- } else {
- //fprintf(stderr, "Bummer can't switch banks\n");
- ;
- }
- }
-
- pcprev = pc;
- pc = findNextInstruction(pc->next);
-
- }
-
- if(pcprev && cur_bank) {
- /* Brute force - make sure that we point to bank 0 at the
- * end of each flow block */
- new_pc = newpCode(POC_BCF,
- popCopyGPR2Bit(PCOP(&pc_status),PIC_RP0_BIT));
- pCodeInsertAfter(pcprev, new_pc);
- cur_bank = 0;
- }
-
-}
-
-/*-----------------------------------------------------------------*/
-/*int compareBankFlow - compare the banking requirements between */
-/* flow objects. */
-/*-----------------------------------------------------------------*/
-int compareBankFlow(pCodeFlow *pcflow, pCodeFlowLink *pcflowLink, int toORfrom)
-{
-
- if(!pcflow || !pcflowLink || !pcflowLink->pcflow)
- return 0;
-
- if(!isPCFL(pcflow) || !isPCFL(pcflowLink->pcflow))
- return 0;
-
- if(pcflow->firstBank == -1)
- return 0;
-
-
- if(pcflowLink->pcflow->firstBank == -1) {
- pCodeFlowLink *pctl = setFirstItem( toORfrom ?
- pcflowLink->pcflow->to :
- pcflowLink->pcflow->from);
- return compareBankFlow(pcflow, pctl, toORfrom);
- }
-
- if(toORfrom) {
- if(pcflow->lastBank == pcflowLink->pcflow->firstBank)
- return 0;
-
- pcflowLink->bank_conflict++;
- pcflowLink->pcflow->FromConflicts++;
- pcflow->ToConflicts++;
- } else {
-
- if(pcflow->firstBank == pcflowLink->pcflow->lastBank)
- return 0;
-
- pcflowLink->bank_conflict++;
- pcflowLink->pcflow->ToConflicts++;
- pcflow->FromConflicts++;
-
- }
- /*
- fprintf(stderr,"compare flow found conflict: seq %d from conflicts %d, to conflicts %d\n",
- pcflowLink->pcflow->pc.seq,
- pcflowLink->pcflow->FromConflicts,
- pcflowLink->pcflow->ToConflicts);
- */
- return 1;
-
-}
-/*-----------------------------------------------------------------*/
-/*-----------------------------------------------------------------*/
-void FixBankFlow(pBlock *pb)
-{
- pCode *pc=NULL;
- pCode *pcflow;
- pCodeFlowLink *pcfl;
-
- pCode *pcflow_max_To=NULL;
- pCode *pcflow_max_From=NULL;
- int max_ToConflicts=0;
- int max_FromConflicts=0;
-
- //fprintf(stderr,"Fix Bank flow \n");
- pcflow = findNextpCode(pb->pcHead, PC_FLOW);
-
-
- /*
- First loop through all of the flow objects in this pcode block
- and fix the ones that have banking conflicts between the
- entry and exit.
- */
-
- //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.");
+ new_bank = "UNKNOWN";
+ new_mask = 0; // unknown, assume worst case
+ }
+
+ // 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, previous_reg, new_bank, cur_bank, max_mask)) {
+ // 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;
+ previous_reg = reg;
+ insertBankSel(pci, cur_bank);
+ } // if
+ } // if
+ } // for