Introduce inxy macro, which increments as a 16-bit value

This pattern is one byte shorter than CLC / ADC #1, and is used
in a handful of places already. Introduce a macro so it's clearer
what is going on.

No functional changes.

inc/macros.inc

@@ -254,6 +254,15 @@ end:
         sty     arg+1
 .endmacro
 
+;;; Increment X,Y as a 16-bit number (x lo, y hi)
+.macro inxy
+        .local skip
+        inx
+        bne     skip
+        iny
+skip:
+.endmacro
+
 ;;; Core for add16/sub16
 .macro _addsub16 op, opc, arg1, arg2, arg3, arg4, arg5, arg6
     .if _is_register {arg2} && _is_register {arg4} && _is_register {arg6}

lib/alert_dialog.s

@@ -342,13 +342,9 @@ done_buttons:
 .ifdef AD_WRAP
 .scope
         ;; Measure for splitting
-        ldx     alert_params::text
-        ldy     alert_params::text + 1
-        inx
-        bne     :+
-        iny
-:       stx     textwidth_params::data
-        sty     textwidth_params::data + 1
+        ldxy    alert_params::text
+        inxy
+        stxy    textwidth_params::data
 
         ptr := $06
         copy16  alert_params::text, ptr

toolkits/icontk.s

@@ -2111,15 +2111,10 @@ start:  lda     more_drawing_needed_flag
 
         ;; cr_l = cr_r + 1
         ;; vx   = cr_r + 1
-        ldx     cr_r
-        ldy     cr_r+1
-        inx
-        stx     cr_l
-        stx     vx
-        bne     :+
-        iny
-:       sty     cr_l+1
-        sty     vx+1
+        ldxy    cr_r
+        inxy
+        stxy    cr_l
+        stxy    vx
 
         ;; cr_t = clip_bounds::y1
         ;; cr_r = clip_bounds::x2
@@ -2277,20 +2272,15 @@ vert:   scmp16  cr_t, win_t
 
         ;; Cases 1/4 (and done)
         ;; if (win_b < cr_b)
-        ;; . cr_t = win_b + 2
-        ;; . vy   = win_b + 2
+        ;; . cr_t = win_b + 1
+        ;; . vy   = win_b + 1
 :       scmp16  win_b, cr_b
         bpl     case2
 
-        ldx     win_b
-        ldy     win_b+1
-        inx
-        stx     cr_t
-        stx     vy
-        bne     :+
-        iny
-:       sty     cr_t+1
-        sty     vy+1
+        ldxy    win_b
+        inxy
+        stxy    cr_t
+        stxy    vy
         jmp     reclip
 
         ;; Case 2
@@ -2302,27 +2292,18 @@ case2:
         scmp16  stash_r, win_r
         bmi     :+
 
-        lda     win_r
-        clc
-        adc     #1
-        sta     cr_l
-        sta     vx
-        lda     win_r+1
-        adc     #0
-        sta     cr_l+1
-        sta     vx+1
+        ldxy    win_r
+        inxy
+        stxy    cr_l
+        stxy    vx
         add16   stash_r, #2, cr_r
         jmp     reclip
 
         ;; Case 5 - done!
 :       copy16  clip_bounds::x2, cr_r
-        ldx     clip_bounds::x2
-        ldy     clip_bounds::x2 + 1
-        inx
-        bne     :+
-        iny
-:       stx     cr_l
-        sty     cr_l + 1
+        ldxy    clip_bounds::x2
+        inxy
+        stxy    cr_l
         jmp     set_bits
 .endproc ; CalcWindowIntersections