Merge pull request #425 from clbr/arrayaccess

Add fast paths for char postinc/dec

src/cc65/expr.c

@@ -1534,6 +1534,14 @@ static void PostInc (ExprDesc* Expr)
     /* Get the data type */
     Flags = TypeOf (Expr->Type);
 
+    /* Emit smaller code if a char variable is at a constant location */
+    if ((Flags & CF_CHAR) == CF_CHAR && ED_IsLocConst(Expr)) {
+
+        LoadExpr (CF_NONE, Expr);
+        AddCodeLine ("inc %s", ED_GetLabelName(Expr, 0));
+
+    } else {
+
         /* Push the address if needed */
         PushAddr (Expr);
 
@@ -1553,6 +1561,7 @@ static void PostInc (ExprDesc* Expr)
 
         /* Restore the original value in the primary register */
         g_restore (Flags | CF_FORCECHAR);
+    }
 
     /* The result is always an expression, no reference */
     ED_MakeRValExpr (Expr);
@@ -1581,6 +1590,14 @@ static void PostDec (ExprDesc* Expr)
     /* Get the data type */
     Flags = TypeOf (Expr->Type);
 
+    /* Emit smaller code if a char variable is at a constant location */
+    if ((Flags & CF_CHAR) == CF_CHAR && ED_IsLocConst(Expr)) {
+
+        LoadExpr (CF_NONE, Expr);
+        AddCodeLine ("dec %s", ED_GetLabelName(Expr, 0));
+
+    } else {
+
         /* Push the address if needed */
         PushAddr (Expr);
 
@@ -1600,6 +1617,7 @@ static void PostDec (ExprDesc* Expr)
 
         /* Restore the original value in the primary register */
         g_restore (Flags | CF_FORCECHAR);
+    }
 
     /* The result is always an expression, no reference */
     ED_MakeRValExpr (Expr);

test/val/postincdec.c

@@ -0,0 +1,23 @@
+/*
+  !!DESCRIPTION!! char-sized post-increment and -decrement
+  !!ORIGIN!!      cc65 regression tests
+  !!LICENCE!!     Public Domain
+  !!AUTHOR!!      Lauri Kasanen
+*/
+
+
+static unsigned char val, array[2];
+
+int main() {
+
+	val = 0;
+	array[0] = array[1] = 10;
+
+	array[val++] = 2;
+	array[val++] = 2;
+	--val;
+	array[val--] = 0;
+	array[val--] = 0;
+
+	return (array[0] == array[1] && array[0] == 0 && val == 0xff) ? 0 : 1;
+}