Substantial cleanups:

[oota-llvm.git] / tools / bugpoint / ListReducer.h

diff --git a/tools/bugpoint/ListReducer.h b/tools/bugpoint/ListReducer.h
index 1751c77b1853d4d1d21765de7a7ffa586f42edb5..cc8ab20c1953bc9c1b7b5bfc116828eda7e20dd8 100644 (file)
--- a/tools/bugpoint/ListReducer.h
+++ b/tools/bugpoint/ListReducer.h
@@ -23,25 +23,42 @@ struct ListReducer {
   // if the Kept list still satisfies the property, but if it is going to check
   // the prefix anyway, it can.
   //
-  virtual TestResult doTest(const std::vector<ElTy> &Prefix,
-                            const std::vector<ElTy> &Kept) = 0;
+  virtual TestResult doTest(std::vector<ElTy> &Prefix,
+                            std::vector<ElTy> &Kept) = 0;
 
   // reduceList - This function attempts to reduce the length of the specified
   // list while still maintaining the "test" property.  This is the core of the
   // "work" that bugpoint does.
   //
-  void reduceList(std::vector<ElTy> &TheList) {
+  bool reduceList(std::vector<ElTy> &TheList) {
+    std::vector<ElTy> empty;
+    switch (doTest(TheList, empty)) {
+    case KeepPrefix:
+      if (TheList.size() == 1) // we are done, it's the base case and it fails
+        return true;
+      else 
+        break; // there's definitely an error, but we need to narrow it down
+
+    case KeepSuffix:
+      // cannot be reached!
+      std::cerr << "bugpoint ListReducer internal error: selected empty set.\n";
+      abort();
+
+    case NoFailure:
+      return false; // there is no failure with the full set of passes/funcs!
+    }
+
     unsigned MidTop = TheList.size();
     while (MidTop > 1) {
       unsigned Mid = MidTop / 2;
-      std::vector<ElTy> Prefix(TheList.begin()+Mid, TheList.end());
-      std::vector<ElTy> Kept  (TheList.begin(), TheList.begin()+Mid);
+      std::vector<ElTy> Prefix(TheList.begin(), TheList.begin()+Mid);
+      std::vector<ElTy> Suffix(TheList.begin()+Mid, TheList.end());
 
-      switch (doTest(Prefix, Kept)) {
+      switch (doTest(Prefix, Suffix)) {
       case KeepSuffix:
         // The property still holds.  We can just drop the prefix elements, and
         // shorten the list to the "kept" elements.
-        TheList.swap(Kept);
+        TheList.swap(Suffix);
         MidTop = TheList.size();
         break;
       case KeepPrefix:
@@ -51,7 +68,7 @@ struct ListReducer {
         break;
       case NoFailure:
         // Otherwise the property doesn't hold.  Some of the elements we removed
-        // must be neccesary to maintain the property.
+        // must be necessary to maintain the property.
         MidTop = Mid;
         break;
       }
@@ -80,6 +97,8 @@ struct ListReducer {
         }
       }
     }
+
+    return true; // there are some failure and we've narrowed them down
   }
 };