[Pixman] [PATCH 2/2] Buffer override support for bilinear and x8r8g8b8/r5g6b5/a8 iterators

[Siarhei Siamashka]

By providing the new "offer_buffer" iterator method, redundant
memcpy combiners are now avoided for compositing with SRC
operator in some cases. One good example is src_0565_8888.
Running lowlevel-blt-bench on Intel Core-i7 860 @2.8GHz:

before:    src_0565_8888 =  L1: 931.54  L2: 888.93  M:638.34
after:     src_0565_8888 =  L1:1031.66  L2:1003.42  M:871.54

The simple fast paths, which exist only to convert between a8r8g8b8
and the other formats, can also be dropped in the future.
---
 pixman/pixman-fast-path.c | 14 ++++++++------
 pixman/pixman-mmx.c       |  6 +++---
 pixman/pixman-sse2.c      |  6 +++---
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/pixman/pixman-fast-path.c b/pixman/pixman-fast-path.c
index 2608268..bf32ac3 100644
--- a/pixman/pixman-fast-path.c
+++ b/pixman/pixman-fast-path.c
@@ -2475,6 +2475,7 @@ fast_bilinear_cover_iter_init (pixman_iter_t *iter, const pixman_iter_info_t *it
     info->line1.y = -1;
     info->line1.buffer = &(info->data[width]);
 
+    iter->offer_buffer = _pixman_iter_accept_buffer_offers;
     iter->get_scanline = fast_fetch_bilinear_cover;
     iter->fini = bilinear_cover_iter_fini;
 
@@ -2499,17 +2500,18 @@ fail:
 static const pixman_iter_info_t fast_iters[] = 
 {
     { PIXMAN_r5g6b5, IMAGE_FLAGS, ITER_NARROW | ITER_SRC,
-      _pixman_iter_init_bits_stride, fast_fetch_r5g6b5, NULL },
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers,
+      fast_fetch_r5g6b5, NULL },
+
+    { PIXMAN_r5g6b5, FAST_PATH_STD_DEST_FLAGS,
+      ITER_NARROW | ITER_DEST | ITER_IGNORE_RGB | ITER_IGNORE_ALPHA,
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers,
+      fast_dest_fetch_noop, fast_write_back_r5g6b5 },
 
     { PIXMAN_r5g6b5, FAST_PATH_STD_DEST_FLAGS,
       ITER_NARROW | ITER_DEST,
       _pixman_iter_init_bits_stride,
       fast_fetch_r5g6b5, fast_write_back_r5g6b5 },
-    
-    { PIXMAN_r5g6b5, FAST_PATH_STD_DEST_FLAGS,
-      ITER_NARROW | ITER_DEST | ITER_IGNORE_RGB | ITER_IGNORE_ALPHA,
-      _pixman_iter_init_bits_stride,
-      fast_dest_fetch_noop, fast_write_back_r5g6b5 },
 
     { PIXMAN_a8r8g8b8,
       (FAST_PATH_STANDARD_FLAGS			|
diff --git a/pixman/pixman-mmx.c b/pixman/pixman-mmx.c
index c94d282..4ccd3ab 100644
--- a/pixman/pixman-mmx.c
+++ b/pixman/pixman-mmx.c
@@ -3929,13 +3929,13 @@ mmx_fetch_a8 (pixman_iter_t *iter, const uint32_t *mask)
 static const pixman_iter_info_t mmx_iters[] = 
 {
     { PIXMAN_x8r8g8b8, IMAGE_FLAGS, ITER_NARROW,
-      _pixman_iter_init_bits_stride, mmx_fetch_x8r8g8b8, NULL
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers, mmx_fetch_x8r8g8b8, NULL
     },
     { PIXMAN_r5g6b5, IMAGE_FLAGS, ITER_NARROW,
-      _pixman_iter_init_bits_stride, mmx_fetch_r5g6b5, NULL
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers, mmx_fetch_r5g6b5, NULL
     },
     { PIXMAN_a8, IMAGE_FLAGS, ITER_NARROW,
-      _pixman_iter_init_bits_stride, mmx_fetch_a8, NULL
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers, mmx_fetch_a8, NULL
     },
     { PIXMAN_null },
 };
diff --git a/pixman/pixman-sse2.c b/pixman/pixman-sse2.c
index dde9235..539096c 100644
--- a/pixman/pixman-sse2.c
+++ b/pixman/pixman-sse2.c
@@ -6347,13 +6347,13 @@ sse2_fetch_a8 (pixman_iter_t *iter, const uint32_t *mask)
 static const pixman_iter_info_t sse2_iters[] = 
 {
     { PIXMAN_x8r8g8b8, IMAGE_FLAGS, ITER_NARROW,
-      _pixman_iter_init_bits_stride, sse2_fetch_x8r8g8b8, NULL
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers, sse2_fetch_x8r8g8b8, NULL
     },
     { PIXMAN_r5g6b5, IMAGE_FLAGS, ITER_NARROW,
-      _pixman_iter_init_bits_stride, sse2_fetch_r5g6b5, NULL
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers, sse2_fetch_r5g6b5, NULL
     },
     { PIXMAN_a8, IMAGE_FLAGS, ITER_NARROW,
-      _pixman_iter_init_bits_stride, sse2_fetch_a8, NULL
+      _pixman_iter_init_bits_stride_and_accept_buffer_offers, sse2_fetch_a8, NULL
     },
     { PIXMAN_null },
 };
-- 
1.8.1.5