Add a coins benchmark from nofib

examples/Makefile

@@ -14,7 +14,8 @@ PROGRAMS= \
 	dedup \
 	nqueens \
 	reverb \
-	seam-carve
+	seam-carve \
+	coins
 
 DBG_PROGRAMS := $(addsuffix .dbg,$(PROGRAMS))
 SYSMPL_PROGRAMS := $(addsuffix .sysmpl,$(PROGRAMS))

examples/src/coins/coins.sml

@@ -0,0 +1,87 @@
+(* https://github.com/ghc/nofib/blob/f481777acf608c132db47cb8badb618ef39a0d6f/parallel/coins/coins.hs *)
+
+structure L = List
+
+datatype AList
+  = ANil
+  | ASing of int
+  | Append of (AList * AList)
+
+fun lenA (ls : AList) : int =
+  case ls of
+    ANil => 0
+  | ASing _ => 1
+  | Append (l, r) => lenA l + lenA r
+
+fun append (ls1 : AList) (ls2 : AList) : AList =
+  case (ls1,ls2) of
+    (ANil, r) => r
+  | (l, ANil) => l
+  | (l, r) => Append (l, r)
+
+type coin = int * int
+
+fun payA_seq (amt : int) (coins : coin L.list) : AList =
+  if amt = 0
+  then ASing 1
+  else
+    case coins of
+      ((c,q) :: coins_rst) =>
+      if c > amt
+      then payA_seq amt coins_rst
+      else
+        let
+          val coins1 = if q = 1 then coins_rst else (c,q-1) :: coins_rst
+          val left = payA_seq (amt - c) coins1
+          val right = payA_seq amt coins_rst
+        in
+          append left right
+        end
+    | [] => ANil
+
+fun payA_par (depth : int) (amt : int) (coins : coin L.list) : AList =
+  if depth = 0
+  then payA_seq amt coins
+  else if amt = 0
+  then ASing 1
+  else
+    case coins of
+      ((c,q) :: coins_rst) =>
+      if c > amt
+      then payA_par depth amt coins_rst
+      else
+        let
+          val (coins1,depth1) = if q = 1
+                                then (coins_rst, depth - 1)
+                                else ((c,q-1) :: coins_rst, depth)
+          val (left, right) = ForkJoin.par
+                                ( fn _ => payA_par depth1 (amt - c) coins1
+                                , fn _ => payA_par (depth-1) amt coins_rst
+                                )
+        in
+          append left right
+        end
+    | [] => ANil
+
+val coins_input : coin list =
+  let
+    val cs = [250, 100, 25, 10, 5, 1]
+    val qs = [55, 88, 88, 99, 122, 177]
+  in
+    ListPair.zip (cs, qs)
+  end
+
+
+val amt = CommandLineArgs.parseInt "N" 777
+
+(* Sequential *)
+val t0 = Time.now ()
+val result_seq = payA_seq amt coins_input
+val t1 = Time.now ()
+val _ = print ("Sequential: " ^ Int.toString (lenA result_seq) ^ ". Finished in: " ^ Time.fmt 4 (Time.- (t1, t0)) ^ "s.\n")
+
+(* Parallel *)
+val t2 = Time.now ()
+val result_par = payA_par 3 amt coins_input
+val t3 = Time.now ()
+val _ = print ("Parallel: " ^ Int.toString (lenA result_par) ^ ". Finished in: " ^ Time.fmt 4 (Time.- (t3, t2)) ^ "s.")

examples/src/coins/sources.mlb

@@ -0,0 +1,2 @@
+../../lib/sources.mlb
+coins.sml