* src/ds390/gen.c (opIsGptr, adjustArithmeticResult, genAddrOf, genAssign),

[fw/sdcc] / src / pic / pcoderegs.c

diff --git a/src/pic/pcoderegs.c b/src/pic/pcoderegs.c
index 0c8f4bebed9c1dc485ee9726b5e23259cb100b97..3b29b904d9e7d24178eed5e67e8187b3a96e31e3 100644 (file)
--- a/src/pic/pcoderegs.c
+++ b/src/pic/pcoderegs.c
@@ -192,6 +192,7 @@ void pCodeRegMapLiveRangesInFlow(pCodeFlow *pcfl)
                                addSetIfnotP(& (reg->reglives.assignedpFlows), pcfl);
                        
                        addSetIfnotP(& (reg->reglives.usedpCodes), pc);
+                       reg->wasUsed = 1;
                }
                
                
@@ -522,24 +523,27 @@ int pCodeOptime2pCodes(pCode *pc1, pCode *pc2, pCode *pcfl_used, regs *reg, int
        if (!isPCI(pc1) || !isPCI(pc2)) return 0;
        if (PCI(pc1)->pcflow != PCI(pc2)->pcflow) return 0;
        
-       if(pc2->seq < pc1->seq) {
+       if (pc2->seq < pc1->seq) {
                pct1 = pc2;
                pc2 = pc1;
                pc1 = pct1;
        }
 
        /* disable this optimization for now -- it's buggy */
-       if(pic14_options.disable_df) return 0;
+       if (pic14_options.disable_df) return 0;
        
        //fprintf(stderr,"pCodeOptime2pCodes\n");
        //pc1->print(stderr,pc1);
        //pc2->print(stderr,pc2);
 
        if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_MOVFW) ){
+           /*
+            * CLRF sets Z
+            * MOVFW affects Z
+            * MOVWF does not touch Z
+            * MOVLW does not touch Z
+            */
                pCode *newpc;
-               int regUsed = 0;
-               int wUsed   = 0;
-               int wSaved  = 0;
                /*
                clrf  reg    ; pc1
                stuff...
@@ -552,41 +556,26 @@ int pCodeOptime2pCodes(pCode *pc1, pCode *pc2, pCode *pcfl_used, regs *reg, int
                */
                DFPRINTF((stderr, "   optimising CLRF reg ... MOVF reg,W to ... MOVLW 0\n"));
                pct2 = findNextInstruction(pc2->next);
-               
-               if(pct2 && PCI(pct2)->op == POC_MOVWF) {
-                       wSaved = wUsed = 1; /* Maybe able to replace with clrf pc2->next->reg. */
-               } else {
-                       wUsed = pCodeSearchCondition(pct2,PCC_W,1) != -1;
-               }
-               regUsed = regUsedinRange(pct2,0,reg);
-               if ((regUsed&&wUsed) || (pCodeSearchCondition(pct2,PCC_Z,0) != -1)) {
-                       /* Do not optimise as exisiting code is required. */
-               } else {
-                       /* Can optimise. */
-                       if(regUsed) {
-                               newpc = newpCode(POC_CLRF, PCI(pc1)->pcop);
-                       } else if(wSaved && !wUsed) {
-                               newpc = newpCode(POC_CLRF, PCI(pct2)->pcop);
-                               pct2->destruct(pct2);
-                       } else {
-                               newpc = newpCode(POC_MOVLW, newpCodeOpLit(0));
-                       }
+               if (pCodeSearchCondition(pct2, PCC_Z, 0) == -1) {
+                       /* Z is definitely overwritten before use */
+                       newpc = newpCode(POC_MOVLW, newpCodeOpLit(0));
                        
                        pCodeInsertAfter(pc2, newpc);
                        PCI(newpc)->pcflow = PCFL(pcfl_used);
                        newpc->seq = pc2->seq;
                        
                        //fprintf (stderr, "%s:%d(%s): Remove2pcodes (CLRF reg, ..., MOVF reg,W)\n", __FILE__, __LINE__, __FUNCTION__);
-                       Remove2pcodes(pcfl_used, pc1, pc2, reg, can_free);
-                       total_registers_saved++;  // debugging stats.
+                       //Remove2pcodes(pcfl_used, pc2, NULL, reg, 0);
+                       pc2->destruct(pc2);
+                       //total_registers_saved++;  // debugging stats.
                }
        } else if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_IORFW) ){
                DFPRINTF((stderr, "   optimising CLRF/IORFW\n"));
                
                pct2 = findNextInstruction(pc2->next);
                
-               /* We must ensure that is destroyed before being read---IORLW must be performed unless this is proven. */
-               if(pCodeSearchCondition(pct2, PCC_Z,0) != -1) {
+               /* We must ensure that Z is destroyed before being read---IORLW must be performed unless this is proven. */
+               if (pCodeSearchCondition(pct2, PCC_Z, 0) != -1) {
                        pct2 = newpCode(POC_IORLW, newpCodeOpLit(0));
                        pct2->seq = pc2->seq;
                        PCI(pct2)->pcflow = PCFL(pcfl_used);
@@ -859,7 +848,7 @@ void OptimizeRegUsage(set *fregs, int optimize_multi_uses, int optimize_level)
                                                        
                                                }
                                        }
-                                       rset1 = rset1->next;
+                                       rset1 = rset2;
                                }
                        }
                }