Rewrite horizontal loopfilter

Loop inside SIMD (instead of in the caller) so that we can handle
multiple 4px blocks per iteration, allowing for more efficient
SIMD. To make this easier, also transpose the masks for the hor
filter.

1 files changed, 30 insertions, 40 deletions

diff --git a/src/lf_mask.c b/src/lf_mask.c
index 40fcb91..b6f7746 100644
--- a/src/lf_mask.c
+++ b/src/lf_mask.c
@@ -98,30 +98,24 @@ static inline void mask_edges_inter(uint32_t (*masks)[32][3],
                       max_tx, 0, y_off, x_off, tx_masks);
 
     // left block edge
-    unsigned mask = 1U << bx4;
-    for (y = 0; y < h4; y++)
-        masks[0][by4 + y][imin(txa[0][0][y][0], l[y])] |= mask;
+    unsigned mask = 1U << by4;
+    for (y = 0; y < h4; y++, mask <<= 1)
+        masks[0][bx4][imin(txa[0][0][y][0], l[y])] |= mask;
 
     // top block edge
-    for (x = 0; x < w4; x++, mask <<= 1)
+    for (mask = 1U << bx4, x = 0; x < w4; x++, mask <<= 1)
         masks[1][by4][imin(txa[1][0][0][x], a[x])] |= mask;
 
     if (!skip) {
         // inner (tx) left|right edges
-        for (y = 0; y < h4; y++) {
+        for (y = 0, mask = 1U << by4; y < h4; y++, mask <<= 1) {
             int ltx = txa[0][0][y][0];
             int step = txa[0][1][y][0];
-            if (step < w4) {
-                x = step;
-                mask = 1U << (bx4 + step);
-                do {
-                    const int rtx = txa[0][0][y][x];
-                    masks[0][by4 + y][imin(rtx, ltx)] |= mask;
-                    ltx = rtx;
-                    step = txa[0][1][y][x];
-                    x += step;
-                    mask <<= step;
-                } while (x < w4);
+            for (x = step; x < w4; x += step) {
+                const int rtx = txa[0][0][y][x];
+                masks[0][bx4 + x][imin(rtx, ltx)] |= mask;
+                ltx = rtx;
+                step = txa[0][1][y][x];
             }
         }
 
@@ -157,29 +151,27 @@ static inline void mask_edges_intra(uint32_t (*const masks)[32][3],
     int y, x;
 
     // left block edge
-    unsigned mask = 1U << bx4;
-    for (y = 0; y < h4; y++)
-        masks[0][by4 + y][imin(twl4c, l[y])] |= mask;
+    unsigned mask = 1U << by4;
+    for (y = 0; y < h4; y++, mask <<= 1)
+        masks[0][bx4][imin(twl4c, l[y])] |= mask;
 
     // top block edge
     for (mask = 1U << bx4, x = 0; x < w4; x++, mask <<= 1)
         masks[1][by4][imin(thl4c, a[x])] |= mask;
 
-    static const uint32_t hstep[] = {
-        0xffffffff, 0x55555555, 0x11111111, 0x01010101, 0x00010001
-    };
-
     // inner (tx) left|right edges
-    const unsigned t = 1U << bx4;
-    const unsigned inner = (((uint64_t) t) << w4) - t;
-    mask = (inner - t) & hstep[twl4];
-    for (y = 0; y < h4; y++)
-        masks[0][by4 + y][twl4c] |= mask;
+    const int hstep = t_dim->w;
+    unsigned t = 1U << by4;
+    unsigned inner = (((uint64_t) t) << h4) - t;
+    for (x = hstep; x < w4; x += hstep)
+        masks[0][bx4 + x][twl4c] |= inner;
 
     //            top
     // inner (tx) --- edges
     //           bottom
     const int vstep = t_dim->h;
+    t = 1U << bx4;
+    inner = (((uint64_t) t) << w4) - t;
     for (y = vstep; y < h4; y += vstep)
         masks[1][by4 + y][thl4c] |= inner;
 
@@ -200,30 +192,28 @@ static inline void mask_edges_chroma(uint32_t (*const masks)[32][2],
     int y, x;
 
     // left block edge
-    unsigned mask = 1U << cbx4;
-    for (y = 0; y < ch4; y++)
-        masks[0][cby4 + y][imin(twl4c, l[y])] |= mask;
+    unsigned mask = 1U << cby4;
+    for (y = 0; y < ch4; y++, mask <<= 1)
+        masks[0][cbx4][imin(twl4c, l[y])] |= mask;
 
     // top block edge
     for (mask = 1U << cbx4, x = 0; x < cw4; x++, mask <<= 1)
         masks[1][cby4][imin(thl4c, a[x])] |= mask;
 
     if (!skip_inter) {
-        static const uint32_t hstep[] = {
-            0xffffffff, 0x55555555, 0x11111111, 0x01010101
-        };
-
         // inner (tx) left|right edges
-        const int t = 1U << cbx4;
-        const unsigned inner = (((uint64_t) t) << cw4) - t;
-        mask = (inner - t) & hstep[twl4];
-        for (y = 0; y < ch4; y++)
-            masks[0][cby4 + y][twl4c] |= mask;
+        const int hstep = t_dim->w;
+        int t = 1U << cby4;
+        unsigned inner = (((uint64_t) t) << ch4) - t;
+        for (x = hstep; x < cw4; x += hstep)
+            masks[0][cbx4 + x][twl4c] |= inner;
 
         //            top
         // inner (tx) --- edges
         //           bottom
         const int vstep = t_dim->h;
+        t = 1U << cbx4;
+        inner = (((uint64_t) t) << cw4) - t;
         for (y = vstep; y < ch4; y += vstep)
             masks[1][cby4 + y][thl4c] |= inner;
     }