cdef: pull some expressions out of loops

xiph · Apr 24, 2019 · 7fc15a1 · 7fc15a1
1 parent 158446c
commit 7fc15a1
Showing 1 changed file with 11 additions and 8 deletions.
diff --git a/src/cdef.rs b/src/cdef.rs
@@ -151,27 +151,30 @@ unsafe fn cdef_filter_block<T: Pixel>(
       let mut max = x;
       let mut min = x;
       for k in 0..2usize {
-        let p = [*ptr_in.offset(cdef_directions[dir][k]),
-                 *ptr_in.offset(-cdef_directions[dir][k])];
-        sum = p.iter().fold(sum, |sum, &elem| { sum + pri_taps[k] * constrain(i32::cast_from(elem) - i32::cast_from(x), pri_strength, damping) });
+        let cdef_dirs = [cdef_directions[dir][k], cdef_directions[(dir + 2) & 7][k], cdef_directions[(dir + 6) & 7][k]];
+        let pri_tap = pri_taps[k];
+        let p = [*ptr_in.offset(cdef_dirs[0]),
+                 *ptr_in.offset(-cdef_dirs[0])];
         for p_elem in p.iter() {
+          sum += pri_tap * constrain(i32::cast_from(*p_elem) - i32::cast_from(x), pri_strength, damping);
           if *p_elem != CDEF_VERY_LARGE {
             max = cmp::max(*p_elem, max);
           }
           min = cmp::min(*p_elem, min);
         }
 
-        let s = [*ptr_in.offset(cdef_directions[(dir + 2) & 7][k]),
-                 *ptr_in.offset(-cdef_directions[(dir + 2) & 7][k]),
-                 *ptr_in.offset(cdef_directions[(dir + 6) & 7][k]),
-                 *ptr_in.offset(-cdef_directions[(dir + 6) & 7][k])];
+        let s = [*ptr_in.offset(cdef_dirs[1]),
+                 *ptr_in.offset(-cdef_dirs[1]),
+                 *ptr_in.offset(cdef_dirs[2]),
+                 *ptr_in.offset(-cdef_dirs[2])];
+        let sec_tap = sec_taps[k];
         for s_elem in s.iter() {
           if *s_elem != CDEF_VERY_LARGE {
             max = cmp::max(*s_elem, max);
           }
           min = cmp::min(*s_elem, min);
+          sum += sec_tap * constrain(i32::cast_from(*s_elem) - i32::cast_from(x), sec_strength, damping);
         }
-        sum = s.iter().fold(sum, |sum, &elem| { sum + sec_taps[k] * constrain(i32::cast_from(elem) - i32::cast_from(x), sec_strength, damping) });
       }
       let v = T::cast_from(i32::cast_from(x) + ((8 + sum - (sum < 0) as i32) >> 4));
       *ptr_out = clamp(v, T::cast_from(min), T::cast_from(max));