* improved fannkuch benchmark

git-svn-id: trunk@9668 -

tests/bench/shootout/src/fannkuch.pp

@@ -1,3 +1,4 @@
+program fannkuch;
 { The Computer Language Shootout
   http://shootout.alioth.debian.org/
 
@@ -25,21 +26,12 @@ procedure swap(var a, b: longint); inline;
 var  tmp: longint;
 begin  tmp := a;  a := b;  b := tmp   end;
 
-procedure roll_down( var a : array of longint ); inline;
-var  tmp : longint;
-begin
-  tmp := a[ 0 ];
-  move( a[1], a[0], high(a)*sizeof(longint) );
-  a[ high(a) ] := tmp;
-end;
-
-
-procedure reverse( var a: array of longint ); inline;
+procedure reverse( k: longint); inline;
 var
   pi, pj : pLongint;
 begin
-  pi := @a[0];
-  pj := @a[high(a)];
+  pi := @permu_copy[1];
+  pj := @permu_copy[k-1];
   while pi<pj do
   begin
     swap(pi^, pj^);
@@ -51,6 +43,8 @@ end;
 function NextPermutation: boolean;
 var
   r0: longint;
+  tmp: LongInt;
+  i : longint;
 begin
   r0 := r; // use local variable
   NextPermutation := true;
@@ -60,7 +54,11 @@ begin
       NextPermutation := false;
       break;
     end;
-    roll_down( permu[ 0 .. r0 ] );
+    tmp := permu[0];
+    for i := 1 to r0 do
+      permu[i-1] := permu[i];
+    permu[r0] := tmp;
+
     dec(count[r0]);
     if count[r0] > 0 then
       break;
@@ -69,9 +67,26 @@ begin
   r := r0;
 end;
 
+function countflips: integer; inline;
+var
+  last: LongInt;
+  tmp: LongInt;
+begin
+  countflips := 0;
+  last := permu_copy[0];
+  repeat
+    // Reverse part of the array.
+    reverse(last);
+    tmp := permu_copy[ last ];
+    permu_copy[ last ] := last;
+    last := tmp;
+    inc(countflips);
+  until last = 0;
+end;
+
 function fannkuch: longint;
 var
-  print30, m, i, last, tmp, flips: longint;
+  print30, m, i, flips: longint;
 begin
   print30 := 0;
   fannkuch := 0;
@@ -84,8 +99,10 @@ begin
   repeat
     if print30 < 30 then
     begin
-      for i := 0 to m do   write(permu[i] + 1);
-      writeln;   inc(print30);
+      for i := 0 to m do
+        write(permu[i] + 1);
+      writeln;
+      inc(print30);
     end;
     while r <> 1 do
     begin
@@ -95,18 +112,7 @@ begin
     if (permu[0]<>0) and (permu[m]<>m) then
     begin
       move(permu[0], permu_copy[0], sizeof(longint)*n);
-      flips := 0;
-
-      last := permu_copy[0];
-      repeat
-        // Reverse part of the array.
-        reverse( permu_copy[ 1 .. last-1 ] );
-        tmp := permu_copy[ last ];
-        permu_copy[ last ] := last;
-        last := tmp;
-        inc(flips);
-      until last = 0;
-
+      flips := countflips;
       if flips > fannkuch then
         fannkuch := flips;
     end;