Various comment and whitespace cleanups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79533 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 459a188..2dab8dd 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -208,7 +208,7 @@
          "Computed GetElementPtr has unexpected type!");
 
   // If we ended up indexing a member with a type that doesn't match
-  // type type of what the original indices indexed, add a cast.
+  // the type of what the original indices indexed, add a cast.
   if (Ty != cast<PointerType>(ResultTy)->getElementType())
     C = ConstantExpr::getBitCast(C, ResultTy);
 
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index efd2450..5c223a3 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1682,7 +1682,7 @@
 
   if (const SCEVConstant *RHSC = dyn_cast<SCEVConstant>(RHS)) {
     if (RHSC->getValue()->equalsInt(1))
-      return LHS;                            // X udiv 1 --> x
+      return LHS;                               // X udiv 1 --> x
     if (RHSC->isZero())
       return getIntegerSCEV(0, LHS->getType()); // value is undefined
 
@@ -3533,8 +3533,8 @@
     if (!isa<SCEVCouldNotCompute>(TC)) return TC;
     break;
   }
-  case ICmpInst::ICMP_EQ: {
-    // Convert to: while (X-Y == 0)           // while (X == Y)
+  case ICmpInst::ICMP_EQ: {                     // while (X == Y)
+    // Convert to: while (X-Y == 0)
     const SCEV *TC = HowFarToNonZero(getMinusSCEV(LHS, RHS), L);
     if (!isa<SCEVCouldNotCompute>(TC)) return TC;
     break;
@@ -3986,7 +3986,7 @@
                                               getContext());
         else
           C = ConstantFoldInstOperands(I->getOpcode(), I->getType(),
-                                       &Operands[0], Operands.size(), 
+                                       &Operands[0], Operands.size(),
                                        getContext());
         Pair.first->second = C;
         return getSCEV(C);
@@ -4235,7 +4235,7 @@
 
       // First, handle unitary steps.
       if (StepC->getValue()->equalsInt(1))      // 1*N = -Start (mod 2^BW), so:
-        return getNegativeSCEV(Start);       //   N = -Start (as unsigned)
+        return getNegativeSCEV(Start);          //   N = -Start (as unsigned)
       if (StepC->getValue()->isAllOnesValue())  // -1*N = -Start (mod 2^BW), so:
         return Start;                           //    N = Start (as unsigned)
 
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index 999fd55..3472470 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -53,10 +53,9 @@
         return CE->getOperand(0);
   }
 
-  // FIXME: keep track of the cast instruction.
   if (Constant *C = dyn_cast<Constant>(V))
     return ConstantExpr::getCast(Op, C, Ty);
-  
+
   if (Argument *A = dyn_cast<Argument>(V)) {
     // Check to see if there is already a cast!
     for (Value::use_iterator UI = A->use_begin(), E = A->use_end();
@@ -317,13 +316,17 @@
   }
 }
 
-/// expandAddToGEP - Expand a SCEVAddExpr with a pointer type into a GEP
-/// instead of using ptrtoint+arithmetic+inttoptr. This helps
-/// BasicAliasAnalysis and other passes analyze the result.
+/// expandAddToGEP - Expand an addition expression with a pointer type into
+/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps
+/// BasicAliasAnalysis and other passes analyze the result. See the rules
+/// for getelementptr vs. inttoptr in
+/// http://llvm.org/docs/LangRef.html#pointeraliasing
+/// for details.
 ///
-/// Design note: This depends on ScalarEvolution not recognizing inttoptr
-/// and ptrtoint operators, as they may introduce pointer arithmetic
-/// which may not be safely converted into getelementptr.
+/// Design note: The correctness of using getelmeentptr here depends on
+/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as
+/// they may introduce pointer arithmetic which may not be safely converted
+/// into getelementptr.
 ///
 /// Design note: It might seem desirable for this function to be more
 /// loop-aware. If some of the indices are loop-invariant while others