Extra cfg filtering to keep inline functions as small as possible

Author: tibvdm

sa-index/src/array/mod.rs

@@ -87,6 +87,16 @@ impl SuffixArray {
     /// Issues a non-blocking hardware prefetch hint for the cache line holding SA entry `index`.
     #[inline]
     pub fn prefetch_sa_index(&self, index: usize) {
+        #[cfg(feature = "mmap")]
+        if let SuffixArray::MmapBacked { mmap, data_offset, bits_per_value, .. } = self {
+            let byte_offset = data_offset + (index * bits_per_value) / 8;
+            if byte_offset < mmap.len() {
+                let ptr: *const u8 = &mmap[byte_offset];
+                prefetch::prefetch_read(ptr);
+            }
+        }
+
+        #[cfg(not(feature = "mmap"))]
         match self {
             SuffixArray::Original(sa, _) => {
                 if index < sa.len() {
@@ -104,14 +114,6 @@ impl SuffixArray {
                     prefetch::prefetch_read(ptr);
                 }
             }
-            #[cfg(feature = "mmap")]
-            SuffixArray::MmapBacked { mmap, data_offset, bits_per_value, .. } => {
-                let byte_offset = data_offset + (index * bits_per_value) / 8;
-                if byte_offset < mmap.len() {
-                    let ptr: *const u8 = &mmap[byte_offset];
-                    prefetch::prefetch_read(ptr);
-                }
-            }
         }
     }