[llvm-commits] [llvm] r70510 - in /llvm/trunk: include/llvm/Analysis/ScalarEvolution.h lib/Analysis/ScalarEvolution.cpp

[Dan Gohman]

Author: djg
Date: Thu Apr 30 15:48:53 2009
New Revision: 70510

URL: http://llvm.org/viewvc/llvm-project?rev=70510&view=rev
Log:
Add some comments, and tidy up some whitespace.

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

Modified: llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ScalarEvolution.h?rev=70510&r1=70509&r2=70510&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Analysis/ScalarEvolution.h (original)
+++ llvm/trunk/include/llvm/Analysis/ScalarEvolution.h Thu Apr 30 15:48:53 2009
@@ -449,7 +449,8 @@
     SCEVHandle getSCEVAtScope(Value *V, const Loop *L);
 
     /// isLoopGuardedByCond - Test whether entry to the loop is protected by
-    /// a conditional between LHS and RHS.
+    /// a conditional between LHS and RHS.  This is used to help avoid max
+    /// expressions in loop trip counts.
     bool isLoopGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
                              SCEV *LHS, SCEV *RHS);
 

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=70510&r1=70509&r2=70510&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Thu Apr 30 15:48:53 2009
@@ -2986,8 +2986,9 @@
 ///
 BasicBlock *
 ScalarEvolution::getPredecessorWithUniqueSuccessorForBB(BasicBlock *BB) {
-  // If the block has a unique predecessor, the predecessor must have
-  // no other successors from which BB is reachable.
+  // If the block has a unique predecessor, then there is no path from the
+  // predecessor to the block that does not go through the direct edge
+  // from the predecessor to the block.
   if (BasicBlock *Pred = BB->getSinglePredecessor())
     return Pred;
 
@@ -3002,10 +3003,11 @@
 }
 
 /// isLoopGuardedByCond - Test whether entry to the loop is protected by
-/// a conditional between LHS and RHS.
+/// a conditional between LHS and RHS.  This is used to help avoid max
+/// expressions in loop trip counts.
 bool ScalarEvolution::isLoopGuardedByCond(const Loop *L,
-                                               ICmpInst::Predicate Pred,
-                                               SCEV *LHS, SCEV *RHS) {
+                                          ICmpInst::Predicate Pred,
+                                          SCEV *LHS, SCEV *RHS) {
   BasicBlock *Preheader = L->getLoopPreheader();
   BasicBlock *PreheaderDest = L->getHeader();