Minor optimizations

widemeadows · Jan 19, 2023 · 8978707 · 8978707
1 parent bc10ebc
commit 8978707
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Showing 2 changed files with 5 additions and 7 deletions.
diff --git a/src/context/transform_unit.rs b/src/context/transform_unit.rs
@@ -782,10 +782,10 @@ impl<'a> ContextWriter<'a> {
   ) {
     // Coefficients and levels are transposed from how they work in the spec
     for (coeffs_col, levels_col) in
-      coeffs.chunks(height).zip(levels.chunks_mut(levels_stride))
+      coeffs.chunks_exact(height).zip(levels.chunks_exact_mut(levels_stride))
     {
-      for (coeff, level) in coeffs_col.iter().zip(levels_col.iter_mut()) {
-        *level = clamp(coeff.abs(), T::cast_from(0), T::cast_from(127)).as_();
+      for (coeff, level) in coeffs_col.iter().zip(levels_col) {
+        *level = coeff.abs().min(T::cast_from(127)).as_();
       }
     }
   }

diff --git a/src/dist.rs b/src/dist.rs
@@ -323,10 +323,8 @@ pub(crate) mod rust {
     let mut sum_s2: u32 = 0; // sum(src_{i,j}^2)
     let mut sum_d2: u32 = 0; // sum(dst_{i,j}^2)
     let mut sum_sd: u32 = 0; // sum(src_{i,j} * dst_{i,j})
-    for j in 0..h {
-      let row1 = &src[j][0..w];
-      let row2 = &dst[j][0..w];
-      for (s, d) in row1.iter().zip(row2) {
+    for (row1, row2) in src.rows_iter().take(h).zip(dst.rows_iter()) {
+      for (s, d) in row1[..w].iter().zip(row2) {
         let s: u32 = u32::cast_from(*s);
         let d: u32 = u32::cast_from(*d);
         sum_s += s;