minor improvement to register allocator in --stack10bit mode

[fw/sdcc] / src / ds390 / ralloc.c

diff --git a/src/ds390/ralloc.c b/src/ds390/ralloc.c
index 2ff9574eaee311ea60c4446c7d9fb17caf86ad49..a310023bd3103a407e687b8915238b4f966d69d6 100644 (file)
--- a/src/ds390/ralloc.c
+++ b/src/ds390/ralloc.c
@@ -508,7 +508,11 @@ createStackSpil (symbol * sym)
   /* set the type to the spilling symbol */
   sloc->type = copyLinkChain (sym->type);
   sloc->etype = getSpec (sloc->type);
-  SPEC_SCLS (sloc->etype) = options.model ? S_XDATA : S_DATA;
+  if (options.model == MODEL_SMALL) {
+    SPEC_SCLS (sloc->etype) = S_DATA;
+  } else {
+    SPEC_SCLS (sloc->etype) = S_XDATA;
+  }
   SPEC_EXTR (sloc->etype) = 0;
 
   /* we don't allow it to be allocated`
@@ -613,7 +617,7 @@ spillThis (symbol * sym)
      LIVE ranges */
   if (!ds390_ptrRegReq && isSpiltOnStack (sym))
     {
-      ds390_ptrRegReq++;
+      ds390_ptrRegReq += !options.stack10bit;
       spillLRWithPtrReg (sym);
     }
 
@@ -756,9 +760,9 @@ spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
 
   /* if spilt on stack then free up r0 & r1 
      if they could have been assigned to as gprs */
-  if (!ds390_ptrRegReq && isSpiltOnStack (ssym))
+  if (!ds390_ptrRegReq && isSpiltOnStack (ssym) && !options.stack10bit)
     {
-      ds390_ptrRegReq++;
+           ds390_ptrRegReq++;
       spillLRWithPtrReg (ssym);
     }
 
@@ -1437,6 +1441,7 @@ regTypeNum ()
              (ic = hTabItemWithKey (iCodehTab,
                                     bitVectFirstBit (sym->defs))) &&
              POINTER_GET (ic) &&
+             !sym->noSpilLoc &&
              !IS_BITVAR (sym->etype))
            {
 
@@ -1619,24 +1624,12 @@ packRegsForAssign (iCode * ic, eBBlock * ebp)
      we cannot */
   for (dic = ic->prev; dic; dic = dic->prev)
     {
-#if 0 // jwk 20010410, the JanVanBelle case
-      /* if there is a function call and this is
-         a parameter & not my parameter then don't pack it */
-      if ((dic->op == CALL || dic->op == PCALL) &&
-         (OP_SYMBOL (IC_RESULT (ic))->_isparm &&
-          !OP_SYMBOL (IC_RESULT (ic))->ismyparm))
-       {
-         dic = NULL;
-         break;
-       }
-#else
       /* if there is a function call then don't pack it */
       if ((dic->op == CALL || dic->op == PCALL))
        {
          dic = NULL;
          break;
        }
-#endif
 
       if (SKIP_IC2 (dic))
        continue;
@@ -1752,9 +1745,9 @@ findAssignToSym (operand * op, iCode * ic)
          /* or in stack space in case of + & - */
 
          /* if assigned to a non-symbol then return
-            true */
+            FALSE */
          if (!IS_SYMOP (IC_RIGHT (dic)))
-           break;
+           return NULL;
 
          /* if the symbol is in far space then
             we should not */
@@ -1932,6 +1925,16 @@ packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
                         bitVectFirstBit (OP_DEFS (op)))))
     return NULL;
 
+  /* if that only usage is a cast */
+  if (dic->op == CAST) {
+    /* to a bigger type */
+    if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) > 
+       getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
+      /* than we can not, since we cannot predict the usage of b & acc */
+      return NULL;
+    }
+  }
+
   /* found the definition now check if it is local */
   if (dic->seq < ebp->fSeq ||
       dic->seq > ebp->lSeq)
@@ -2153,6 +2156,10 @@ packRegsForAccUse (iCode * ic)
       IC_LEFT (uic)->key != IC_RESULT (ic)->key)
     return;
 
+#if 0
+  // this is too dangerous and need further restrictions
+  // see bug #447547
+
   /* if one of them is a literal then we can */
   if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
       (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
@@ -2160,6 +2167,7 @@ packRegsForAccUse (iCode * ic)
       OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
       return;
     }
+#endif
 
   /* if the other one is not on stack then we can */
   if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
@@ -2327,22 +2335,22 @@ packRegisters (eBBlock * ebp)
          /* if we are using a symbol on the stack
             then we should say ds390_ptrRegReq */
          if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
-           ds390_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
-                                OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
+                 ds390_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ? !options.stack10bit : 0) +
+                                     OP_SYMBOL (IC_COND (ic))->iaccess);
          else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
-           ds390_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
-                             OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
+                 ds390_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ? !options.stack10bit : 0) +
+                                     OP_SYMBOL (IC_JTCOND (ic))->iaccess);
          else
            {
              if (IS_SYMOP (IC_LEFT (ic)))
-               ds390_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
-                               OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
+                     ds390_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ? !options.stack10bit : 0) +
+                                         OP_SYMBOL (IC_LEFT (ic))->iaccess);
              if (IS_SYMOP (IC_RIGHT (ic)))
-               ds390_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
-                              OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
+                     ds390_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ? !options.stack10bit : 0) +
+                                         OP_SYMBOL (IC_RIGHT (ic))->iaccess);
              if (IS_SYMOP (IC_RESULT (ic)))
-               ds390_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
-                             OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
+                     ds390_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ? !options.stack10bit : 0) +
+                                         OP_SYMBOL (IC_RESULT (ic))->iaccess);
            }
        }
 
@@ -2506,7 +2514,7 @@ ds390_assignRegisters (eBBlock ** ebbs, int count)
   setToNull ((void *) &_G.funcrUsed);
   ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
   ds390_nRegs = 8;
-
+  if (options.model != MODEL_FLAT24) options.stack10bit = 0;
   /* change assignments this will remove some
      live ranges reducing some register pressure */
   for (i = 0; i < count; i++)