X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=src%2FSDCCopt.c;h=a4c7de2261b6a42e56537c9821350e8ce2ef8f14;hb=291fc11550e1c00e40aa0c7e0403a6db200cb9ac;hp=cb7c6bc3d6885b4704f9002eeba603162bf2fb13;hpb=3f26b7d9381cd2399e95d2ccb88ecc77ae0458d0;p=fw%2Fsdcc

diff --git a/src/SDCCopt.c b/src/SDCCopt.c
index cb7c6bc3..a4c7de22 100644
--- a/src/SDCCopt.c
+++ b/src/SDCCopt.c
@@ -106,28 +106,30 @@ cnvToFcall (iCode * ic, eBBlock * ebp)
     {
 
       /* first one */
-      if (IS_REGPARM (func->args->etype))
+      if (IS_REGPARM (FUNC_ARGS(func->type)->etype))
 	{
 	  newic = newiCode (SEND, IC_LEFT (ic), NULL);
+	  newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
 	}
       else
 	{
 	  newic = newiCode ('=', NULL, IC_LEFT (ic));
-	  IC_RESULT (newic) = operandFromValue (func->args);
+	  IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type));
 	}
 
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
 
       /* second one */
-      if (IS_REGPARM (func->args->next->etype))
+      if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype))
 	{
-	  newic = newiCode (SEND, IC_LEFT (ic), NULL);
+	  newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	  newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->next->etype);
 	}
       else
 	{
 	  newic = newiCode ('=', NULL, IC_RIGHT (ic));
-	  IC_RESULT (newic) = operandFromValue (func->args->next);
+	  IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type)->next);
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
@@ -137,30 +139,34 @@ cnvToFcall (iCode * ic, eBBlock * ebp)
     {
 
       /* push right */
-      if (IS_REGPARM (func->args->next->etype))
+      if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype))
 	{
 	  newic = newiCode (SEND, right, NULL);
+	  newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->next->etype);
 	}
       else
 	{
 	  newic = newiCode (IPUSH, right, NULL);
 	  newic->parmPush = 1;
-	  bytesPushed+=4;
+	  //bytesPushed+=4;
+	  bytesPushed += getSize(operandType(right));
 	}
 
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
 
       /* insert push left */
-      if (IS_REGPARM (func->args->etype))
+      if (IS_REGPARM (FUNC_ARGS(func->type)->etype))
 	{
 	  newic = newiCode (SEND, left, NULL);
+	  newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
 	}
       else
 	{
 	  newic = newiCode (IPUSH, left, NULL);
 	  newic->parmPush = 1;
-	  bytesPushed+=4;
+	  //bytesPushed+=4;
+	  bytesPushed += getSize(operandType(left));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
@@ -180,10 +186,11 @@ static void
 cnvToFloatCast (iCode * ic, eBBlock * ebp)
 {
   iCode *ip, *newic;
-  symbol *func;
+  symbol *func = NULL;
   sym_link *type = operandType (IC_RIGHT (ic));
   int linenno = ic->lineno;
   int bwd, su;
+  int bytesPushed=0;
 
   ip = ic->next;
   /* remove it from the iCode */
@@ -193,7 +200,7 @@ cnvToFloatCast (iCode * ic, eBBlock * ebp)
     {
       for (su = 0; su < 2; su++)
 	{
-	  if (checkType (type, __multypes[bwd][su]) == 1)
+	  if (compareType (type, __multypes[bwd][su]) == 1)
 	    {
 	      func = __conv[0][bwd][su];
 	      goto found;
@@ -207,12 +214,15 @@ found:
   if (!options.float_rent)
     {
       /* first one */
-      if (IS_REGPARM (func->args->etype))
-	newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) 
+	    {
+		newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+		newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
+	    }
       else
 	{
 	  newic = newiCode ('=', NULL, IC_RIGHT (ic));
-	  IC_RESULT (newic) = operandFromValue (func->args);
+	  IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = linenno;
@@ -221,12 +231,15 @@ found:
   else
     {
       /* push the left */
-      if (IS_REGPARM (func->args->etype))
-	newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) {
+	    newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	    newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
+	}
       else
 	{
 	  newic = newiCode (IPUSH, IC_RIGHT (ic), NULL);
 	  newic->parmPush = 1;
+	  bytesPushed += getSize(operandType(IC_RIGHT(ic)));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = linenno;
@@ -236,6 +249,7 @@ found:
   /* make the call */
   newic = newiCode (CALL, operandFromSymbol (func), NULL);
   IC_RESULT (newic) = IC_RESULT (ic);
+  newic->parmBytes+=bytesPushed;
   addiCodeToeBBlock (ebp, newic, ip);
   newic->lineno = linenno;
 
@@ -248,10 +262,11 @@ static void
 cnvFromFloatCast (iCode * ic, eBBlock * ebp)
 {
   iCode *ip, *newic;
-  symbol *func;
+  symbol *func = NULL;
   sym_link *type = operandType (IC_LEFT (ic));
   int lineno = ic->lineno;
   int bwd, su;
+  int bytesPushed=0;
 
   ip = ic->next;
   /* remove it from the iCode */
@@ -262,7 +277,7 @@ cnvFromFloatCast (iCode * ic, eBBlock * ebp)
     {
       for (su = 0; su < 2; su++)
 	{
-	  if (checkType (type, __multypes[bwd][su]) == 1)
+	  if (compareType (type, __multypes[bwd][su]) == 1)
 	    {
 	      func = __conv[1][bwd][su];
 	      goto found;
@@ -276,12 +291,14 @@ found:
   if (!options.float_rent)
     {
       /* first one */
-      if (IS_REGPARM (func->args->etype))
-	newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) {
+	    newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	    newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
+	}
       else
 	{
 	  newic = newiCode ('=', NULL, IC_RIGHT (ic));
-	  IC_RESULT (newic) = operandFromValue (func->args);
+	  IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
@@ -291,12 +308,15 @@ found:
     {
 
       /* push the left */
-      if (IS_REGPARM (func->args->etype))
-	newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) {
+	    newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	    newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
+	}
       else
 	{
 	  newic = newiCode (IPUSH, IC_RIGHT (ic), NULL);
 	  newic->parmPush = 1;
+	  bytesPushed += getSize(operandType(IC_RIGHT(ic)));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
@@ -306,11 +326,14 @@ found:
   /* make the call */
   newic = newiCode (CALL, operandFromSymbol (func), NULL);
   IC_RESULT (newic) = IC_RESULT (ic);
+  newic->parmBytes+=bytesPushed;
   addiCodeToeBBlock (ebp, newic, ip);
   newic->lineno = lineno;
 
 }
 
+extern operand *geniCodeRValue (operand *, bool);
+
 /*-----------------------------------------------------------------*/
 /* convilong - converts int or long mults or divs to fcalls        */
 /*-----------------------------------------------------------------*/
@@ -325,14 +348,40 @@ convilong (iCode * ic, eBBlock * ebp, sym_link * type, int op)
   int su;
   int bytesPushed=0;
 
-  remiCodeFromeBBlock (ebp, ic);
-
+  // Easy special case which avoids function call: modulo by a literal power 
+  // of two can be replaced by a bitwise AND.
+  if (op == '%' && isOperandLiteral(IC_RIGHT(ic)))
+  {
+      unsigned litVal = (unsigned)(operandLitValue(IC_RIGHT(ic)));
+      
+      // See if literal value is a power of 2.
+      while (litVal && !(litVal & 1))
+      {
+	  litVal >>= 1;
+      }
+      if (litVal)
+      {
+	  // discard first high bit set.
+	  litVal >>= 1;
+      }
+	  
+      if (!litVal)
+      {
+	  ic->op = BITWISEAND;
+	  IC_RIGHT(ic) = operandFromLit(operandLitValue(IC_RIGHT(ic)) - 1);
+	  return;
+      }
+  }
+    
+  remiCodeFromeBBlock (ebp, ic);    
+    
+    
   /* depending on the type */
   for (bwd = 0; bwd < 3; bwd++)
     {
       for (su = 0; su < 2; su++)
 	{
-	  if (checkType (type, __multypes[bwd][su]) == 1)
+	  if (compareType (type, __multypes[bwd][su]) == 1)
 	    {
 	      if (op == '*')
 		func = __muldiv[0][bwd][su];
@@ -340,6 +389,14 @@ convilong (iCode * ic, eBBlock * ebp, sym_link * type, int op)
 		func = __muldiv[1][bwd][su];
 	      else if (op == '%')
 		func = __muldiv[2][bwd][su];
+              else if (op == RRC)
+		func = __rlrr[1][bwd][su];
+              else if (op == RLC)
+		func = __rlrr[0][bwd][su];
+              else if (op == RIGHT_OP)
+		func = __rlrr[1][bwd][su];
+              else if (op == LEFT_OP)
+		func = __rlrr[0][bwd][su];
 	      else
 		assert (0);
 	      goto found;
@@ -352,53 +409,63 @@ found:
   if (!options.intlong_rent)
     {
       /* first one */
-      if (IS_REGPARM (func->args->etype))
-	newic = newiCode (SEND, IC_LEFT (ic), NULL);
+	if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) {
+	    newic = newiCode (SEND, IC_LEFT (ic), NULL);
+	    newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
+	}
       else
 	{
 	  newic = newiCode ('=', NULL, IC_LEFT (ic));
-	  IC_RESULT (newic) = operandFromValue (func->args);
+	  IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
 
       /* second one */
-      if (IS_REGPARM (func->args->next->etype))
-	newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+      if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype)) {
+	  newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	  newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->next->etype);
+      }
       else
 	{
 	  newic = newiCode ('=', NULL, IC_RIGHT (ic));
-	  IC_RESULT (newic) = operandFromValue (func->args->next);
+	  IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type)->next);
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
 
-
     }
   else
     {
-
       /* compiled as reentrant then push */
       /* push right */
-      if (IS_REGPARM (func->args->next->etype))
-	newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+      if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype))
+        {
+          newic = newiCode (SEND, IC_RIGHT (ic), NULL);
+	  newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->next->etype);
+        }
       else
 	{
 	  newic = newiCode (IPUSH, IC_RIGHT (ic), NULL);
 	  newic->parmPush = 1;
-	  bytesPushed=getSize(type);
+
+	  bytesPushed += getSize(operandType(IC_RIGHT(ic)));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
 
       /* insert push left */
-      if (IS_REGPARM (func->args->etype))
-	newic = newiCode (SEND, IC_LEFT (ic), NULL);
+      if (IS_REGPARM (FUNC_ARGS(func->type)->etype))
+        {
+          newic = newiCode (SEND, IC_LEFT (ic), NULL);
+	  newic->argreg = SPEC_ARGREG(FUNC_ARGS(func->type)->etype);
+        }
       else
 	{
 	  newic = newiCode (IPUSH, IC_LEFT (ic), NULL);
 	  newic->parmPush = 1;
-	  bytesPushed=getSize(type);
+
+	  bytesPushed += getSize(operandType(IC_LEFT(ic)));
 	}
       addiCodeToeBBlock (ebp, newic, ip);
       newic->lineno = lineno;
@@ -452,15 +519,65 @@ convertToFcall (eBBlock ** ebbs, int count)
 	  /* if long / int mult or divide or mod */
 	  if (ic->op == '*' || ic->op == '/' || ic->op == '%')
 	    {
-
-	      sym_link *type = operandType (IC_LEFT (ic));
-	      if (IS_INTEGRAL (type) && getSize (type) > port->muldiv.native_below)
-		convilong (ic, ebbs[i], type, ic->op);
+	      sym_link *leftType = operandType (IC_LEFT (ic));
+
+	      if (IS_INTEGRAL (leftType) && getSize (leftType) > port->support.muldiv)
+                {
+                  sym_link *rightType = operandType (IC_RIGHT (ic));
+
+                  if (port->hasNativeMulFor != NULL &&
+                      port->hasNativeMulFor (ic, leftType, rightType))
+                    {
+                      /* Leave as native */
+                    }
+                  else
+                    {
+                      convilong (ic, ebbs[i], leftType, ic->op);
+                    }
+                }
 	    }
+          
+          if (ic->op == RRC || ic->op == RLC || ic->op == LEFT_OP || ic->op == RIGHT_OP)
+            {
+	      sym_link *type = operandType (IC_LEFT (ic));
+
+	      if (IS_INTEGRAL (type) && getSize (type) > port->support.shift && port->support.shift >= 0)
+                {
+                  convilong (ic, ebbs[i], type, ic->op);
+                }
+            }
 	}
     }
 }
 
+/*-----------------------------------------------------------------*/
+/* isLocalWithoutDef - return 1 if sym might be used without a     */
+/*                     defining iCode                              */
+/*-----------------------------------------------------------------*/
+static int
+isLocalWithoutDef (symbol * sym)
+{
+  if (!sym->level)
+    return 0;
+  
+  if (IS_STATIC (sym->etype))
+    return 0;
+  
+  if (IS_VOLATILE (sym->type))
+    return 0;
+  
+  if (sym->_isparm)
+    return 0;
+  
+  if (IS_AGGREGATE (sym->type))
+    return 0;
+  
+  if (sym->addrtaken)
+    return 0;
+  
+  return !sym->defs;
+}
+
 /*-----------------------------------------------------------------*/
 /* replaceRegEqv - replace all local variables with their reqv     */
 /*-----------------------------------------------------------------*/
@@ -469,6 +586,12 @@ replaceRegEqv (eBBlock ** ebbs, int count)
 {
   int i;
 
+  /* Update the symbols' def bitvector so we know if there is   */
+  /* a defining iCode or not. Only replace a local variable     */
+  /* with its register equivalent if there is a defining iCode; */
+  /* otherwise, the port's register allocater may choke.        */
+  cseAllBlocks (ebbs, count, TRUE);
+
   for (i = 0; i < count; i++)
     {
 
@@ -482,7 +605,17 @@ replaceRegEqv (eBBlock ** ebbs, int count)
 
 	  if (ic->op == IFX)
 	    {
-
+	      if (IC_COND (ic) &&
+		  IS_TRUE_SYMOP (IC_COND (ic)) &&
+                  isLocalWithoutDef (OP_SYMBOL (IC_COND (ic))))
+		{
+		  werrorfl (ic->filename, ic->lineno,
+			  W_LOCAL_NOINIT,
+			  OP_SYMBOL (IC_COND (ic))->name);
+		  OP_REQV (IC_COND (ic)) = NULL;
+		  OP_SYMBOL (IC_COND (ic))->allocreq = 1;
+		}
+	      
 	      if (IS_TRUE_SYMOP (IC_COND (ic)) &&
 		  OP_REQV (IC_COND (ic)))
 		IC_COND (ic) = opFromOpWithDU (OP_REQV (IC_COND (ic)),
@@ -492,8 +625,20 @@ replaceRegEqv (eBBlock ** ebbs, int count)
 	      continue;
 	    }
 
+	  
 	  if (ic->op == JUMPTABLE)
 	    {
+	      if (IC_JTCOND (ic) &&
+		  IS_TRUE_SYMOP (IC_JTCOND (ic)) &&
+                  isLocalWithoutDef (OP_SYMBOL (IC_JTCOND (ic))))
+		{
+		  werrorfl (ic->filename, ic->lineno,
+			  W_LOCAL_NOINIT,
+			  OP_SYMBOL (IC_JTCOND (ic))->name);
+		  OP_REQV (IC_JTCOND (ic)) = NULL;
+		  OP_SYMBOL (IC_JTCOND (ic))->allocreq = 1;
+		}
+	      
 	      if (IS_TRUE_SYMOP (IC_JTCOND (ic)) &&
 		  OP_REQV (IC_JTCOND (ic)))
 		IC_JTCOND (ic) = opFromOpWithDU (OP_REQV (IC_JTCOND (ic)),
@@ -526,6 +671,17 @@ replaceRegEqv (eBBlock ** ebbs, int count)
 					  OP_SYMBOL (IC_RESULT (ic))->uses);
 	    }
 
+	  if (IC_RIGHT (ic) &&
+	      IS_TRUE_SYMOP (IC_RIGHT (ic)) &&
+	      isLocalWithoutDef (OP_SYMBOL (IC_RIGHT (ic))))
+	    {
+	      werrorfl (ic->filename, ic->lineno,
+		        W_LOCAL_NOINIT,
+		        OP_SYMBOL (IC_RIGHT (ic))->name);
+	      OP_REQV (IC_RIGHT (ic)) = NULL;
+	      OP_SYMBOL (IC_RIGHT (ic))->allocreq = 1;
+	    }
+	  
 	  if (IC_RIGHT (ic) &&
 	      IS_TRUE_SYMOP (IC_RIGHT (ic)) &&
 	      OP_REQV (IC_RIGHT (ic)))
@@ -536,6 +692,17 @@ replaceRegEqv (eBBlock ** ebbs, int count)
 	      IC_RIGHT (ic)->isaddr = 0;
 	    }
 
+	  if (IC_LEFT (ic) &&
+	      IS_TRUE_SYMOP (IC_LEFT (ic)) &&
+	      isLocalWithoutDef (OP_SYMBOL (IC_LEFT (ic))))
+	    {
+	      werrorfl (ic->filename, ic->lineno,
+		        W_LOCAL_NOINIT,
+		        OP_SYMBOL (IC_LEFT (ic))->name);
+	      OP_REQV (IC_LEFT (ic)) = NULL;
+	      OP_SYMBOL (IC_LEFT (ic))->allocreq = 1;
+	    }
+            
 	  if (IC_LEFT (ic) &&
 	      IS_TRUE_SYMOP (IC_LEFT (ic)) &&
 	      OP_REQV (IC_LEFT (ic)))
@@ -590,9 +757,16 @@ killDeadCode (eBBlock ** ebbs, int count)
 
 	      if (SKIP_IC (ic) ||
 		  ic->op == IFX ||
-		  ic->op == RETURN)
+		  ic->op == RETURN ||
+                  ic->op == DUMMY_READ_VOLATILE ||
+                  ic->op == CRITICAL ||
+                  ic->op == ENDCRITICAL)
 		continue;
 
+	      /* Since both IFX & JUMPTABLE (in SKIP_IC) have been tested for */
+	      /* it is now safe to assume IC_LEFT, IC_RIGHT, & IC_RESULT are  */
+	      /* valid. */
+
 	      /* if the result is volatile then continue */
 	      if (IC_RESULT (ic) && isOperandVolatile (IC_RESULT (ic), FALSE))
 		continue;
@@ -600,6 +774,9 @@ killDeadCode (eBBlock ** ebbs, int count)
 	      /* if the result is a temp & isaddr then skip */
 	      if (IC_RESULT (ic) && POINTER_SET (ic))
 		continue;
+              
+              if (POINTER_GET (ic) && IS_VOLATILE (operandType (IC_LEFT (ic))->next))
+                continue;
 
 	      /* if the result is used in the remainder of the */
 	      /* block then skip */
@@ -636,17 +813,32 @@ killDeadCode (eBBlock ** ebbs, int count)
 		    continue;
 
 		  kill = 1;
-		}
+                }
 
 	    kill:
 	      /* kill this one if required */
 	      if (kill)
 		{
+		  bool volLeft = IS_SYMOP (IC_LEFT (ic))
+				 && isOperandVolatile (IC_LEFT (ic), FALSE);
+		  bool volRight = IS_SYMOP (IC_RIGHT (ic)) 
+				  && isOperandVolatile (IC_RIGHT (ic), FALSE);
+
+		  
+		  if (ic->next && ic->seqPoint == ic->next->seqPoint
+		      && (ic->next->op == '+' || ic->next->op == '-'))
+		    {
+		      if (isOperandEqual (IC_LEFT(ic), IC_LEFT(ic->next))
+		          || isOperandEqual (IC_LEFT(ic), IC_RIGHT(ic->next)))
+		        volLeft = FALSE;
+		      if (isOperandEqual (IC_RIGHT(ic), IC_LEFT(ic->next))
+		          || isOperandEqual (IC_RIGHT(ic), IC_RIGHT(ic->next)))
+		        volRight = FALSE;
+		    }
+		  
 		  change = 1;
 		  gchange++;
-		  /* eliminate this */
-		  remiCodeFromeBBlock (ebbs[i], ic);
-
+		  
 		  /* now delete from defUseSet */
 		  deleteItemIf (&ebbs[i]->outExprs, ifDiCodeIsX, ic);
 		  bitVectUnSetBit (ebbs[i]->outDefs, ic->key);
@@ -654,12 +846,33 @@ killDeadCode (eBBlock ** ebbs, int count)
 		  /* and defset of the block */
 		  bitVectUnSetBit (ebbs[i]->defSet, ic->key);
 
-		  /* for the left & right remove the usage */
-		  if (IS_SYMOP (IC_LEFT (ic)))
-		    bitVectUnSetBit (OP_USES (IC_LEFT (ic)), ic->key);
+		  /* delete the result */
+		  IC_RESULT (ic) = NULL;
+		  
+		  if (volLeft || volRight)
+		    {
+		      /* something is volatile, so keep the iCode */
+		      /* and change the operator instead */
+		      ic->op = DUMMY_READ_VOLATILE;
+
+		      /* keep only the volatile operands */      
+		      if (!volLeft)
+			IC_LEFT (ic) = NULL;
+		      if (!volRight)
+			IC_RIGHT (ic) = NULL;
+		    }
+		  else
+		    {
+		      /* nothing is volatile, eliminate the iCode */
+		      remiCodeFromeBBlock (ebbs[i], ic);
 
-		  if (IS_SYMOP (IC_RIGHT (ic)))
-		    bitVectUnSetBit (OP_USES (IC_RIGHT (ic)), ic->key);
+		      /* for the left & right remove the usage */
+		      if (IS_SYMOP (IC_LEFT (ic)))
+			bitVectUnSetBit (OP_USES (IC_LEFT (ic)), ic->key);
+
+		      if (IS_SYMOP (IC_RIGHT (ic)))
+			bitVectUnSetBit (OP_USES (IC_RIGHT (ic)), ic->key);
+		    }
 		}
 
 	    }			/* end of all instructions */
@@ -756,6 +969,12 @@ eBBlockFromiCode (iCode * ic)
   ebbs = iCodeBreakDown (ic, &count);
   saveCount = count;
 
+  /* hash the iCode keys so that we can quickly index */
+  /* them in the rest of the optimization steps */
+  setToNull ((void *) &iCodehTab);
+  iCodehTab = newHashTable (iCodeKey);
+  hashiCodeKeys (ebbs, count);
+  
   /* compute the control flow */
   computeControlFlow (ebbs, count, 0);
 
@@ -777,7 +996,7 @@ eBBlockFromiCode (iCode * ic)
     dumpEbbsToFileExt (DUMP_RAW1, ebbs, count);
 
   /* do common subexpression elimination for each block */
-  change = cseAllBlocks (ebbs, saveCount);
+  change = cseAllBlocks (ebbs, saveCount, FALSE);
 
   /* dumpraw if asked for */
   if (options.dump_raw)
@@ -793,10 +1012,15 @@ eBBlockFromiCode (iCode * ic)
   /* global common subexpression elimination  */
   if (optimize.global_cse)
     {
-      change += cseAllBlocks (ebbs, saveCount);
+      change += cseAllBlocks (ebbs, saveCount, FALSE);
       if (options.dump_gcse)
 	dumpEbbsToFileExt (DUMP_GCSE, ebbs, saveCount);
     }
+  else
+    {
+      // compute the dataflow only
+      assert(cseAllBlocks (ebbs, saveCount, TRUE)==0);
+    }
   /* kill dead code */
   kchange = killDeadCode (ebbs, saveCount);
 
@@ -817,9 +1041,8 @@ eBBlockFromiCode (iCode * ic)
      subexpression once more */
   if (lchange || kchange)
     {
-
       computeDataFlow (ebbs, saveCount);
-      change += cseAllBlocks (ebbs, saveCount);
+      change += cseAllBlocks (ebbs, saveCount, FALSE);
       if (options.dump_loop)
 	dumpEbbsToFileExt (DUMP_LOOPG, ebbs, count);
 
@@ -834,22 +1057,39 @@ eBBlockFromiCode (iCode * ic)
 
     }
 
-
   /* sort it back by block number */
   qsort (ebbs, saveCount, sizeof (eBBlock *), bbNumCompare);
 
+  if (!options.lessPedantic) {
+    // this is a good place to check missing return values
+    if (currFunc) {
+      // the user is on his own with naked functions...
+      if (!IS_VOID(currFunc->etype)
+       && !FUNC_ISNAKED(currFunc->type)) {
+	eBBlock *bp;
+	// make sure all predecessors of the last block end in a return
+	for (bp=setFirstItem(ebbs[saveCount-1]->predList); 
+	     bp; 
+	     bp=setNextItem(ebbs[saveCount-1]->predList)) {
+	  if (bp->ech->op != RETURN) {
+	    werrorfl (bp->ech->filename, bp->ech->lineno,
+		      W_VOID_FUNC, currFunc->name);
+	  }
+	}
+      }
+    }
+  }
+
   /* if cyclomatic info requested then print it */
   if (options.cyclomatic)
     printCyclomatic (ebbs, saveCount);
 
-
   /* convert operations with support routines
      written in C to function calls : Iam doing
      this at this point since I want all the
      operations to be as they are for optimzations */
   convertToFcall (ebbs, count);
 
-
   /* compute the live ranges */
   computeLiveRanges (ebbs, count);
 
@@ -865,10 +1105,9 @@ eBBlockFromiCode (iCode * ic)
   port->assignRegisters (ebbs, count);
 
   /* throw away blocks */
-  setToNull ((void **) &graphEdges);
+  setToNull ((void *) &graphEdges);
   ebbs = NULL;
-
-
+  
   return NULL;
 }