Merge pull request #265 from bcarlet/hanoi

Add Hanoi benchmark

benchmarks/core/hanoi.bril

@@ -0,0 +1,27 @@
+# Tower of Hanoi puzzle.
+#
+# Input:  Number of disks.
+# Output: Each move in order, one on each line, where a move `src dst` indicates
+#         that the top disk from rod `src` should be moved to rod `dst`.
+
+@hanoi (disks: int, src: int, dst: int, spare: int) {
+  zero: int = const 0;
+  pos: bool = gt disks zero;
+  br pos .then .else;
+.then:
+  one: int = const 1;
+  above: int = sub disks one;
+  call @hanoi above src spare dst;
+  print src dst;
+  call @hanoi above spare dst src;
+.else:
+  ret;
+}
+
+# ARGS: 3
+@main (disks: int) {
+  src: int = const 0;
+  dst: int = const 2;
+  spare: int = const 1;
+  call @hanoi disks src dst spare;
+}

benchmarks/core/hanoi.out

@@ -0,0 +1,7 @@
+0 2
+0 1
+2 1
+0 2
+1 0
+1 2
+0 2

benchmarks/core/hanoi.prof

@@ -0,0 +1 @@
+total_dyn_inst: 99

docs/tools/bench.md

@@ -29,6 +29,7 @@ The current benchmarks are:
 * `fizz-buzz`: The infamous [programming test][fizzbuzz].
 * `function_call`: For benchmarking the overhead of simple function calls.
 * `gcd`: Calculate Greatest Common Divisor (GCD) of two input positive integer using [Euclidean algorithm][euclidean_into].
+* `hanoi`: Print the solution to the *n*-disk [Tower of Hanoi][hanoi] puzzle.
 * `loopfact`: Compute *n!* imperatively using a loop.
 * `mandelbrot`: Generates a really low resolution, ascii, [mandelbrot set][mandelbrot].
 * `mat-inv` : Calculates the inverse of a 3x3 matrix and prints it out.
@@ -79,4 +80,5 @@ Credit for several of these benchmarks goes to Alexa VanHattum and Gregory Yaune
 [uparrow]: https://en.wikipedia.org/wiki/Knuth%27s_up-arrow_notation
 [riemann]: https://en.wikipedia.org/wiki/Riemann_sum
 [mandelbrot]: https://en.wikipedia.org/wiki/Mandelbrot_set
+[hanoi]: https://en.wikipedia.org/wiki/Tower_of_Hanoi
 [euler]: https://en.wikipedia.org/wiki/E_(mathematical_constant)