Added isqrt benchmark with uniform distribution.

Author: ChaiTRex

library/core/benches/num/int_sqrt/mod.rs

@@ -2,7 +2,7 @@ use rand::Rng;
 use test::{black_box, Bencher};
 
 macro_rules! int_sqrt_bench {
-    ($t:ty, $predictable:ident, $random:ident, $random_small:ident) => {
+    ($t:ty, $predictable:ident, $random:ident, $random_small:ident, $random_uniform:ident) => {
         #[bench]
         fn $predictable(bench: &mut Bencher) {
             bench.iter(|| {
@@ -20,10 +20,7 @@ macro_rules! int_sqrt_bench {
             let mut rng = crate::bench_rng();
             /* Exponentially distributed random numbers from the whole range of the type.  */
             let numbers: Vec<$t> = (0..256)
-                .map(|_| {
-                    let x = rng.gen::<$t>() >> rng.gen_range(0..<$t>::BITS);
-                    if x != 0 { x } else { 1 }
-                })
+                .map(|_| rng.gen::<$t>() >> rng.gen_range(0..<$t>::BITS))
                 .collect();
             bench.iter(|| {
                 for x in &numbers {
@@ -37,10 +34,21 @@ macro_rules! int_sqrt_bench {
             let mut rng = crate::bench_rng();
             /* Exponentially distributed random numbers from the range 0..256.  */
             let numbers: Vec<$t> = (0..256)
-                .map(|_| {
-                    let x = (rng.gen::<u8>() >> rng.gen_range(0..u8::BITS)) as $t;
-                    if x != 0 { x } else { 1 }
-                })
+                .map(|_| (rng.gen::<u8>() >> rng.gen_range(0..u8::BITS)) as $t)
+                .collect();
+            bench.iter(|| {
+                for x in &numbers {
+                    black_box(black_box(x).isqrt());
+                }
+            });
+        }
+
+        #[bench]
+        fn $random_uniform(bench: &mut Bencher) {
+            let mut rng = crate::bench_rng();
+            /* Exponentially distributed random numbers from the whole range of the type.  */
+            let numbers: Vec<$t> = (0..256)
+                .map(|_| rng.gen::<$t>())
                 .collect();
             bench.iter(|| {
                 for x in &numbers {
@@ -51,8 +59,8 @@ macro_rules! int_sqrt_bench {
     };
 }
 
-int_sqrt_bench! {u8, u8_sqrt_predictable, u8_sqrt_random, u8_sqrt_random_small}
-int_sqrt_bench! {u16, u16_sqrt_predictable, u16_sqrt_random, u16_sqrt_random_small}
-int_sqrt_bench! {u32, u32_sqrt_predictable, u32_sqrt_random, u32_sqrt_random_small}
-int_sqrt_bench! {u64, u64_sqrt_predictable, u64_sqrt_random, u64_sqrt_random_small}
-int_sqrt_bench! {u128, u128_sqrt_predictable, u128_sqrt_random, u128_sqrt_random_small}
+int_sqrt_bench! {u8, u8_sqrt_predictable, u8_sqrt_random, u8_sqrt_random_small, u8_sqrt_uniform}
+int_sqrt_bench! {u16, u16_sqrt_predictable, u16_sqrt_random, u16_sqrt_random_small, u16_sqrt_uniform}
+int_sqrt_bench! {u32, u32_sqrt_predictable, u32_sqrt_random, u32_sqrt_random_small, u32_sqrt_uniform}
+int_sqrt_bench! {u64, u64_sqrt_predictable, u64_sqrt_random, u64_sqrt_random_small, u64_sqrt_uniform}
+int_sqrt_bench! {u128, u128_sqrt_predictable, u128_sqrt_random, u128_sqrt_random_small, u128_sqrt_uniform}