New upstream version 1.22.1+dfsg1

[rustc.git] / src / libcore / benches / iter.rs

diff --git a/src/libcore/benches/iter.rs b/src/libcore/benches/iter.rs
index 5b06229c21f23367f0682273c1926884659afe12..1f16f5b1df3f309a62b1864708fec8ccba968746 100644 (file)
--- a/src/libcore/benches/iter.rs
+++ b/src/libcore/benches/iter.rs
@@ -146,3 +146,132 @@ fn bench_for_each_chain_ref_fold(b: &mut Bencher) {
         acc
     });
 }
+
+
+/// Helper to benchmark `sum` for iterators taken by value which
+/// can optimize `fold`, and by reference which cannot.
+macro_rules! bench_sums {
+    ($bench_sum:ident, $bench_ref_sum:ident, $iter:expr) => {
+        #[bench]
+        fn $bench_sum(b: &mut Bencher) {
+            b.iter(|| -> i64 {
+                $iter.map(black_box).sum()
+            });
+        }
+
+        #[bench]
+        fn $bench_ref_sum(b: &mut Bencher) {
+            b.iter(|| -> i64 {
+                $iter.map(black_box).by_ref().sum()
+            });
+        }
+    }
+}
+
+bench_sums! {
+    bench_flat_map_sum,
+    bench_flat_map_ref_sum,
+    (0i64..1000).flat_map(|x| x..x+1000)
+}
+
+bench_sums! {
+    bench_flat_map_chain_sum,
+    bench_flat_map_chain_ref_sum,
+    (0i64..1000000).flat_map(|x| once(x).chain(once(x)))
+}
+
+bench_sums! {
+    bench_enumerate_sum,
+    bench_enumerate_ref_sum,
+    (0i64..1000000).enumerate().map(|(i, x)| x * i as i64)
+}
+
+bench_sums! {
+    bench_enumerate_chain_sum,
+    bench_enumerate_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).enumerate().map(|(i, x)| x * i as i64)
+}
+
+bench_sums! {
+    bench_filter_sum,
+    bench_filter_ref_sum,
+    (0i64..1000000).filter(|x| x % 2 == 0)
+}
+
+bench_sums! {
+    bench_filter_chain_sum,
+    bench_filter_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).filter(|x| x % 2 == 0)
+}
+
+bench_sums! {
+    bench_filter_map_sum,
+    bench_filter_map_ref_sum,
+    (0i64..1000000).filter_map(|x| x.checked_mul(x))
+}
+
+bench_sums! {
+    bench_filter_map_chain_sum,
+    bench_filter_map_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).filter_map(|x| x.checked_mul(x))
+}
+
+bench_sums! {
+    bench_fuse_sum,
+    bench_fuse_ref_sum,
+    (0i64..1000000).fuse()
+}
+
+bench_sums! {
+    bench_fuse_chain_sum,
+    bench_fuse_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).fuse()
+}
+
+bench_sums! {
+    bench_inspect_sum,
+    bench_inspect_ref_sum,
+    (0i64..1000000).inspect(|_| {})
+}
+
+bench_sums! {
+    bench_inspect_chain_sum,
+    bench_inspect_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).inspect(|_| {})
+}
+
+bench_sums! {
+    bench_peekable_sum,
+    bench_peekable_ref_sum,
+    (0i64..1000000).peekable()
+}
+
+bench_sums! {
+    bench_peekable_chain_sum,
+    bench_peekable_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).peekable()
+}
+
+bench_sums! {
+    bench_skip_sum,
+    bench_skip_ref_sum,
+    (0i64..1000000).skip(1000)
+}
+
+bench_sums! {
+    bench_skip_chain_sum,
+    bench_skip_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).skip(1000)
+}
+
+bench_sums! {
+    bench_skip_while_sum,
+    bench_skip_while_ref_sum,
+    (0i64..1000000).skip_while(|&x| x < 1000)
+}
+
+bench_sums! {
+    bench_skip_while_chain_sum,
+    bench_skip_while_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).skip_while(|&x| x < 1000)
+}