* src/mcs51/ralloc.c (deassignLR),

[fw/sdcc] / src / mcs51 / ralloc.c

diff --git a/src/mcs51/ralloc.c b/src/mcs51/ralloc.c
index 919ded657f5f71c9b9056e01a9d1997372d01b91..ec01a64642e23b935a55a847a41fa9527828b4a5 100644 (file)
--- a/src/mcs51/ralloc.c
+++ b/src/mcs51/ralloc.c
@@ -981,6 +981,7 @@ deassignLRs (iCode * ic, eBBlock * ebp)
              (result = OP_SYMBOL (IC_RESULT (ic))) &&  /* has a result */
              result->liveTo > ic->seq &&       /* and will live beyond this */
              result->liveTo <= ebp->lSeq &&    /* does not go beyond this block */
+             result->liveFrom == ic->seq &&    /* does not start before here */
              result->regType == sym->regType &&        /* same register types */
              result->nRegs &&  /* which needs registers */
              !result->isspilt &&       /* and does not already have them */
@@ -1237,6 +1238,16 @@ serialRegAssign (eBBlock ** ebbs, int count)
                    spillThis (sym);
                    continue;                 
                }
+               
+               /* If the live range preceeds the point of definition 
+                  then ideally we must take into account registers that 
+                  have been allocated after sym->liveFrom but freed
+                  before ic->seq. This is complicated, so spill this
+                  symbol instead and let fillGaps handle the allocation. */
+               if (sym->liveFrom < ic->seq) {
+                   spillThis (sym);
+                   continue;                 
+               }
 
                /* if it has a spillocation & is used less than
                   all other live ranges then spill this */
@@ -1399,7 +1410,7 @@ static void fillGaps()
                bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
                continue ;
 
-               clr = hTabItemWithKey(liveRanges,i);
+           clr = hTabItemWithKey(liveRanges,i);
            assert(clr);
 
            /* mark these registers as used */
@@ -1762,35 +1773,13 @@ regTypeNum (eBBlock *ebbs)
              (ic = hTabItemWithKey (iCodehTab,
                                     bitVectFirstBit (sym->defs))) &&
              POINTER_GET (ic) &&
-             !sym->noSpilLoc &&
-             !IS_BITVAR (sym->etype))
+             !IS_BITVAR (sym->etype) &&
+             (aggrToPtrDclType (operandType (IC_LEFT (ic)), FALSE) == POINTER))
            {
 
-
-             /* and that pointer is remat in data space */
-              if (IS_SYMOP (IC_LEFT (ic)) &&
-                 OP_SYMBOL (IC_LEFT (ic))->remat &&
-                 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
-                 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
+             if (ptrPseudoSymSafe (sym, ic))
                {
-                 /* create a psuedo symbol & force a spil */
-                 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
-                 psym->type = sym->type;
-                 psym->etype = sym->etype;
-                  
-                 strcpy (psym->rname, psym->name);
-                 sym->isspilt = 1;
-                 sym->usl.spillLoc = psym;
-#if 0 // an alternative fix for bug #480076
-                 /* now this is a useless assignment to itself */
-                 remiCodeFromeBBlock (ebbs, ic);
-#else
-                 /* now this really is an assignment to itself, make it so;
-                    it will be optimized out later */
-                 ic->op='=';
-                 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
-                 IC_LEFT(ic)=NULL;
-#endif
+                 ptrPseudoSymConvert (sym, ic, rematStr (OP_SYMBOL (IC_LEFT (ic))));
                  continue;
                }