Second pass for register allocator

set DISABLE_FILL_GAPS envirornment variable to disable

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@1592 4a8a32a2-be11-0410-ad9d-d568d2c75423

diff --git a/src/ds390/ralloc.c b/src/ds390/ralloc.c
index a46422179ab38fc02a3736c2012fc4233f1cd980..c00e4994125c62c03157108b9cce720123f64175 100644 (file)
--- a/src/ds390/ralloc.c
+++ b/src/ds390/ralloc.c
@@ -496,7 +496,6 @@ createStackSpil (symbol * sym)
       sym->usl.spillLoc = sloc;      
       sym->stackSpil = 1;
       sloc->isFree = 0;
-      sloc->allocreq++;
       addSetHead (&sloc->usl.itmpStack, sym);
       return sym;
     }
@@ -523,6 +522,7 @@ createStackSpil (symbol * sym)
     SPEC_SCLS (sloc->etype) = S_XDATA;
   }
   SPEC_EXTR (sloc->etype) = 0;
+  SPEC_STAT (sloc->etype) = 0;
 
   /* we don't allow it to be allocated`
      onto the external stack since : so we
@@ -1082,7 +1082,7 @@ willCauseSpill (int nr, int rt)
 /* position as the operand otherwise chaos results                 */
 /*-----------------------------------------------------------------*/
 static int
-positionRegs (symbol * result, symbol * opsym, int lineno)
+positionRegs (symbol * result, symbol * opsym)
 {
   int count = min (result->nRegs, opsym->nRegs);
   int i, j = 0, shared = 0;
@@ -1255,12 +1255,12 @@ serialRegAssign (eBBlock ** ebbs, int count)
              if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
                  OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
                positionRegs (OP_SYMBOL (IC_RESULT (ic)),
-                             OP_SYMBOL (IC_LEFT (ic)), ic->lineno);
+                             OP_SYMBOL (IC_LEFT (ic)));
              /* do the same for the right operand */
              if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
                  OP_SYMBOL (IC_RIGHT (ic))->nRegs)
                positionRegs (OP_SYMBOL (IC_RESULT (ic)),
-                             OP_SYMBOL (IC_RIGHT (ic)), ic->lineno);
+                             OP_SYMBOL (IC_RIGHT (ic)));
 
              if (ptrRegSet)
                {
@@ -1281,12 +1281,13 @@ static void fillGaps()
     symbol *sym =NULL;
     int key =0;    
     
-    return ; /* NOT YET .. MORE TESTING IN PROGRESS */
+    if (getenv("DISABLE_FILL_GAPS")) return;
     /* look for livernages that was spilt by the allocator */
     for (sym = hTabFirstItem(liveRanges,&key) ; sym ; 
         sym = hTabNextItem(liveRanges,&key)) {
 
        int i;
+       int pdone = 0;
 
        if (!sym->spillA || !sym->clashes || sym->remat) continue ;
        
@@ -1320,6 +1321,41 @@ static void fillGaps()
            else
                sym->regs[i] = getRegGprNoSpil ();                
        }
+
+       /* for all its definitions check if the registers
+          allocated needs positioning NOTE: we can position
+          only ONCE if more than One positioning required 
+          then give up */
+       sym->isspilt = 0;
+       for (i = 0 ; i < sym->defs->size ; i++ ) {
+           if (bitVectBitValue(sym->defs,i)) {
+               iCode *ic;
+               if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
+               if (SKIP_IC(ic)) continue;
+               assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
+               /* if left is assigned to registers */
+               if (IS_SYMOP(IC_LEFT(ic)) && 
+                   bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
+                   pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
+               }
+               if (IS_SYMOP(IC_RIGHT(ic)) && 
+                   bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
+                   pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
+               }
+               if (pdone > 1) break;
+           }
+       }
+       /* had to position more than once GIVE UP */
+       if (pdone > 1) {
+           /* UNDO all the changes we made to try this */
+           sym->isspilt = 0;
+           for (i=0; i < sym->nRegs ; i++ ) {
+               sym->regs[i] = NULL;
+           }
+           freeAllRegs();
+           printf("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN");
+           continue ;      
+       }
        printf("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN");
        _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
        sym->isspilt = sym->spillA = 0 ;
@@ -1459,7 +1495,7 @@ createRegMask (eBBlock ** ebbs, int count)
                }
              
              /* special case for ruonly */
-             if (sym->ruonly) {
+             if (sym->ruonly && sym->liveFrom != sym->liveTo) {
                  int size = getSize(sym->type);
                  int j = DPL_IDX;
                  for (k = 0 ; k < size; k++ )