From: Søren Sandmann Pedersen <ssp@redhat.com>
Date: Wed, 17 Mar 2010 14:50:42 +0000 (-0400)
Subject: Specialize the fast_composite_scaled_nearest_* scalers to positive x units
X-Git-Tag: pixman-0.17.12~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=265ea1fb4d05a920323f23a02f9dc379312bbdae;p=platform%2Fupstream%2Fpixman.git

Specialize the fast_composite_scaled_nearest_* scalers to positive x units

This avoids a test in the inner loop, which improves performance
especially for tiled sources.

On x86-32, I get these results:

Before:
op=1, src_fmt=20028888, dst_fmt=20028888, speed=306.96 MPix/s (73.18 FPS)
op=1, src_fmt=20028888, dst_fmt=10020565, speed=102.67 MPix/s (24.48 FPS)
op=1, src_fmt=10020565, dst_fmt=10020565, speed=324.85 MPix/s (77.45 FPS)

After:
op=1, src_fmt=20028888, dst_fmt=20028888, speed=332.19 MPix/s (79.20 FPS)
op=1, src_fmt=20028888, dst_fmt=10020565, speed=110.41 MPix/s (26.32 FPS)
op=1, src_fmt=10020565, dst_fmt=10020565, speed=363.28 MPix/s (86.61 FPS)
---

diff --git a/pixman/pixman-fast-path.c b/pixman/pixman-fast-path.c
index 5b8ff5c..bf5b298 100644
--- a/pixman/pixman-fast-path.c
+++ b/pixman/pixman-fast-path.c
@@ -1485,13 +1485,21 @@ fast_composite_scaled_nearest_ ## scale_func_name ## _ ## OP (pixman_implementat
 	    x1 = vx >> 16;									\
 	    vx += unit_x;									\
 	    if (do_repeat)									\
-		repeat (PIXMAN_REPEAT_NORMAL, &vx, max_vx);					\
+	    {											\
+		/* This works because we know that unit_x is positive */			\
+		while (vx >= max_vx)								\
+		    vx -= max_vx;								\
+	    }											\
 	    s1 = src[x1];									\
 												\
 	    x2 = vx >> 16;									\
 	    vx += unit_x;									\
 	    if (do_repeat)									\
-		repeat (PIXMAN_REPEAT_NORMAL, &vx, max_vx);					\
+	    {											\
+		/* This works because we know that unit_x is positive */			\
+		while (vx >= max_vx)								\
+		    vx -= max_vx;								\
+	    }											\
 	    s2 = src[x2];									\
 												\
 	    if (PIXMAN_OP_ ## OP == PIXMAN_OP_OVER)						\
@@ -1537,7 +1545,11 @@ fast_composite_scaled_nearest_ ## scale_func_name ## _ ## OP (pixman_implementat
 	    x1 = vx >> 16;									\
 	    vx += unit_x;									\
 	    if (do_repeat)									\
-		repeat (PIXMAN_REPEAT_NORMAL, &vx, max_vx);					\
+	    {											\
+		/* This works because we know that unit_x is positive */			\
+		while (vx >= max_vx)								\
+		    vx -= max_vx;								\
+	    }											\
 	    s1 = src[x1];									\
 												\
 	    if (PIXMAN_OP_ ## OP == PIXMAN_OP_OVER)						\
@@ -1806,7 +1818,7 @@ static const pixman_fast_path_t c_fast_paths[] =
 #define SIMPLE_NEAREST_FAST_PATH(op,s,d,func)				\
     {   PIXMAN_OP_ ## op,						\
 	PIXMAN_ ## s,							\
-	SCALED_NEAREST_FLAGS | HAS_NORMAL_REPEAT_FLAGS | FAST_PATH_16BIT_SAFE,	\
+	SCALED_NEAREST_FLAGS | HAS_NORMAL_REPEAT_FLAGS | FAST_PATH_16BIT_SAFE | FAST_PATH_X_UNIT_POSITIVE, \
 	PIXMAN_null, 0,							\
 	PIXMAN_ ## d, FAST_PATH_STD_DEST_FLAGS,				\
 	fast_composite_scaled_nearest_ ## func ## _normal ## _ ## op,	\