From bf09388604224bdebd63db622829015578fddd85 Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Fri, 21 Feb 2020 16:33:00 -0500
Subject: [PATCH] Attempt to benchmark gcd algorithm

---
 benches/stock_functions.rs | 42 ++++++++++++++++++++++++++++++--------
 src/num.rs                 | 15 ++++++++++++++
 2 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/benches/stock_functions.rs b/benches/stock_functions.rs
index 2255c29..f920b18 100644
--- a/benches/stock_functions.rs
+++ b/benches/stock_functions.rs
@@ -1,4 +1,5 @@
 use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
+use rusty_numbers::num::Unsigned;
 use rusty_numbers::{factorial, fibonacci, it_factorial, mem_fibonacci, rec_fibonacci};
 
 fn bench_factorial(c: &mut Criterion) {
@@ -6,10 +7,10 @@ fn bench_factorial(c: &mut Criterion) {
 
     for i in [0usize, 5, 10, 15, 20, 25, 30, 34].iter() {
         group.bench_with_input(BenchmarkId::new("Recursive naive", i), i, |b, i| {
-            b.iter(|| factorial(*i))
+            b.iter(|| factorial(black_box(*i)))
         });
         group.bench_with_input(BenchmarkId::new("Iterative", i), i, |b, i| {
-            b.iter(|| it_factorial(*i))
+            b.iter(|| it_factorial(black_box(*i)))
         });
     }
     group.finish();
@@ -18,26 +19,49 @@ fn bench_factorial(c: &mut Criterion) {
 fn bench_fibonacci(c: &mut Criterion) {
     let mut group = c.benchmark_group("Fibonacci");
 
-    for i in [0usize, 5, 10, 15, 20, 30].iter() {
+    for i in [0usize, 10, 20, 30, 40, 50, 70, 93, 140, 186].iter() {
         group.bench_with_input(BenchmarkId::new("Recursive memoized", i), i, |b, i| {
-            b.iter(|| mem_fibonacci(*i))
+            b.iter(|| mem_fibonacci(black_box(*i)))
         });
-        // group.bench_with_input(BenchmarkId::new("Recursive naive", i), i, |b, i| b.iter(|| rec_fibonacci(*i)));
         group.bench_with_input(BenchmarkId::new("Iterative", i), i, |b, i| {
-            b.iter(|| fibonacci(*i))
+            b.iter(|| fibonacci(black_box(*i)))
         });
     }
 
     group.finish();
 
     let mut group = c.benchmark_group("Recursive Fibonacci");
-    for i in [0usize, 5, 10, 15, 20, 25, 26, 27, 28, 29, 30].iter() {
+    for i in [0usize, 10, 20, 25, 26, 27, 28, 29, 30].iter() {
         group.bench_with_input(BenchmarkId::new("Naive Recursive", i), i, |b, i| {
-            b.iter(|| rec_fibonacci(*i))
+            b.iter(|| rec_fibonacci(black_box(*i)))
         });
     }
     group.finish();
 }
 
-criterion_group!(benches, bench_factorial, bench_fibonacci);
+fn bench_gcd(c: &mut Criterion) {
+    let mut group = c.benchmark_group("GCD");
+
+    let max = fibonacci(186).unwrap();
+    let max_1 = fibonacci(185).unwrap();
+
+    let med = fibonacci(93).unwrap();
+    let med_1 = fibonacci(92).unwrap();
+
+    let small = fibonacci(15).unwrap();
+    let small_1 = fibonacci(14).unwrap();
+
+    for input in [(small_1, small), (med_1, med), (max_1, max)].iter() {
+        let param = format!("{},{}", input.0, input.1);
+        group.bench_with_input(BenchmarkId::new("Binary", &param), input, |b, input| {
+            b.iter(|| u128::gcd(black_box(input.0), black_box(input.1)))
+        });
+        group.bench_with_input(BenchmarkId::new("Euclid", &param), input, |b, input| {
+            b.iter(|| u128::e_gcd(black_box(input.0), black_box(input.1)))
+        });
+    }
+    group.finish();
+}
+
+criterion_group!(benches, bench_factorial, bench_fibonacci, bench_gcd);
 criterion_main!(benches);
diff --git a/src/num.rs b/src/num.rs
index e28d0ed..1b554b8 100644
--- a/src/num.rs
+++ b/src/num.rs
@@ -108,6 +108,9 @@ pub trait Unsigned:
     /// Find the greatest common denominator of two numbers
     fn gcd(a: Self, b: Self) -> Self;
 
+    /// Euclid gcd algorithm
+    fn e_gcd(a: Self, b: Self) -> Self;
+
     /// Find the least common multiple of two numbers
     fn lcm(a: Self, b: Self) -> Self;
 }
@@ -205,6 +208,17 @@ macro_rules! impl_unsigned {
                     Self::gcd((b - a) >> 1, a)
                 }
 
+                fn e_gcd(x: $Type, y: $Type) -> $Type {
+                    let mut x = x;
+                    let mut y = y;
+                    while y != 0 {
+                        let t = y;
+                        y = x % y;
+                        x = t;
+                    }
+                    x
+                }
+
                 fn lcm(a: $Type, b: $Type) -> $Type {
                     if (a == 0 && b == 0) {
                         return 0;
@@ -254,6 +268,7 @@ mod tests {
         assert_eq!(u8::gcd(2, 2), 2);
         assert_eq!(u8::gcd(2, 8), 2);
         assert_eq!(u16::gcd(36, 48), 12);
+        assert_eq!(u16::e_gcd(36, 48), 12);
     }
 
     #[test]