Optimize set_origin() use in some screensavers to stop them eating

cpu power when the origin hasn't changed.

PR:		kern/100683
Submitted by:	Gareth McCaughan <gareth -dot- mccaughan -at- pobox.com>
MFC after:	3 days

4 files changed, 40 insertions, 12 deletions

diff --git a/sys/dev/syscons/fire/fire_saver.c b/sys/dev/syscons/fire/fire_saver.c
index 0bc031c..de60a20 100644
--- a/sys/dev/syscons/fire/fire_saver.c
+++ b/sys/dev/syscons/fire/fire_saver.c
@@ -52,6 +52,12 @@
 #define GREEN(n)	 ((n) * 3 + 1)
 #define BLUE(n)		 ((n) * 3 + 2)
 
+#define SET_ORIGIN(adp, o) do {				\
+	int oo = o;					\
+	if (oo != last_origin)				\
+	    set_origin(adp, last_origin = oo);		\
+	} while (0)
+
 static u_char		*buf;
 static u_char		*vid;
 static int		 banksize, scrmode, bpsl, scrw, scrh;
@@ -63,6 +69,7 @@ fire_update(video_adapter_t *adp)
 {
 	int x, y;
 	int o, p;
+	int last_origin = -1;
 
 	/* make a new bottom line */
 	for (x = 0, y = scrh; x < scrw; x++)
@@ -87,12 +94,12 @@ fire_update(video_adapter_t *adp)
 			p -= banksize;
 			o += banksize;
 		}
-		set_origin(adp, o);
+		SET_ORIGIN(adp, o);
 		if (p + scrw < banksize) {
 			bcopy(buf + y * scrw, vid + p, scrw);
 		} else {
 			bcopy(buf + y * scrw, vid + p, banksize - p);
-			set_origin(adp, o + banksize);
+			SET_ORIGIN(adp, o + banksize);
 			bcopy(buf + y * scrw + (banksize - p), vid,
 			      scrw - (banksize - p));
 			p -= banksize;
diff --git a/sys/dev/syscons/logo/logo_saver.c b/sys/dev/syscons/logo/logo_saver.c
index 0a75886..20f2bdc 100644
--- a/sys/dev/syscons/logo/logo_saver.c
+++ b/sys/dev/syscons/logo/logo_saver.c
@@ -42,6 +42,12 @@
 
 #define SAVER_NAME	 "logo_saver"
 
+#define SET_ORIGIN(adp, o) do {				\
+	int oo = o;					\
+	if (oo != last_origin)				\
+	    set_origin(adp, last_origin = oo);		\
+	} while (0)
+
 extern unsigned int	 logo_w;
 extern unsigned int	 logo_h;
 extern unsigned char	 logo_pal[];
@@ -56,10 +62,11 @@ static void
 logo_blit(video_adapter_t *adp, int x, int y)
 {
 	int d, l, o, p;
+	int last_origin = -1;
 	
 	for (o = 0, p = y * bpsl + x; p > banksize; p -= banksize)
 		o += banksize;
-	set_origin(adp, o);
+	SET_ORIGIN(adp, o);
 	
 	for (d = 0; d < logo_img_size; d += logo_w) {
 		if (p + logo_w < banksize) {
@@ -68,12 +75,12 @@ logo_blit(video_adapter_t *adp, int x, int y)
 		} else if (p < banksize) {
 			l = banksize - p;
 			bcopy(logo_img + d, vid + p, l);
-			set_origin(adp, (o += banksize));
+			SET_ORIGIN(adp, (o += banksize));
 			bcopy(logo_img + d + l, vid, logo_w - l);
 			p += bpsl - banksize;
 		} else {
 			p -= banksize;
-			set_origin(adp, (o += banksize));
+			SET_ORIGIN(adp, (o += banksize));
 			bcopy(logo_img + d, vid + p, logo_w);
 			p += bpsl;
 		}
diff --git a/sys/dev/syscons/rain/rain_saver.c b/sys/dev/syscons/rain/rain_saver.c
index 80e2212..3cdf980 100644
--- a/sys/dev/syscons/rain/rain_saver.c
+++ b/sys/dev/syscons/rain/rain_saver.c
@@ -51,6 +51,12 @@
 #define GREEN(n)	 ((n) * 3 + 1)
 #define BLUE(n)		 ((n) * 3 + 2)
 
+#define SET_ORIGIN(adp, o) do {				\
+	int oo = o;					\
+	if (oo != last_origin)				\
+	    set_origin(adp, last_origin = oo);		\
+	} while (0)
+
 static u_char		*vid;
 static int		 banksize, scrmode, bpsl, scrw, scrh;
 static u_char		 rain_pal[768];
@@ -73,6 +79,7 @@ rain_saver(video_adapter_t *adp, int blank)
 {
 	int i, j, o, p, pl;
 	u_char temp;
+	int last_origin = -1;
 
 	if (blank) {
 		/* switch to graphics mode */
@@ -87,18 +94,18 @@ rain_saver(video_adapter_t *adp, int blank)
 			bpsl = adp->va_line_width;
 			splx(pl);
 			for (i = 0; i < bpsl*scrh; i += banksize) {
-				set_origin(adp, i);
+				SET_ORIGIN(adp, i);
 				if ((bpsl * scrh - i) < banksize)
 					bzero(vid, bpsl * scrh - i);
 				else
 					bzero(vid, banksize);
 			}
-			set_origin(adp, 0);
+			SET_ORIGIN(adp, 0);
 			for (i = 0, o = 0, p = 0; i < scrw; i += 2, p += 2) {
 				if (p > banksize) {
 					p -= banksize;
 					o += banksize;
-					set_origin(adp, o);
+					SET_ORIGIN(adp, o);
 				}
 				vid[p] = 1 + (random() % MAX);
 			}
@@ -109,12 +116,12 @@ rain_saver(video_adapter_t *adp, int blank)
 					p -= banksize;
 					o += banksize;
 				}
-				set_origin(adp, o);
+				SET_ORIGIN(adp, o);
 				temp = (vid[p] < MAX) ? 1 + vid[p] : 1;
 				if (p + bpsl < banksize) {
 					vid[p + bpsl] = temp;
 				} else {
-					set_origin(adp, o + banksize);
+					SET_ORIGIN(adp, o + banksize);
 					vid[p + bpsl - banksize] = temp;
 				}
 			  }
diff --git a/sys/dev/syscons/warp/warp_saver.c b/sys/dev/syscons/warp/warp_saver.c
index 050790d..aba2439 100644
--- a/sys/dev/syscons/warp/warp_saver.c
+++ b/sys/dev/syscons/warp/warp_saver.c
@@ -44,6 +44,12 @@
 #define SPP		 15
 #define STARS		 (SPP * (1 + 2 + 4 + 8))
 
+#define SET_ORIGIN(adp, o) do {				\
+	int oo = o;					\
+	if (oo != last_origin)				\
+	    set_origin(adp, last_origin = oo);		\
+	} while (0)
+
 static u_char		*vid;
 static int		 banksize, scrmode, bpsl, scrw, scrh;
 static int		 blanked;
@@ -61,6 +67,7 @@ static void
 warp_update(video_adapter_t *adp)
 {
 	int i, j, k, n, o, p;
+	int last_origin = -1;
 
 	for (i = 1, k = 0, n = SPP*8; i < 5; i++, n /= 2) {
 		for (j = 0; j < n; j++, k++) {
@@ -70,7 +77,7 @@ warp_update(video_adapter_t *adp)
 				p -= banksize;
 				o += banksize;
 			}
-			set_origin(adp, o);
+			SET_ORIGIN(adp, o);
 			vid[p] = 0;
 			star[k] += i;
 			if (star[k] > scrw*scrh)
@@ -81,7 +88,7 @@ warp_update(video_adapter_t *adp)
 				p -= banksize;
 				o += banksize;
 			}
-			set_origin(adp, o);
+			SET_ORIGIN(adp, o);
 			vid[p] = i;
 		}
 	}