diff --git a/src/cc65/asmstmt.c b/src/cc65/asmstmt.c
index d680f0b69..8c66bcbd7 100644
--- a/src/cc65/asmstmt.c
+++ b/src/cc65/asmstmt.c
@@ -6,7 +6,7 @@
 /*                                                                           */
 /*                                                                           */
 /*                                                                           */
-/* (C) 2001-2003 Ullrich von Bassewitz                                       */
+/* (C) 2001-2004 Ullrich von Bassewitz                                       */
 /*               R�merstrasse 52                                             */
 /*               D-70794 Filderstadt                                         */
 /* EMail:        uz@musoftware.de                                            */
@@ -132,23 +132,23 @@ static void ParseByteArg (StrBuf* T, unsigned Arg)
     ConsumeComma ();
 
     /* Evaluate the expression */
-    ConstSubExpr (hie1, &Expr);
+    ConstAbsIntExpr (hie1, &Expr);
 
     /* Check the range but allow negative values if the type is signed */
     if (IsSignUnsigned (Expr.Type)) {
-    	if (Expr.ConstVal < 0 || Expr.ConstVal > 0xFF) {
+    	if (Expr.Val < 0 || Expr.Val > 0xFF) {
     	    AsmRangeError (Arg);
-	    Expr.ConstVal = 0;
+	    Expr.Val = 0;
 	}
     } else {
-	if (Expr.ConstVal < -128 || Expr.ConstVal > 127) {
+	if (Expr.Val < -128 || Expr.Val > 127) {
     	    AsmRangeError (Arg);
-	    Expr.ConstVal = 0;
+	    Expr.Val = 0;
 	}
     }
 
     /* Convert into a hex number */
-    xsprintf (Buf, sizeof (Buf), "$%02lX", Expr.ConstVal & 0xFF);
+    xsprintf (Buf, sizeof (Buf), "$%02lX", Expr.Val & 0xFF);
 
     /* Add the number to the target buffer */
     SB_AppendStr (T, Buf);
@@ -166,23 +166,23 @@ static void ParseWordArg (StrBuf* T, unsigned Arg)
     ConsumeComma ();
 
     /* Evaluate the expression */
-    ConstSubExpr (hie1, &Expr);
+    ConstAbsIntExpr (hie1, &Expr);
 
     /* Check the range but allow negative values if the type is signed */
     if (IsSignUnsigned (Expr.Type)) {
-    	if (Expr.ConstVal < 0 || Expr.ConstVal > 0xFFFF) {
+    	if (Expr.Val < 0 || Expr.Val > 0xFFFF) {
     	    AsmRangeError (Arg);
-	    Expr.ConstVal = 0;
+	    Expr.Val = 0;
 	}
     } else {
-	if (Expr.ConstVal < -32768 || Expr.ConstVal > 32767) {
+	if (Expr.Val < -32768 || Expr.Val > 32767) {
     	    AsmRangeError (Arg);
-	    Expr.ConstVal = 0;
+	    Expr.Val = 0;
 	}
     }
 
     /* Convert into a hex number */
-    xsprintf (Buf, sizeof (Buf), "$%04lX", Expr.ConstVal & 0xFFFF);
+    xsprintf (Buf, sizeof (Buf), "$%04lX", Expr.Val & 0xFFFF);
 
     /* Add the number to the target buffer */
     SB_AppendStr (T, Buf);
@@ -200,10 +200,10 @@ static void ParseLongArg (StrBuf* T, unsigned Arg attribute ((unused)))
     ConsumeComma ();
 
     /* Evaluate the expression */
-    ConstSubExpr (hie1, &Expr);
+    ConstAbsIntExpr (hie1, &Expr);
 
     /* Convert into a hex number */
-    xsprintf (Buf, sizeof (Buf), "$%08lX", Expr.ConstVal & 0xFFFFFFFF);
+    xsprintf (Buf, sizeof (Buf), "$%08lX", Expr.Val & 0xFFFFFFFF);
 
     /* Add the number to the target buffer */
     SB_AppendStr (T, Buf);
@@ -265,7 +265,7 @@ static void ParseLVarArg (StrBuf* T, unsigned Arg)
     }
 
     /* Calculate the current offset from SP */
-    Offs = Sym->V.Offs - oursp;
+    Offs = Sym->V.Offs - StackPtr;
 
     /* Output the offset */
     xsprintf (Buf, sizeof (Buf), (Offs > 0xFF)? "$%04X" : "$%02X", Offs);
@@ -300,8 +300,8 @@ static void ParseStrArg (StrBuf* T, unsigned Arg attribute ((unused)))
             break;
 
         default:
-            ConstSubExpr (hie1, InitExprDesc (&Expr));
-            xsprintf (Buf, sizeof (Buf), "%ld", Expr.ConstVal);
+            ConstAbsIntExpr (hie1, &Expr);
+            xsprintf (Buf, sizeof (Buf), "%ld", Expr.Val);
             SB_AppendStr (T, Buf);
             break;
     }
diff --git a/src/cc65/assignment.c b/src/cc65/assignment.c
index df9cc50c8..9f0d96802 100644
--- a/src/cc65/assignment.c
+++ b/src/cc65/assignment.c
@@ -52,15 +52,15 @@
 
 
 
-void Assignment (ExprDesc* lval)
+void Assignment (ExprDesc* Expr)
 /* Parse an assignment */
 {
     ExprDesc lval2;
-    type* ltype = lval->Type;
+    type* ltype = Expr->Type;
 
 
     /* We must have an lvalue for an assignment */
-    if (ED_IsRVal (lval)) {
+    if (ED_IsRVal (Expr)) {
         Error ("Invalid lvalue in assignment");
     }
 
@@ -94,9 +94,9 @@ void Assignment (ExprDesc* lval)
             default:            stype = ltype; UseReg = 0;      break;
         }
         if (UseReg) {
-            PushAddr (lval);
+            PushAddr (Expr);
         } else {
-    	    ExprLoad (CF_NONE, lval);
+    	    ExprLoad (CF_NONE, Expr);
             g_push (CF_PTR | CF_UNSIGNED, 0);
         }
 
@@ -119,7 +119,7 @@ void Assignment (ExprDesc* lval)
                 ExprLoad (CF_FORCECHAR, &lval2);
 
                 /* Store it into the new location */
-                Store (lval, stype);
+                Store (Expr, stype);
 
             } else {
 
@@ -146,7 +146,7 @@ void Assignment (ExprDesc* lval)
              */
             if (UseReg) {
                 /* Do the store */
-                Store (lval, stype);
+                Store (Expr, stype);
             } else {
                 /* Print a diagnostic */
                 Error ("Structs of this size are not supported");
@@ -159,7 +159,7 @@ void Assignment (ExprDesc* lval)
     } else {
 
      	/* Get the address on stack if needed */
-     	PushAddr (lval);
+     	PushAddr (Expr);
 
      	/* Read the expression on the right side of the '=' */
      	hie1 (&lval2);
@@ -171,12 +171,12 @@ void Assignment (ExprDesc* lval)
      	ExprLoad (CF_NONE, &lval2);
 
      	/* Generate a store instruction */
-     	Store (lval, 0);
+     	Store (Expr, 0);
 
     }
 
     /* Value is still in primary and not an lvalue */
-    lval->Flags = E_MEXPR | E_RVAL;
+    ED_MakeRValExpr (Expr);
 }
 
 
diff --git a/src/cc65/codegen.c b/src/cc65/codegen.c
index cc041f7ae..278ecc9b4 100644
--- a/src/cc65/codegen.c
+++ b/src/cc65/codegen.c
@@ -67,7 +67,7 @@
 
 
 /* Compiler relative stack pointer */
-int oursp 	= 0;
+int StackPtr 	= 0;
 
 
 
@@ -291,7 +291,7 @@ unsigned sizeofarg (unsigned flags)
 int pop (unsigned flags)
 /* Pop an argument of the given size */
 {
-    return oursp += sizeofarg (flags);
+    return StackPtr += sizeofarg (flags);
 }
 
 
@@ -299,7 +299,7 @@ int pop (unsigned flags)
 int push (unsigned flags)
 /* Push an argument of the given size */
 {
-    return oursp -= sizeofarg (flags);
+    return StackPtr -= sizeofarg (flags);
 }
 
 
@@ -464,7 +464,7 @@ void g_leave (void)
 /* Function epilogue */
 {
     /* How many bytes of locals do we have to drop? */
-    int k = -oursp;
+    int k = -StackPtr;
 
     /* If we didn't have a variable argument list, don't call leave */
     if (funcargs >= 0) {
@@ -509,7 +509,7 @@ void g_swap_regvars (int StackOffs, int RegOffs, unsigned Bytes)
 /* Swap a register variable with a location on the stack */
 {
     /* Calculate the actual stack offset and check it */
-    StackOffs -= oursp;
+    StackOffs -= StackPtr;
     CheckLocalOffs (StackOffs);
 
     /* Generate code */
@@ -577,7 +577,7 @@ void g_save_regvars (int RegOffs, unsigned Bytes)
     }
 
     /* We pushed stuff, correct the stack pointer */
-    oursp -= Bytes;
+    StackPtr -= Bytes;
 }
 
 
@@ -586,7 +586,7 @@ void g_restore_regvars (int StackOffs, int RegOffs, unsigned Bytes)
 /* Restore register variables */
 {
     /* Calculate the actual stack offset and check it */
-    StackOffs -= oursp;
+    StackOffs -= StackPtr;
     CheckLocalOffs (StackOffs);
 
     /* Don't loop for up to two bytes */
@@ -807,7 +807,7 @@ void g_getstatic (unsigned flags, unsigned long label, long offs)
 void g_getlocal (unsigned flags, int offs)
 /* Fetch specified local object (local var). */
 {
-    offs -= oursp;
+    offs -= StackPtr;
     CheckLocalOffs (offs);
     switch (flags & CF_TYPE) {
 
@@ -912,7 +912,7 @@ void g_leasp (int offs)
 /* Fetch the address of the specified symbol into the primary register */
 {
     /* Calculate the offset relative to sp */
-    offs -= oursp;
+    offs -= StackPtr;
 
     /* For value 0 we do direct code */
     if (offs == 0) {
@@ -953,13 +953,13 @@ void g_leavariadic (int Offs)
     unsigned ArgSizeOffs;
 
     /* Calculate the offset relative to sp */
-    Offs -= oursp;
+    Offs -= StackPtr;
 
     /* Get the offset of the parameter which is stored at sp+0 on function
      * entry and check if this offset is reachable with a byte offset.
      */
-    CHECK (oursp <= 0);
-    ArgSizeOffs = -oursp;
+    CHECK (StackPtr <= 0);
+    ArgSizeOffs = -StackPtr;
     CheckLocalOffs (ArgSizeOffs);
 
     /* Get the size of all parameters. */
@@ -1033,7 +1033,7 @@ void g_putstatic (unsigned flags, unsigned long label, long offs)
 void g_putlocal (unsigned Flags, int Offs, long Val)
 /* Put data into local object. */
 {
-    Offs -= oursp;
+    Offs -= StackPtr;
     CheckLocalOffs (Offs);
     switch (Flags & CF_TYPE) {
 
@@ -1552,7 +1552,7 @@ void g_addlocal (unsigned flags, int offs)
     unsigned L;
 
     /* Correct the offset and check it */
-    offs -= oursp;
+    offs -= StackPtr;
     CheckLocalOffs (offs);
 
     switch (flags & CF_TYPE) {
@@ -1759,7 +1759,7 @@ void g_addeqlocal (unsigned flags, int offs, unsigned long val)
 /* Emit += for a local variable */
 {
     /* Calculate the true offset, check it, load it into Y */
-    offs -= oursp;
+    offs -= StackPtr;
     CheckLocalOffs (offs);
 
     /* Check the size and determine operation */
@@ -1990,7 +1990,7 @@ void g_subeqlocal (unsigned flags, int offs, unsigned long val)
 /* Emit -= for a local variable */
 {
     /* Calculate the true offset, check it, load it into Y */
-    offs -= oursp;
+    offs -= StackPtr;
     CheckLocalOffs (offs);
 
     /* Check the size and determine operation */
@@ -2113,7 +2113,7 @@ void g_addaddr_local (unsigned flags attribute ((unused)), int offs)
     unsigned L = 0;
 
     /* Add the offset */
-    offs -= oursp;
+    offs -= StackPtr;
     if (offs != 0) {
 	/* We cannot address more then 256 bytes of locals anyway */
 	L = GetLocalLabel();
@@ -2438,7 +2438,7 @@ void g_call (unsigned Flags, const char* Label, unsigned ArgSize)
 	ldyconst (ArgSize);
     }
     AddCodeLine ("jsr _%s", Label);
-    oursp += ArgSize;		/* callee pops args */
+    StackPtr += ArgSize;		/* callee pops args */
 }
 
 
@@ -2455,7 +2455,7 @@ void g_callind (unsigned Flags, unsigned ArgSize, int Offs)
 	AddCodeLine ("jsr callax");
     } else {
 	/* The address is on stack, offset is on Val */
-	Offs -= oursp;
+	Offs -= StackPtr;
 	CheckLocalOffs (Offs);
 	AddCodeLine ("pha");
 	AddCodeLine ("ldy #$%02X", Offs);
@@ -2469,7 +2469,7 @@ void g_callind (unsigned Flags, unsigned ArgSize, int Offs)
     }
 
     /* Callee pops args */
-    oursp += ArgSize;
+    StackPtr += ArgSize;
 }
 
 
diff --git a/src/cc65/codegen.h b/src/cc65/codegen.h
index 72feb2eac..e251029f6 100644
--- a/src/cc65/codegen.h
+++ b/src/cc65/codegen.h
@@ -86,7 +86,7 @@
 
 
 /* Compiler relative stackpointer */
-extern int oursp;
+extern int StackPtr;
 
 /* Forward */
 struct StrBuf;
diff --git a/src/cc65/declare.c b/src/cc65/declare.c
index 414c353d8..b22d7b04f 100644
--- a/src/cc65/declare.c
+++ b/src/cc65/declare.c
@@ -269,8 +269,8 @@ static void ParseEnumDecl (void)
    	if (CurTok.Tok == TOK_ASSIGN) {
     	    ExprDesc lval;
    	    NextToken ();
-   	    ConstExpr (&lval);
-   	    EnumVal = lval.ConstVal;
+   	    ConstAbsIntExpr (hie1, &lval);
+   	    EnumVal = lval.Val;
     	}
 
 	/* Add an entry to the symbol table */
@@ -1046,16 +1046,16 @@ static void Decl (const DeclSpec* Spec, Declaration* D, unsigned Mode)
 	    /* Read the size if it is given */
        	    if (CurTok.Tok != TOK_RBRACK) {
     	     	ExprDesc lval;
-       	       	ConstExpr (&lval);
-                if (lval.ConstVal <= 0) {
+       	       	ConstAbsIntExpr (hie1, &lval);
+                if (lval.Val <= 0) {
                     if (D->Ident[0] != '\0') {
                         Error ("Size of array `%s' is invalid", D->Ident);
                     } else {
                         Error ("Size of array is invalid");
                     }
-                    lval.ConstVal = 1;
+                    lval.Val = 1;
                 }
-       	       	Size = lval.ConstVal;
+       	       	Size = lval.Val;
        	    }
        	    ConsumeRBrack ();
 
@@ -1222,7 +1222,7 @@ static unsigned ParseScalarInit (type* T)
     }
 
     /* Get the expression and convert it to the target type */
-    ConstExpr (&ED);
+    ConstExpr (hie1, &ED);
     TypeConversion (&ED, T);
 
     /* Output the data */
@@ -1245,11 +1245,7 @@ static unsigned ParsePointerInit (type* T)
 
     /* Expression */
     ExprDesc ED;
-    ConstExpr (&ED);
-    if ((ED.Flags & E_MCTYPE) == E_TCONST) {
-        /* Make the const value the correct size */
-        ED.ConstVal &= 0xFFFF;
-    }
+    ConstExpr (hie1, &ED);
     TypeConversion (&ED, T);
 
     /* Output the data */
@@ -1419,7 +1415,7 @@ static unsigned ParseVoidInit (void)
  * Return the number of bytes initialized.
  */
 {
-    ExprDesc lval;
+    ExprDesc Expr;
     unsigned Size;
 
     /* Opening brace */
@@ -1428,16 +1424,16 @@ static unsigned ParseVoidInit (void)
     /* Allow an arbitrary list of values */
     Size = 0;
     do {
-	ConstExpr (&lval);
-	switch (UnqualifiedType (lval.Type[0])) {
+	ConstExpr (hie1, &Expr);
+	switch (UnqualifiedType (Expr.Type[0])) {
 
 	    case T_SCHAR:
 	    case T_UCHAR:
-		if ((lval.Flags & E_MCTYPE) == E_TCONST) {
+		if (ED_IsConstAbsInt (&Expr)) {
 		    /* Make it byte sized */
-		    lval.ConstVal &= 0xFF;
+		    Expr.Val &= 0xFF;
 		}
-		DefineData (&lval);
+		DefineData (&Expr);
                 Size += SIZEOF_CHAR;
                 break;
 
@@ -1447,17 +1443,21 @@ static unsigned ParseVoidInit (void)
 	    case T_UINT:
 	    case T_PTR:
 	    case T_ARRAY:
-	   	if ((lval.Flags & E_MCTYPE) == E_TCONST) {
+	   	if (ED_IsConstAbsInt (&Expr)) {
     	      	    /* Make it word sized */
-	   	    lval.ConstVal &= 0xFFFF;
+	   	    Expr.Val &= 0xFFFF;
 	   	}
-	   	DefineData (&lval);
+	   	DefineData (&Expr);
 	   	Size += SIZEOF_INT;
                 break;
 
 	    case T_LONG:
 	    case T_ULONG:
-	   	DefineData (&lval);
+	   	if (ED_IsConstAbsInt (&Expr)) {
+    	      	    /* Make it dword sized */
+	   	    Expr.Val &= 0xFFFFFFFF;
+	   	}
+	   	DefineData (&Expr);
 	   	Size += SIZEOF_LONG;
                 break;
 
@@ -1527,7 +1527,7 @@ static unsigned ParseInitInternal (type* T, int AllowFlexibleMembers)
 unsigned ParseInit (type* T)
 /* Parse initialization of variables. Return the number of data bytes. */
 {
-    /* Parse the initialization */
+    /* Parse the initialization */    
     unsigned Size = ParseInitInternal (T, !ANSI);
 
     /* The initialization may not generate code on global level, because code
diff --git a/src/cc65/expr.c b/src/cc65/expr.c
index c525b8132..d0ff65a3a 100644
--- a/src/cc65/expr.c
+++ b/src/cc65/expr.c
@@ -75,9 +75,6 @@ static GenDesc GenOASGN  = { TOK_OR_ASSIGN,	GEN_NOPUSH,     g_or  };
 void hie0 (ExprDesc *lval);
 /* Parse comma operator. */
 
-void expr (void (*Func) (ExprDesc*), ExprDesc *Expr);
-/* Expression parser; func is either hie0 or hie1. */
-
 
 
 /*****************************************************************************/
@@ -86,30 +83,40 @@ void expr (void (*Func) (ExprDesc*), ExprDesc *Expr);
 
 
 
-static unsigned GlobalModeFlags (unsigned flags)
+static unsigned GlobalModeFlags (unsigned Flags)
 /* Return the addressing mode flags for the variable with the given flags */
 {
-    flags &= E_MCTYPE;
-    if (flags == E_TGLAB) {
-	/* External linkage */
-	return CF_EXTERNAL;
-    } else if (flags == E_TREGISTER) {
-	/* Register variable */
-	return CF_REGVAR;
-    } else {
-	/* Static */
-	return CF_STATIC;
+    switch (Flags & E_MASK_LOC) {
+        case E_LOC_GLOBAL:      return CF_EXTERNAL;
+        case E_LOC_STATIC:      return CF_STATIC;
+        case E_LOC_REGISTER:    return CF_REGVAR;
+        default:
+            Internal ("GlobalModeFlags: Invalid flags value: %u", Flags);
     }
 }
 
 
 
-static int IsNullPtr (ExprDesc* lval)
-/* Return true if this is the NULL pointer constant */
+static void ExprWithCheck (void (*Func) (ExprDesc*), ExprDesc *Expr)
+/* Call an expression function with checks. */
 {
-    return (IsClassInt (lval->Type) && 	        /* Is it an int? */
-       	    lval->Flags == E_MCONST && 	        /* Is it constant? */
-	    lval->ConstVal == 0);		/* And is it's value zero? */
+    /* Remember the stack pointer */
+    int OldSP = StackPtr;
+
+    /* Call the expression function */
+    (*Func) (Expr);
+
+    /* Do some checks if code generation is still constistent */
+    if (StackPtr != OldSP) {
+     	if (Debug) {
+       	    fprintf (stderr,
+                     "Code generation messed up!\n"
+                     "StackPtr is %d, should be %d",
+                     StackPtr, OldSP);
+     	} else {
+       	    Internal ("StackPtr is %d, should be %d\n", StackPtr, OldSP);
+     	}
+    }
 }
 
 
@@ -158,7 +165,7 @@ static unsigned typeadjust (ExprDesc* lhs, ExprDesc* rhs, int NoPush)
 
     /* Generate type adjustment code if needed */
     ltype = TypeOf (lhst);
-    if (lhs->Flags == E_MCONST) {
+    if (ED_IsLocAbs (lhs)) {
 	ltype |= CF_CONST;
     }
     if (NoPush) {
@@ -166,7 +173,7 @@ static unsigned typeadjust (ExprDesc* lhs, ExprDesc* rhs, int NoPush)
      	ltype |= CF_REG;
     }
     rtype = TypeOf (rhst);
-    if (rhs->Flags == E_MCONST) {
+    if (ED_IsLocAbs (rhs)) {
 	rtype |= CF_CONST;
     }
     flags = g_typeadjust (ltype, rtype);
@@ -183,37 +190,40 @@ static unsigned typeadjust (ExprDesc* lhs, ExprDesc* rhs, int NoPush)
 void DefineData (ExprDesc* Expr)
 /* Output a data definition for the given expression */
 {
-    unsigned Flags = Expr->Flags;
+    switch (ED_GetLoc (Expr)) {
 
-    switch (Flags & E_MCTYPE) {
+        case E_LOC_ABS:
+            /* Absolute: numeric address or const */
+	    g_defdata (TypeOf (Expr->Type) | CF_CONST, Expr->Val, 0);
+            break;
 
-       	case E_TCONST:
-	    /* Number */
-	    g_defdata (TypeOf (Expr->Type) | CF_CONST, Expr->ConstVal, 0);
-       	    break;
+        case E_LOC_GLOBAL:
+            /* Global variable */
+            g_defdata (CF_EXTERNAL, Expr->Name, Expr->Val);
+            break;
 
-	case E_TREGISTER:
+        case E_LOC_STATIC:
+            /* Static variable */
+            g_defdata (CF_STATIC, Expr->Name, Expr->Val);
+            break;
+
+        case E_LOC_REGISTER:
 	    /* Register variable. Taking the address is usually not
 	     * allowed.
 	     */
 	    if (IS_Get (&AllowRegVarAddr) == 0) {
 	     	Error ("Cannot take the address of a register variable");
 	    }
-	    /* FALLTHROUGH */
+            g_defdata (CF_REGVAR, Expr->Name, Expr->Val);
+            break;
 
-       	case E_TGLAB:
-        case E_TLLAB:
-       	    /* Local or global symbol */
-	    g_defdata (GlobalModeFlags (Flags), Expr->Name, Expr->ConstVal);
-	    break;
-
-       	case E_TLIT:
-	    /* a literal of some kind */
-       	    g_defdata (CF_STATIC, LiteralPoolLabel, Expr->ConstVal);
-       	    break;
+        case E_LOC_LITERAL:
+            /* Literal in the literal pool */
+            g_defdata (CF_STATIC, LiteralPoolLabel, Expr->Val);
+            break;
 
        	default:
-	    Internal ("Unknown constant type: %04X", Flags);
+	    Internal ("Unknown constant type: 0x%04X", ED_GetLoc (Expr));
     }
 }
 
@@ -222,37 +232,39 @@ void DefineData (ExprDesc* Expr)
 static void LoadConstant (unsigned Flags, ExprDesc* Expr)
 /* Load the primary register with some constant value. */
 {
-    switch (Expr->Flags & E_MCTYPE) {
+    switch (ED_GetLoc (Expr)) {
 
-    	case E_TLOFFS:
-       	    g_leasp (Expr->ConstVal);
-	    break;
-
-       	case E_TCONST:
+       	case E_LOC_ABS:
 	    /* Number constant */
-       	    g_getimmed (Flags | TypeOf (Expr->Type) | CF_CONST, Expr->ConstVal, 0);
+       	    g_getimmed (Flags | TypeOf (Expr->Type) | CF_CONST, Expr->Val, 0);
        	    break;
 
-	case E_TREGISTER:
+        case E_LOC_GLOBAL:
+       	    /* Global symbol, load address */
+	    g_getimmed ((Flags | CF_EXTERNAL) & ~CF_CONST, Expr->Name, Expr->Val);
+       	    break;
+
+       	case E_LOC_STATIC:
+       	    /* Static symbol, load address */
+       	    g_getimmed ((Flags | CF_STATIC) & ~CF_CONST, Expr->Name, Expr->Val);
+       	    break;
+
+       	case E_LOC_REGISTER:
 	    /* Register variable. Taking the address is usually not
 	     * allowed.
 	     */
 	    if (IS_Get (&AllowRegVarAddr) == 0) {
 	     	Error ("Cannot take the address of a register variable");
 	    }
-	    /* FALLTHROUGH */
+       	    g_getimmed ((Flags | CF_REGVAR) & ~CF_CONST, Expr->Name, Expr->Val);
 
-       	case E_TGLAB:
-        case E_TLLAB:
-       	    /* Local or global symbol, load address */
-	    Flags |= GlobalModeFlags (Expr->Flags);
-	    Flags &= ~CF_CONST;
-	    g_getimmed (Flags, Expr->Name, Expr->ConstVal);
-       	    break;
+    	case E_LOC_STACK:
+       	    g_leasp (Expr->Val);
+	    break;
 
-       	case E_TLIT:
+       	case E_LOC_LITERAL:
 	    /* Literal string */
-	    g_getimmed (CF_STATIC, LiteralPoolLabel, Expr->ConstVal);
+	    g_getimmed (CF_STATIC, LiteralPoolLabel, Expr->Val);
        	    break;
 
        	default:
@@ -333,10 +345,10 @@ static int TypeSpecAhead (void)
 
     /* There's a type waiting if:
      *
-     *   1.    We have an opening paren, and
-     *     a.  the next token is a type, or
-     *     b.  the next token is a type qualifier, or
-     *     c.  the next token is a typedef'd type
+     * We have an opening paren, and
+     *   a.  the next token is a type, or
+     *   b.  the next token is a type qualifier, or
+     *   c.  the next token is a typedef'd type
      */
     return CurTok.Tok == TOK_LPAREN && (
        	   TokIsType (&NextTok)                         ||
@@ -348,7 +360,7 @@ static int TypeSpecAhead (void)
 
 
 
-void PushAddr (ExprDesc* Expr)
+void PushAddr (const ExprDesc* Expr)
 /* If the expression contains an address that was somehow evaluated,
  * push this address on the stack. This is a helper function for all
  * sorts of implicit or explicit assignment functions where the lvalue
@@ -356,7 +368,7 @@ void PushAddr (ExprDesc* Expr)
  */
 {
     /* Get the address on stack if needed */
-    if (Expr->Flags != E_MREG && (Expr->Flags & E_MEXPR)) {
+    if (ED_IsLocExpr (Expr)) {
      	/* Push the address (always a pointer) */
      	g_push (CF_PTR, 0);
     }
@@ -364,40 +376,6 @@ void PushAddr (ExprDesc* Expr)
 
 
 
-void ConstSubExpr (void (*Func) (ExprDesc*), ExprDesc* Expr)
-/* Will evaluate an expression via the given function. If the result is not
- * a constant, a diagnostic will be printed, and the value is replaced by
- * a constant one to make sure there are no internal errors that result
- * from this input error.
- */
-{
-    Func (InitExprDesc (Expr));
-    if (ED_IsLVal (Expr) != 0 || Expr->Flags != E_MCONST) {
-       	Error ("Constant expression expected");
-       	/* To avoid any compiler errors, make the expression a valid const */
-     	ED_MakeConstInt (Expr, 1);
-    }
-}
-
-
-
-void CheckBoolExpr (ExprDesc* Expr)
-/* Check if the given expression is a boolean expression, output a diagnostic
- * if not.
- */
-{
-    /* If it's an integer, it's ok. If it's not an integer, but a pointer,
-     * the pointer used in a boolean context is also ok
-     */
-    if (!IsClassInt (Expr->Type) && !IsClassPtr (Expr->Type)) {
- 	Error ("Boolean expression expected");
- 	/* To avoid any compiler errors, make the expression a valid int */
-	ED_MakeConstInt (Expr, 1);
-    }
-}
-
-
-
 /*****************************************************************************/
 /*   	     	     		     code				     */
 /*****************************************************************************/
@@ -409,43 +387,74 @@ void ExprLoad (unsigned Flags, ExprDesc* Expr)
  * already there.
  */
 {
-    int f;
-
-    f = Expr->Flags;
     if (ED_IsLVal (Expr)) {
+
        	/* Dereferenced lvalue */
        	Flags |= TypeOf (Expr->Type);
      	if (Expr->Test & E_FORCETEST) {
      	    Flags |= CF_TEST;
      	    Expr->Test &= ~E_FORCETEST;
      	}
-       	if (f & E_MGLOBAL) {
-     	    /* Reference to a global variable */
-     	    Flags |= GlobalModeFlags (f);
-       	    g_getstatic (Flags, Expr->Name, Expr->ConstVal);
-       	} else if (f & E_MLOCAL) {
-     	    /* Reference to a local variable */
-       	    g_getlocal (Flags, Expr->ConstVal);
-     	} else if (f & E_MCONST) {
-     	    /* Reference to an absolute address */
-     	    g_getstatic (Flags | CF_ABSOLUTE, Expr->ConstVal, 0);
-     	} else if (f == E_MEOFFS) {
-     	    /* Reference to address in primary with offset in Expr */
-     	    g_getind (Flags, Expr->ConstVal);
-     	} else if (f != E_MREG) {
-     	    /* Reference with address in primary */
-     	    g_getind (Flags, 0);
-     	} else if (Flags & CF_TEST) {
-            /* The value is already in the primary but needs a test */
-            g_test (Flags);
+
+        switch (ED_GetLoc (Expr)) {
+
+            case E_LOC_ABS:
+                /* Absolute: numeric address or const */
+                g_getstatic (Flags | CF_ABSOLUTE, Expr->Val, 0);
+                break;
+
+            case E_LOC_GLOBAL:
+                /* Global variable */
+                g_getstatic (Flags | CF_EXTERNAL, Expr->Name, Expr->Val);
+                break;
+
+            case E_LOC_STATIC:
+                /* Static variable */
+                g_getstatic (Flags | CF_STATIC, Expr->Name, Expr->Val);
+                break;
+
+            case E_LOC_REGISTER:
+                /* Register variable */
+                g_getstatic (Flags | CF_REGVAR, Expr->Name, Expr->Val);
+                break;
+
+            case E_LOC_STACK:
+                /* Value on the stack */
+                g_getlocal (Flags, Expr->Val);
+                break;
+
+            case E_LOC_PRIMARY:
+                /* The primary register - just test if necessary */
+                if (Flags & CF_TEST) {
+                    g_test (Flags);
+                }
+                break;
+
+            case E_LOC_EXPR:
+                /* Reference to address in primary with offset in Expr */
+                g_getind (Flags, Expr->Val);
+                break;
+
+            case E_LOC_LITERAL:
+                /* Literal in the literal pool */
+                g_getstatic (Flags | CF_STATIC, LiteralPoolLabel, Expr->Val);
+                break;
+
+            default:
+                Internal ("Invalid location in ExprLoad: 0x%04X", ED_GetLoc (Expr));
         }
+
     } else {
      	/* An rvalue */
-     	if (f == E_MEOFFS) {
-     	    /* reference not storable */
-     	    Flags |= TypeOf (Expr->Type);
-     	    g_inc (Flags | CF_CONST, Expr->ConstVal);
-     	} else if ((f & E_MEXPR) == 0) {
+       	if (ED_IsLocExpr (Expr)) {
+            if (Expr->Val != 0) {
+                /* We have an expression in the primary plus a constant
+                 * offset. Adjust the value in the primary accordingly.
+                 */
+                Flags |= TypeOf (Expr->Type);
+                g_inc (Flags | CF_CONST, Expr->Val);
+            }
+     	} else {
      	    /* Constant of some sort, load it into the primary */
      	    LoadConstant (Flags, Expr);
      	}
@@ -458,6 +467,13 @@ void ExprLoad (unsigned Flags, ExprDesc* Expr)
             Expr->Test &= ~E_FORCETEST;
         }
     }
+
+#if 0
+    /* Regardless of the original contents, Expr is now an rvalue in the
+     * primary. ### Later...
+     */
+    ED_MakeRValExpr (Expr);
+#endif
 }
 
 
@@ -508,9 +524,9 @@ static unsigned FunctionParamList (FuncDesc* Func)
 	/* Do we have more than one parameter in the frame? */
 	if (FrameParams > 1) {
 	    /* Okeydokey, setup the frame */
-	    FrameOffs = oursp;
+	    FrameOffs = StackPtr;
 	    g_space (FrameSize);
-	    oursp -= FrameSize;
+	    StackPtr -= FrameSize;
 	} else {
 	    /* Don't use a preallocated frame */
 	    FrameSize = 0;
@@ -556,7 +572,7 @@ static unsigned FunctionParamList (FuncDesc* Func)
      	}
 
         /* Evaluate the parameter expression */
-        hie1 (InitExprDesc (&Expr));
+        hie1 (&Expr);
 
       	/* If we don't have an argument spec, accept anything, otherwise
 	 * convert the actual argument to the type needed.
@@ -593,10 +609,10 @@ static unsigned FunctionParamList (FuncDesc* Func)
                 }
 	    	FrameOffs -= ArgSize;
 	    	/* Store */
-	      	g_putlocal (Flags | CF_NOKEEP, FrameOffs, Expr.ConstVal);
+	      	g_putlocal (Flags | CF_NOKEEP, FrameOffs, Expr.Val);
 	    } else {
 	    	/* Push the argument */
-	    	g_push (Flags, Expr.ConstVal);
+	    	g_push (Flags, Expr.Val);
 	    }
 
 	    /* Calculate total parameter size */
@@ -660,21 +676,21 @@ static void FunctionCall (ExprDesc* Expr)
 	 * For fastcall functions we do also need to place a copy of the
 	 * pointer on stack, since we cannot use a/x.
 	 */
-	PtrOnStack = IsFastCall || ((Expr->Flags & (E_MGLOBAL | E_MLOCAL)) == 0);
+	PtrOnStack = IsFastCall || !ED_IsConst (Expr);
 	if (PtrOnStack) {
 
 	    /* Not a global or local variable, or a fastcall function. Load
 	     * the pointer into the primary and mark it as an expression.
 	     */
        	    ExprLoad (CF_NONE, Expr);
-	    Expr->Flags |= E_MEXPR;
+       	    ED_MakeRValExpr (Expr);
 
 	    /* Remember the code position */
 	    Mark = GetCodePos ();
 
 	    /* Push the pointer onto the stack and remember the offset */
 	    g_push (CF_PTR, 0);
-	    PtrOffs = oursp;
+	    PtrOffs = StackPtr;
 	}
 
     /* Check for known standard functions and inline them if requested */
@@ -682,7 +698,7 @@ static void FunctionCall (ExprDesc* Expr)
 
 	/* Inline this function */
        	HandleStdFunc (Func, Expr);
-       	return;
+       	goto ExitPoint;
 
     }
 
@@ -747,6 +763,11 @@ static void FunctionCall (ExprDesc* Expr)
        	g_call (TypeOf (Expr->Type), (const char*) Expr->Name, ParamSize);
 
     }
+
+ExitPoint:
+    /* The function result is an rvalue in the primary register */
+    ED_MakeRValExpr (Expr);
+    Expr->Type = GetFuncReturn (Expr->Type);
 }
 
 
@@ -757,14 +778,13 @@ static void Primary (ExprDesc* E)
     SymEntry* Sym;
 
     /* Initialize fields in the expression stucture */
-    E->Test = 0;        /* No test */
-    E->Sym  = 0;        /* Symbol unknown */
+    ED_Init (E);
 
     /* Character and integer constants. */
     if (CurTok.Tok == TOK_ICONST || CurTok.Tok == TOK_CCONST) {
-    	E->Flags = E_MCONST | E_TCONST | E_RVAL;
+    	E->Flags = E_LOC_ABS | E_RTYPE_RVAL;
     	E->Type  = CurTok.Type;
-    	E->ConstVal = CurTok.IVal;
+    	E->Val   = CurTok.IVal;
     	NextToken ();
     	return;
     }
@@ -774,7 +794,7 @@ static void Primary (ExprDesc* E)
      */
     if (CurTok.Tok == TOK_LPAREN) {
     	NextToken ();
-        hie0 (InitExprDesc (E));
+        hie0 (E);
        	ConsumeRParen ();
     	return;
     }
@@ -783,7 +803,7 @@ static void Primary (ExprDesc* E)
      * is an undefined macro and replace it by a constant value of zero.
      */
     if (Preprocessing && CurTok.Tok == TOK_IDENT) {
-        ED_MakeConstInt (E, 0);
+        ED_MakeConstAbsInt (E, 0);
         return;
     }
 
@@ -793,7 +813,7 @@ static void Primary (ExprDesc* E)
     if (Preprocessing) {
        	/* Illegal expression in PP mode */
 	Error ("Preprocessor expression expected");
-	ED_MakeConstInt (E, 1);
+	ED_MakeConstAbsInt (E, 1);
 	return;
     }
 
@@ -809,34 +829,32 @@ static void Primary (ExprDesc* E)
                 /* We found the symbol - skip the name token */
                 NextToken ();
 
-                /* The expression type is the symbol type */
-                E->Type = Sym->Type;
-
                 /* Check for illegal symbol types */
                 CHECK ((Sym->Flags & SC_LABEL) != SC_LABEL);
                 if (Sym->Flags & SC_TYPE) {
                     /* Cannot use type symbols */
                     Error ("Variable identifier expected");
                     /* Assume an int type to make E valid */
-                    E->Flags = E_MLOCAL | E_TLOFFS | E_LVAL;
+                    E->Flags = E_LOC_STACK | E_RTYPE_LVAL;
                     E->Type  = type_int;
-                    E->ConstVal = 0;
                     return;
                 }
 
                 /* Mark the symbol as referenced */
                 Sym->Flags |= SC_REF;
 
+                /* The expression type is the symbol type */
+                E->Type = Sym->Type;
+
                 /* Check for legal symbol types */
                 if ((Sym->Flags & SC_CONST) == SC_CONST) {
                     /* Enum or some other numeric constant */
-                    E->Flags = E_MCONST | E_TCONST | E_RVAL;
-                    E->ConstVal = Sym->V.ConstVal;
+                    E->Flags = E_LOC_ABS | E_RTYPE_RVAL;
+                    E->Val = Sym->V.ConstVal;
                 } else if ((Sym->Flags & SC_FUNC) == SC_FUNC) {
                     /* Function */
-                    E->Flags = E_MGLOBAL | E_MCONST | E_TGLAB | E_RVAL;
+                    E->Flags = E_LOC_GLOBAL | E_RTYPE_LVAL;
                     E->Name = (unsigned long) Sym->Name;
-                    E->ConstVal = 0;
                 } else if ((Sym->Flags & SC_AUTO) == SC_AUTO) {
                     /* Local variable. If this is a parameter for a variadic
                      * function, we have to add some address calculations, and the
@@ -845,41 +863,40 @@ static void Primary (ExprDesc* E)
                     if ((Sym->Flags & SC_PARAM) == SC_PARAM && F_IsVariadic (CurrentFunc)) {
                         /* Variadic parameter */
                         g_leavariadic (Sym->V.Offs - F_GetParamSize (CurrentFunc));
-                        E->Flags = E_MEXPR | E_LVAL;
-                        E->ConstVal = 0;
+                        E->Flags = E_LOC_EXPR | E_RTYPE_LVAL;
                     } else {
                         /* Normal parameter */
-                        E->Flags = E_MLOCAL | E_TLOFFS | E_LVAL;
-                        E->ConstVal = Sym->V.Offs;
+                        E->Flags = E_LOC_STACK | E_RTYPE_LVAL;
+                        E->Val = Sym->V.Offs;
                     }
                 } else if ((Sym->Flags & SC_REGISTER) == SC_REGISTER) {
                     /* Register variable, zero page based */
-                    E->Flags = E_MGLOBAL | E_MCONST | E_TREGISTER | E_LVAL;
+                    E->Flags = E_LOC_REGISTER | E_RTYPE_LVAL;
                     E->Name  = Sym->V.R.RegOffs;
-                    E->ConstVal = 0;
                 } else if ((Sym->Flags & SC_STATIC) == SC_STATIC) {
                     /* Static variable */
                     if (Sym->Flags & (SC_EXTERN | SC_STORAGE)) {
-                        E->Flags = E_MGLOBAL | E_MCONST | E_TGLAB | E_LVAL;
+                        E->Flags = E_LOC_GLOBAL | E_RTYPE_LVAL;
                         E->Name = (unsigned long) Sym->Name;
                     } else {
-                        E->Flags = E_MGLOBAL | E_MCONST | E_TLLAB | E_LVAL;
+                        E->Flags = E_LOC_STATIC | E_RTYPE_LVAL;
                         E->Name = Sym->V.Label;
                     }
-                    E->ConstVal = 0;
                 } else {
                     /* Local static variable */
-                    E->Flags = E_MGLOBAL | E_MCONST | E_TLLAB | E_LVAL;
+                    E->Flags = E_LOC_STATIC | E_RTYPE_LVAL;
                     E->Name  = Sym->V.Offs;
-                    E->ConstVal = 0;
                 }
 
-                /* The following should not be necessary if the reference flag is
-                 * set right above, but currently I do not oversee if it's really
-                 * needed and the old code did it.
-                 * ###
+                /* We've made all variables lvalues above. However, this is
+                 * not always correct: An array is actually the address of its
+                 * first element, which is a rvalue, and a function is a
+                 * rvalue, too, because we cannot store anything in a function.
+                 * So fix the flags depending on the type.
                  */
-                ED_SetValType (E, !IsTypeFunc (E->Type) && !IsTypeArray (E->Type));
+                if (IsTypeArray (E->Type) || IsTypeFunc (E->Type)) {
+                    ED_MakeRVal (E);
+                }
 
             } else {
 
@@ -897,15 +914,13 @@ static void Primary (ExprDesc* E)
                     Warning ("Function call without a prototype");
                     Sym = AddGlobalSym (Ident, GetImplicitFuncType(), SC_EXTERN | SC_REF | SC_FUNC);
                     E->Type  = Sym->Type;
-                    E->Flags = E_MGLOBAL | E_MCONST | E_TGLAB | E_RVAL;
+                    E->Flags = E_LOC_GLOBAL | E_RTYPE_RVAL;
                     E->Name  = (unsigned long) Sym->Name;
-                    E->ConstVal = 0;
                 } else {
                     /* Undeclared Variable */
                     Sym = AddLocalSym (Ident, type_int, SC_AUTO | SC_REF, 0);
-                    E->Flags = E_MLOCAL | E_TLOFFS | E_LVAL;
+                    E->Flags = E_LOC_STACK | E_RTYPE_LVAL;
                     E->Type = type_int;
-                    E->ConstVal = 0;
                     Error ("Undefined symbol: `%s'", Ident);
                 }
 
@@ -914,8 +929,8 @@ static void Primary (ExprDesc* E)
 
         case TOK_SCONST:
             /* String literal */
-            E->Flags = E_MCONST | E_TLIT | E_RVAL;
-            E->ConstVal = CurTok.IVal;
+            E->Flags = E_LOC_LITERAL | E_RTYPE_RVAL;
+            E->Val = CurTok.IVal;
             E->Type  = GetCharArrayType (GetLiteralPoolOffs () - CurTok.IVal);
             NextToken ();
             break;
@@ -923,25 +938,35 @@ static void Primary (ExprDesc* E)
         case TOK_ASM:
             /* ASM statement */
             AsmStatement ();
-            E->Flags = E_MEXPR | E_RVAL;
-            E->ConstVal = 0;
+            E->Flags = E_LOC_EXPR | E_RTYPE_RVAL;
             E->Type  = type_void;
             break;
 
+        case TOK_A:
+            /* Register pseudo variable */
+            E->Type  = type_uchar;
+            E->Flags = E_LOC_PRIMARY | E_RTYPE_LVAL;
+            NextToken ();
+            break;
+
         case TOK_AX:
+            /* Register pseudo variable */
+            E->Type  = type_uint;
+            E->Flags = E_LOC_PRIMARY | E_RTYPE_LVAL;
+            NextToken ();
+            break;
+
         case TOK_EAX:
-            /* __AX__ and __EAX__ pseudo values */
-            E->Type  = (CurTok.Tok == TOK_AX)? type_uint : type_ulong;
-            E->Flags = E_MREG | E_LVAL;      /* May be used as lvalue */
-            E->Test &= ~E_CC;
-            E->ConstVal = 0;
+            /* Register pseudo variable */
+            E->Type  = type_ulong;
+            E->Flags = E_LOC_PRIMARY | E_RTYPE_LVAL;
             NextToken ();
             break;
 
         default:
             /* Illegal primary. */
             Error ("Expression expected");
-            ED_MakeConstInt (E, 1);
+            ED_MakeConstAbsInt (E, 1);
             break;
     }
 }
@@ -951,15 +976,12 @@ static void Primary (ExprDesc* E)
 static void ArrayRef (ExprDesc* Expr)
 /* Handle an array reference */
 {
-    unsigned lflags;
-    unsigned rflags;
-    int ConstBaseAddr;
-    int ConstSubAddr;
-    ExprDesc lval2;
-    CodeMark Mark1;
-    CodeMark Mark2;
-    type* tptr1;
-    type* tptr2;
+    int         ConstBaseAddr;
+    ExprDesc    SubScript;
+    CodeMark    Mark1;
+    CodeMark    Mark2;
+    type*       ElementType;
+    type*       tptr1;
 
 
     /* Skip the bracket */
@@ -972,14 +994,11 @@ static void ArrayRef (ExprDesc* Expr)
      * address. This is true for most arrays and will produce a lot better
      * code. Check if this is a const base address.
      */
-    lflags = Expr->Flags & ~E_MCTYPE;
-    ConstBaseAddr = (lflags == E_MCONST)       || /* Constant numeric address */
-       	       	     (lflags & E_MGLOBAL) != 0 || /* Static array, or ... */
-       	       	     lflags == E_MLOCAL;     	  /* Local array */
+    ConstBaseAddr = (ED_IsLocConst (Expr) || ED_IsLocStack (Expr));
 
     /* If we have a constant base, we delay the address fetch */
     Mark1 = GetCodePos ();
-    Mark2 = 0;	       	/* Silence gcc */
+    Mark2 = 0; 	       	/* Silence gcc */
     if (!ConstBaseAddr) {
     	/* Get a pointer to the array into the primary */
     	ExprLoad (CF_NONE, Expr);
@@ -993,10 +1012,48 @@ static void ArrayRef (ExprDesc* Expr)
     }
 
     /* TOS now contains ptr to array elements. Get the subscript. */
-    hie0 (&lval2);
-    if (ED_IsRVal (&lval2) && lval2.Flags == E_MCONST) {
+    ExprWithCheck (hie0, &SubScript);
 
-     	/* The array subscript is a constant - remove value from stack */
+    /* Check the types of array and subscript. We can either have a
+     * pointer/array to the left, in which case the subscript must be of an
+     * integer type, or we have an integer to the left, in which case the
+     * subscript must be a pointer/array.
+     * Since we do the necessary checking here, we can rely later on the
+     * correct types.
+     */
+    if (IsClassPtr (Expr->Type)) {
+        if (!IsClassInt (SubScript.Type))  {
+            Error ("Array subscript is not an integer");
+            /* To avoid any compiler errors, make the expression a valid int */
+            ED_MakeConstAbsInt (&SubScript, 0);
+        }
+        ElementType = Indirect (Expr->Type);
+    } else if (IsClassInt (Expr->Type)) {
+        if (!IsClassPtr (SubScript.Type)) {
+            Error ("Subscripted value is neither array nor pointer");
+            /* To avoid compiler errors, make the subscript a char[] at
+             * address 0.
+             */
+            ED_MakeConstAbs (&SubScript, 0, GetCharArrayType (1));
+        }
+        ElementType = Indirect (SubScript.Type);
+    } else {
+        Error ("Cannot subscript");
+        /* To avoid compiler errors, fake both the array and the subscript, so
+         * we can just proceed.
+         */
+        ED_MakeConstAbs (Expr, 0, GetCharArrayType (1));
+        ED_MakeConstAbsInt (&SubScript, 0);
+        ElementType = Indirect (Expr->Type);
+    }
+
+    /* Check if the subscript is constant absolute value */
+    if (ED_IsConstAbs (&SubScript)) {
+
+       	/* The array subscript is a numeric constant. If we had pushed the
+         * array base address onto the stack before, we can remove this value,
+         * since we can generate expression+offset.
+         */
     	if (!ConstBaseAddr) {
      	    RemoveCode (Mark2);
      	    pop (CF_PTR);
@@ -1005,177 +1062,180 @@ static void ArrayRef (ExprDesc* Expr)
     	    ExprLoad (CF_NONE, Expr);
     	}
 
-     	if (IsClassPtr (tptr1)) {
+     	if (IsClassPtr (Expr->Type)) {
 
-     	    /* Scale the subscript value according to element size */
-     	    lval2.ConstVal *= CheckedPSizeOf (tptr1);
+       	    /* Lhs is pointer/array. Scale the subscript value according to
+             * the element size.
+             */
+     	    SubScript.Val *= CheckedSizeOf (ElementType);
 
-	    /* Remove code for lhs load */
-	    RemoveCode (Mark1);
+            /* Remove the address load code */
+            RemoveCode (Mark1);
 
-    	    /* Handle constant base array on stack. Be sure NOT to
-    	     * handle pointers the same way, and check for character literals
-             * (both won't work).
-    	     */
-    	    if (IsTypeArray (tptr1) && Expr->Flags != (E_MCONST | E_TLIT) &&
-    	       	((Expr->Flags & ~E_MCTYPE) == E_MCONST ||
-    	   	(Expr->Flags & ~E_MCTYPE) == E_MLOCAL ||
-    	   	(Expr->Flags & E_MGLOBAL) != 0 ||
-    	   	(Expr->Flags == E_MEOFFS))) {
-    	   	Expr->ConstVal += lval2.ConstVal;
+            /* In case of an array, we can adjust the offset of the expression
+             * already in Expr. If the base address was a constant, we can even
+             * remove the code that loaded the address into the primary.
+             */
+            if (IsTypeArray (Expr->Type)) {
 
-    	    } else {
-	   	/* Pointer - load into primary and remember offset */
-	   	if ((Expr->Flags & E_MEXPR) == 0 || ED_IsLVal (Expr)) {
-	   	    ExprLoad (CF_NONE, Expr);
-	   	}
-	   	Expr->ConstVal = lval2.ConstVal;
-	   	Expr->Flags = E_MEOFFS;
-	    }
+                /* Adjust the offset */
+                Expr->Val += SubScript.Val;
 
-       	    /* Result is of element type */
-	    Expr->Type = Indirect (tptr1);
+            } else {
 
-	    /* Done */
-    	    goto end_array;
+                /* It's a pointer, so we do have to load it into the primary
+                 * first (if it's not already there).
+                 */
+                if (ConstBaseAddr) {
+                    ExprLoad (CF_NONE, Expr);
+                    ED_MakeRValExpr (Expr);
+                }
 
-       	} else if (IsClassPtr (tptr2 = lval2.Type)) {
-    	    /* Subscript is pointer, get element type */
-    	    lval2.Type = Indirect (tptr2);
+                /* Use the offset */
+                Expr->Val = SubScript.Val;
+            }
+
+       	} else {
+
+    	    /* Scale the rhs value according to the element type */
+    	    g_scale (TypeOf (tptr1), CheckedSizeOf (ElementType));
+
+            /* Add the subscript. Since arrays are indexed by integers,
+             * we will ignore the true type of the subscript here and
+             * use always an int. #### Use offset but beware of ExprLoad!
+             */
+            g_inc (CF_INT | CF_CONST, SubScript.Val);
 
-    	    /* Scale the rhs value in the primary register */
-    	    g_scale (TypeOf (tptr1), CheckedSizeOf (lval2.Type));
-    	    /* */
-    	    Expr->Type = lval2.Type;
-    	} else {
-    	    Error ("Cannot subscript");
     	}
 
-    	/* Add the subscript. Since arrays are indexed by integers,
-    	 * we will ignore the true type of the subscript here and
-    	 * use always an int.
-    	 */
-    	g_inc (CF_INT | CF_CONST, lval2.ConstVal);
-
     } else {
 
     	/* Array subscript is not constant. Load it into the primary */
 	Mark2 = GetCodePos ();
-        ExprLoad (CF_NONE, &lval2);
+        ExprLoad (CF_NONE, &SubScript);
 
-	tptr2 = lval2.Type;
-	if (IsClassPtr (tptr1)) {
+        /* Do scaling */
+	if (IsClassPtr (Expr->Type)) {
 
- 	    /* Get the element type */
-	    Expr->Type = Indirect (tptr1);
-
-       	    /* Indexing is based on int's, so we will just use the integer
+       	    /* Indexing is based on unsigneds, so we will just use the integer
 	     * portion of the index (which is in (e)ax, so there's no further
 	     * action required).
 	     */
-	    g_scale (CF_INT, CheckedSizeOf (Expr->Type));
+	    g_scale (CF_INT | CF_UNSIGNED, CheckedSizeOf (ElementType));
 
-	} else if (IsClassPtr (tptr2)) {
+       	} else {
 
-	    /* Get the element type */
-	    lval2.Type = Indirect (tptr2);
-
-	    /* Get the int value on top. If we go here, we're sure,
-	     * both values are 16 bit (the first one was truncated
-       	     * if necessary and the second one is a pointer).
-	     * Note: If ConstBaseAddr is true, we don't have a value on
-	     * stack, so to "swap" both, just push the subscript.
+	    /* Get the int value on top. If we come here, we're sure, both
+             * values are 16 bit (the first one was truncated if necessary
+             * and the second one is a pointer). Note: If ConstBaseAddr is
+             * true, we don't have a value on stack, so to "swap" both, just
+             * push the subscript.
     	     */
 	    if (ConstBaseAddr) {
-	    	g_push (CF_INT, 0);
-	    	ExprLoad (CF_NONE, Expr);
-	    	ConstBaseAddr = 0;
+	       	g_push (CF_INT, 0);
+	       	ExprLoad (CF_NONE, Expr);
+	       	ConstBaseAddr = 0;
 	    } else {
 	        g_swap (CF_INT);
 	    }
 
 	    /* Scale it */
-	    g_scale (TypeOf (tptr1), CheckedSizeOf (lval2.Type));
-	    Expr->Type = lval2.Type;
-	} else {
-	    Error ("Cannot subscript");
+	    g_scale (TypeOf (tptr1), CheckedSizeOf (ElementType));
+
 	}
 
-	/* The offset is now in the primary register. It didn't have a
+	/* The offset is now in the primary register. It we didn't have a
 	 * constant base address for the lhs, the lhs address is already
 	 * on stack, and we must add the offset. If the base address was
 	 * constant, we call special functions to add the address to the
 	 * offset value.
 	 */
 	if (!ConstBaseAddr) {
-	    /* Add the subscript. Both values are int sized. */
-	    g_add (CF_INT, 0);
-	} else {
 
-	    /* If the subscript has itself a constant address, it is often
-	     * a better idea to reverse again the order of the evaluation.
-	     * This will generate better code if the subscript is a byte
-	     * sized variable. But beware: This is only possible if the
+       	    /* The array base address is on stack and the subscript is in the
+             * primary. Add both.
+             */
+	    g_add (CF_INT | CF_UNSIGNED, 0);
+
+    	} else {
+
+            /* The subscript is in the primary, and the array base address is
+             * in Expr. If the subscript has itself a constant address, it is
+             * often a better idea to reverse again the order of the
+             * evaluation. This will generate better code if the subscript is
+             * a byte sized variable. But beware: This is only possible if the
 	     * subscript was not scaled, that is, if this was a byte array
 	     * or pointer.
 	     */
- 	    rflags = lval2.Flags & ~E_MCTYPE;
-	    ConstSubAddr = (rflags == E_MCONST)       || /* Constant numeric address */
-       	       	       	    (rflags & E_MGLOBAL) != 0 || /* Static array, or ... */
-	    	    	    rflags == E_MLOCAL;      	 /* Local array */
+            if ((ED_IsLocConst (&SubScript) || ED_IsLocStack (&SubScript)) &&
+                CheckedSizeOf (ElementType) == SIZEOF_CHAR) {
 
-       	    if (ConstSubAddr && CheckedSizeOf (Expr->Type) == SIZEOF_CHAR) {
-
-	    	type* SavedType;
+                unsigned Flags;
 
 	    	/* Reverse the order of evaluation */
-	    	unsigned flags = (CheckedSizeOf (lval2.Type) == SIZEOF_CHAR)? CF_CHAR : CF_INT;
+                if (CheckedSizeOf (SubScript.Type) == SIZEOF_CHAR) {
+                    Flags = CF_CHAR;
+                } else {
+                    Flags = CF_INT;
+                }
     	     	RemoveCode (Mark2);
 
-	    	/* Get a pointer to the array into the primary. We have changed
-	    	 * Type above but we need the original type to load the
-	    	 * address, so restore it temporarily.
-	    	 */
-	    	SavedType = Expr->Type;
-	     	Expr->Type = tptr1;
+	    	/* Get a pointer to the array into the primary. */
 	    	ExprLoad (CF_NONE, Expr);
-	    	Expr->Type = SavedType;
 
 	    	/* Add the variable */
-	    	if (rflags == E_MLOCAL) {
-	    	    g_addlocal (flags, lval2.ConstVal);
+	    	if (ED_IsLocStack (&SubScript)) {
+	    	    g_addlocal (Flags, SubScript.Val);
 	    	} else {
-	   	    flags |= GlobalModeFlags (lval2.Flags);
-	    	    g_addstatic (flags, lval2.Name, lval2.ConstVal);
+	   	    Flags |= GlobalModeFlags (SubScript.Flags);
+	    	    g_addstatic (Flags, SubScript.Name, SubScript.Val);
 	    	}
 	    } else {
-	     	if (lflags == E_MCONST) {
+	     	if (ED_IsLocAbs (Expr)) {
 	     	    /* Constant numeric address. Just add it */
-	     	    g_inc (CF_INT | CF_UNSIGNED, Expr->ConstVal);
-	     	} else if (lflags == E_MLOCAL) {
+	     	    g_inc (CF_INT | CF_UNSIGNED, Expr->Val);
+	     	} else if (ED_IsLocStack (Expr)) {
 	       	    /* Base address is a local variable address */
-	   	    if (IsTypeArray (tptr1)) {
-	     	        g_addaddr_local (CF_INT, Expr->ConstVal);
+	   	    if (IsTypeArray (Expr->Type)) {
+	     	        g_addaddr_local (CF_INT, Expr->Val);
 	   	    } else {
-	   		g_addlocal (CF_PTR, Expr->ConstVal);
+	   		g_addlocal (CF_PTR, Expr->Val);
 	   	    }
 	     	} else {
 	     	    /* Base address is a static variable address */
-	     	    unsigned flags = CF_INT;
-	   	    flags |= GlobalModeFlags (Expr->Flags);
-	   	    if (IsTypeArray (tptr1)) {
-	     	        g_addaddr_static (flags, Expr->Name, Expr->ConstVal);
+	     	    unsigned Flags = CF_INT | GlobalModeFlags (Expr->Flags);
+	   	    if (IsTypeArray (Expr->Type)) {
+	     	        g_addaddr_static (Flags, Expr->Name, Expr->Val);
 	   	    } else {
-	   		g_addstatic (flags, Expr->Name, Expr->ConstVal);
+	   		g_addstatic (Flags, Expr->Name, Expr->Val);
 	   	    }
 	     	}
 	    }
+
+
 	}
+
+        /* The result is an expression in the primary */
+        ED_MakeRValExpr (Expr);
+
     }
-    Expr->Flags = E_MEXPR;
-end_array:
+
+    /* Result is of element type */
+    Expr->Type = ElementType;
+
+    /* An array element is actually a variable. So the rules for variables
+     * with respect to the reference type apply: If it's an array, it is
+     * a rvalue, otherwise it's an lvalue. (A function would also be a rvalue,
+     * but an array cannot contain functions).
+     */
+    if (IsTypeArray (Expr->Type)) {
+        ED_MakeRVal (Expr);
+    } else {
+        ED_MakeLVal (Expr);
+    }
+
+    /* Consume the closing bracket */
     ConsumeRBrack ();
-    ED_SetValType (Expr, !IsTypeArray (Expr->Type));
 }
 
 
@@ -1185,7 +1245,6 @@ static void StructRef (ExprDesc* Expr)
 {
     ident Ident;
     SymEntry* Field;
-    int Flags;
 
     /* Skip the token and check for an identifier */
     NextToken ();
@@ -1205,22 +1264,34 @@ static void StructRef (ExprDesc* Expr)
      	return;
     }
 
-    /* If we have constant input data, the result is also constant */
-    Flags = (Expr->Flags & ~E_MCTYPE);
-    if (Flags == E_MCONST ||
-       	(ED_IsRVal (Expr) && (Flags == E_MLOCAL ||
-	       	             (Flags & E_MGLOBAL) != 0 ||
-	       	              Expr->Flags  == E_MEOFFS))) {
-	Expr->ConstVal += Field->V.Offs;
-    } else {
-	if ((Flags & E_MEXPR) == 0 || ED_IsLVal (Expr)) {
-	    ExprLoad (CF_NONE, Expr);
-	}
-	Expr->ConstVal = Field->V.Offs;
-	Expr->Flags = E_MEOFFS;
+    /* If we have a struct pointer that is not already in the primary, load
+     * it now.
+     */
+    if (IsTypePtr (Expr->Type)) {
+
+        /* Load into the primary */
+        ExprLoad (CF_NONE, Expr);
+
+        /* Make it an lvalue expression */
+        ED_MakeLValExpr (Expr);
     }
+
+    /* Set the struct field offset */
+    Expr->Val += Field->V.Offs;
+
+    /* The type is now the type of the field */
     Expr->Type = Field->Type;
-    ED_SetValType (Expr, !IsTypeArray (Field->Type));
+
+    /* An struct member is actually a variable. So the rules for variables
+     * with respect to the reference type apply: If it's an array, it is
+     * a rvalue, otherwise it's an lvalue. (A function would also be a rvalue,
+     * but a struct field cannot be a function).
+     */
+    if (IsTypeArray (Expr->Type)) {
+        ED_MakeRVal (Expr);
+    } else {
+        ED_MakeLVal (Expr);
+    }
 }
 
 
@@ -1244,28 +1315,24 @@ static void hie11 (ExprDesc *Expr)
 
             case TOK_LPAREN:
                 /* Function call. */
-                if (IsTypeFunc (Expr->Type) || IsTypeFuncPtr (Expr->Type)) {
-
-                    /* Call the function */
-                    FunctionCall (Expr);
-
-                    /* Result is in the primary register */
-                    Expr->Flags = E_MEXPR | E_RVAL;
-
-                    /* Set to result */
-                    Expr->Type = GetFuncReturn (Expr->Type);
-
-                } else {
+                if (!IsTypeFunc (Expr->Type) && !IsTypeFuncPtr (Expr->Type)) {
+                    /* Not a function */
                     Error ("Illegal function call");
-                    ED_MakeRVal (Expr);
+                    /* Force the type to be a implicitly defined function, one
+                     * returning an int and taking any number of arguments.
+                     * Since we don't have a name, place it at absolute address
+                     * zero.
+                     */
+                    ED_MakeConstAbs (Expr, 0, GetImplicitFuncType ());
                 }
+                /* Call the function */
+                FunctionCall (Expr);
                 break;
 
             case TOK_DOT:
                 if (!IsClassStruct (Expr->Type)) {
                     Error ("Struct expected");
                 }
-                ED_MakeRVal (Expr);         /* #### ? */
                 StructRef (Expr);
                 break;
 
@@ -1297,39 +1364,63 @@ void Store (ExprDesc* Expr, const type* StoreType)
 {
     unsigned Flags;
 
-    unsigned f = Expr->Flags;
-
     /* If StoreType was not given, use Expr->Type instead */
     if (StoreType == 0) {
         StoreType = Expr->Type;
     }
 
-    /* Get the code generator flags */
+    /* Prepare the code generator flags */
     Flags = TypeOf (StoreType);
-    if (f & E_MGLOBAL) {
-     	Flags |= GlobalModeFlags (f);
-     	if (Expr->Test) {
-   	    /* Just testing */
-       	    Flags |= CF_TEST;
-   	}
+    if (Expr->Test) {
+        /* Testing the value */
+        Flags |= CF_TEST;
+    }
 
-    	/* Generate code */
-       	g_putstatic (Flags, Expr->Name, Expr->ConstVal);
+    /* Do the store depending on the location */
+    switch (ED_GetLoc (Expr)) {
 
-    } else if (f & E_MLOCAL) {
-        /* Store an auto variable */
-       	g_putlocal (Flags, Expr->ConstVal, 0);
-    } else if (f == E_MEOFFS) {
-        /* Store indirect with offset */
-    	g_putind (Flags, Expr->ConstVal);
-    } else if (f != E_MREG) {
-    	if (f & E_MEXPR) {
-            /* Indirect without offset */
-    	    g_putind (Flags, 0);
-    	} else {
-    	    /* Store into absolute address */
-    	    g_putstatic (Flags | CF_ABSOLUTE, Expr->ConstVal, 0);
-    	}
+        case E_LOC_ABS:
+            /* Absolute: numeric address or const */
+            g_putstatic (Flags | CF_ABSOLUTE, Expr->Val, 0);
+            break;
+
+        case E_LOC_GLOBAL:
+            /* Global variable */
+            g_putstatic (Flags | CF_EXTERNAL, Expr->Name, Expr->Val);
+            break;
+
+        case E_LOC_STATIC:
+            /* Static variable */
+            g_putstatic (Flags | CF_STATIC, Expr->Name, Expr->Val);
+            break;
+
+        case E_LOC_REGISTER:
+            /* Register variable */
+            g_putstatic (Flags | CF_REGVAR, Expr->Name, Expr->Val);
+            break;
+
+        case E_LOC_STACK:
+            /* Value on the stack */
+            g_putlocal (Flags, Expr->Val, 0);
+            break;
+
+        case E_LOC_PRIMARY:
+            /* The primary register (value is already there) */
+            /* ### Do we need a test here if the flag is set? */
+            break;
+
+        case E_LOC_EXPR:
+            /* An expression in the primary register */
+            g_putind (Flags, Expr->Val);
+            break;
+
+        case E_LOC_LITERAL:
+            /* Literal in the literal pool */
+            g_putstatic (Flags | CF_STATIC, LiteralPoolLabel, Expr->Val);
+            break;
+
+        default:
+            Internal ("Invalid location in Store(): 0x%04X", ED_GetLoc (Expr));
     }
 
     /* Assume that each one of the stores will invalidate CC */
@@ -1338,78 +1429,152 @@ void Store (ExprDesc* Expr, const type* StoreType)
 
 
 
-static void PreIncDec (ExprDesc* Expr, void (*inc) (unsigned, unsigned long))
-/* Handle --i and ++i */
+static void PreInc (ExprDesc* Expr)
+/* Handle the preincrement operators */
 {
-    unsigned flags;
-    unsigned long val;
+    unsigned Flags;
+    unsigned long Val;
 
     /* Skip the operator token */
     NextToken ();
 
     /* Evaluate the expression and check that it is an lvalue */
     hie10 (Expr);
-    if (ED_IsRVal (Expr) == 0) {
-    	Error ("Invalid lvalue");
-    	return;
+    if (!ED_IsLVal (Expr)) {
+     	Error ("Invalid lvalue");
+     	return;
     }
 
     /* Get the data type */
-    flags = TypeOf (Expr->Type) | CF_FORCECHAR | CF_CONST;
+    Flags = TypeOf (Expr->Type) | CF_FORCECHAR | CF_CONST;
 
     /* Get the increment value in bytes */
-    val = (Expr->Type[0] == T_PTR)? CheckedPSizeOf (Expr->Type) : 1;
+    Val = IsTypePtr (Expr->Type)? CheckedPSizeOf (Expr->Type) : 1;
 
-    /* Check for special addressing modes */
-    if (Expr->Flags & E_MGLOBAL) {
-        /* Global address */
-        flags |= GlobalModeFlags (Expr->Flags);
-        if (inc == g_inc) {
-            g_addeqstatic (flags, Expr->Name, Expr->ConstVal, val);
-        } else {
-            g_subeqstatic (flags, Expr->Name, Expr->ConstVal, val);
-        }
-    } else if (Expr->Flags & E_MLOCAL) {
-        /* Local address */
-        if (inc == g_inc) {
-            g_addeqlocal (flags, Expr->ConstVal, val);
-        } else {
-            g_subeqlocal (flags, Expr->ConstVal, val);
-        }
-    } else if (Expr->Flags & E_MCONST) {
-        /* Constant absolute address */
-        flags |= CF_ABSOLUTE;
-        if (inc == g_inc) {
-            g_addeqstatic (flags, Expr->ConstVal, 0, val);
-        } else {
-            g_subeqstatic (flags, Expr->ConstVal, 0, val);
-        }
-    } else if (Expr->Flags & E_MEXPR) {
-        /* Address in a/x, check if we have an offset */
-        unsigned Offs = (Expr->Flags == E_MEOFFS)? Expr->ConstVal : 0;
-        if (inc == g_inc) {
-            g_addeqind (flags, Offs, val);
-        } else {
-            g_subeqind (flags, Offs, val);
-        }
-    } else {
+    /* Check the location of the data */
+    switch (ED_GetLoc (Expr)) {
 
-        /* Use generic code. Push the address if needed */
-        PushAddr (Expr);
+        case E_LOC_ABS:
+            /* Absolute: numeric address or const */
+            g_addeqstatic (Flags | CF_ABSOLUTE, Expr->Val, 0, Val);
+            break;
 
-        /* Fetch the value */
-        ExprLoad (CF_NONE, Expr);
+        case E_LOC_GLOBAL:
+            /* Global variable */
+            g_addeqstatic (Flags | CF_EXTERNAL, Expr->Name, Expr->Val, Val);
+            break;
 
-        /* Increment value in primary */
-        inc (flags, val);
+        case E_LOC_STATIC:
+            /* Static variable */
+            g_addeqstatic (Flags | CF_STATIC, Expr->Name, Expr->Val, Val);
+            break;
 
-        /* Store the result back */
-        Store (Expr, 0);
+        case E_LOC_REGISTER:
+            /* Register variable */
+            g_addeqstatic (Flags | CF_REGVAR, Expr->Name, Expr->Val, Val);
+            break;
 
+        case E_LOC_STACK:
+            /* Value on the stack */
+            g_addeqlocal (Flags, Expr->Val, Val);
+            break;
+
+        case E_LOC_PRIMARY:
+            /* The primary register */
+            g_inc (Flags, Val);
+            break;
+
+        case E_LOC_EXPR:
+            /* An expression in the primary register */
+            g_addeqind (Flags, Expr->Val, Val);
+            break;
+
+        case E_LOC_LITERAL:
+            /* Literal in the literal pool */
+            g_addeqstatic (Flags | CF_STATIC, LiteralPoolLabel, Expr->Val, Val);
+            break;
+
+        default:
+            Internal ("Invalid location in PreInc(): 0x%04X", ED_GetLoc (Expr));
     }
 
     /* Result is an expression, no reference */
-    Expr->Flags = E_MEXPR | E_RVAL;
+    ED_MakeRValExpr (Expr);
+}
+
+
+
+static void PreDec (ExprDesc* Expr)
+/* Handle the predecrement operators */
+{
+    unsigned Flags;
+    unsigned long Val;
+
+    /* Skip the operator token */
+    NextToken ();
+
+    /* Evaluate the expression and check that it is an lvalue */
+    hie10 (Expr);
+    if (!ED_IsLVal (Expr)) {
+     	Error ("Invalid lvalue");
+     	return;
+    }
+
+    /* Get the data type */
+    Flags = TypeOf (Expr->Type) | CF_FORCECHAR | CF_CONST;
+
+    /* Get the increment value in bytes */
+    Val = IsTypePtr (Expr->Type)? CheckedPSizeOf (Expr->Type) : 1;
+
+    /* Check the location of the data */
+    switch (ED_GetLoc (Expr)) {
+
+        case E_LOC_ABS:
+            /* Absolute: numeric address or const */
+            g_subeqstatic (Flags | CF_ABSOLUTE, Expr->Val, 0, Val);
+            break;
+
+        case E_LOC_GLOBAL:
+            /* Global variable */
+            g_subeqstatic (Flags | CF_EXTERNAL, Expr->Name, Expr->Val, Val);
+            break;
+
+        case E_LOC_STATIC:
+            /* Static variable */
+            g_subeqstatic (Flags | CF_STATIC, Expr->Name, Expr->Val, Val);
+            break;
+
+        case E_LOC_REGISTER:
+            /* Register variable */
+            g_subeqstatic (Flags | CF_REGVAR, Expr->Name, Expr->Val, Val);
+            break;
+
+        case E_LOC_STACK:
+            /* Value on the stack */
+            g_subeqlocal (Flags, Expr->Val, Val);
+            break;
+
+        case E_LOC_PRIMARY:
+            /* The primary register */
+            g_inc (Flags, Val);
+            break;
+
+        case E_LOC_EXPR:
+            /* An expression in the primary register */
+            g_subeqind (Flags, Expr->Val, Val);
+            break;
+
+        case E_LOC_LITERAL:
+            /* Literal in the literal pool */
+            g_subeqstatic (Flags | CF_STATIC, LiteralPoolLabel, Expr->Val, Val);
+            break;
+
+        default:
+            Internal ("Invalid location in PreDec(): 0x%04X", ED_GetLoc (Expr));
+    }
+
+    /* Result is an expression, no reference */
+    ED_MakeRValExpr (Expr);
 }
 
 
@@ -1417,41 +1582,41 @@ static void PreIncDec (ExprDesc* Expr, void (*inc) (unsigned, unsigned long))
 static void PostIncDec (ExprDesc* Expr, void (*inc) (unsigned, unsigned long))
 /* Handle i-- and i++ */
 {
-    unsigned flags;
+    unsigned Flags;
 
     NextToken ();
 
     /* The expression to increment must be an lvalue */
-    if (ED_IsRVal (Expr)) {
+    if (!ED_IsLVal (Expr)) {
     	Error ("Invalid lvalue");
        	return;
     }
 
     /* Get the data type */
-    flags = TypeOf (Expr->Type);
+    Flags = TypeOf (Expr->Type);
 
     /* Push the address if needed */
     PushAddr (Expr);
 
     /* Fetch the value and save it (since it's the result of the expression) */
     ExprLoad (CF_NONE, Expr);
-    g_save (flags | CF_FORCECHAR);
+    g_save (Flags | CF_FORCECHAR);
 
     /* If we have a pointer expression, increment by the size of the type */
-    if (Expr->Type[0] == T_PTR) {
-    	inc (flags | CF_CONST | CF_FORCECHAR, CheckedSizeOf (Expr->Type + 1));
+    if (IsTypePtr (Expr->Type)) {
+     	inc (Flags | CF_CONST | CF_FORCECHAR, CheckedSizeOf (Expr->Type + 1));
     } else {
-     	inc (flags | CF_CONST | CF_FORCECHAR, 1);
+     	inc (Flags | CF_CONST | CF_FORCECHAR, 1);
     }
 
     /* Store the result back */
     Store (Expr, 0);
 
     /* Restore the original value in the primary register */
-    g_restore (flags | CF_FORCECHAR);
+    g_restore (Flags | CF_FORCECHAR);
 
     /* The result is always an expression, no reference */
-    Expr->Flags = E_MEXPR | E_RVAL;
+    ED_MakeRValExpr (Expr);
 }
 
 
@@ -1459,7 +1624,7 @@ static void PostIncDec (ExprDesc* Expr, void (*inc) (unsigned, unsigned long))
 static void UnaryOp (ExprDesc* Expr)
 /* Handle unary -/+ and ~ */
 {
-    unsigned flags;
+    unsigned Flags;
 
     /* Remember the operator token and skip it */
     token_t Tok = CurTok.Tok;
@@ -1468,13 +1633,19 @@ static void UnaryOp (ExprDesc* Expr)
     /* Get the expression */
     hie10 (Expr);
 
+    /* We can only handle integer types */
+    if (!IsClassInt (Expr->Type)) {
+        Error ("Argument must have integer type");
+        ED_MakeConstAbsInt (Expr, 1);
+    }
+
     /* Check for a constant expression */
-    if (ED_IsRVal (Expr) && (Expr->Flags & E_MCONST) != 0) {
+    if (ED_IsConstAbs (Expr)) {
     	/* Value is constant */
 	switch (Tok) {
-	    case TOK_MINUS: Expr->ConstVal = -Expr->ConstVal;	break;
-	    case TOK_PLUS:  	  			   	break;
-	    case TOK_COMP:  Expr->ConstVal = ~Expr->ConstVal; 	break;
+	    case TOK_MINUS: Expr->Val = -Expr->Val;	break;
+	    case TOK_PLUS:  	  			break;
+	    case TOK_COMP:  Expr->Val = ~Expr->Val; 	break;
 	    default: 	    Internal ("Unexpected token: %d", Tok);
 	}
     } else {
@@ -1482,18 +1653,18 @@ static void UnaryOp (ExprDesc* Expr)
      	ExprLoad (CF_NONE, Expr);
 
     	/* Get the type of the expression */
-    	flags = TypeOf (Expr->Type);
+    	Flags = TypeOf (Expr->Type);
 
     	/* Handle the operation */
 	switch (Tok) {
-       	    case TOK_MINUS: g_neg (flags);  break;
+       	    case TOK_MINUS: g_neg (Flags);  break;
 	    case TOK_PLUS:  	       	    break;
-	    case TOK_COMP:  g_com (flags);  break;
-	    default: 	Internal ("Unexpected token: %d", Tok);
+	    case TOK_COMP:  g_com (Flags);  break;
+	    default: 	    Internal ("Unexpected token: %d", Tok);
 	}
 
         /* The result is a rvalue in the primary */
-     	Expr->Flags = E_MEXPR | E_RVAL;
+        ED_MakeRValExpr (Expr);
     }
 }
 
@@ -1502,14 +1673,16 @@ static void UnaryOp (ExprDesc* Expr)
 void hie10 (ExprDesc* Expr)
 /* Handle ++, --, !, unary - etc. */
 {
+    unsigned long Size;
+
     switch (CurTok.Tok) {
 
      	case TOK_INC:
-     	    PreIncDec (Expr, g_inc);
+       	    PreInc (Expr);
      	    break;
 
      	case TOK_DEC:
-     	    PostIncDec (Expr, g_dec);
+     	    PreDec (Expr);
      	    break;
 
 	case TOK_PLUS:
@@ -1522,11 +1695,11 @@ void hie10 (ExprDesc* Expr)
      	    NextToken ();
     	    if (evalexpr (CF_NONE, hie10, Expr) == 0) {
     	       	/* Constant expression */
-    	       	Expr->ConstVal = !Expr->ConstVal;
+    	       	Expr->Val = !Expr->Val;
     	    } else {
     	       	g_bneg (TypeOf (Expr->Type));
+                ED_MakeRValExpr (Expr);
     	       	Expr->Test |= E_CC;		/* bneg will set cc */
-    	       	Expr->Flags = E_MEXPR | E_RVAL;  /* say it's an expr */
     	    }
      	    break;
 
@@ -1534,8 +1707,7 @@ void hie10 (ExprDesc* Expr)
      	    NextToken ();
     	    if (evalexpr (CF_NONE, hie10, Expr) != 0) {
     	       	/* Expression is not const, indirect value loaded into primary */
-	       	Expr->Flags = E_MEXPR | E_RVAL;
-	       	Expr->ConstVal = 0;		/* Offset is zero now */
+       	       	ED_MakeRValExpr (Expr);
     	    }
             /* If the expression is already a pointer to function, the
              * additional dereferencing operator must be ignored.
@@ -1575,18 +1747,17 @@ void hie10 (ExprDesc* Expr)
        	    if (TypeSpecAhead ()) {
     	       	type Type[MAXTYPELEN];
      	       	NextToken ();
-	       	Expr->ConstVal = CheckedSizeOf (ParseType (Type));
+	       	Size = CheckedSizeOf (ParseType (Type));
      	       	ConsumeRParen ();
      	    } else {
     	       	/* Remember the output queue pointer */
     	       	CodeMark Mark = GetCodePos ();
      	       	hie10 (Expr);
-     	       	Expr->ConstVal = CheckedSizeOf (Expr->Type);
+     	       	Size = CheckedSizeOf (Expr->Type);
     	       	/* Remove any generated code */
     	       	RemoveCode (Mark);
      	    }
-     	    Expr->Flags = E_MCONST | E_TCONST | E_RVAL;
-     	    Expr->Type = type_size_t;
+            ED_MakeConstAbs (Expr, Size, type_size_t);
 	    Expr->Test &= ~E_CC;
        	    break;
 
@@ -1621,11 +1792,11 @@ static void hie_internal (const GenDesc* Ops,   /* List of generators */
     	       	       	  int* UsedGen)
 /* Helper function */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
     CodeMark Mark1;
     CodeMark Mark2;
     const GenDesc* Gen;
-    token_t Tok;       	     		/* The operator token */
+    token_t Tok;       	     	 	/* The operator token */
     unsigned ltype, type;
     int rconst;	       	       	       	/* Operand is a constant */
 
@@ -1650,10 +1821,10 @@ static void hie_internal (const GenDesc* Ops,   /* List of generators */
 	/* Get the lhs on stack */
        	Mark1 = GetCodePos ();
 	ltype = TypeOf (Expr->Type);
-	if (ED_IsRVal (Expr) && Expr->Flags == E_MCONST) {
+       	if (ED_IsConstAbs (Expr)) {
 	    /* Constant value */
 	    Mark2 = GetCodePos ();
-       	    g_push (ltype | CF_CONST, Expr->ConstVal);
+       	    g_push (ltype | CF_CONST, Expr->Val);
 	} else {
 	    /* Value not constant */
 	    ExprLoad (CF_NONE, Expr);
@@ -1662,25 +1833,25 @@ static void hie_internal (const GenDesc* Ops,   /* List of generators */
 	}
 
 	/* Get the right hand side */
-	rconst = (evalexpr (CF_NONE, hienext, &lval2) == 0);
+	rconst = (evalexpr (CF_NONE, hienext, &Expr2) == 0);
 
 	/* Check the type of the rhs */
-	if (!IsClassInt (lval2.Type)) {
+	if (!IsClassInt (Expr2.Type)) {
 	    Error ("Integer expression expected");
 	}
 
 	/* Check for const operands */
-	if (ED_IsRVal (Expr) && Expr->Flags == E_MCONST && rconst) {
+	if (ED_IsConstAbs (Expr) && rconst) {
 
 	    /* Both operands are constant, remove the generated code */
     	    RemoveCode (Mark1);
 	    pop (ltype);
 
 	    /* Evaluate the result */
-	    Expr->ConstVal = kcalc (Tok, Expr->ConstVal, lval2.ConstVal);
+	    Expr->Val = kcalc (Tok, Expr->Val, Expr2.Val);
 
 	    /* Get the type of the result */
-	    Expr->Type = promoteint (Expr->Type, lval2.Type);
+	    Expr->Type = promoteint (Expr->Type, Expr2.Type);
 
 	} else {
 
@@ -1688,15 +1859,15 @@ static void hie_internal (const GenDesc* Ops,   /* List of generators */
 	     * expects the lhs in the primary, remove the push of the primary
 	     * now.
 	     */
-	    unsigned rtype = TypeOf (lval2.Type);
+	    unsigned rtype = TypeOf (Expr2.Type);
 	    type = 0;
 	    if (rconst) {
 	     	/* Second value is constant - check for div */
 	     	type |= CF_CONST;
 	 	rtype |= CF_CONST;
-	     	if (Tok == TOK_DIV && lval2.ConstVal == 0) {
+	     	if (Tok == TOK_DIV && Expr2.Val == 0) {
 	      	    Error ("Division by zero");
-	     	} else if (Tok == TOK_MOD && lval2.ConstVal == 0) {
+	     	} else if (Tok == TOK_MOD && Expr2.Val == 0) {
 	     	    Error ("Modulo operation with zero");
 	     	}
 	 	if ((Gen->Flags & GEN_NOPUSH) != 0) {
@@ -1708,13 +1879,13 @@ static void hie_internal (const GenDesc* Ops,   /* List of generators */
 
  	    /* Determine the type of the operation result. */
        	    type |= g_typeadjust (ltype, rtype);
-	    Expr->Type = promoteint (Expr->Type, lval2.Type);
+	    Expr->Type = promoteint (Expr->Type, Expr2.Type);
 
 	    /* Generate code */
-	    Gen->Func (type, lval2.ConstVal);
+	    Gen->Func (type, Expr2.Val);
 
             /* We have a rvalue in the primary now */
-	    Expr->Flags = E_MEXPR | E_RVAL;
+	    ED_MakeRValExpr (Expr);
 	}
     }
 }
@@ -1726,7 +1897,7 @@ static void hie_compare (const GenDesc* Ops,    /* List of generators */
        	                 void (*hienext) (ExprDesc*))
 /* Helper function for the compare operators */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
     CodeMark Mark1;
     CodeMark Mark2;
     const GenDesc* Gen;
@@ -1746,10 +1917,10 @@ static void hie_compare (const GenDesc* Ops,    /* List of generators */
     	/* Get the lhs on stack */
     	Mark1 = GetCodePos ();
     	ltype = TypeOf (Expr->Type);
-    	if (ED_IsRVal (Expr) && Expr->Flags == E_MCONST) {
+    	if (ED_IsConstAbs (Expr)) {
     	    /* Constant value */
     	    Mark2 = GetCodePos ();
-       	    g_push (ltype | CF_CONST, Expr->ConstVal);
+       	    g_push (ltype | CF_CONST, Expr->Val);
     	} else {
     	    /* Value not constant */
     	    ExprLoad (CF_NONE, Expr);
@@ -1758,38 +1929,38 @@ static void hie_compare (const GenDesc* Ops,    /* List of generators */
       	}
 
 	/* Get the right hand side */
-	rconst = (evalexpr (CF_NONE, hienext, &lval2) == 0);
+	rconst = (evalexpr (CF_NONE, hienext, &Expr2) == 0);
 
 	/* Make sure, the types are compatible */
 	if (IsClassInt (Expr->Type)) {
-	    if (!IsClassInt (lval2.Type) && !(IsClassPtr(lval2.Type) && IsNullPtr(Expr))) {
+	    if (!IsClassInt (Expr2.Type) && !(IsClassPtr(Expr2.Type) && ED_IsNullPtr(Expr))) {
 	   	Error ("Incompatible types");
 	    }
 	} else if (IsClassPtr (Expr->Type)) {
-	    if (IsClassPtr (lval2.Type)) {
+	    if (IsClassPtr (Expr2.Type)) {
 	   	/* Both pointers are allowed in comparison if they point to
 	   	 * the same type, or if one of them is a void pointer.
 	         */
        	       	type* left  = Indirect (Expr->Type);
-	   	type* right = Indirect (lval2.Type);
+	   	type* right = Indirect (Expr2.Type);
 	   	if (TypeCmp (left, right) < TC_EQUAL && *left != T_VOID && *right != T_VOID) {
 	   	    /* Incomatible pointers */
 	   	    Error ("Incompatible types");
 	   	}
-	    } else if (!IsNullPtr (&lval2)) {
+	    } else if (!ED_IsNullPtr (&Expr2)) {
 	   	Error ("Incompatible types");
 	    }
 	}
 
 	/* Check for const operands */
-	if (ED_IsRVal (Expr) && Expr->Flags == E_MCONST && rconst) {
+	if (ED_IsConstAbs (Expr) && rconst) {
 
 	    /* Both operands are constant, remove the generated code */
     	    RemoveCode (Mark1);
 	    pop (ltype);
 
 	    /* Evaluate the result */
-	    Expr->ConstVal = kcalc (tok, Expr->ConstVal, lval2.ConstVal);
+	    Expr->Val = kcalc (tok, Expr->Val, Expr2.Val);
 
 	} else {
 
@@ -1813,22 +1984,24 @@ static void hie_compare (const GenDesc* Ops,    /* List of generators */
 	     * operation as char operation. Otherwise the default
 	     * promotions are used.
 	     */
-	    if (IsTypeChar (Expr->Type) && (IsTypeChar (lval2.Type) || rconst)) {
+	    if (IsTypeChar (Expr->Type) && (IsTypeChar (Expr2.Type) || rconst)) {
 	       	flags |= CF_CHAR;
-	       	if (IsSignUnsigned (Expr->Type) || IsSignUnsigned (lval2.Type)) {
+	       	if (IsSignUnsigned (Expr->Type) || IsSignUnsigned (Expr2.Type)) {
 	       	    flags |= CF_UNSIGNED;
 	       	}
 	       	if (rconst) {
 	       	    flags |= CF_FORCECHAR;
 	       	}
 	    } else {
-		unsigned rtype = TypeOf (lval2.Type) | (flags & CF_CONST);
+		unsigned rtype = TypeOf (Expr2.Type) | (flags & CF_CONST);
        	        flags |= g_typeadjust (ltype, rtype);
 	    }
 
 	    /* Generate code */
-	    Gen->Func (flags, lval2.ConstVal);
-	    Expr->Flags = E_MEXPR | E_RVAL;
+	    Gen->Func (flags, Expr2.Val);
+
+            /* The result is an rvalue in the primary */
+	    ED_MakeRValExpr (Expr);
 	}
 
 	/* Result type is always int */
@@ -1863,7 +2036,7 @@ static void parseadd (ExprDesc* Expr)
  * result of the expression on return.
  */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
     unsigned flags;          	/* Operation flags */
     CodeMark Mark;    	     	/* Remember code position */
     type* lhst;	      	     	/* Type of left hand side */
@@ -1878,29 +2051,29 @@ static void parseadd (ExprDesc* Expr)
     flags = 0;
 
     /* Check for constness on both sides */
-    if (ED_IsRVal (Expr) && (Expr->Flags & E_MCONST) != 0) {
+    if (ED_IsConst (Expr)) {
 
-    	/* The left hand side is a constant. Good. Get rhs */
-	hie9 (&lval2);
-       	if (ED_IsRVal (&lval2) && lval2.Flags == E_MCONST) {
+    	/* The left hand side is a constant of some sort. Good. Get rhs */
+	hie9 (&Expr2);
+       	if (ED_IsConstAbs (&Expr2)) {
 
-       	    /* Right hand side is also constant. Get the rhs type */
-    	    rhst = lval2.Type;
+       	    /* Right hand side is a constant numeric value. Get the rhs type */
+    	    rhst = Expr2.Type;
 
     	    /* Both expressions are constants. Check for pointer arithmetic */
        	    if (IsClassPtr (lhst) && IsClassInt (rhst)) {
        	    	/* Left is pointer, right is int, must scale rhs */
-       	       	Expr->ConstVal += lval2.ConstVal * CheckedPSizeOf (lhst);
+       	       	Expr->Val += Expr2.Val * CheckedPSizeOf (lhst);
     	    	/* Result type is a pointer */
     	    } else if (IsClassInt (lhst) && IsClassPtr (rhst)) {
     	    	/* Left is int, right is pointer, must scale lhs */
-       	       	Expr->ConstVal = Expr->ConstVal * CheckedPSizeOf (rhst) + lval2.ConstVal;
+       	       	Expr->Val = Expr->Val * CheckedPSizeOf (rhst) + Expr2.Val;
     	    	/* Result type is a pointer */
-    	    	Expr->Type = lval2.Type;
+    	    	Expr->Type = Expr2.Type;
        	    } else if (IsClassInt (lhst) && IsClassInt (rhst)) {
     	    	/* Integer addition */
-    	    	Expr->ConstVal += lval2.ConstVal;
-    	    	typeadjust (Expr, &lval2, 1);
+    	    	Expr->Val += Expr2.Val;
+    	    	typeadjust (Expr, &Expr2, 1);
     	    } else {
        	       	/* OOPS */
     	    	Error ("Invalid operands for binary operator `+'");
@@ -1911,7 +2084,7 @@ static void parseadd (ExprDesc* Expr)
 	    /* lhs is a constant and rhs is not constant. Load rhs into
 	     * the primary.
 	     */
-    	    ExprLoad (CF_NONE, &lval2);
+    	    ExprLoad (CF_NONE, &Expr2);
 
        	    /* Beware: The check above (for lhs) lets not only pass numeric
 	     * constants, but also constant addresses (labels), maybe even
@@ -1919,10 +2092,10 @@ static void parseadd (ExprDesc* Expr)
 	     */
 
     	    /* First, get the rhs type. */
-       	    rhst = lval2.Type;
+       	    rhst = Expr2.Type;
 
 	    /* Setup flags */
-	    if (Expr->Flags == E_MCONST) {
+	    if (ED_IsLocAbs (Expr)) {
 	    	/* A numerical constant */
 	    	flags |= CF_CONST;
 	    } else {
@@ -1937,12 +2110,12 @@ static void parseadd (ExprDesc* Expr)
     	    	/* Operate on pointers, result type is a pointer */
       	    	flags |= CF_PTR;
 	    	/* Generate the code for the add */
-	    	if (Expr->Flags == E_MCONST) {
+	    	if (ED_GetLoc (Expr) == E_LOC_ABS) {
 	    	    /* Numeric constant */
-	    	    g_inc (flags, Expr->ConstVal);
+	    	    g_inc (flags, Expr->Val);
 	    	} else {
 	    	    /* Constant address */
-	    	    g_addaddr_static (flags, Expr->Name, Expr->ConstVal);
+	    	    g_addaddr_static (flags, Expr->Name, Expr->Val);
 	    	}
     	    } else if (IsClassInt (lhst) && IsClassPtr (rhst)) {
 
@@ -1951,37 +2124,37 @@ static void parseadd (ExprDesc* Expr)
 
        	       	/* Operate on pointers, result type is a pointer */
 	    	flags |= CF_PTR;
-	    	Expr->Type = lval2.Type;
+	    	Expr->Type = Expr2.Type;
 
 	    	/* Since we do already have rhs in the primary, if lhs is
 	    	 * not a numeric constant, and the scale factor is not one
 	    	 * (no scaling), we must take the long way over the stack.
 	    	 */
-	    	if (Expr->Flags == E_MCONST) {
+	    	if (ED_IsLocAbs (Expr)) {
 	    	    /* Numeric constant, scale lhs */
-	    	    Expr->ConstVal *= ScaleFactor;
+	    	    Expr->Val *= ScaleFactor;
 	    	    /* Generate the code for the add */
-	    	    g_inc (flags, Expr->ConstVal);
+	    	    g_inc (flags, Expr->Val);
 	    	} else if (ScaleFactor == 1) {
 	    	    /* Constant address but no need to scale */
-    	    	    g_addaddr_static (flags, Expr->Name, Expr->ConstVal);
+    	    	    g_addaddr_static (flags, Expr->Name, Expr->Val);
 	    	} else {
 	    	    /* Constant address that must be scaled */
-       	       	    g_push (TypeOf (lval2.Type), 0);   	/* rhs --> stack */
-	    	    g_getimmed (flags, Expr->Name, Expr->ConstVal);
+       	       	    g_push (TypeOf (Expr2.Type), 0);   	/* rhs --> stack */
+	    	    g_getimmed (flags, Expr->Name, Expr->Val);
 	    	    g_scale (CF_PTR, ScaleFactor);
 	    	    g_add (CF_PTR, 0);
 	    	}
        	    } else if (IsClassInt (lhst) && IsClassInt (rhst)) {
     	      	/* Integer addition */
-       	       	flags |= typeadjust (Expr, &lval2, 1);
+       	       	flags |= typeadjust (Expr, &Expr2, 1);
 	    	/* Generate the code for the add */
-	    	if (Expr->Flags == E_MCONST) {
+	    	if (ED_IsLocAbs (Expr)) {
 	    	    /* Numeric constant */
-	    	    g_inc (flags, Expr->ConstVal);
+	    	    g_inc (flags, Expr->Val);
 	    	} else {
 	    	    /* Constant address */
-	    	    g_addaddr_static (flags, Expr->Name, Expr->ConstVal);
+	    	    g_addaddr_static (flags, Expr->Name, Expr->Val);
 	    	}
     	    } else {
        	       	/* OOPS */
@@ -1989,7 +2162,7 @@ static void parseadd (ExprDesc* Expr)
        	    }
 
     	    /* Result is a rvalue in primary register */
-    	    Expr->Flags = E_MEXPR | E_RVAL;
+    	    ED_MakeRValExpr (Expr);
        	}
 
     } else {
@@ -2000,10 +2173,10 @@ static void parseadd (ExprDesc* Expr)
     	g_push (TypeOf (Expr->Type), 0);	/* --> stack */
 
     	/* Evaluate the rhs */
-       	if (evalexpr (CF_NONE, hie9, &lval2) == 0) {
+       	if (evalexpr (CF_NONE, hie9, &Expr2) == 0) {
 
        	    /* Right hand side is a constant. Get the rhs type */
-    	    rhst = lval2.Type;
+    	    rhst = Expr2.Type;
 
       	    /* Remove pushed value from stack */
     	    RemoveCode (Mark);
@@ -2012,7 +2185,7 @@ static void parseadd (ExprDesc* Expr)
        	    /* Check for pointer arithmetic */
        	    if (IsClassPtr (lhst) && IsClassInt (rhst)) {
     	       	/* Left is pointer, right is int, must scale rhs */
-    	       	lval2.ConstVal *= CheckedPSizeOf (lhst);
+    	       	Expr2.Val *= CheckedPSizeOf (lhst);
     	      	/* Operate on pointers, result type is a pointer */
     	      	flags = CF_PTR;
     	    } else if (IsClassInt (lhst) && IsClassPtr (rhst)) {
@@ -2020,22 +2193,22 @@ static void parseadd (ExprDesc* Expr)
        	       	g_scale (CF_INT | CF_CONST, CheckedPSizeOf (rhst));
        	       	/* Operate on pointers, result type is a pointer */
     	      	flags = CF_PTR;
-    	      	Expr->Type = lval2.Type;
+    	      	Expr->Type = Expr2.Type;
        	    } else if (IsClassInt (lhst) && IsClassInt (rhst)) {
     	      	/* Integer addition */
-       	      	flags = typeadjust (Expr, &lval2, 1);
+       	      	flags = typeadjust (Expr, &Expr2, 1);
        	    } else {
        	       	/* OOPS */
     	    	Error ("Invalid operands for binary operator `+'");
     	    }
 
     	    /* Generate code for the add */
-       	    g_inc (flags | CF_CONST, lval2.ConstVal);
+       	    g_inc (flags | CF_CONST, Expr2.Val);
 
     	} else {
 
     	    /* lhs and rhs are not constant. Get the rhs type. */
-    	    rhst = lval2.Type;
+    	    rhst = Expr2.Type;
 
     	    /* Check for pointer arithmetic */
       	    if (IsClassPtr (lhst) && IsClassInt (rhst)) {
@@ -2050,7 +2223,7 @@ static void parseadd (ExprDesc* Expr)
     	    	g_scale (CF_INT, CheckedPSizeOf (rhst));
     	      	/* Operate on pointers, result type is a pointer */
     	      	flags = CF_PTR;
-    	      	Expr->Type = lval2.Type;
+    	      	Expr->Type = Expr2.Type;
        	    } else if (IsClassInt (lhst) && IsClassInt (rhst)) {
     	      	/* Integer addition. Note: Result is never constant.
                  * Problem here is that typeadjust does not know if the
@@ -2061,7 +2234,7 @@ static void parseadd (ExprDesc* Expr)
                  * whole parser is such a mess that I fear to break anything
                  * when trying to apply another solution.
                  */
-       	       	flags = typeadjust (Expr, &lval2, 0) & ~CF_CONST;
+       	       	flags = typeadjust (Expr, &Expr2, 0) & ~CF_CONST;
     	    } else {
        	       	/* OOPS */
     	    	Error ("Invalid operands for binary operator `+'");
@@ -2073,7 +2246,7 @@ static void parseadd (ExprDesc* Expr)
        	}
 
         /* Result is a rvalue in primary register */
-        Expr->Flags = E_MEXPR | E_RVAL;
+        ED_MakeRValExpr (Expr);
     }
 
     /* Condition codes not set */
@@ -2089,11 +2262,11 @@ static void parsesub (ExprDesc* Expr)
  * result of the expression on return.
  */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
     unsigned flags;         	/* Operation flags */
     type* lhst;	    	    	/* Type of left hand side */
     type* rhst;	    	    	/* Type of right hand side */
-    CodeMark Mark1;		/* Save position of output queue */
+    CodeMark Mark1;	   	/* Save position of output queue */
     CodeMark Mark2;    	       	/* Another position in the queue */
     int rscale;     	    	/* Scale factor for the result */
 
@@ -2113,13 +2286,13 @@ static void parsesub (ExprDesc* Expr)
     g_push (TypeOf (lhst), 0);	/* --> stack */
 
     /* Parse the right hand side */
-    if (evalexpr (CF_NONE, hie9, &lval2) == 0) {
+    if (evalexpr (CF_NONE, hie9, &Expr2) == 0) {
 
     	/* The right hand side is constant. Get the rhs type. */
-       	rhst = lval2.Type;
+       	rhst = Expr2.Type;
 
     	/* Check left hand side */
-    	if (ED_IsRVal (Expr) && (Expr->Flags & E_MCONST) != 0) {
+    	if (ED_IsConstAbs (Expr)) {
 
     	    /* Both sides are constant, remove generated code */
       	    RemoveCode (Mark1);
@@ -2128,29 +2301,28 @@ static void parsesub (ExprDesc* Expr)
     	    /* Check for pointer arithmetic */
     	    if (IsClassPtr (lhst) && IsClassInt (rhst)) {
     	    	/* Left is pointer, right is int, must scale rhs */
-    	    	Expr->ConstVal -= lval2.ConstVal * CheckedPSizeOf (lhst);
+    	    	Expr->Val -= Expr2.Val * CheckedPSizeOf (lhst);
     	    	/* Operate on pointers, result type is a pointer */
     	    } else if (IsClassPtr (lhst) && IsClassPtr (rhst)) {
     	    	/* Left is pointer, right is pointer, must scale result */
     	    	if (TypeCmp (Indirect (lhst), Indirect (rhst)) < TC_QUAL_DIFF) {
     	    	    Error ("Incompatible pointer types");
     	    	} else {
-    	    	    Expr->ConstVal = (Expr->ConstVal - lval2.ConstVal) /
+    	    	    Expr->Val = (Expr->Val - Expr2.Val) /
                                       CheckedPSizeOf (lhst);
     	    	}
     	    	/* Operate on pointers, result type is an integer */
     	    	Expr->Type = type_int;
     	    } else if (IsClassInt (lhst) && IsClassInt (rhst)) {
     	    	/* Integer subtraction */
-       	       	typeadjust (Expr, &lval2, 1);
-    	    	Expr->ConstVal -= lval2.ConstVal;
+       	       	typeadjust (Expr, &Expr2, 1);
+    	    	Expr->Val -= Expr2.Val;
     	    } else {
     	    	/* OOPS */
     	    	Error ("Invalid operands for binary operator `-'");
     	    }
 
     	    /* Result is constant, condition codes not set */
-    	    /* Expr->Flags = E_MCONST; ### */
     	    Expr->Test &= ~E_CC;
 
     	} else {
@@ -2163,7 +2335,7 @@ static void parsesub (ExprDesc* Expr)
 
     	    if (IsClassPtr (lhst) && IsClassInt (rhst)) {
     	    	/* Left is pointer, right is int, must scale rhs */
-       	       	lval2.ConstVal *= CheckedPSizeOf (lhst);
+       	       	Expr2.Val *= CheckedPSizeOf (lhst);
     	    	/* Operate on pointers, result type is a pointer */
     	    	flags = CF_PTR;
     	    } else if (IsClassPtr (lhst) && IsClassPtr (rhst)) {
@@ -2178,14 +2350,14 @@ static void parsesub (ExprDesc* Expr)
     	    	Expr->Type = type_int;
     	    } else if (IsClassInt (lhst) && IsClassInt (rhst)) {
     	    	/* Integer subtraction */
-       	       	flags = typeadjust (Expr, &lval2, 1);
+       	       	flags = typeadjust (Expr, &Expr2, 1);
     	    } else {
     	    	/* OOPS */
     	    	Error ("Invalid operands for binary operator `-'");
     	    }
 
     	    /* Do the subtraction */
-    	    g_dec (flags | CF_CONST, lval2.ConstVal);
+    	    g_dec (flags | CF_CONST, Expr2.Val);
 
  	    /* If this was a pointer subtraction, we must scale the result */
  	    if (rscale != 1) {
@@ -2193,7 +2365,7 @@ static void parsesub (ExprDesc* Expr)
  	    }
 
  	    /* Result is a rvalue in the primary register */
- 	    Expr->Flags = E_MEXPR | E_RVAL;
+ 	    ED_MakeRValExpr (Expr);
  	    Expr->Test &= ~E_CC;
 
  	}
@@ -2201,7 +2373,7 @@ static void parsesub (ExprDesc* Expr)
     } else {
 
  	/* Right hand side is not constant. Get the rhs type. */
- 	rhst = lval2.Type;
+ 	rhst = Expr2.Type;
 
        	/* Check for pointer arithmetic */
  	if (IsClassPtr (lhst) && IsClassInt (rhst)) {
@@ -2224,11 +2396,11 @@ static void parsesub (ExprDesc* Expr)
 	     * the lhs is const, we have to remove this mark, since this is no
 	     * longer true, lhs is on stack instead.
 	     */
-	    if (Expr->Flags == E_MCONST) {
-		Expr->Flags = E_MEXPR | E_RVAL;
+	    if (ED_IsLocAbs (Expr)) {
+		ED_MakeRValExpr (Expr);
 	    }
 	    /* Adjust operand types */
- 	    flags = typeadjust (Expr, &lval2, 0);
+ 	    flags = typeadjust (Expr, &Expr2, 0);
     	} else {
  	    /* OOPS */
 	    Error ("Invalid operands for binary operator `-'");
@@ -2243,7 +2415,7 @@ static void parsesub (ExprDesc* Expr)
       	}
 
 	/* Result is a rvalue in the primary register */
-	Expr->Flags = E_MEXPR | E_RVAL;
+	ED_MakeRValExpr (Expr);
 	Expr->Test &= ~E_CC;
     }
 }
@@ -2265,7 +2437,6 @@ static void hie8 (ExprDesc* Expr)
 
 
 
-
 static void hie7 (ExprDesc* Expr)
 /* Parse << and >>. */
 {
@@ -2356,31 +2527,19 @@ static void hieAndPP (ExprDesc* Expr)
  * called recursively from the preprocessor.
  */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
 
-    ConstSubExpr (hie2, Expr);
+    ConstAbsIntExpr (hie2, Expr);
     while (CurTok.Tok == TOK_BOOL_AND) {
 
-	/* Left hand side must be an int */
-	if (!IsClassInt (Expr->Type)) {
-	    Error ("Left hand side must be of integer type");
-	    ED_MakeConstInt (Expr, 1);
-	}
-
 	/* Skip the && */
 	NextToken ();
 
 	/* Get rhs */
-	ConstSubExpr (hie2, &lval2);
-
-	/* Since we are in PP mode, all we know about is integers */
-	if (!IsClassInt (lval2.Type)) {
-	    Error ("Right hand side must be of integer type");
-	    ED_MakeConstInt (&lval2, 1);
-	}
+	ConstAbsIntExpr (hie2, &Expr2);
 
 	/* Combine the two */
-	Expr->ConstVal = (Expr->ConstVal && lval2.ConstVal);
+	Expr->Val = (Expr->Val && Expr2.Val);
     }
 }
 
@@ -2391,31 +2550,19 @@ static void hieOrPP (ExprDesc *Expr)
  * called recursively from the preprocessor.
  */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
 
-    ConstSubExpr (hieAndPP, Expr);
+    ConstAbsIntExpr (hieAndPP, Expr);
     while (CurTok.Tok == TOK_BOOL_OR) {
 
-	/* Left hand side must be an int */
-	if (!IsClassInt (Expr->Type)) {
-	    Error ("Left hand side must be of integer type");
-	    ED_MakeConstInt (Expr, 1);
-	}
-
 	/* Skip the && */
 	NextToken ();
 
 	/* Get rhs */
-	ConstSubExpr (hieAndPP, &lval2);
-
-	/* Since we are in PP mode, all we know about is integers */
-	if (!IsClassInt (lval2.Type)) {
-	    Error ("Right hand side must be of integer type");
-	    ED_MakeConstInt (&lval2, 1);
-	}
+	ConstAbsIntExpr (hieAndPP, &Expr2);
 
 	/* Combine the two */
-	Expr->ConstVal = (Expr->ConstVal || lval2.ConstVal);
+	Expr->Val = (Expr->Val || Expr2.Val);
     }
 }
 
@@ -2425,7 +2572,7 @@ static void hieAnd (ExprDesc* Expr, unsigned TrueLab, int* BoolOp)
 /* Process "exp && exp" */
 {
     int lab;
-    ExprDesc lval2;
+    ExprDesc Expr2;
 
     hie2 (Expr);
     if (CurTok.Tok == TOK_BOOL_AND) {
@@ -2454,11 +2601,11 @@ static void hieAnd (ExprDesc* Expr, unsigned TrueLab, int* BoolOp)
     	    NextToken ();
 
     	    /* Get rhs */
-    	    hie2 (&lval2);
-    	    if ((lval2.Test & E_CC) == 0) {
-    		lval2.Test |= E_FORCETEST;
+    	    hie2 (&Expr2);
+    	    if ((Expr2.Test & E_CC) == 0) {
+    		Expr2.Test |= E_FORCETEST;
     	    }
-    	    ExprLoad (CF_FORCECHAR, &lval2);
+    	    ExprLoad (CF_FORCECHAR, &Expr2);
 
        	    /* Do short circuit evaluation */
     	    if (CurTok.Tok == TOK_BOOL_AND) {
@@ -2473,7 +2620,7 @@ static void hieAnd (ExprDesc* Expr, unsigned TrueLab, int* BoolOp)
        	g_defcodelabel (lab);
 
        	/* The result is an rvalue in primary */
-       	Expr->Flags = E_MEXPR | E_RVAL;
+       	ED_MakeRValExpr (Expr);
        	Expr->Test |= E_CC;	/* Condition codes are set */
     }
 }
@@ -2483,10 +2630,10 @@ static void hieAnd (ExprDesc* Expr, unsigned TrueLab, int* BoolOp)
 static void hieOr (ExprDesc *Expr)
 /* Process "exp || exp". */
 {
-    ExprDesc lval2;
-    int BoolOp = 0;  		/* Did we have a boolean op? */
-    int AndOp;			/* Did we have a && operation? */
-    unsigned TrueLab;		/* Jump to this label if true */
+    ExprDesc Expr2;
+    int BoolOp = 0;  	   	/* Did we have a boolean op? */
+    int AndOp;		   	/* Did we have a && operation? */
+    unsigned TrueLab;	   	/* Jump to this label if true */
     unsigned DoneLab;
 
     /* Get a label */
@@ -2524,11 +2671,11 @@ static void hieOr (ExprDesc *Expr)
 
        	    /* Get a subexpr */
     	    AndOp = 0;
-    	    hieAnd (&lval2, TrueLab, &AndOp);
-       	    if ((lval2.Test & E_CC) == 0) {
-    	    	lval2.Test |= E_FORCETEST;
+    	    hieAnd (&Expr2, TrueLab, &AndOp);
+       	    if ((Expr2.Test & E_CC) == 0) {
+    	    	Expr2.Test |= E_FORCETEST;
     	    }
-    	    ExprLoad (CF_FORCECHAR, &lval2);
+    	    ExprLoad (CF_FORCECHAR, &Expr2);
 
        	    /* If there is more to come, add shortcut boolean eval. */
     	    g_truejump (CF_NONE, TrueLab);
@@ -2536,7 +2683,7 @@ static void hieOr (ExprDesc *Expr)
 	}
 
        	/* The result is an rvalue in primary */
-    	Expr->Flags = E_MEXPR | E_RVAL;
+    	ED_MakeRValExpr (Expr);
     	Expr->Test |= E_CC;	     	       	/* Condition codes are set */
     }
 
@@ -2586,12 +2733,12 @@ static void hieQuest (ExprDesc* Expr)
     	/* Parse second expression. Remember for later if it is a NULL pointer
          * expression, then load it into the primary.
          */
-        expr (hie1, &Expr2);
-        Expr2IsNULL = IsNullPtr (&Expr2);
+        ExprWithCheck (hie1, &Expr2);
+        Expr2IsNULL = ED_IsNullPtr (&Expr2);
         if (!IsTypeVoid (Expr2.Type)) {
             /* Load it into the primary */
             ExprLoad (CF_NONE, &Expr2);
-	    Expr2.Flags = E_MEXPR | E_RVAL;
+            ED_MakeRValExpr (&Expr2);
         }
     	labt = GetLocalLabel ();
     	ConsumeColon ();
@@ -2603,12 +2750,12 @@ static void hieQuest (ExprDesc* Expr)
     	/* Parse second expression. Remember for later if it is a NULL pointer
          * expression, then load it into the primary.
          */
-        expr (hie1, &Expr3);
-        Expr3IsNULL = IsNullPtr (&Expr3);
+        ExprWithCheck (hie1, &Expr3);
+        Expr3IsNULL = ED_IsNullPtr (&Expr3);
         if (!IsTypeVoid (Expr3.Type)) {
             /* Load it into the primary */
             ExprLoad (CF_NONE, &Expr3);
-	    Expr3.Flags = E_MEXPR | E_RVAL;
+            ED_MakeRValExpr (&Expr3);
         }
 
     	/* Check if any conversions are needed, if so, do them.
@@ -2675,7 +2822,7 @@ static void hieQuest (ExprDesc* Expr)
       	}
 
       	/* Setup the target expression */
-       	Expr->Flags = E_MEXPR | E_RVAL;
+       	ED_MakeRValExpr (Expr);
       	Expr->Type  = ResultType;
     }
 }
@@ -2685,21 +2832,31 @@ static void hieQuest (ExprDesc* Expr)
 static void opeq (const GenDesc* Gen, ExprDesc* Expr)
 /* Process "op=" operators. */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
     unsigned flags;
     CodeMark Mark;
     int MustScale;
 
-    NextToken ();
-    if (ED_IsRVal (Expr)) {
+    /* op= can only be used with lvalues */
+    if (!ED_IsLVal (Expr)) {
      	Error ("Invalid lvalue in assignment");
      	return;
     }
 
+    /* There must be an integer or pointer on the left side */
+    if (!IsClassInt (Expr->Type) && !IsTypePtr (Expr->Type)) {
+        Error ("Invalid left operand type");
+        /* Continue. Wrong code will be generated, but the compiler won't
+         * break, so this is the best error recovery.
+         */
+    }
+
+    /* Skip the operator token */
+    NextToken ();
+
     /* Determine the type of the lhs */
     flags = TypeOf (Expr->Type);
-    MustScale = (Gen->Func == g_add || Gen->Func == g_sub) &&
-	    	Expr->Type [0] == T_PTR;
+    MustScale = (Gen->Func == g_add || Gen->Func == g_sub) && IsTypePtr (Expr->Type);
 
     /* Get the lhs address on stack (if needed) */
     PushAddr (Expr);
@@ -2712,7 +2869,7 @@ static void opeq (const GenDesc* Gen, ExprDesc* Expr)
     g_push (flags, 0);
 
     /* Evaluate the rhs */
-    if (evalexpr (CF_NONE, hie1, &lval2) == 0) {
+    if (evalexpr (CF_NONE, hie1, &Expr2) == 0) {
 	/* The resulting value is a constant. If the generator has the NOPUSH
 	 * flag set, don't push the lhs.
 	 */
@@ -2722,7 +2879,7 @@ static void opeq (const GenDesc* Gen, ExprDesc* Expr)
 	}
        	if (MustScale) {
 	    /* lhs is a pointer, scale rhs */
-	    lval2.ConstVal *= CheckedSizeOf (Expr->Type+1);
+	    Expr2.Val *= CheckedSizeOf (Expr->Type+1);
 	}
 
 	/* If the lhs is character sized, the operation may be later done
@@ -2734,17 +2891,17 @@ static void opeq (const GenDesc* Gen, ExprDesc* Expr)
 
      	/* Special handling for add and sub - some sort of a hack, but short code */
 	if (Gen->Func == g_add) {
-	    g_inc (flags | CF_CONST, lval2.ConstVal);
+	    g_inc (flags | CF_CONST, Expr2.Val);
 	} else if (Gen->Func == g_sub) {
-	    g_dec (flags | CF_CONST, lval2.ConstVal);
+	    g_dec (flags | CF_CONST, Expr2.Val);
 	} else {
-       	    Gen->Func (flags | CF_CONST, lval2.ConstVal);
+       	    Gen->Func (flags | CF_CONST, Expr2.Val);
 	}
     } else {
 	/* rhs is not constant and already in the primary register */
        	if (MustScale) {
  	    /* lhs is a pointer, scale rhs */
-       	    g_scale (TypeOf (lval2.Type), CheckedSizeOf (Expr->Type+1));
+       	    g_scale (TypeOf (Expr2.Type), CheckedSizeOf (Expr->Type+1));
 	}
 
 	/* If the lhs is character sized, the operation may be later done
@@ -2755,10 +2912,10 @@ static void opeq (const GenDesc* Gen, ExprDesc* Expr)
 	}
 
 	/* Adjust the types of the operands if needed */
-       	Gen->Func (g_typeadjust (flags, TypeOf (lval2.Type)), 0);
+       	Gen->Func (g_typeadjust (flags, TypeOf (Expr2.Type)), 0);
     }
     Store (Expr, 0);
-    Expr->Flags = E_MEXPR | E_RVAL;
+    ED_MakeRValExpr (Expr);
 }
 
 
@@ -2766,100 +2923,136 @@ static void opeq (const GenDesc* Gen, ExprDesc* Expr)
 static void addsubeq (const GenDesc* Gen, ExprDesc *Expr)
 /* Process the += and -= operators */
 {
-    ExprDesc lval2;
+    ExprDesc Expr2;
     unsigned lflags;
     unsigned rflags;
     int      MustScale;
 
 
+    /* We're currently only able to handle some adressing modes */
+    if (ED_GetLoc (Expr) == E_LOC_EXPR || ED_GetLoc (Expr) == E_LOC_PRIMARY) {
+	/* Use generic routine */
+       	opeq (Gen, Expr);
+	return;
+    }
+
     /* We must have an lvalue */
     if (ED_IsRVal (Expr)) {
      	Error ("Invalid lvalue in assignment");
      	return;
     }
 
-    /* We're currently only able to handle some adressing modes */
-    if ((Expr->Flags & E_MGLOBAL) == 0 && 	/* Global address? */
-	(Expr->Flags & E_MLOCAL) == 0  && 	/* Local address? */
-       	(Expr->Flags & E_MCONST) == 0) {	/* Constant address? */
-	/* Use generic routine */
-       	opeq (Gen, Expr);
-	return;
+    /* There must be an integer or pointer on the left side */
+    if (!IsClassInt (Expr->Type) && !IsTypePtr (Expr->Type)) {
+        Error ("Invalid left operand type");
+        /* Continue. Wrong code will be generated, but the compiler won't
+         * break, so this is the best error recovery.
+         */
     }
 
     /* Skip the operator */
     NextToken ();
 
     /* Check if we have a pointer expression and must scale rhs */
-    MustScale = (Expr->Type [0] == T_PTR);
+    MustScale = IsTypePtr (Expr->Type);
 
     /* Initialize the code generator flags */
     lflags = 0;
     rflags = 0;
 
     /* Evaluate the rhs */
-    hie1 (&lval2);
-    if (ED_IsRVal (&lval2) && lval2.Flags == E_MCONST) {
-    	/* The resulting value is a constant. */
-       	if (MustScale) {
-    	    /* lhs is a pointer, scale rhs */
-    	    lval2.ConstVal *= CheckedSizeOf (Expr->Type+1);
-    	}
+    hie1 (&Expr2);
+    if (ED_IsConstAbs (&Expr2)) {
+    	/* The resulting value is a constant. Scale it. */
+        if (MustScale) {
+            Expr2.Val *= CheckedSizeOf (Indirect (Expr->Type));
+        }
      	rflags |= CF_CONST;
     	lflags |= CF_CONST;
     } else {
      	/* Not constant, load into the primary */
-        ExprLoad (CF_NONE, &lval2);
+        ExprLoad (CF_NONE, &Expr2);
        	if (MustScale) {
      	    /* lhs is a pointer, scale rhs */
-       	    g_scale (TypeOf (lval2.Type), CheckedSizeOf (Expr->Type+1));
+       	    g_scale (TypeOf (Expr2.Type), CheckedSizeOf (Indirect (Expr->Type)));
      	}
     }
 
     /* Setup the code generator flags */
     lflags |= TypeOf (Expr->Type) | CF_FORCECHAR;
-    rflags |= TypeOf (lval2.Type);
+    rflags |= TypeOf (Expr2.Type);
 
     /* Convert the type of the lhs to that of the rhs */
     g_typecast (lflags, rflags);
 
-    /* Output apropriate code */
-    if (Expr->Flags & E_MGLOBAL) {
-	/* Static variable */
-	lflags |= GlobalModeFlags (Expr->Flags);
-	if (Gen->Tok == TOK_PLUS_ASSIGN) {
-	    g_addeqstatic (lflags, Expr->Name, Expr->ConstVal, lval2.ConstVal);
-	} else {
-       	    g_subeqstatic (lflags, Expr->Name, Expr->ConstVal, lval2.ConstVal);
-	}
-    } else if (Expr->Flags & E_MLOCAL) {
-	/* ref to localvar */
-	if (Gen->Tok == TOK_PLUS_ASSIGN) {
-    	    g_addeqlocal (lflags, Expr->ConstVal, lval2.ConstVal);
-	} else {
-	    g_subeqlocal (lflags, Expr->ConstVal, lval2.ConstVal);
-	}
-    } else if (Expr->Flags & E_MCONST) {
-	/* ref to absolute address */
-	lflags |= CF_ABSOLUTE;
-	if (Gen->Tok == TOK_PLUS_ASSIGN) {
-	    g_addeqstatic (lflags, Expr->ConstVal, 0, lval2.ConstVal);
-	} else {
-       	    g_subeqstatic (lflags, Expr->ConstVal, 0, lval2.ConstVal);
-	}
-    } else if (Expr->Flags & E_MEXPR) {
-       	/* Address in a/x. */
-	if (Gen->Tok == TOK_PLUS_ASSIGN) {
-       	    g_addeqind (lflags, Expr->ConstVal, lval2.ConstVal);
-	} else {
-       	    g_subeqind (lflags, Expr->ConstVal, lval2.ConstVal);
-	}
-    } else {
-       	Internal ("Invalid addressing mode");
+    /* Output apropriate code depending on the location */
+    switch (ED_GetLoc (Expr)) {
+
+        case E_LOC_ABS:
+            /* Absolute: numeric address or const */
+            lflags |= CF_ABSOLUTE;
+            if (Gen->Tok == TOK_PLUS_ASSIGN) {
+                g_addeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            } else {
+                g_subeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            }
+            break;
+
+        case E_LOC_GLOBAL:
+            /* Global variable */
+            lflags |= CF_EXTERNAL;
+            if (Gen->Tok == TOK_PLUS_ASSIGN) {
+                g_addeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            } else {
+                g_subeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            }
+            break;
+
+        case E_LOC_STATIC:
+            /* Static variable */
+            lflags |= CF_STATIC;
+            if (Gen->Tok == TOK_PLUS_ASSIGN) {
+                g_addeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            } else {
+                g_subeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            }
+            break;
+
+        case E_LOC_REGISTER:
+            /* Register variable */
+            lflags |= CF_REGVAR;
+            if (Gen->Tok == TOK_PLUS_ASSIGN) {
+                g_addeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            } else {
+                g_subeqstatic (lflags, Expr->Name, Expr->Val, Expr2.Val);
+            }
+            break;
+
+        case E_LOC_STACK:
+            /* Value on the stack */
+            if (Gen->Tok == TOK_PLUS_ASSIGN) {
+                g_addeqlocal (lflags, Expr->Val, Expr2.Val);
+            } else {
+                g_subeqlocal (lflags, Expr->Val, Expr2.Val);
+            }
+            break;
+
+        case E_LOC_LITERAL:
+            /* Literal in the literal pool */
+            lflags |= CF_STATIC;
+            if (Gen->Tok == TOK_PLUS_ASSIGN) {
+                g_addeqstatic (lflags, LiteralPoolLabel, Expr->Val, Expr2.Val);
+            } else {
+                g_subeqstatic (lflags, LiteralPoolLabel, Expr->Val, Expr2.Val);
+            }
+            break;
+
+        default:
+            Internal ("Invalid location in Store(): 0x%04X", ED_GetLoc (Expr));
     }
 
     /* Expression is a rvalue in the primary now */
-    Expr->Flags = E_MEXPR | E_RVAL;
+    ED_MakeRValExpr (Expr);
 }
 
 
@@ -2941,10 +3134,10 @@ int evalexpr (unsigned Flags, void (*Func) (ExprDesc*), ExprDesc* Expr)
  */
 {
     /* Evaluate */
-    Func (Expr);
+    ExprWithCheck (Func, Expr);
 
     /* Check for a constant expression */
-    if (ED_IsRVal (Expr) && Expr->Flags == E_MCONST) {
+    if (ED_IsConstAbs (Expr)) {
      	/* Constant expression */
      	return 0;
     } else {
@@ -2956,81 +3149,61 @@ int evalexpr (unsigned Flags, void (*Func) (ExprDesc*), ExprDesc* Expr)
 
 
 
-void expr (void (*Func) (ExprDesc*), ExprDesc *Expr)
-/* Expression parser; func is either hie0 or hie1. */
+void Expression0 (ExprDesc* Expr)
+/* Evaluate an expression via hie0 and put the result into the primary register */
 {
-    /* Remember the stack pointer */
-    int savsp = oursp;
-
-    /* Call the expression function */
-    (*Func) (Expr);
-
-    /* Do some checks if code generation is still constistent */
-    if (savsp != oursp) {
-     	if (Debug) {
-     	    fprintf (stderr, "oursp != savesp (%d != %d)\n", oursp, savsp);
-     	} else {
-     	    Internal ("oursp != savsp (%d != %d)", oursp, savsp);
-     	}
-    }
+    ExprWithCheck (hie0, Expr);
+    ExprLoad (CF_NONE, Expr);
 }
 
 
 
-void expression1 (ExprDesc* Expr)
-/* Evaluate an expression on level 1 (no comma operator) and put it into
- * the primary register
+void ConstExpr (void (*Func) (ExprDesc*), ExprDesc* Expr)
+/* Will evaluate an expression via the given function. If the result is not
+ * a constant of some sort, a diagnostic will be printed, and the value is
+ * replaced by a constant one to make sure there are no internal errors that
+ * result from this input error.
  */
 {
-    expr (hie1, InitExprDesc (Expr));
-    ExprLoad (CF_NONE, Expr);
-}
-
-
-
-void expression0 (ExprDesc* Expr)
-/* Evaluate an expression via hie0 and put it into the primary register */
-{
-    expr (hie0, InitExprDesc (Expr));
-    ExprLoad (CF_NONE, Expr);
-}
-
-
-
-void ConstExpr (ExprDesc* Expr)
-/* Get a constant value */
-{
-    expr (hie1, InitExprDesc (Expr));
-    if (ED_IsLVal (Expr) || (Expr->Flags & E_MCONST) == 0) {
+    ExprWithCheck (Func, Expr);
+    if (!ED_IsConst (Expr)) {
      	Error ("Constant expression expected");
      	/* To avoid any compiler errors, make the expression a valid const */
-     	ED_MakeConstInt (Expr, 1);
+     	ED_MakeConstAbsInt (Expr, 1);
     }
 }
 
 
 
-void ConstIntExpr (ExprDesc* Expr)
-/* Get a constant int value */
+void BoolExpr (void (*Func) (ExprDesc*), ExprDesc* Expr)
+/* Will evaluate an expression via the given function. If the result is not
+ * something that may be evaluated in a boolean context, a diagnostic will be
+ * printed, and the value is replaced by a constant one to make sure there
+ * are no internal errors that result from this input error.
+ */
 {
-    expr (hie1, InitExprDesc (Expr));
-    if (ED_IsLVal (Expr) || (Expr->Flags & E_MCONST) == 0 || !IsClassInt (Expr->Type)) {
-     	Error ("Constant integer expression expected");
-     	/* To avoid any compiler errors, make the expression a valid const */
-     	ED_MakeConstInt (Expr, 1);
+    ExprWithCheck (Func, Expr);
+    if (!ED_IsBool (Expr)) {
+ 	Error ("Boolean expression expected");
+ 	/* To avoid any compiler errors, make the expression a valid int */
+	ED_MakeConstAbsInt (Expr, 1);
     }
 }
 
 
 
-void intexpr (ExprDesc* lval)
-/* Get an integer expression */
+void ConstAbsIntExpr (void (*Func) (ExprDesc*), ExprDesc* Expr)
+/* Will evaluate an expression via the given function. If the result is not
+ * a constant numeric integer value, a diagnostic will be printed, and the
+ * value is replaced by a constant one to make sure there are no internal
+ * errors that result from this input error.
+ */
 {
-    expression0 (lval);
-    if (!IsClassInt (lval->Type)) {
-     	Error ("Integer expression expected");
-     	/* To avoid any compiler errors, make the expression a valid int */
-     	ED_MakeConstInt (lval, 1);
+    ExprWithCheck (Func, Expr);
+    if (!ED_IsConstAbsInt (Expr)) {
+       	Error ("Constant integer expression expected");
+       	/* To avoid any compiler errors, make the expression a valid const */
+     	ED_MakeConstAbsInt (Expr, 1);
     }
 }
 
diff --git a/src/cc65/expr.h b/src/cc65/expr.h
index f5ea0a34e..acf442986 100644
--- a/src/cc65/expr.h
+++ b/src/cc65/expr.h
@@ -18,68 +18,60 @@
 
 
 /*****************************************************************************/
-/*		     	   	     code  				     */
+/*		     	     	     code  				     */
 /*****************************************************************************/
 
 
 
-void PushAddr (ExprDesc* lval);
+void PushAddr (const ExprDesc* Expr);                           
 /* If the expression contains an address that was somehow evaluated,
  * push this address on the stack. This is a helper function for all
  * sorts of implicit or explicit assignment functions where the lvalue
  * must be saved if it's not constant, before evaluating the rhs.
  */
 
-void ConstSubExpr (void (*F) (ExprDesc*), ExprDesc* Expr);
-/* Will evaluate an expression via the given function. If the result is not
- * a constant, a diagnostic will be printed, and the value is replaced by
- * a constant one to make sure there are no internal errors that result
- * from this input error.
- */
-
-void CheckBoolExpr (ExprDesc* lval);
-/* Check if the given expression is a boolean expression, output a diagnostic
- * if not.
- */
-
-void ExprLoad (unsigned flags, ExprDesc *lval);
+void ExprLoad (unsigned flags, ExprDesc* Expr);
 /* Put the result of an expression into the primary register */
 
-void Store (ExprDesc* lval, const type* StoreType);
+void Store (ExprDesc* Expr, const type* StoreType);
 /* Store the primary register into the location denoted by lval. If StoreType
  * is given, use this type when storing instead of lval->Type. If StoreType
  * is NULL, use lval->Type instead.
  */
 
-void hie0 (ExprDesc *lval);
+void hie0 (ExprDesc* Expr);
 /* Parse comma operator. */
 
-int evalexpr (unsigned flags, void (*f) (ExprDesc*), ExprDesc* lval);
+int evalexpr (unsigned flags, void (*Func) (ExprDesc*), ExprDesc* Expr);
 /* Will evaluate an expression via the given function. If the result is a
  * constant, 0 is returned and the value is put in the lval struct. If the
  * result is not constant, ExprLoad is called to bring the value into the
  * primary register and 1 is returned.
  */
 
-void expr (void (*Func) (ExprDesc*), ExprDesc *Expr);
-/* Expression parser; func is either hie0 or hie1. */
+void Expression0 (ExprDesc* Expr);
+/* Evaluate an expression via hie0 and put the result into the primary register */
 
-void expression1 (ExprDesc* lval);
-/* Evaluate an expression on level 1 (no comma operator) and put it into
- * the primary register
+void ConstExpr (void (*Func) (ExprDesc*), ExprDesc* Expr);
+/* Will evaluate an expression via the given function. If the result is not
+ * a constant of some sort, a diagnostic will be printed, and the value is
+ * replaced by a constant one to make sure there are no internal errors that
+ * result from this input error.
  */
 
-void expression0 (ExprDesc* lval);
-/* Evaluate an expression via hie0 and put it into the primary register */
+void BoolExpr (void (*Func) (ExprDesc*), ExprDesc* Expr);
+/* Will evaluate an expression via the given function. If the result is not
+ * something that may be evaluated in a boolean context, a diagnostic will be
+ * printed, and the value is replaced by a constant one to make sure there
+ * are no internal errors that result from this input error.
+ */
 
-void ConstExpr (ExprDesc* lval);
-/* Get a constant value */
-
-void ConstIntExpr (ExprDesc* Val);
-/* Get a constant int value */
-
-void intexpr (ExprDesc* lval);
-/* Get an integer expression */
+void ConstAbsIntExpr (void (*Func) (ExprDesc*), ExprDesc* Expr);
+/* Will evaluate an expression via the given function. If the result is not
+ * a constant numeric integer value, a diagnostic will be printed, and the
+ * value is replaced by a constant one to make sure there are no internal
+ * errors that result from this input error.
+ */
 
 void hie10 (ExprDesc* lval);
 /* Handle ++, --, !, unary - etc. */
diff --git a/src/cc65/exprdesc.c b/src/cc65/exprdesc.c
index 4b5de5bfc..585e137c8 100644
--- a/src/cc65/exprdesc.c
+++ b/src/cc65/exprdesc.c
@@ -46,20 +46,137 @@
 
 
 
-ExprDesc* ED_MakeConstInt (ExprDesc* Expr, long Value)
+ExprDesc* ED_Init (ExprDesc* Expr)
+/* Initialize an ExprDesc */
+{
+    Expr->Sym   = 0;
+    Expr->Type  = 0;
+    Expr->Val   = 0;
+    Expr->Flags = 0;
+    Expr->Test  = 0;
+    Expr->Name  = 0;
+    return Expr;
+}
+
+
+
+ExprDesc* ED_MakeConstAbs (ExprDesc* Expr, long Value, type* Type)
+/* Make Expr an absolute const with the given value and type. */
+{
+    Expr->Sym   = 0;
+    Expr->Type  = Type;
+    Expr->Val   = Value;
+    Expr->Flags = E_LOC_ABS | E_RTYPE_RVAL;
+    Expr->Test  = 0;
+    Expr->Name  = 0;
+    return Expr;
+}
+
+
+
+ExprDesc* ED_MakeConstAbsInt (ExprDesc* Expr, long Value)
 /* Make Expr a constant integer expression with the given value */
 {
-    Expr->Flags = E_MCONST | E_RVAL;
-    Expr->Type = type_int;
-    Expr->ConstVal = Value;
+    Expr->Sym   = 0;
+    Expr->Type  = type_int;
+    Expr->Val   = Value;
+    Expr->Flags = E_LOC_ABS | E_RTYPE_RVAL;
+    Expr->Test  = 0;
+    Expr->Name  = 0;
     return Expr;
 }
 
 
 
+ExprDesc* ED_MakeRValExpr (ExprDesc* Expr)
+/* Convert Expr into a rvalue which is in the primary register without an
+ * offset.
+ */
+{
+    Expr->Sym   = 0;
+    Expr->Val   = 0;    /* No offset */
+    Expr->Flags = (Expr->Flags & ~(E_MASK_LOC|E_MASK_RTYPE)) | (E_LOC_EXPR|E_RTYPE_RVAL);
+    Expr->Test  = 0;
+    Expr->Name  = 0;
+    return Expr;
+}
+
+
+
+ExprDesc* ED_MakeLValExpr (ExprDesc* Expr)
+/* Convert Expr into a lvalue which is in the primary register without an
+ * offset.
+ */
+{
+    Expr->Sym   = 0;
+    Expr->Val   = 0;    /* No offset */
+    Expr->Flags = (Expr->Flags & ~(E_MASK_LOC|E_MASK_RTYPE)) | (E_LOC_EXPR|E_RTYPE_LVAL);
+    Expr->Test  = 0;
+    Expr->Name  = 0;
+    return Expr;
+}
+
+
+
+int ED_IsConst (const ExprDesc* Expr)
+/* Return true if the expression denotes a constant of some sort. This can be a
+ * numeric constant, the address of a global variable (maybe with offset) or
+ * similar.
+ */
+{
+    return ED_IsRVal (Expr) && (Expr->Flags & E_LOC_CONST) != 0;
+}
+
+
+
+int ED_IsConstAbs (const ExprDesc* Expr)
+/* Return true if the expression denotes a constant absolute value. This can be
+ * a numeric constant, cast to any type.
+ */
+{
+    return ED_IsConst (Expr) && ED_IsLocAbs (Expr);
+}
+
+
+
+int ED_IsConstAbsInt (const ExprDesc* Expr)
+/* Return true if the expression is a constant (numeric) integer. */
+{
+    return (Expr->Flags & (E_MASK_LOC|E_MASK_RTYPE)) == (E_LOC_ABS|E_RTYPE_RVAL) &&
+           IsClassInt (Expr->Type);
+}
+
+
+
+int ED_IsNullPtr (const ExprDesc* Expr)
+/* Return true if the given expression is a NULL pointer constant */
+{
+    return (Expr->Flags & (E_MASK_LOC|E_MASK_RTYPE)) == (E_LOC_ABS|E_RTYPE_RVAL) &&
+           Expr->Val == 0                                                        &&
+           IsClassInt (Expr->Type);
+}
+
+
+
+int ED_IsBool (const ExprDesc* Expr)
+/* Return true of the expression can be treated as a boolean, that is, it can
+ * be an operand to a compare operation.
+ */
+{
+    /* Either ints, floats, or pointers can be used in a boolean context */
+    return IsClassInt (Expr->Type)   ||
+           IsClassFloat (Expr->Type) ||
+           IsClassPtr (Expr->Type);
+}
+
+
+
 void PrintExprDesc (FILE* F, ExprDesc* E)
 /* Print an ExprDesc */
 {
+    unsigned Flags;
+    char     Sep;
+
     fprintf (F, "Symbol:   %s\n", E->Sym? E->Sym->Name : "(none)");
     if (E->Type) {
         fprintf (F, "Type:     ");
@@ -70,33 +187,64 @@ void PrintExprDesc (FILE* F, ExprDesc* E)
         fprintf (F, "Type:     (unknown)\n"
                     "Raw type: (unknown)\n");
     }
-    fprintf (F, "Value:    0x%08lX\n", E->ConstVal);
-    fprintf (F, "Flags:    ");
-    switch (E->Flags & E_MCTYPE) {
-        case E_TCONST:    fprintf (F, "E_TCONST ");                    break;
-        case E_TGLAB:     fprintf (F, "E_TGLAB ");                     break;
-        case E_TLIT:      fprintf (F, "E_TLIT ");                      break;
-        case E_TLOFFS:    fprintf (F, "E_TLOFFS ");                    break;
-        case E_TLLAB:     fprintf (F, "E_TLLAB ");                     break;
-        case E_TREGISTER: fprintf (F, "E_TREGISTER ");                 break;
-        default:          fprintf (F, "0x%02X ", E->Flags & E_MCTYPE); break;
+    fprintf (F, "Value:    0x%08lX\n", E->Val);
+
+    Flags = E->Flags;
+    Sep   = '(';
+    fprintf (F, "Flags:    0x%04X ", Flags);
+    if (Flags & E_LOC_ABS) {
+        fprintf (F, "%cE_LOC_ABS", Sep);
+        Flags &= ~E_LOC_ABS;
+        Sep = ',';
     }
-    if ((E->Flags & E_MREG) == E_MREG) {
-        fprintf (F, "E_MREG ");
-    } else if ((E->Flags & E_MEOFFS) == E_MEOFFS) {
-        fprintf (F, "E_MEOFFS ");
-    } else if ((E->Flags & E_MEXPR) == E_MEXPR) {
-        fprintf (F, "E_MEXPR ");
+    if (Flags & E_LOC_GLOBAL) {
+        fprintf (F, "%cE_LOC_GLOBAL", Sep);
+        Flags &= ~E_LOC_GLOBAL;
+        Sep = ',';
     }
-    if ((E->Flags & E_MGLOBAL) == E_MGLOBAL) {
-        fprintf (F, "E_MGLOBAL ");
+    if (Flags & E_LOC_STATIC) {
+        fprintf (F, "%cE_LOC_STATIC", Sep);
+        Flags &= ~E_LOC_STATIC;
+        Sep = ',';
     }
-    if ((E->Flags & E_MLOCAL) == E_MLOCAL) {
-        fprintf (F, "E_MLOCAL ");
+    if (Flags & E_LOC_REGISTER) {
+        fprintf (F, "%cE_LOC_REGISTER", Sep);
+        Flags &= ~E_LOC_REGISTER;
+        Sep = ',';
     }
-    if ((E->Flags & E_MCONST) == E_MCONST) {
-        fprintf (F, "E_MCONST ");
+    if (Flags & E_LOC_STACK) {
+        fprintf (F, "%cE_LOC_STACK", Sep);
+        Flags &= ~E_LOC_STACK;
+        Sep = ',';
     }
+    if (Flags & E_LOC_PRIMARY) {
+        fprintf (F, "%cE_LOC_PRIMARY", Sep);
+        Flags &= ~E_LOC_PRIMARY;
+        Sep = ',';
+    }
+    if (Flags & E_LOC_EXPR) {
+        fprintf (F, "%cE_LOC_EXPR", Sep);
+        Flags &= ~E_LOC_EXPR;
+        Sep = ',';
+    }
+    if (Flags & E_LOC_LITERAL) {
+        fprintf (F, "%cE_LOC_LITERAL", Sep);
+        Flags &= ~E_LOC_LITERAL;
+        Sep = ',';
+    }
+    if (Flags & E_RTYPE_LVAL) {
+        fprintf (F, "%cE_RTYPE_LVAL", Sep);
+        Flags &= ~E_RTYPE_LVAL;
+        Sep = ',';
+    }
+    if (Flags) {
+        fprintf (F, "%c,0x%04X", Sep, Flags);
+        Sep = ',';
+    }
+    if (Sep != '(') {
+        fputc (')', F);
+    }
+    fputc ('\n', F);
 
     fprintf (F, "\nTest:     ");
     if (E->Test & E_CC) {
diff --git a/src/cc65/exprdesc.h b/src/cc65/exprdesc.h
index bdae371b8..2b4ca0132 100644
--- a/src/cc65/exprdesc.h
+++ b/src/cc65/exprdesc.h
@@ -55,37 +55,41 @@
 
 
 /* Defines for the flags field of the expression descriptor */
-#define E_MREG 	       	0x0110U	/* Special: Expression is primary register */
-#define E_MGLOBAL      	0x0080U	/* Reference to static variable */
-#define E_MLOCAL    	0x0040U	/* Reference to local variable (stack offset) */
-#define E_MCONST    	0x0020U	/* Constant value */
-#define E_MEXPR	    	0x0010U	/* Result is in primary register */
-#define E_MEOFFS       	0x0011U	/* Base is in primary register, const offset */
+enum {
+    /* Location: Where is the value we're talking about? */
+    E_MASK_LOC          = 0x00FF,
+    E_LOC_ABS           = 0x0001,       /* Absolute: numeric address or const */
+    E_LOC_GLOBAL        = 0x0002,       /* Global variable */
+    E_LOC_STATIC        = 0x0004,       /* Static variable */
+    E_LOC_REGISTER      = 0x0008,       /* Register variable */
+    E_LOC_STACK         = 0x0010,       /* Value on the stack */
+    E_LOC_PRIMARY       = 0x0020,       /* The primary register */
+    E_LOC_EXPR          = 0x0040,       /* An expression in the primary register */
+    E_LOC_LITERAL       = 0x0080,       /* Literal in the literal pool */
 
-#define E_MCTYPE       	0x0007U /* Type of a constant */
-#define E_TCONST       	0x0000U /* Constant */
-#define E_TGLAB	       	0x0001U /* Global label */
-#define E_TLIT 	       	0x0002U /* Literal of some kind */
-#define E_TLOFFS       	0x0003U /* Constant stack offset */
-#define E_TLLAB	       	0x0004U /* Local label */
-#define E_TREGISTER    	0x0005U	/* Register variable */
+    /* Constant location of some sort (only if rval) */
+    E_LOC_CONST         = E_LOC_ABS | E_LOC_GLOBAL | E_LOC_STATIC |
+                          E_LOC_REGISTER | E_LOC_LITERAL,
 
-#define E_RVAL          0x0000U /* Expression node is a value */
-#define E_LVAL          0x1000U /* Expression node is a reference */
+    /* Reference? */
+    E_MASK_RTYPE        = 0x8000,
+    E_RTYPE_RVAL        = 0x0000,
+    E_RTYPE_LVAL        = 0x8000
+};
 
 /* Defines for the test field of the expression descriptor */
-#define E_CC   	       	0x0001U	/* expr has set cond codes apropos result value */
-#define E_FORCETEST    	0x0002U /* if expr has NOT set CC, force a test */
+#define E_CC   	       	0x0001U	        /* Condition codes are set */
+#define E_FORCETEST    	0x0002U         /* Force test to set condition codes */
 
 /* Describe the result of an expression */
 typedef struct ExprDesc ExprDesc;
 struct ExprDesc {
-    struct SymEntry*	Sym;	 /* Symbol table entry if known */
-    type*	       	Type;    /* Type array of expression */
-    long       	       	ConstVal;/* Value if expression constant */
+    struct SymEntry*	Sym;	/* Symbol table entry if known */
+    type*	       	Type;   /* Type array of expression */
+    long       	       	Val;    /* Value if expression constant */
     unsigned short     	Flags;
-    unsigned short  	Test;	 /* */
-    unsigned long 	Name;	 /* Name or label number */
+    unsigned short  	Test;	/* */
+    unsigned long 	Name;	/* Name or label number */
 };
 
 
@@ -96,73 +100,137 @@ struct ExprDesc {
 
 
 
-#if defined(HAVE_INLINE)
-INLINE ExprDesc* InitExprDesc (ExprDesc* Expr)
+ExprDesc* ED_Init (ExprDesc* Expr);
 /* Initialize an ExprDesc */
+
+#if defined(HAVE_INLINE)
+INLINE int ED_GetLoc (const ExprDesc* Expr)
+/* Return the location flags from the expression */
 {
-    return memset (Expr, 0, sizeof (*Expr));
+    return (Expr->Flags & E_MASK_LOC);
 }
 #else
-#  define InitExprDesc(E)       memset ((E), 0, sizeof (*(E)))
+#  define ED_GetLoc(Expr)       ((Expr)->Flags & E_MASK_LOC)
+#endif
+
+#if defined(HAVE_INLINE)
+INLINE int ED_IsLocAbs (const ExprDesc* Expr)
+/* Return true if the expression is an absolute value */
+{
+    return (Expr->Flags & E_MASK_LOC) == E_LOC_ABS;
+}
+#else
+#  define ED_IsLocAbs(Expr)     (((Expr)->Flags & E_MASK_LOC) == E_LOC_ABS)
+#endif
+
+#if defined(HAVE_INLINE)
+INLINE int ED_IsLocStack (const ExprDesc* Expr)
+/* Return true if the expression is located on the stack */
+{
+    return (Expr->Flags & E_MASK_LOC) == E_LOC_STACK;
+}
+#else
+#  define ED_IsLocStack(Expr)     (((Expr)->Flags & E_MASK_LOC) == E_LOC_STACK)
+#endif
+
+#if defined(HAVE_INLINE)
+INLINE int ED_IsLocExpr (const ExprDesc* Expr)
+/* Return true if the expression is an expression in the primary */
+{
+    return (Expr->Flags & E_MASK_LOC) == E_LOC_EXPR;
+}
+#else
+#  define ED_IsLocExpr(Expr)     (((Expr)->Flags & E_MASK_LOC) == E_LOC_EXPR)
+#endif
+
+#if defined(HAVE_INLINE)
+INLINE int ED_IsLocConst (const ExprDesc* Expr)
+/* Return true if the expression is a constant location of some sort */
+{
+    return (Expr->Flags & E_LOC_CONST) != 0;
+}
+#else
+#  define ED_IsLocConst(Expr)  (((Expr)->Flags & E_LOC_CONST) != 0)
 #endif
 
 #if defined(HAVE_INLINE)
 INLINE int ED_IsLVal (const ExprDesc* Expr)
 /* Return true if the expression is a reference */
 {
-    return (Expr->Flags & E_LVAL) != 0;
+    return (Expr->Flags & E_MASK_RTYPE) == E_RTYPE_LVAL;
 }
 #else
-#  define ED_IsLVal(Expr)       (((Expr)->Flags & E_LVAL) != 0)
+#  define ED_IsLVal(Expr)       (((Expr)->Flags & E_MASK_RTYPE) == E_RTYPE_LVAL)
 #endif
 
 #if defined(HAVE_INLINE)
 INLINE int ED_IsRVal (const ExprDesc* Expr)
 /* Return true if the expression is a rvalue */
 {
-    return (Expr->Flags & E_LVAL) == 0;
+    return (Expr->Flags & E_MASK_RTYPE) == E_RTYPE_RVAL;
 }
 #else
-#  define ED_IsRVal(Expr)       (((Expr)->Flags & E_LVAL) == 0)
+#  define ED_IsRVal(Expr)       (((Expr)->Flags & E_MASK_RTYPE) == E_RTYPE_RVAL)
 #endif
 
 #if defined(HAVE_INLINE)
-INLINE int ED_SetValType (ExprDesc* Expr, int Ref)
-/* Set the reference flag for an expression and return it (the flag) */
+INLINE void ED_MakeLVal (ExprDesc* Expr)
+/* Make the expression a lvalue. */
 {
-    Expr->Flags = Ref? (Expr->Flags | E_LVAL) : (Expr->Flags & ~E_LVAL);
-    return Ref;
+    Expr->Flags |= E_RTYPE_LVAL;
 }
 #else
-/* Beware: Just one occurance of R below, since it may have side effects! */
-#  define ED_SetValType(E, R)                                                   \
-        (((E)->Flags = (R)? ((E)->Flags | E_LVAL) : ((E)->Flags & ~E_LVAL)),    \
-        ED_IsLVal (E))
+#  define ED_MakeLVal(Expr)       do { (Expr)->Flags |= R_RTYPE_LVAL; } while (0)
 #endif
 
 #if defined(HAVE_INLINE)
-INLINE int ED_MakeLVal (ExprDesc* Expr)
-/* Make the expression a lvalue and return true */
+INLINE void ED_MakeRVal (ExprDesc* Expr)
+/* Make the expression a rvalue. */
 {
-    return ED_SetValType (Expr, 1);
+    Expr->Flags &= ~E_RTYPE_LVAL;
 }
 #else
-#  define ED_MakeLVal(Expr)       ED_SetValType (Expr, 1)
+#  define ED_MakeRVal(Expr)       do { (Expr)->Flags &= ~E_RTYPE_LVAL; } while (0)
 #endif
 
-#if defined(HAVE_INLINE)
-INLINE int ED_MakeRVal (ExprDesc* Expr)
-/* Make the expression a rvalue and return false */
-{
-    return ED_SetValType (Expr, 0);
-}
-#else
-#  define ED_MakeRVal(Expr)       ED_SetValType (Expr, 0)
-#endif
+ExprDesc* ED_MakeConstAbs (ExprDesc* Expr, long Value, type* Type);
+/* Make Expr an absolute const with the given value and type. */
 
-ExprDesc* ED_MakeConstInt (ExprDesc* Expr, long Value);
+ExprDesc* ED_MakeConstAbsInt (ExprDesc* Expr, long Value);
 /* Make Expr a constant integer expression with the given value */
 
+ExprDesc* ED_MakeRValExpr (ExprDesc* Expr);
+/* Convert Expr into a rvalue which is in the primary register without an
+ * offset.
+ */
+
+ExprDesc* ED_MakeLValExpr (ExprDesc* Expr);
+/* Convert Expr into a lvalue which is in the primary register without an
+ * offset.
+ */
+
+int ED_IsConst (const ExprDesc* Expr);
+/* Return true if the expression denotes a constant of some sort. This can be a
+ * numeric constant, the address of a global variable (maybe with offset) or
+ * similar.
+ */
+
+int ED_IsConstAbs (const ExprDesc* Expr);
+/* Return true if the expression denotes a constant absolute value. This can be
+ * a numeric constant, cast to any type.
+ */
+
+int ED_IsConstAbsInt (const ExprDesc* Expr);
+/* Return true if the expression is a constant (numeric) integer. */
+
+int ED_IsNullPtr (const ExprDesc* Expr);
+/* Return true if the given expression is a NULL pointer constant */
+
+int ED_IsBool (const ExprDesc* Expr);
+/* Return true of the expression can be treated as a boolean, that is, it can
+ * be an operand to a compare operation.
+ */
+
 void PrintExprDesc (FILE* F, ExprDesc* Expr);
 /* Print an ExprDesc */
 
diff --git a/src/cc65/function.c b/src/cc65/function.c
index 6de9ba7b1..505e6804a 100644
--- a/src/cc65/function.c
+++ b/src/cc65/function.c
@@ -197,7 +197,7 @@ int F_ReserveLocalSpace (Function* F, unsigned Size)
  */
 {
     F->Reserved += Size;
-    return oursp - F->Reserved;
+    return StackPtr - F->Reserved;
 }
 
 
@@ -213,7 +213,7 @@ void F_AllocLocalSpace (Function* F)
        	g_space (F->Reserved);
 
        	/* Correct the stack pointer */
-       	oursp -= F->Reserved;
+       	StackPtr -= F->Reserved;
 
        	/* Nothing more reserved */
        	F->Reserved = 0;
@@ -408,7 +408,7 @@ void NewFunc (SymEntry* Func)
     }
 
     /* Setup the stack */
-    oursp = 0;
+    StackPtr = 0;
 
     /* Walk through the parameter list and allocate register variable space
      * for parameters declared as register. Generate code to swap the contents
@@ -450,7 +450,7 @@ void NewFunc (SymEntry* Func)
     /* Remember the current stack pointer. All variables allocated elsewhere
      * must be dropped when doing a return from an inner block.
      */
-    CurrentFunc->TopLevelSP = oursp;
+    CurrentFunc->TopLevelSP = StackPtr;
 
     /* Now process statements in this block */
     HadReturn = 0;
diff --git a/src/cc65/locals.c b/src/cc65/locals.c
index 2c465d3a2..44662577c 100644
--- a/src/cc65/locals.c
+++ b/src/cc65/locals.c
@@ -78,7 +78,7 @@ static unsigned ParseRegisterDecl (Declaration* Decl, unsigned* SC, int Reg)
     /* Check for an optional initialization */
     if (CurTok.Tok == TOK_ASSIGN) {
 
-        ExprDesc lval;
+        ExprDesc Expr;
 
         /* Skip the '=' */
         NextToken ();
@@ -111,13 +111,13 @@ static unsigned ParseRegisterDecl (Declaration* Decl, unsigned* SC, int Reg)
         } else {
 
             /* Parse the expression */
-            hie1 (InitExprDesc (&lval));
+            hie1 (&Expr);
 
             /* Convert it to the target type */
-            TypeConversion (&lval, Decl->Type);
+            TypeConversion (&Expr, Decl->Type);
 
             /* Load the value into the primary */
-            ExprLoad (CF_NONE, &lval);
+            ExprLoad (CF_NONE, &Expr);
 
             /* Store the value into the variable */
             g_putstatic (CF_REGVAR | TypeOf (Decl->Type), Reg, 0);
@@ -161,7 +161,7 @@ static unsigned ParseAutoDecl (Declaration* Decl, unsigned* SC)
         /* Check for an optional initialization */
         if (CurTok.Tok == TOK_ASSIGN) {
 
-            ExprDesc lval;
+            ExprDesc Expr;
 
             /* Skip the '=' */
             NextToken ();
@@ -207,23 +207,23 @@ static unsigned ParseAutoDecl (Declaration* Decl, unsigned* SC)
                 Flags = (Size == SIZEOF_CHAR)? CF_FORCECHAR : CF_NONE;
 
                 /* Parse the expression */
-                hie1 (InitExprDesc (&lval));
+                hie1 (&Expr);
 
                 /* Convert it to the target type */
-                TypeConversion (&lval, Decl->Type);
+                TypeConversion (&Expr, Decl->Type);
 
                 /* If the value is not const, load it into the primary.
                  * Otherwise pass the information to the code generator.
-                 */
-                if (ED_IsLVal (&lval) || lval.Flags != E_MCONST) {
-                    ExprLoad (CF_NONE, &lval);
-                    ED_MakeRVal (&lval);
-                } else {
+                 */ 
+                if (ED_IsConstAbsInt (&Expr)) {
                     Flags |= CF_CONST;
+                } else {
+                    ExprLoad (CF_NONE, &Expr);
+                    ED_MakeRVal (&Expr);
                 }
 
                 /* Push the value */
-                g_push (Flags | TypeOf (Decl->Type), lval.ConstVal);
+                g_push (Flags | TypeOf (Decl->Type), Expr.Val);
 
             }
 
@@ -231,7 +231,7 @@ static unsigned ParseAutoDecl (Declaration* Decl, unsigned* SC)
             *SC |= SC_REF;
 
             /* Variable is located at the current SP */
-            SymData = oursp;
+            SymData = StackPtr;
 
         } else {
             /* Non-initialized local variable. Just keep track of
@@ -258,7 +258,7 @@ static unsigned ParseAutoDecl (Declaration* Decl, unsigned* SC)
         /* Allow assignments */
         if (CurTok.Tok == TOK_ASSIGN) {
 
-            ExprDesc lval;
+            ExprDesc Expr;
 
             /* Skip the '=' */
             NextToken ();
@@ -283,13 +283,13 @@ static unsigned ParseAutoDecl (Declaration* Decl, unsigned* SC)
             } else {
 
                 /* Parse the expression */
-                hie1 (InitExprDesc (&lval));
+                hie1 (&Expr);
 
                 /* Convert it to the target type */
-                TypeConversion (&lval, Decl->Type);
+                TypeConversion (&Expr, Decl->Type);
 
                 /* Load the value into the primary */
-                ExprLoad (CF_NONE, &lval);
+                ExprLoad (CF_NONE, &Expr);
 
                 /* Store the value into the variable */
                 g_putstatic (TypeOf (Decl->Type), SymData, 0);
@@ -447,7 +447,7 @@ void DeclareLocals (void)
 /* Declare local variables and types. */
 {
     /* Remember the current stack pointer */
-    int InitialStack = oursp;
+    int InitialStack = StackPtr;
 
     /* Loop until we don't find any more variables */
     while (1) {
@@ -501,7 +501,7 @@ void DeclareLocals (void)
     /* In case we've allocated local variables in this block, emit a call to
      * the stack checking routine if stack checks are enabled.
      */
-    if (IS_Get (&CheckStack) && InitialStack != oursp) {
+    if (IS_Get (&CheckStack) && InitialStack != StackPtr) {
        	g_cstackcheck ();
     }
 }
diff --git a/src/cc65/make/gcc.mak b/src/cc65/make/gcc.mak
index f60e9d69a..8aaf2005c 100644
--- a/src/cc65/make/gcc.mak
+++ b/src/cc65/make/gcc.mak
@@ -56,7 +56,6 @@ OBJS =	anonname.o	\
 	error.o	  	\
 	expr.o	 	\
         exprdesc.o      \
-	exprheap.o     	\
 	exprnode.o	\
 	funcdesc.o	\
 	function.o     	\
diff --git a/src/cc65/make/watcom.mak b/src/cc65/make/watcom.mak
index 63684c449..ca3bcb07e 100644
--- a/src/cc65/make/watcom.mak
+++ b/src/cc65/make/watcom.mak
@@ -90,7 +90,6 @@ OBJS =	anonname.obj	\
 	error.obj	\
 	expr.obj 	\
         exprdesc.obj    \
-	exprheap.obj	\
 	exprnode.obj	\
 	funcdesc.obj	\
 	function.obj	\
diff --git a/src/cc65/preproc.c b/src/cc65/preproc.c
index 9df75ab40..87eec2ae1 100644
--- a/src/cc65/preproc.c
+++ b/src/cc65/preproc.c
@@ -804,7 +804,7 @@ static int DoIf (int Skip)
     NextToken ();
 
     /* Call the expression parser */
-    ConstExpr (&lval);
+    ConstExpr (hie1, &lval);
 
     /* End preprocessing mode */
     Preprocessing = 0;
@@ -814,7 +814,7 @@ static int DoIf (int Skip)
     NextTok = sv2;
 
     /* Set the #if condition according to the expression result */
-    return PushIf (Skip, 1, lval.ConstVal != 0);
+    return PushIf (Skip, 1, lval.Val != 0);
 }
 
 
diff --git a/src/cc65/stdfunc.c b/src/cc65/stdfunc.c
index 7877f6c9d..5e31221ea 100644
--- a/src/cc65/stdfunc.c
+++ b/src/cc65/stdfunc.c
@@ -6,7 +6,7 @@
 /*                                                                           */
 /*                                                                           */
 /*                                                                           */
-/* (C) 1998-2003 Ullrich von Bassewitz                                       */
+/* (C) 1998-2004 Ullrich von Bassewitz                                       */
 /*               R�merstrasse 52                                             */
 /*               D-70794 Filderstadt                                         */
 /* EMail:        uz@cc65.org                                                 */
@@ -117,23 +117,21 @@ static unsigned ParseArg (type* Type, ExprDesc* Arg)
     unsigned Flags = CF_FORCECHAR;
 
     /* Read the expression we're going to pass to the function */
-    hie1 (InitExprDesc (Arg));
+    hie1 (Arg);
 
     /* Convert this expression to the expected type */
     TypeConversion (Arg, Type);
 
-    /* If the value is not a constant, load it into the primary */
-    if (ED_IsLVal (Arg) || Arg->Flags != E_MCONST) {
-
+    /* If the value is a constant, set the flag, otherwise load it into the
+     * primary register.
+     */
+    if (ED_IsConstAbsInt (Arg)) {
+        /* Remember that we have a constant value */
+        Flags |= CF_CONST;
+    } else {
         /* Load into the primary */
         ExprLoad (CF_NONE, Arg);
         ED_MakeRVal (Arg);
-
-    } else {
-
-        /* Remember that we have a constant value */
-        Flags |= CF_CONST;
-
     }
 
     /* Use the type of the argument for the push */
@@ -164,7 +162,7 @@ static void StdFunc_memset (FuncDesc* F attribute ((unused)),
 
     /* Argument #1 */
     Flags = ParseArg (Arg1Type, &Arg);
-    g_push (Flags, Arg.ConstVal);
+    g_push (Flags, Arg.Val);
     ParamSize += SizeOf (Arg1Type);
     ConsumeComma ();
 
@@ -172,12 +170,12 @@ static void StdFunc_memset (FuncDesc* F attribute ((unused)),
      * function if it is a constant zero.
      */
     Flags = ParseArg (Arg2Type, &Arg);
-    if ((Flags & CF_CONST) != 0 && Arg.ConstVal == 0) {
+    if ((Flags & CF_CONST) != 0 && Arg.Val == 0) {
         /* Don't call memset, call bzero instead */
         MemSet = 0;
     } else {
         /* Push the argument */
-        g_push (Flags, Arg.ConstVal);
+        g_push (Flags, Arg.Val);
         ParamSize += SizeOf (Arg2Type);
     }
     ConsumeComma ();
@@ -189,7 +187,7 @@ static void StdFunc_memset (FuncDesc* F attribute ((unused)),
      */
     Flags = ParseArg (Arg3Type, &Arg);
     if (Flags & CF_CONST) {
-	if (Arg.ConstVal == 0) {
+	if (Arg.Val == 0) {
 	    Warning ("Call to memset has no effect");
 	}
         ExprLoad (CF_FORCECHAR, &Arg);
@@ -217,7 +215,7 @@ static void StdFunc_strlen (FuncDesc* F attribute ((unused)),
     ParamType[1] = GetDefaultChar () | T_QUAL_CONST;
 
     /* Fetch the parameter and convert it to the type needed */
-    hie1 (InitExprDesc (&Param));
+    hie1 (&Param);
     TypeConversion (&Param, ParamType);
 
     /* Check if the parameter is a constant array of some type, or a numeric
@@ -225,33 +223,33 @@ static void StdFunc_strlen (FuncDesc* F attribute ((unused)),
      */
     CodeFlags = 0;
     ParamName = Param.Name;
-    if ((IsTypeArray (Param.Type) && (Param.Flags & E_MCONST) != 0) ||
-        (IsTypePtr (Param.Type) && Param.Flags == (E_MCONST | E_TCONST))) {
+    if ((ED_IsLocConst (&Param) && IsTypeArray (Param.Type)) ||
+        (ED_IsLocAbs (&Param) && IsTypePtr (Param.Type))) {
 
         /* Check which type of constant it is */
-        switch (Param.Flags & E_MCTYPE) {
+        switch (ED_GetLoc (&Param)) {
 
-            case E_TCONST:
+            case E_LOC_ABS:
                 /* Numerical address */
                 CodeFlags |= CF_CONST | CF_ABSOLUTE;
                 break;
 
-            case E_TREGISTER:
-                /* Register variable */
-                CodeFlags |= CF_CONST | CF_REGVAR;
-                break;
-
-            case E_TGLAB:
+            case E_LOC_GLOBAL:
                 /* Global label */
                 CodeFlags |= CF_CONST | CF_EXTERNAL;
                 break;
 
-            case E_TLLAB:
+            case E_LOC_STATIC:
                 /* Local symbol */
                 CodeFlags |= CF_CONST | CF_STATIC;
                 break;
 
-            case E_TLIT:
+            case E_LOC_REGISTER:
+                /* Register variable */
+                CodeFlags |= CF_CONST | CF_REGVAR;
+                break;
+
+            case E_LOC_LITERAL:
                 /* A literal of some kind. If string literals are read only,
                  * we can calculate the length of the string and remove it
                  * from the literal pool. Otherwise we have to calculate the
@@ -260,8 +258,8 @@ static void StdFunc_strlen (FuncDesc* F attribute ((unused)),
                 if (!WriteableStrings) {
                     /* String literals are const */
                     ExprDesc Length;
-                    ED_MakeConstInt (&Length, strlen (GetLiteral (Param.ConstVal)));
-                    ResetLiteralPoolOffs (Param.ConstVal);
+                    ED_MakeConstAbsInt (&Length, strlen (GetLiteral (Param.Val)));
+                    ResetLiteralPoolOffs (Param.Val);
                     ExprLoad (CF_NONE, &Length);
                     goto ExitPoint;
                 } else {
@@ -282,7 +280,7 @@ static void StdFunc_strlen (FuncDesc* F attribute ((unused)),
     }
 
     /* Generate the strlen code */
-    g_strlen (CodeFlags, ParamName, Param.ConstVal);
+    g_strlen (CodeFlags, ParamName, Param.Val);
 
 ExitPoint:
     /* We expect the closing brace */
diff --git a/src/cc65/stmt.c b/src/cc65/stmt.c
index 42c8a2a96..cd4c53dc3 100644
--- a/src/cc65/stmt.c
+++ b/src/cc65/stmt.c
@@ -6,7 +6,7 @@
 /*                                                                           */
 /*                                                                           */
 /*                                                                           */
-/* (C) 1998-2003 Ullrich von Bassewitz                                       */
+/* (C) 1998-2004 Ullrich von Bassewitz                                       */
 /*               R�merstra�e 52                                              */
 /*               D-70794 Filderstadt                                         */
 /* EMail:        uz@cc65.org                                                 */
@@ -201,7 +201,7 @@ static void DoStatement (void)
     NextToken ();
 
     /* Add the loop to the loop stack */
-    AddLoop (oursp, BreakLabel, ContinueLabel);
+    AddLoop (StackPtr, BreakLabel, ContinueLabel);
 
     /* Define the loop label */
     g_defcodelabel (LoopLabel);
@@ -241,7 +241,7 @@ static void WhileStatement (void)
     /* Add the loop to the loop stack. In case of a while loop, the loop head
      * label is used for continue statements.
      */
-    AddLoop (oursp, BreakLabel, LoopLabel);
+    AddLoop (StackPtr, BreakLabel, LoopLabel);
 
     /* Define the head label */
     g_defcodelabel (LoopLabel);
@@ -283,7 +283,7 @@ static void ReturnStatement (void)
        	}
 
 	/* Evaluate the return expression */
-	hie0 (InitExprDesc (&Expr));
+	hie0 (&Expr);
 
 	/* Ignore the return expression if the function returns void */
     	if (!F_HasVoidReturn (CurrentFunc)) {
@@ -300,7 +300,7 @@ static void ReturnStatement (void)
     }
 
     /* Cleanup the stack in case we're inside a block with locals */
-    g_space (oursp - F_GetTopLevelSP (CurrentFunc));
+    g_space (StackPtr - F_GetTopLevelSP (CurrentFunc));
 
     /* Output a jump to the function exit code */
     g_jump (F_GetRetLab (CurrentFunc));
@@ -327,7 +327,7 @@ static void BreakStatement (void)
     }
 
     /* Correct the stack pointer if needed */
-    g_space (oursp - L->StackPtr);
+    g_space (StackPtr - L->StackPtr);
 
     /* Jump to the exit label of the loop */
     g_jump (L->BreakLabel);
@@ -362,7 +362,7 @@ static void ContinueStatement (void)
     }
 
     /* Correct the stackpointer if needed */
-    g_space (oursp - L->StackPtr);
+    g_space (StackPtr - L->StackPtr);
 
     /* Jump to next loop iteration */
     g_jump (L->ContinueLabel);
@@ -392,14 +392,14 @@ static void ForStatement (void)
     /* Add the loop to the loop stack. A continue jumps to the start of the
      * the increment condition.
      */
-    AddLoop (oursp, BreakLabel, IncLabel);
+    AddLoop (StackPtr, BreakLabel, IncLabel);
 
     /* Skip the opening paren */
     ConsumeLParen ();
 
     /* Parse the initializer expression */
     if (CurTok.Tok != TOK_SEMI) {
-    	expression0 (&lval1);
+    	Expression0 (&lval1);
     }
     ConsumeSemi ();
 
@@ -424,7 +424,7 @@ static void ForStatement (void)
     /* Parse the increment expression */
     HaveIncExpr = (CurTok.Tok != TOK_RPAREN);
     if (HaveIncExpr) {
-    	expression0 (&lval3);
+    	Expression0 (&lval3);
     }
 
     /* Jump to the test */
@@ -471,7 +471,7 @@ static int CompoundStatement (void)
     int GotBreak;
 
     /* Remember the stack at block entry */
-    int OldStack = oursp;
+    int OldStack = StackPtr;
 
     /* Enter a new lexical level */
     EnterBlockLevel ();
@@ -491,9 +491,9 @@ static int CompoundStatement (void)
 
     /* Clean up the stack. */
     if (!GotBreak) {
-	g_space (oursp - OldStack);
+	g_space (StackPtr - OldStack);
     }
-    oursp = OldStack;
+    StackPtr = OldStack;
 
     /* Emit references to imports/exports for this block */
     EmitExternals ();
@@ -590,7 +590,7 @@ int Statement (int* PendingToken)
 
 	    default:
 	        /* Actual statement */
-		expression0 (&lval);
+		Expression0 (&lval);
 	    	CheckSemi (PendingToken);
 	}
     }
diff --git a/src/cc65/swstmt.c b/src/cc65/swstmt.c
index 5c50f5e6a..44cc25842 100644
--- a/src/cc65/swstmt.c
+++ b/src/cc65/swstmt.c
@@ -6,7 +6,7 @@
 /*                                                                           */
 /*                                                                           */
 /*                                                                           */
-/* (C) 1998-2003 Ullrich von Bassewitz                                       */
+/* (C) 1998-2004 Ullrich von Bassewitz                                       */
 /*               Wacholderweg 14                                             */
 /*               D-70597 Stuttgart                                           */
 /* EMail:        uz@cc65.org                                                 */
@@ -81,9 +81,17 @@ void SwitchStatement (void)
     /* Eat the "switch" token */
     NextToken ();
 
-    /* Read the switch expression */
+    /* Read the switch expression and load it into the primary. It must have
+     * integer type.
+     */
     ConsumeLParen ();
-    intexpr (&SwitchExpr);
+    Expression0 (&SwitchExpr);
+    if (!IsClassInt (SwitchExpr.Type))  {
+        Error ("Switch quantity is not an integer");
+     	/* To avoid any compiler errors, make the expression a valid int */
+     	ED_MakeConstAbsInt (&SwitchExpr, 1);
+    }
+    /* Load the expression into the primary register */
     ConsumeRParen ();
 
     /* Add a jump to the switch code. This jump is usually unnecessary,
@@ -117,7 +125,7 @@ void SwitchStatement (void)
     ExitLabel = GetLocalLabel ();
 
     /* Create a loop so we may use break. */
-    AddLoop (oursp, ExitLabel, 0);
+    AddLoop (StackPtr, ExitLabel, 0);
 
     /* Create the collection for the case node tree */
     Nodes = NewCollection ();
@@ -137,13 +145,10 @@ void SwitchStatement (void)
 		NextToken ();
 
 		/* Read the selector expression */
-		ConstExpr (&CaseExpr);
-		if (!IsClassInt (CaseExpr.Type)) {
-       		    Error ("Switch quantity not an integer");
-		}
+		ConstAbsIntExpr (hie1, &CaseExpr);
 
 		/* Check the range of the expression */
-		Val = CaseExpr.ConstVal;
+		Val = CaseExpr.Val;
 		switch (SwitchExprType) {
 
 		    case T_SCHAR:
diff --git a/src/cc65/symtab.c b/src/cc65/symtab.c
index c9304454b..c3eca39d9 100644
--- a/src/cc65/symtab.c
+++ b/src/cc65/symtab.c
@@ -6,7 +6,7 @@
 /*                                                                           */
 /*                                                                           */
 /*                                                                           */
-/* (C) 2000-2003 Ullrich von Bassewitz                                       */
+/* (C) 2000-2004 Ullrich von Bassewitz                                       */
 /*               R�merstrasse 52                                             */
 /*               D-70794 Filderstadt                                         */
 /* EMail:        uz@cc65.org                                                 */
@@ -672,7 +672,7 @@ SymEntry* AddLocalSym (const char* Name, const type* Type, unsigned Flags, int O
             Entry->V.Offs = Offs;
         } else if ((Flags & SC_REGISTER) == SC_REGISTER) {
             Entry->V.R.RegOffs  = Offs;
-            Entry->V.R.SaveOffs = oursp;        /* ### Cleaner! */
+            Entry->V.R.SaveOffs = StackPtr;        /* ### Cleaner! */
         } else if ((Flags & SC_STATIC) == SC_STATIC) {
             /* Generate the assembler name from the label number */
             Entry->V.Label = Offs;
diff --git a/src/cc65/testexpr.c b/src/cc65/testexpr.c
index a8d559f4f..6fb573b93 100644
--- a/src/cc65/testexpr.c
+++ b/src/cc65/testexpr.c
@@ -53,26 +53,23 @@ unsigned Test (unsigned Label, int Invert)
  * defined above. If the jump is always true, a warning is output.
  */
 {
-    ExprDesc lval;
+    ExprDesc Expr;
     unsigned Result;
 
-    /* Evaluate the expression */
-    expr (hie0, InitExprDesc (&lval));
-
-    /* Check for a boolean expression */
-    CheckBoolExpr (&lval);
+    /* Read a boolean expression */
+    BoolExpr (hie0, &Expr);
 
     /* Check for a constant expression */
-    if (ED_IsRVal (&lval) && lval.Flags == E_MCONST) {
+    if (ED_IsConstAbs (&Expr)) {
 
         /* Result is constant, so we know the outcome */
-        Result = (lval.ConstVal != 0);
+        Result = (Expr.Val != 0);
 
       	/* Constant rvalue */
-       	if (!Invert && lval.ConstVal == 0) {
+       	if (!Invert && Expr.Val == 0) {
       	    g_jump (Label);
      	    Warning ("Unreachable code");
-     	} else if (Invert && lval.ConstVal != 0) {
+     	} else if (Invert && Expr.Val != 0) {
  	    g_jump (Label);
       	}
 
@@ -82,12 +79,12 @@ unsigned Test (unsigned Label, int Invert)
         Result = TESTEXPR_UNKNOWN;
 
         /* If the expr hasn't set condition codes, set the force-test flag */
-        if ((lval.Test & E_CC) == 0) {
-            lval.Test |= E_FORCETEST;
+        if ((Expr.Test & E_CC) == 0) {
+            Expr.Test |= E_FORCETEST;
         }
 
         /* Load the value into the primary register */
-        ExprLoad (CF_FORCECHAR, &lval);
+        ExprLoad (CF_FORCECHAR, &Expr);
 
         /* Generate the jump */
         if (Invert) {
diff --git a/src/cc65/typeconv.c b/src/cc65/typeconv.c
index b3fbedb48..34498259a 100644
--- a/src/cc65/typeconv.c
+++ b/src/cc65/typeconv.c
@@ -118,13 +118,13 @@ static void DoConversion (ExprDesc* Expr, type* NewType)
             g_typecast (TypeOf (NewType), TypeOf (OldType));
 
             /* Value is now in primary and an rvalue */
-            Expr->Flags = E_MEXPR | E_RVAL;
+            ED_MakeRValExpr (Expr);
         }
 
     } else {
 
         /* We have an rvalue. Check for a constant. */
-        if (Expr->Flags == E_MCONST) {
+        if (ED_IsLocAbs (Expr)) {
 
             /* A cast of a constant to an integer. Be sure to handle sign
              * extension correctly.
@@ -141,13 +141,13 @@ static void DoConversion (ExprDesc* Expr, type* NewType)
             if (NewBits <= OldBits) {
 
                 /* Cut the value to the new size */
-                Expr->ConstVal &= (0xFFFFFFFFUL >> (32 - NewBits));
+                Expr->Val &= (0xFFFFFFFFUL >> (32 - NewBits));
 
                 /* If the new type is signed, sign extend the value */
                 if (!IsSignUnsigned (NewType)) {
-                    if (Expr->ConstVal & (0x01UL << (NewBits-1))) {
+                    if (Expr->Val & (0x01UL << (NewBits-1))) {
                         /* Beware: Use the safe shift routine here. */
-                        Expr->ConstVal |= shl_l (~0UL, NewBits);
+                        Expr->Val |= shl_l (~0UL, NewBits);
                     }
                 }
             }
@@ -166,8 +166,8 @@ static void DoConversion (ExprDesc* Expr, type* NewType)
                 /* Emit typecast code. */
                 g_typecast (TypeOf (NewType) | CF_FORCECHAR, TypeOf (OldType));
 
-                /* Value is now a rvalie in the primary */
-                Expr->Flags = E_MEXPR | E_RVAL;
+                /* Value is now a rvalue in the primary */
+                ED_MakeRValExpr (Expr);
             }
         }
     }
@@ -237,7 +237,7 @@ void TypeConversion (ExprDesc* Expr, type* NewType)
 	    }
      	} else if (IsClassInt (Expr->Type)) {
      	    /* Int to pointer assignment is valid only for constant zero */
-     	    if (Expr->Flags != E_MCONST || Expr->ConstVal != 0) {
+     	    if (!ED_IsConstAbsInt (Expr) || Expr->Val != 0) {
      	       	Warning ("Converting integer to pointer without a cast");
      	    }
 	} else if (IsTypeFuncPtr (NewType) && IsTypeFunc(Expr->Type)) {