more bench

wasm/test/fannkuch2.ml

@@ -0,0 +1,93 @@
+(* The Computer Language Benchmarks Game
+   http://shootout.alioth.debian.org/
+
+   contributed by Isaac Gouy, transliterated from Mike Pall's Lua program
+*)
+
+let fannkuch n =
+  let p = Array.make n 0 in
+  let q = Array.make n 0 in
+  let s = Array.make n 0 in
+  let sign = ref 1 in
+  let maxflips = ref 0 in
+  let sum = ref 0 in
+  for i = 0 to n - 1 do
+    p.(i) <- i;
+    q.(i) <- i;
+    s.(i) <- i
+  done;
+  while true do
+    let q0 = ref p.(0) in
+    if !q0 <> 0
+    then (
+      for i = 1 to n - 1 do
+        q.(i) <- p.(i)
+      done;
+      let flips = ref 1 in
+      while
+        let qq = q.(!q0) in
+        if qq = 0
+        then (
+          sum := !sum + (!sign * !flips);
+          if !flips > !maxflips then maxflips := !flips;
+          false)
+        else true
+      do
+        let qq = q.(!q0) in
+        q.(!q0) <- !q0;
+        (if !q0 >= 3
+         then
+           let i = ref 1 in
+           let j = ref (!q0 - 1) in
+           while
+             let t = q.(!i) in
+             q.(!i) <- q.(!j);
+             q.(!j) <- t;
+             incr i;
+             decr j;
+             !i < !j
+           do
+             ()
+           done);
+        q0 := qq;
+        incr flips
+      done);
+    if !sign = 1
+    then (
+      let t = p.(1) in
+      p.(1) <- p.(0);
+      p.(0) <- t;
+      sign := -1)
+    else
+      let t = p.(1) in
+      p.(1) <- p.(2);
+      p.(2) <- t;
+      sign := 1;
+      try
+        for i = 2 to n - 1 do
+          let sx = s.(i) in
+          if sx <> 0
+          then (
+            s.(i) <- sx - 1;
+            raise Exit);
+          if i = n - 1
+          then (
+            if false then Format.eprintf "%d %d@." !sum !maxflips;
+            exit 0);
+          s.(i) <- i;
+          let t = p.(0) in
+          for j = 0 to i do
+            p.(j) <- p.(j + 1)
+          done;
+          p.(i + 1) <- t
+        done
+      with Exit -> ()
+  done
+
+let n = 10
+
+let pf = fannkuch n
+
+(*
+//print(pf[0] + "\n" + "Pfannkuchen(" + n + ") = " + pf[1]);
+*)