Clarify some or exclusive expressions

Since relational expresions are always evaluated to 0 or 1, we can use
bitwise xor operator instead of using more complex boolean expressions.
---
 st.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

1 files changed, 7 insertions, 7 deletions

diff --git a/st.c b/st.c
index 67fa790..9864442 100644
--- a/st.c
+++ b/st.c
@@ -1475,15 +1475,15 @@ tsetmode(bool priv, bool set, int *args, int narg) {
                                 break;
                         case 1049: /* = 1047 and 1048 */
                         case 47:
-                        case 1047:
-                                if(IS_SET(MODE_ALTSCREEN))
+                        case 1047: {
+                                bool alt = IS_SET(MODE_ALTSCREEN) != 0;
+                                if(alt)
                                         tclearregion(0, 0, term.col-1, term.row-1);
-                                if((set && !IS_SET(MODE_ALTSCREEN)) ||
-                                                (!set && IS_SET(MODE_ALTSCREEN))) {
+                                if(set ^ alt)           /* set is always 1 or 0 */
                                         tswapscreen();
-                                }
                                 if(*args != 1049)
                                         break;
+                        }
                                 /* pass through */
                         case 1048:
                                 tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
@@ -2546,9 +2546,9 @@ drawregion(int x1, int y1, int x2, int y2) {
         int ic, ib, x, y, ox, sl;
         Glyph base, new;
         char buf[DRAW_BUF_SIZ];
-        bool ena_sel = sel.bx != -1, alt = IS_SET(MODE_ALTSCREEN);
+        bool ena_sel = sel.bx != -1, alt = IS_SET(MODE_ALTSCREEN) != 0;
 
-        if((sel.alt && !alt) || (!sel.alt && alt))
+        if((sel.alt != 0) ^ alt)
                 ena_sel = 0;
         if(!(xw.state & WIN_VISIBLE))
                 return;