"fixed" bug 447547

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

diff --git a/src/mcs51/ralloc.c b/src/mcs51/ralloc.c
index 1bc23245e1277e97f4a46c536dd9528ebcce87b6..b17dcf80b0db9088a71160bbd8ee4e118436bdf4 100644 (file)
--- a/src/mcs51/ralloc.c
+++ b/src/mcs51/ralloc.c
@@ -1583,55 +1583,33 @@ static int
 packRegsForAssign (iCode * ic, eBBlock * ebp)
 {
   iCode *dic, *sic;
-  sym_link *etype = operandType (IC_RIGHT (ic));
+  //sym_link *etype = operandType (IC_RIGHT (ic));
 
   if (!IS_ITEMP (IC_RIGHT (ic)) ||
       OP_SYMBOL (IC_RIGHT (ic))->isind ||
-      OP_LIVETO (IC_RIGHT (ic)) > ic->seq ||
-      IS_BITFIELD (etype))
+      OP_LIVETO (IC_RIGHT (ic)) > ic->seq
+      /* why? || IS_BITFIELD (etype) */ )
     {
       return 0;
     }
 
   /* if the true symbol is defined in far space or on stack
      then we should not since this will increase register pressure */
-#if 0
-  if (isOperandInFarSpace (IC_RESULT (ic)))
-    {
-      if ((dic = farSpacePackable (ic)))
-       goto pack;
-      else
-       return 0;
-    }
-#else
   if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
     return 0;
   }
-#endif
 
   /* find the definition of iTempNN scanning backwards if we find a 
      a use of the true symbol in before we find the definition then 
      we cannot */
   for (dic = ic->prev; dic; dic = dic->prev)
     {
-#if 0 // jwk 20010410
-      /* 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;
@@ -1924,6 +1902,16 @@ 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)
@@ -2151,6 +2139,10 @@ 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))))
@@ -2158,6 +2150,7 @@ 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 &&
@@ -2297,8 +2290,6 @@ packRegisters (eBBlock * ebp)
 
       /* if this is a +/- operation with a rematerizable 
          then mark this as rematerializable as well */
-#if 0
-      // jwk 20010716: temporary disabled because of bug #441448
       if ((ic->op == '+' || ic->op == '-') &&
          (IS_SYMOP (IC_LEFT (ic)) &&
           IS_ITEMP (IC_RESULT (ic)) &&
@@ -2310,7 +2301,6 @@ packRegisters (eBBlock * ebp)
          OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
          OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
        }
-#endif
 
       /* mark the pointer usages */
       if (POINTER_SET (ic))
@@ -2343,20 +2333,6 @@ packRegisters (eBBlock * ebp)
            }
        }
 
-#if 0
-      /* if the condition of an if instruction
-         is defined in the previous instruction then
-         mark the itemp as a conditional */
-      if ((IS_CONDITIONAL (ic) ||
-          (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
-         ic->next && ic->next->op == IFX &&
-         isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
-         OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
-       {
-         OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
-         continue;
-       }
-#else
       /* if the condition of an if instruction
          is defined in the previous instruction and
         this is the only usage then
@@ -2371,7 +2347,6 @@ packRegisters (eBBlock * ebp)
          OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
          continue;
        }
-#endif
 
       /* reduce for support function calls */
       if (ic->supportRtn || ic->op == '+' || ic->op == '-')