Add a runnable example program also

examples/main_example.rs

@@ -0,0 +1,98 @@
+#![feature(bench_black_box)]
+
+use core::hint::black_box;
+use staticstep::*;
+
+// You can run this with "--emit asm" as an easy way of comparing the assembly output from this
+// crate's functions to the assembly output from a traditional loop.
+
+#[inline(never)]
+fn inc_by_exclusive() {
+  let mut j = 0;
+  for i in (0..32768).inc_by::<16>() {
+    j += black_box(i);
+  }
+  println!("{}", j);
+}
+
+#[inline(never)]
+fn inc_by_inclusive() {
+  let mut j = 0;
+  for i in (0..=32768).inc_by::<16>() {
+    j += black_box(i);
+  }
+  println!("{}", j);
+}
+
+#[inline(never)]
+fn dec_by_exclusive() {
+  let mut j = 0;
+  for i in (32768..0).dec_by::<16>() {
+    j += black_box(i);
+  }
+  println!("{}", j);
+}
+
+#[inline(never)]
+fn dec_by_inclusive() {
+  let mut j = 0;
+  for i in (32768..=0).dec_by::<16>() {
+    j += black_box(i);
+  }
+  println!("{}", j);
+}
+
+#[inline(never)]
+fn while_loop_inc_exclusive() {
+  let mut j = 0;
+  let mut i = 0;
+  while i < 32768 {
+    j += black_box(i);
+    i += 16;
+  }
+  println!("{}", j);
+}
+
+#[inline(never)]
+fn while_loop_inc_inclusive() {
+  let mut j = 0;
+  let mut i = 0;
+  while i <= 32768 {
+    j += black_box(i);
+    i += 16;
+  }
+  println!("{}", j);
+}
+
+#[inline(never)]
+fn while_loop_dec_exclusive() {
+  let mut j = 0usize;
+  let mut i = 32768isize;
+  while i > 0 {
+    j += black_box(i as usize);
+    i -= 16;
+  }
+  println!("{}", j);
+}
+
+#[inline(never)]
+fn while_loop_dec_inclusive() {
+  let mut j = 0usize;
+  let mut i = 32768isize;
+  while i >= 0 {
+    j += black_box(i as usize);
+    i -= 16;
+  }
+  println!("{}", j);
+}
+
+fn main() {
+  inc_by_exclusive();
+  inc_by_inclusive();
+  dec_by_exclusive();
+  dec_by_inclusive();
+  while_loop_inc_exclusive();
+  while_loop_inc_inclusive();
+  while_loop_dec_exclusive();
+  while_loop_dec_inclusive();
+}