[llvm-commits] [llvm] r86159 - in /llvm/trunk: include/llvm/Analysis/LoopInfo.h lib/Analysis/LoopInfo.cpp

[Dan Gohman]

Author: djg
Date: Thu Nov  5 13:21:41 2009
New Revision: 86159

URL: http://llvm.org/viewvc/llvm-project?rev=86159&view=rev
Log:
Factor out the predicate code for loopsimplify form exit blocks into
a separate helper function.

Modified:
    llvm/trunk/include/llvm/Analysis/LoopInfo.h
    llvm/trunk/lib/Analysis/LoopInfo.cpp

Modified: llvm/trunk/include/llvm/Analysis/LoopInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LoopInfo.h?rev=86159&r1=86158&r2=86159&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Analysis/LoopInfo.h (original)
+++ llvm/trunk/include/llvm/Analysis/LoopInfo.h Thu Nov  5 13:21:41 2009
@@ -572,6 +572,10 @@
   /// normal form.
   bool isLoopSimplifyForm() const;
 
+  /// hasDedicatedExits - Return true if no exit block for the loop
+  /// has a predecessor that is outside the loop.
+  bool hasDedicatedExits() const;
+
   /// getUniqueExitBlocks - Return all unique successor blocks of this loop. 
   /// These are the blocks _outside of the current loop_ which are branched to.
   /// This assumes that loop is in canonical form.

Modified: llvm/trunk/lib/Analysis/LoopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LoopInfo.cpp?rev=86159&r1=86158&r2=86159&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/LoopInfo.cpp (original)
+++ llvm/trunk/lib/Analysis/LoopInfo.cpp Thu Nov  5 13:21:41 2009
@@ -286,12 +286,14 @@
 /// the LoopSimplify form transforms loops to, which is sometimes called
 /// normal form.
 bool Loop::isLoopSimplifyForm() const {
-  // Normal-form loops have a preheader.
-  if (!getLoopPreheader())
-    return false;
-  // Normal-form loops have a single backedge.
-  if (!getLoopLatch())
-    return false;
+  // Normal-form loops have a preheader, a single backedge, and all of their
+  // exits have all their predecessors inside the loop.
+  return getLoopPreheader() && getLoopLatch() && hasDedicatedExits();
+}
+
+/// hasDedicatedExits - Return true if no exit block for the loop
+/// has a predecessor that is outside the loop.
+bool Loop::hasDedicatedExits() const {
   // Sort the blocks vector so that we can use binary search to do quick
   // lookups.
   SmallPtrSet<BasicBlock *, 16> LoopBBs(block_begin(), block_end());