Move option into separate forceLoopUnrollForFewLoops

src/util/loopUnrolling.ml

@@ -334,22 +334,27 @@ end
 
 let loop_unrolling_factor loopStatement func totalLoops =
   let configFactor = get_int "exp.unrolling-factor" in
-  let unrollFunctionCalled = try
-      let thisVisitor = new loopUnrollingCallVisitor in
-      ignore (visitCilStmt thisVisitor loopStatement);
-      false;
-    with
-      Found -> true
-  in
-  (*unroll up to near an instruction count, higher if the loop uses malloc/lock/threads *)
-  let targetInstructions = if unrollFunctionCalled then 50 else 25 in
-  let loopStats = AutoTune0.collectFactors visitCilStmt loopStatement in
-  let targetFactor = if loopStats.instructions > 0 then targetInstructions / loopStats.instructions else 0 in (* Don't unroll empty (= while(1){}) loops*)
-  let fixedLoop = fixedLoopSize loopStatement func in
   if AutoTune0.isActivated "loopUnrollHeuristic" then
-    match fixedLoop with
-    | Some i -> if i * loopStats.instructions < 100 then (print_endline "fixed loop size"; i) else if totalLoops < 17 then max (100 / loopStats.instructions) 10 else 100 / loopStats.instructions
-    | _ -> if totalLoops < 17 then max 10 targetFactor else targetFactor (*unroll at least 10 times if there are only few loops*)
+    let unrollFunctionCalled = try
+        let thisVisitor = new loopUnrollingCallVisitor in
+        ignore (visitCilStmt thisVisitor loopStatement);
+        false;
+      with
+        Found -> true
+    in
+    (*unroll up to near an instruction count, higher if the loop uses malloc/lock/threads *)
+    let targetInstructions = if unrollFunctionCalled then 50 else 25 in
+    let loopStats = AutoTune0.collectFactors visitCilStmt loopStatement in
+    if loopStats.instructions > 0 then
+      let fixedLoop = fixedLoopSize loopStatement func in
+      (* Unroll at least 10 times if there are only few (17?) loops *)
+      let unroll_min = if totalLoops < 17 && AutoTune0.isActivated "forceLoopUnrollForFewLoops" then 10 else 0 in
+      match fixedLoop with
+      | Some i -> if i * loopStats.instructions < 100 then (print_endline "fixed loop size"; i) else max unroll_min (100 / loopStats.instructions)
+      | _ -> max unroll_min (targetInstructions / loopStats.instructions)
+    else
+      (* Don't unroll empty (= while(1){}) loops*)
+      0
   else
     configFactor
 

src/util/options.schema.json

@@ -515,7 +515,7 @@
             },
             "activated": {
               "title": "ana.autotune.activated",
-              "description": "Lists of activated tuning options. By default all are activated",
+              "description": "Lists of activated tuning options.",
               "type": "array",
               "items": { "type": "string" },
               "default": [