yes
[fw/sdcc] / src / pic / pcoderegs.c
index f536987fabb5b6a89776d899b9bcdf06a83e30aa..a7f72cc83f48106cd3c1d8ee98ad6e46edf505fe 100644 (file)
@@ -41,8 +41,10 @@ extern void dbg_dumpregusage(void);
 extern pCode * findPrevInstruction(pCode *pci);
 extern pBranch * pBranchAppend(pBranch *h, pBranch *n);
 void unlinkpCode(pCode *pc);
+extern int pCodeSearchCondition(pCode *pc, unsigned int cond);
 
 int total_registers_saved=0;
+int register_optimization=1;
 
 /*-----------------------------------------------------------------*
  * void AddRegToFlow(regs *reg, pCodeFlow *pcfl)
@@ -206,20 +208,22 @@ void pCodeRegMapLiveRanges(pBlock *pb)
     pCodeRegMapLiveRangesInFlow(PCFL(pcflow));
   }
 
-
+#if 0
   for( pcflow = findNextpCode(pb->pcHead, PC_FLOW); 
        pcflow != NULL;
        pcflow = findNextpCode(pcflow->next, PC_FLOW) ) {
 
     regs *r = setFirstItem(PCFL(pcflow)->registers);
-    //fprintf(stderr,"flow seq %d\n", pcflow->seq);
+    fprintf(stderr,"flow seq %d\n", pcflow->seq);
+
     while (r) {
-      //fprintf(stderr, "  %s\n",r->name);
+      fprintf(stderr, "  %s\n",r->name);
       r = setNextItem(PCFL(pcflow)->registers);
 
     }
 
   }
+#endif
 
 //  dbg_dumpregusage();
 
@@ -279,10 +283,6 @@ void  RemoveRegsFromSet(set *regset)
     reg = regset->item;
     regset = regset->next;
 
-/*
-  for (reg = setFirstItem(regset) ; reg ;
-       reg = setNextItem(regset)) {
-*/
     used = elementsInSet(reg->reglives.usedpCodes);
 
     if(used <= 1) {
@@ -348,8 +348,7 @@ void RemoveUnusedRegisters(void)
 {
   /* First, get rid of registers that are used only one time */
 
-
-  RemoveRegsFromSet(dynInternalRegs);
+  //RemoveRegsFromSet(dynInternalRegs);
   RemoveRegsFromSet(dynAllocRegs);
   RemoveRegsFromSet(dynStackRegs);
   /*
@@ -365,7 +364,7 @@ void RemoveUnusedRegisters(void)
 /*-----------------------------------------------------------------*
  *
  *-----------------------------------------------------------------*/
-static void Remove2pcodes(pCode *pcflow, pCode *pc1, pCode *pc2, regs *reg)
+static void Remove2pcodes(pCode *pcflow, pCode *pc1, pCode *pc2, regs *reg, int can_free)
 {
   if(!reg)
     return;
@@ -377,8 +376,10 @@ static void Remove2pcodes(pCode *pcflow, pCode *pc1, pCode *pc2, regs *reg)
     Remove1pcode(pc2, reg);
     deleteSetItem (&(PCFL(pcflow)->registers), reg);
 
-    reg->isFree = 1;
-    reg->wasUsed = 0;
+    if(can_free) {
+      reg->isFree = 1;
+      reg->wasUsed = 0;
+    }
 
   }
 
@@ -409,17 +410,225 @@ int regUsedinRange(pCode *pc1, pCode *pc2, regs *reg)
   return 0;
 }
 
+/*-----------------------------------------------------------------*
+ * void pCodeOptime2pCodes(pCode *pc1, pCode *pc2) 
+ *
+ * ADHOC pattern checking 
+ * Now look for specific sequences that are easy to optimize.
+ * Many of these sequences are characteristic of the compiler
+ * (i.e. it'd probably be a waste of time to apply these adhoc
+ * checks to hand written assembly.)
+ * 
+ *
+ *-----------------------------------------------------------------*/
+int pCodeOptime2pCodes(pCode *pc1, pCode *pc2, pCode *pcfl_used, regs *reg, int can_free, int optimize_level)
+{
+  pCode *pct1, *pct2;
+  regs  *reg1, *reg2;
+
+  int t = total_registers_saved;
+
+  if(pc2->seq < pc1->seq) {
+    pct1 = pc2;
+    pc2 = pc1;
+    pc1 = pct1;
+  }
+/*
+  fprintf(stderr,"pCodeOptime2pCodes\n");
+  pc1->print(stderr,pc1);
+  pc2->print(stderr,pc2);
+*/
+  if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_MOVFW) ){
+
+    /*
+      clrf  reg
+      stuff...
+      movf  reg,w
+
+      can be replaced with
+
+      stuff...
+      movlw 0
+    */
+
+    pCode *newpc;
+    //fprintf(stderr, "   CLRF/MOVFW. instruction after MOVFW is:\n");
+    pct1 = findNextInstruction(pc2->next);
+
+    if(PCI(pct1)->op == POC_MOVWF) {
+      newpc = newpCode(POC_CLRF, PCI(pct1)->pcop);
+      pct1->destruct(pct1);
+    } else {
+      newpc = newpCode(POC_MOVLW, newpCodeOpLit(0));
+    }
+
+    pCodeInsertAfter(pc2, newpc);
+    PCI(newpc)->pcflow = PCFL(pcfl_used);
+    newpc->seq = pc2->seq;
+
+    Remove2pcodes(pcfl_used, pc1, pc2, reg, can_free);
+    total_registers_saved++;  // debugging stats.
+
+  } else if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_IORFW) ){
+    //fprintf(stderr, "   CLRF/IORFW.\n");
+
+    pct2 = findNextInstruction(pc2->next);
+
+    if(pCodeSearchCondition(pct2, PCC_Z) > 0) {
+      pct2 = newpCode(POC_IORLW, newpCodeOpLit(0));
+      pct2->seq = pc2->seq;
+      PCI(pct2)->pcflow = PCFL(pcfl_used);
+      pCodeInsertAfter(pc1,pct2);
+    }
+    Remove2pcodes(pcfl_used, pc1, pc2, reg, can_free);
+    total_registers_saved++;  // debugging stats.
+
+  }  else if(PCI(pc1)->op == POC_MOVWF) {
+
+    pct2 = findNextInstruction(pc2->next);
+
+    if(PCI(pc2)->op == POC_MOVFW) {
+      /*
+       fprintf(stderr, "   MOVWF/MOVFW. instruction after MOVFW is:\n");
+       pct2->print(stderr,pct2);
+      */
+
+      if(PCI(pct2)->op == POC_MOVWF) {
+       /*
+         Change:
+
+           movwf   reg
+
+           stuff...
+
+           movf    reg,w
+            movwf   reg2
+
+         To:
+
+           
+       */
+       reg2 = getRegFromInstruction(pct2);
+       //if(reg2 && !regUsedinRange(pc1,pc2,reg2) && (reg2->type != REG_SFR)) {
+       if(reg2 && !regUsedinRange(pc1,pc2,reg2)) {
+
+         if(pCodeSearchCondition(pct2, PCC_Z) < 1) {
+           pCode *pct3 = findNextInstruction(pct2->next);
+           pct2->seq = pc1->seq;
+           unlinkpCode(pct2);
+           pCodeInsertAfter(findPrevInstruction(pc1->prev),pct2);
+
+#define usesW(x)       ((x) && (isPCI(x)) && ( (PCI(x)->inCond & PCC_W) != 0))
+
+           if(usesW(pct3))
+             ; // Remove2pcodes(pcfl_used, pc1, NULL, reg, can_free);
+           else
+             Remove2pcodes(pcfl_used, pc1, pc2, reg, can_free);
+
+           total_registers_saved++;  // debugging stats.
+           return 1;
+           } else {
+             //fprintf(stderr,"didn't optimize because Z bit is used\n");
+           }
+       }
+/*
+       fprintf(stderr, " couldn't optimize\n");
+       if(reg2)
+         fprintf(stderr, " %s is used in range\n",reg2->name);
+       else
+         fprintf(stderr, " reg2 is NULL\n");
+*/
+      }
+    }
+
+    pct1 = findPrevInstruction(pc1->prev);
+    if(pct1 && (PCI(pct1)->pcflow == PCI(pc1)->pcflow)) {
+
+      if ( (PCI(pct1)->op == POC_MOVFW) &&
+          (PCI(pc2)->op == POC_MOVFW)) {
+
+       reg1 = getRegFromInstruction(pct1);
+       if(reg1 && !regUsedinRange(pc1,pc2,reg1)) {
+         /*
+           fprintf(stderr, "   MOVF/MOVFW. \n");
+           fprintf(stderr, "     ...optimizing\n");
+         */
+
+         /*
+           Change:
+
+           movf   reg1,w
+           movwf  reg
+
+           stuff...
+           movf   reg,w
+
+           To:
+
+           stuff...
+
+           movf   reg1,w
+
+           Or, if we're not deleting the register then the "To" is:
+
+           stuff...
+
+           movf   reg1,w
+           movwf  reg
+
+
+         */
+         pct2 = newpCode(PCI(pc2)->op, PCI(pct1)->pcop);
+         pCodeInsertAfter(pc2, pct2);
+         PCI(pct2)->pcflow = PCFL(pcfl_used);
+         pct2->seq = pc2->seq;
+
+         if(can_free) {
+           Remove2pcodes(pcfl_used, pc1, pc2, reg, can_free);
+         } else {
+           /* If we're not freeing the register then that means (probably)
+            * the register is needed somewhere else.*/
+           unlinkpCode(pc1);
+           pCodeInsertAfter(pct2, pc1);
+
+           Remove2pcodes(pcfl_used, pc2, NULL, reg, can_free);
+         }
+
+         Remove2pcodes(pcfl_used, pct1, NULL, reg1, 0);
+         total_registers_saved++;  // debugging stats.
+
+       }
+      } else if ( (PCI(pct1)->op == POC_MOVWF) &&
+          (PCI(pc2)->op == POC_MOVFW)) {
+       //fprintf(stderr,"movwf MOVWF/MOVFW\n");
+       if(optimize_level > 1 && can_free) {
+         pct2 = newpCode(POC_MOVFW, PCI(pc1)->pcop);
+         pCodeInsertAfter(pc2, pct2);
+         Remove2pcodes(pcfl_used, pc1, pc2, reg, 1);
+         total_registers_saved++;  // debugging stats.
+       }
+      }
+
+
+    }
+
+  }
+
+  return (total_registers_saved != t);
+}
+
 /*-----------------------------------------------------------------*
  * void pCodeRegOptimeRegUsage(pBlock *pb) 
  *-----------------------------------------------------------------*/
-void OptimizeRegUsage(set *fregs)
+void OptimizeRegUsage(set *fregs, int optimize_multi_uses, int optimize_level)
 {
   regs *reg;
   int used;
+  pCode *pc1=NULL, *pc2=NULL;
 
 
   while(fregs) {
-      pCode *pcfl_used, *pcfl_assigned;
+    pCode *pcfl_used, *pcfl_assigned;
 
     /* Step through the set by directly accessing the 'next' pointer.
      * We could also step through by using the set API, but the 
@@ -445,10 +654,6 @@ void OptimizeRegUsage(set *fregs)
        * instructions are examined. If possible, they're optimized out.
        */
 
-      pCode *pc1, *pc2;
-      pCode *pct1, *pct2; /* two temporaries */
-      regs  *reg1, *reg2;
-
 /*
       fprintf (stderr, "OptimizeRegUsage: %s  addr=0x%03x rIdx=0x%03x type=%d used=%d\n",
               reg->name,
@@ -469,117 +674,12 @@ void OptimizeRegUsage(set *fregs)
        if(pcfl_used->seq == pcfl_assigned->seq) {
 
          //fprintf(stderr, "  and used in same flow\n");
-         if(pc2->seq < pc1->seq) {
-           pct1 = pc2;
-           pc2 = pc1;
-           pc1 = pct1;
-         }
-
-         //pc1->print(stderr,pc1);
-         //pc2->print(stderr,pc2);
-
-
-         /* ADHOC pattern checking 
-          * Now look for specific sequences that are easy to optimize.
-          * Many of these sequences are characteristic of the compiler
-          * (i.e. it'd probably be a waste of time to apply these adhoc
-          * checks to hand written assembly.)
-          * 
-          */
-         if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_MOVFW) ){
-
-           /*
-                clrf  reg
-                stuff...
-                movf  reg,w
-
-                can be replaced with
-
-                stuff...
-                movlw 0
-           */
-
-           pCode *newpc;
-           //fprintf(stderr, "   CLRF/MOVFW. instruction after MOVFW is:\n");
-           pct1 = findNextInstruction(pc2->next);
-           //t->print(stderr,t);
-
-           if(PCI(pct1)->op == POC_MOVWF) {
-             newpc = newpCode(POC_CLRF, PCI(pct1)->pcop);
-             pct1->destruct(pct1);
-           } else {
-             newpc = newpCode(POC_MOVLW, newpCodeOpLit(0));
-           }
-
-           pCodeInsertAfter(pc2, newpc);
-           PCI(newpc)->pcflow = PCFL(pcfl_used);
-           newpc->seq = pc2->seq;
 
-           Remove2pcodes(pcfl_used, pc1, pc2, reg);
-           total_registers_saved++;  // debugging stats.
-
-         } else if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_IORFW) ){
-           //fprintf(stderr, "   CLRF/IORWF.\n");
-
-           Remove2pcodes(pcfl_used, pc1, pc2, reg);
-           total_registers_saved++;  // debugging stats.
-
-         }  else if(PCI(pc1)->op == POC_MOVWF) {
-
-           pct2 = findNextInstruction(pc2->next);
-
-           if(PCI(pc2)->op == POC_MOVFW) {
-             //fprintf(stderr, "   MOVWF/MOVFW. instruction after MOVFW is:\n");
-             // t->print(stderr,t);
-
-             if(PCI(pct2)->op == POC_MOVWF) {
-               reg2 = getRegFromInstruction(pct2);
-               if(reg2 && !regUsedinRange(pc1,pc2,reg2)) {
-                 pct2->seq = pc1->seq;
-                 unlinkpCode(pct2);
-                 pCodeInsertAfter(pc1,pct2);
-                 Remove2pcodes(pcfl_used, pc1, pc2, reg);
-                 total_registers_saved++;  // debugging stats.
-                 continue;
-               }
-             }
-           }
-
-           pct1 = findPrevInstruction(pc1->prev);
-           if(pct1 && 
-              (PCI(pct1)->pcflow == PCI(pc1)->pcflow) && 
-              (PCI(pct1)->op == POC_MOVFW)) {
-
-             reg1 = getRegFromInstruction(pct1);
-             if(reg1 && !regUsedinRange(pc1,pc2,reg1)) {
-               //fprintf(stderr, "   MOVF/MOVFW. \n");
-             /*
-               movf   reg1,w
-               movwf  reg
-
-               stuff...
-               opcode reg,w
-             */
-               pct2 = newpCode(PCI(pc2)->op, PCI(pct1)->pcop);
-               pCodeInsertAfter(pc2, pct2);
-               PCI(pct2)->pcflow = PCFL(pcfl_used);
-               pct2->seq = pc2->seq;
-
-               Remove2pcodes(pcfl_used, pc1, pc2, reg);
-               Remove2pcodes(pcfl_used, pct1, NULL, reg1);
-               total_registers_saved++;  // debugging stats.
-
-             }
-           }
-
-
-         }
+         pCodeOptime2pCodes(pc1, pc2, pcfl_used, reg, 1,optimize_level);
 
        } else {
          // fprintf(stderr, "  and used in different flows\n");
 
-         //pc1->print(stderr,pc1);
-         //pc2->print(stderr,pc2);
        }
 
       } else if(pcfl_used) {
@@ -590,11 +690,13 @@ void OptimizeRegUsage(set *fregs)
 
       } else {
        //fprintf(stderr,"WARNING %s: reg %s assigned without being used\n",__FUNCTION__,reg->name);
-       Remove2pcodes(pcfl_assigned, pc1, pc2, reg);
+       Remove2pcodes(pcfl_assigned, pc1, pc2, reg, 1);
        total_registers_saved++;  // debugging stats.
       }
     } else {
 
+      /* register has been used either once, or more than twice */
+
       if(used && !pcfl_used && pcfl_assigned) {
        pCode *pc;
 
@@ -619,8 +721,44 @@ void OptimizeRegUsage(set *fregs)
        reg->wasUsed = 0;
 
        total_registers_saved++;  // debugging stats.
-      }
+      } else if( (used > 2) && optimize_multi_uses) {
 
+       set *rset1=NULL;
+       set *rset2=NULL;
+       int searching=1;
+
+       pCodeFlow *pcfl1=NULL, *pcfl2=NULL;
+
+       /* examine the number of times this register is used */
+
+
+       rset1 = reg->reglives.usedpCodes;
+       while(rset1 && searching) {
+
+         pc1 = rset1->item;
+         rset2 = rset1->next;
+
+         if(pc1 && isPCI(pc1) &&  ( (pcfl1 = PCI(pc1)->pcflow) != NULL) ) {
+
+           //while(rset2 && searching) {
+           if(rset2) {
+
+             pc2 = rset2->item;
+             if(pc2 && isPCI(pc2)  &&  ( (pcfl2 = PCI(pc2)->pcflow) != NULL) )  {
+               if(pcfl2 == pcfl1) {
+
+                 if(pCodeOptime2pCodes(pc1, pc2, pcfl_used, reg, 0,optimize_level))
+                   searching = 0;
+               }
+             }
+
+             //rset2 = rset2->next;
+             
+           }
+         }
+         rset1 = rset1->next;
+       }
+      }
     }
 
   }
@@ -629,25 +767,38 @@ void OptimizeRegUsage(set *fregs)
 /*-----------------------------------------------------------------*
  * void pCodeRegOptimeRegUsage(pBlock *pb) 
  *-----------------------------------------------------------------*/
-void pCodeRegOptimizeRegUsage(void)
+void pCodeRegOptimizeRegUsage(int level)
 {
 
-  int passes = 4;
+  int passes;
   int saved = 0;
+  int t = total_registers_saved;
+
+  if(!register_optimization)
+    return;
+#define OPT_PASSES 4
+  passes = OPT_PASSES;
 
   do {
     saved = total_registers_saved;
 
     /* Identify registers used in one flow sequence */
-    OptimizeRegUsage(dynAllocRegs);
-    OptimizeRegUsage(dynStackRegs);
-    OptimizeRegUsage(dynDirectRegs);
+    OptimizeRegUsage(dynAllocRegs,level, (OPT_PASSES-passes));
+    OptimizeRegUsage(dynStackRegs,level, (OPT_PASSES-passes));
+    OptimizeRegUsage(dynDirectRegs,0, (OPT_PASSES-passes));
 
     if(total_registers_saved != saved)
-      fprintf(stderr, " *** Saved %d registers, total saved %d ***\n", total_registers_saved-saved,total_registers_saved);
+      fprintf(stderr, " *** pass %d, Saved %d registers, total saved %d ***\n", 
+             (1+OPT_PASSES-passes),total_registers_saved-saved,total_registers_saved);
+      
+    passes--;
+
+  } while( passes && ((total_registers_saved != saved) || (passes==OPT_PASSES-1)) );
+
+  if(total_registers_saved == t) 
+    fprintf(stderr, "No registers saved on this pass\n");
 
 
-  } while( passes-- && (total_registers_saved != saved));
 /*
   fprintf(stderr,"dynamically allocated regs:\n");
   dbg_regusage(dynAllocRegs);
@@ -656,6 +807,38 @@ void pCodeRegOptimizeRegUsage(void)
   fprintf(stderr,"direct regs:\n");
   dbg_regusage(dynDirectRegs);
 */
+}
+
+
+/*-----------------------------------------------------------------*
+ * void RegsUnMapLiveRanges(set *regset)
+ *
+ *-----------------------------------------------------------------*/
+void  RegsSetUnMapLiveRanges(set *regset)
+{
+  regs *reg;
+
+  while(regset) {
+    reg = regset->item;
+    regset = regset->next;
+
+    
+    deleteSet(&reg->reglives.usedpCodes);
+    deleteSet(&reg->reglives.usedpFlows);
+    deleteSet(&reg->reglives.assignedpFlows);
+
+  }
+
+}
+
+void  RegsUnMapLiveRanges(void)
+{
 
+  RegsSetUnMapLiveRanges(dynAllocRegs);
+  RegsSetUnMapLiveRanges(dynStackRegs);
+  RegsSetUnMapLiveRanges(dynDirectRegs);
+  RegsSetUnMapLiveRanges(dynProcessorRegs);
+  RegsSetUnMapLiveRanges(dynDirectBitRegs);
+  RegsSetUnMapLiveRanges(dynInternalRegs);
 
 }