,j+vcount-rcount); } } } } } void alias_propagate(bvtype *set,int i,int t,int wr) { int j,t2; struct Var *v; if(i<0||i>=vcount) ierror(0); t&=NQ; BSET(set,i); if(wr&&i=vcount-rcount){ /* DREFOBJ */ if(noaliasopt||t==CHAR||!ISSCALAR(t)){ bvunite(set,av_drefs,vsize); bvunite(set,av_address,vsize); bvunite(set,av_globals,vsize); }else{ for(j=0;jnesting==0||v->storage_class==EXTERN||(v->flags&USEDASADR)){ struct Typ *tp=v->vtyp; if(!v->vtyp) ierror(0); do{ t2=tp->flags&NQ; tp=tp->next; }while(ISARRAY(t2)); if(t==t2||!ISSCALAR(t2)){ BSET(set,j); if(wr&&jz.flags&VAR){ v=p->z.v; i=v->index; /* Hilfsvariable, die waehrend diesem cse-Durchlauf eingefuehrt */ /* wurde. */ if(i<0) return; if(i>=vcount) ierror(0); if(p->z.flags&DREFOBJ){ if(i>=rcount) ierror(0); alias_propagate(result,i+vcount-rcount,t,1); }else{ alias_propagate(result,i,t,1); if(icode==CALL){ struct function_info *fi; if((p->q1.flags&(VAR|DREFOBJ))==VAR&&(fi=p->q1.v->fi)&&(fi->flags&ALL_MODS)&&!(disable&65536)){ /* we can get the set from the function_info */ for(i=0;ichange_cnt;i++){ if(v=fi->change_list[i].v){ if(v->inr==inr&&v->index>=0){ if(v->index>=vcount) ierror(0); alias_propagate(result,v->index,v->vtyp->flags&NQ,1); }else propagate_pointers(result,v,v->vtyp->flags&NQ,-1); }else{ for(j=0;jnesting==0||v->storage_class==EXTERN||(v->flags&USEDASADR)){ t=v->vtyp->flags&NQ; if(t==(fi->change_list[i].flags&NQ)||!ISSCALAR(t)){ BSET(result,j); if(jchange_list[i].flags) BSET(result,j+vcount-rcount); } } } } }else{ bvunite(result,av_drefs,vsize); bvunite(result,av_address,vsize); bvunite(result,av_globals,vsize); bvunite(result,av_statics,vsize); } } if((p->z.flags&(KONST|DREFOBJ))==(KONST|DREFOBJ)){ bvunite(result,av_drefs,vsize); } } void ic_uses(struct IC *p,bvtype *result) /* Initialisiert den Bitvektor result mit allen Variablen, die durch das */ /* IC p benutzt werden koennten. */ { int i,j,t,t2,c;struct Var *v;struct Typ *tp; memset(result,0,vsize); c=p->code; if(c!=ADDRESS){ if((p->q1.flags&(VAR|VARADR))==VAR&&c!=ADDRESS&&(c!=CALL||(p->q1.flags&DREFOBJ))){ v=p->q1.v; i=v->index; if(i<0||i>=vcount) ierror(0); t=q1typ(p); if(p->q1.flags&DREFOBJ){ if(i>=rcount) ierror(0); alias_propagate(result,i+vcount-rcount,t,0); } alias_propagate(result,i,t,0); } if((p->q2.flags&(VAR|VARADR))==VAR){ v=p->q2.v; i=v->index; if(i<0||i>=vcount) ierror(0); t=q2typ(p); if(p->q2.flags&DREFOBJ){ if(i>=rcount) ierror(0); alias_propagate(result,i+vcount-rcount,t,0); } alias_propagate(result,i,t,0); } } if((p->z.flags&(VAR|VARADR|DREFOBJ))==(VAR|DREFOBJ)){ v=p->z.v; i=v->index; if(i>=vcount) {pric2(stdout,p);ierror(0);} t=(ztyp(p)&NQ); alias_propagate(result,i,t,0); } if(p->code==CALL){ struct function_info *fi; if((p->q1.flags&(VAR|DREFOBJ))==VAR&&(fi=p->q1.v->fi)&&(fi->flags&ALL_USES)&&!(disable&65536)){ /* we can get the set from the function_info */ for(i=0;iuse_cnt;i++){ if(v=fi->use_list[i].v){ if(v->inr==inr&&v->index>=0) alias_propagate(result,v->index,v->vtyp->flags&NQ,0); else propagate_pointers(result,v,v->vtyp->flags&NQ,-1); }else{ for(j=0;jnesting==0||v->storage_class==EXTERN||(v->flags&USEDASADR)){ t=v->vtyp->flags&NQ; if(t==(fi->use_list[i].flags&NQ)||!ISSCALAR(t)) BSET(result,j); } if(juse_list[i].flags) BSET(result,j+vcount-rcount); } } } } }else{ bvunite(result,av_drefs,vsize); bvunite(result,av_address,vsize); bvunite(result,av_globals,vsize); bvunite(result,av_statics,vsize); } } if((p->q1.flags&(KONST|DREFOBJ))==(KONST|DREFOBJ)){ bvunite(result,av_drefs,vsize); } if((p->q2.flags&(KONST|DREFOBJ))==(KONST|DREFOBJ)){ bvunite(result,av_drefs,vsize); } } void free_alias(struct flowgraph *fg) /* Gibt alle use/change-Listen der ICs im Flussgraphen frei. */ { struct IC *p;struct flowgraph *g; if(DEBUG&1024) printf("freeing alias info\n"); for(g=fg;g;g=g->normalout){ for(p=g->start;p;p=p->next){ if(p->code==LABEL&&(p->use_cnt>0||p->change_cnt>0)) ierror(0); if(p->use_cnt>0) {free(p->use_list);p->use_cnt=0;} if(p->change_cnt>0) {free(p->change_list);p->change_cnt=0;} if(p==g->end) break; } } have_alias=0; } void create_alias(struct flowgraph *fg) /* Initialisiert jedes IC mit einer Liste aller Variablen, die dadurch */ /* benutzt und veraendert werden koennten. Z.Z. wird bis auf Typ-basierte */ /* Optimierungen der worst-case angenommen. */ { bvtype *vars=mymalloc(vsize); struct IC *p;struct flowgraph *g; struct flowlist *in; bvtype **ppt; int i,cnt,all_preds,changed; unsigned long heapsize; if(DEBUG&1024) printf("creating alias info\n"); ptsize=0; changed=1; while(changed){ if(DEBUG&1024) printf("create_alias pass\n"); changed=0; if(have_alias) free_alias(fg); heapsize=0; for(g=fg;g;g=g->normalout){ if((optflags&1024)&&!noaliasopt){ /* do all predecessors already have points-to-info? */ all_preds=1; for(in=g->in;in;in=in->next){ if(!in->graph->pt){ all_preds=0; break; } } if(/*all_preds&&*/g->in){ /* calc union of all predecessors */ gpt=clone_pt(g->in->graph->pt); for(in=g->in->next;in;in=in->next){ ppt=in->graph->pt; if(!ppt) continue; for(i=0;istart;p;p=p->next){ ic_uses(p,vars); for(i=0,cnt=0;iuse_cnt=cnt; if(cnt==0){ p->use_list=0; }else{ p->use_list=mymalloc(cnt*VLS); heapsize+=cnt*VLS; for(cnt=0,i=0;iuse_list[cnt].v=vilist[i]; if(i>=vcount-rcount) p->use_list[cnt].flags=DREFOBJ; else p->use_list[cnt].flags=0; cnt++; } } } ic_changes(p,vars); for(i=0,cnt=0;i=vcount-rcount||!is_const(vilist[i]->vtyp))) cnt++; p->change_cnt=cnt; if(cnt==0){ p->change_list=0; }else{ p->change_list=mymalloc(cnt*VLS); heapsize+=cnt*VLS; for(cnt=0,i=0;i=vcount-rcount||!is_const(vilist[i]->vtyp))){ p->change_list[cnt].v=vilist[i]; if(i>=vcount-rcount) p->change_list[cnt].flags=DREFOBJ; else p->change_list[cnt].flags=0; cnt++; } } } if(p->code==CALL){ if((p->q1.flags&(VAR|DREFOBJ))==(VAR|DREFOBJ)){ int i=p->q1.v->index; if(i<0||i>=vcount) ierror(0); if(gpt&&gpt[i]){ int j,cnt; for(cnt=0,j=0;jvtyp->flags)) cnt++; } if(cnt){ if(p->call_cnt) free(p->call_list); p->call_cnt=cnt; p->call_list=mymalloc(sizeof(*p->call_list)*cnt); for(cnt=0,j=0;jvtyp->flags)){ p->call_list[cnt].v=vilist[j]; p->call_list[cnt].flags=0; cnt++; } } if(cnt==1){ p->q1.flags=VAR; p->q1.val.vmax=l2zm(0L); p->q1.v=p->call_list[0].v; } } } } } if((optflags&1024)&&!noaliasopt) trans_pt(gpt,p); if(p==g->end) break; } if((optflags&1024)&&!noaliasopt){ if(!changed){ if(!equal_pt(gpt,g->pt)){ changed=1; free_pt(g->pt); g->pt=gpt; }else{ free_pt(gpt); } }else{ free_pt(g->pt); g->pt=gpt; } } } if(DEBUG&16384) printf("create_alias heapsize=%lu\n",heapsize); have_alias=1; } if(DEBUG&16384) printf("points-to heapsize=%lu\n",ptsize); if((optflags&1024)&&!noaliasopt){ for(g=fg;g;g=g->normalout){ free_pt(g->pt); g->pt=0; } } free(vars); } #if 1 void update_alias(struct Var *old,struct Var *new) /* Aendert alle use/changes von (old) auf (new). Wird aufgerufen, wenn */ /* copy-propagation eine Variable neu zu einem DREFOBJ macht. */ { struct IC *p;int i; if(DEBUG&1024) printf("update-alias\n"); for(p=first_ic;p;p=p->next){ for(i=0;iuse_cnt;i++){ if(p->use_list[i].v==old&&(p->use_list[i].flags&DREFOBJ)){ p->use_cnt++; p->use_list=myrealloc(p->use_list,p->use_cnt*VLS); p->use_list[p->use_cnt-1].v=new; p->use_list[p->use_cnt-1].flags=DREFOBJ; break; } } for(i=0;ichange_cnt;i++){ if(p->change_list[i].v==new||(p->change_list[i].v==old&&(p->change_list[i].flags&DREFOBJ))){ p->change_cnt++; p->change_list=myrealloc(p->change_list,p->change_cnt*VLS); p->change_list[p->change_cnt-1].v=new; p->change_list[p->change_cnt-1].flags=DREFOBJ; break; } } } } #endif