Make the threshold a parameter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26093 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index 3cdfd4738158b840b278920d9fc26d56356b7457..850be78f808be7c85b86b2ccc52f115904722c7f 100644 (file)
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -34,8 +34,9 @@
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Support/Debug.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/CommandLine.h"
 #include <algorithm>
 #include <iostream>
 #include <set>
@@ -43,7 +44,10 @@ using namespace llvm;
 
 namespace {
   Statistic<> NumUnswitched("loop-unswitch", "Number of loops unswitched");
-
+  cl::opt<unsigned>
+  Threshold("loop-unswitch-threshold", cl::desc("Max loop size to unswitch"),
+            cl::init(10), cl::Hidden);
+  
   class LoopUnswitch : public FunctionPass {
     LoopInfo *LI;  // Loop information
   public:
@@ -145,7 +149,7 @@ bool LoopUnswitch::visitLoop(Loop *L) {
       continue;
     
     // Check to see if it would be profitable to unswitch this loop.
-    if (L->getBlocks().size() > 10) {
+    if (L->getBlocks().size() > Threshold) {
       // FIXME: this should estimate growth by the amount of code shared by the
       // resultant unswitched loops.  This should have no code growth:
       //    for () { if (iv) {...} }