- //fprintf(stderr, "FixBankFlow - Phase 1\n");
-
- for( pcflow = findNextpCode(pb->pcHead, PC_FLOW);
- pcflow != NULL;
- pcflow = findNextpCode(pcflow->next, PC_FLOW) ) {
-
- if(!isPCFL(pcflow)) {
- fprintf(stderr, "FixBankFlow - pcflow is not a flow object ");
- continue;
- }
-
- if(PCFL(pcflow)->firstBank != PCFL(pcflow)->lastBank &&
- PCFL(pcflow)->firstBank >= 0 &&
- PCFL(pcflow)->lastBank >= 0 ) {
-
- int cur_bank = (PCFL(pcflow)->firstBank < PCFL(pcflow)->lastBank) ?
- PCFL(pcflow)->firstBank : PCFL(pcflow)->lastBank;
-
- FixRegisterBankingInFlow(PCFL(pcflow),cur_bank);
- BanksUsedFlow2(pcflow);
-
- }
- }
-
- //fprintf(stderr, "FixBankFlow - Phase 2\n");
-
- for( pcflow = findNextpCode(pb->pcHead, PC_FLOW);
- pcflow != NULL;
- pcflow = findNextpCode(pcflow->next, PC_FLOW) ) {
-
- int nFlows;
- int nConflicts;
-
- if(!isPCFL(pcflow)) {
- fprintf(stderr, "FixBankFlow - pcflow is not a flow object ");
- continue;
- }
-
- PCFL(pcflow)->FromConflicts = 0;
- PCFL(pcflow)->ToConflicts = 0;
-
- nFlows = 0;
- nConflicts = 0;
-
- //fprintf(stderr, " FixBankFlow flow seq %d\n",pcflow->seq);
- pcfl = setFirstItem(PCFL(pcflow)->from);
- while (pcfl) {
-
- pc = PCODE(pcfl->pcflow);
-
- if(!isPCFL(pc)) {
- fprintf(stderr,"oops dumpflow - to is not a pcflow\n");
- pc->print(stderr,pc);
- }
-
- nConflicts += compareBankFlow(PCFL(pcflow), pcfl, 0);
- nFlows++;
-
- pcfl=setNextItem(PCFL(pcflow)->from);
- }
-
- if((nFlows >= 2) && nConflicts && (PCFL(pcflow)->firstBank>0)) {
- //fprintf(stderr, " From conflicts flow seq %d, nflows %d ,nconflicts %d\n",pcflow->seq,nFlows, nConflicts);
-
- FixRegisterBankingInFlow(PCFL(pcflow),0);
- BanksUsedFlow2(pcflow);
-
- continue; /* Don't need to check the flow from here - it's already been fixed */
-
- }
-
- nFlows = 0;
- nConflicts = 0;
-
- pcfl = setFirstItem(PCFL(pcflow)->to);
- while (pcfl) {
-
- pc = PCODE(pcfl->pcflow);
- if(!isPCFL(pc)) {
- fprintf(stderr,"oops dumpflow - to is not a pcflow\n");
- pc->print(stderr,pc);
- }
-
- nConflicts += compareBankFlow(PCFL(pcflow), pcfl, 1);
- nFlows++;
-
- pcfl=setNextItem(PCFL(pcflow)->to);
- }
-
- if((nFlows >= 2) && nConflicts &&(nConflicts != nFlows) && (PCFL(pcflow)->lastBank>0)) {
- //fprintf(stderr, " To conflicts flow seq %d, nflows %d ,nconflicts %d\n",pcflow->seq,nFlows, nConflicts);
-
- FixRegisterBankingInFlow(PCFL(pcflow),0);
- BanksUsedFlow2(pcflow);
- }
- }
-
- /*
- Loop through the flow objects again and find the ones with the
- maximum conflicts
- */
-
- for( pcflow = findNextpCode(pb->pcHead, PC_FLOW);
- pcflow != NULL;
- pcflow = findNextpCode(pcflow->next, PC_FLOW) ) {
-
- if(PCFL(pcflow)->ToConflicts > max_ToConflicts)
- pcflow_max_To = pcflow;
-
- if(PCFL(pcflow)->FromConflicts > max_FromConflicts)
- pcflow_max_From = pcflow;
- }
-/*
- if(pcflow_max_To)
- fprintf(stderr,"compare flow Max To conflicts: seq %d conflicts %d\n",
- PCFL(pcflow_max_To)->pc.seq,
- PCFL(pcflow_max_To)->ToConflicts);
-
- if(pcflow_max_From)
- fprintf(stderr,"compare flow Max From conflicts: seq %d conflicts %d\n",
- PCFL(pcflow_max_From)->pc.seq,
- PCFL(pcflow_max_From)->FromConflicts);
-*/
-}
-
-/*-----------------------------------------------------------------*/
-/*-----------------------------------------------------------------*/
-void DumpFlow(pBlock *pb)
-{
- pCode *pc=NULL;
- pCode *pcflow;
- pCodeFlowLink *pcfl;
-
-
- fprintf(stderr,"Dump flow \n");
- pb->pcHead->print(stderr, pb->pcHead);
-
- pcflow = findNextpCode(pb->pcHead, PC_FLOW);
- pcflow->print(stderr,pcflow);
-
- for( pcflow = findNextpCode(pb->pcHead, PC_FLOW);
- pcflow != NULL;
- pcflow = findNextpCode(pcflow->next, PC_FLOW) ) {
-
- if(!isPCFL(pcflow)) {
- fprintf(stderr, "DumpFlow - pcflow is not a flow object ");
- continue;
- }
- fprintf(stderr,"dumping: ");
- pcflow->print(stderr,pcflow);
- FlowStats(PCFL(pcflow));
-
- for(pcfl = setFirstItem(PCFL(pcflow)->to); pcfl; pcfl=setNextItem(PCFL(pcflow)->to)) {
-
- pc = PCODE(pcfl->pcflow);
-
- fprintf(stderr, " from seq %d:\n",pc->seq);
- if(!isPCFL(pc)) {
- fprintf(stderr,"oops dumpflow - from is not a pcflow\n");
- pc->print(stderr,pc);
- }
-
- }
-
- for(pcfl = setFirstItem(PCFL(pcflow)->to); pcfl; pcfl=setNextItem(PCFL(pcflow)->to)) {
-
- pc = PCODE(pcfl->pcflow);
-
- fprintf(stderr, " to seq %d:\n",pc->seq);
- if(!isPCFL(pc)) {
- fprintf(stderr,"oops dumpflow - to is not a pcflow\n");
- pc->print(stderr,pc);
- }
-
- }
-
- }
-
-}
+ // this one modifies STATUS
+ // XXX: this should be checked, but usually BANKSELs are not done this way in generated code
+
+ if (isPCI(pc)) {
+ pci = PCI(pc);
+ if ((pci->inCond | pci->outCond) & PCC_REGISTER) {
+ // might need a BANKSEL
+ reg = getRegFromInstruction(pc);
+
+ if (reg) {
+ new_bank = reg->name;
+ // reg->alias == 0: reg is in only one bank, we do not know which (may be any bank)
+ // reg->alias != 0: reg is in 2/4/8/2**N banks, we select one of them
+ new_mask = reg->alias;
+ } else if (pci->pcop && pci->pcop->name) {
+ new_bank = pci->pcop->name;
+ new_mask = 0; // unknown, assume worst case
+ } else {
+ assert(!"Could not get register from instruction.");
+ }
+
+ // optimizations...
+ // XXX: add switch to disable these
+ if (1) {
+ // reg present in all banks possibly selected?
+ if (new_mask == max_mask || (cur_mask && ((new_mask & cur_mask) == cur_mask))) {
+ // no BANKSEL required
+ addpCodeComment(pc->prev, "BANKOPT1 BANKSEL dropped; %s present in all of %s's banks", new_bank, cur_bank);
+ continue;
+ }
+
+ // only one bank of memory and no SFR accessed?
+ // XXX: We can do better with fixed registers.
+ if (allRAMmshared && reg && (reg->type != REG_SFR) && (!reg->isFixed)) {
+ // no BANKSEL required
+ addpCodeComment(pc->prev, "BANKOPT1b BANKSEL dropped; %s present in all of %s's banks", new_bank, cur_bank);
+ continue;
+ }
+
+ // restrict cur_mask to cover only the banks this register
+ // is in (as well as the previous registers)
+ cur_mask &= new_mask;
+
+ if (sameBank(reg, new_bank, cur_bank)) {
+ // no BANKSEL required
+ addpCodeComment(pc->prev, "BANKOPT2 BANKSEL dropped; %s present in same bank as %s", new_bank, cur_bank);
+ continue;
+ }
+ } // if
+
+ cur_mask = new_mask;
+ cur_bank = new_bank;
+ insertBankSel(pci, cur_bank);
+ } // if
+ } // if
+ } // for
+}