[llvm] r186558 - Give 'hasPath' a longer but clearer name 'isPotentiallyReachable'. Also expand

[Nick Lewycky]

Author: nicholas
Date: Wed Jul 17 21:34:51 2013
New Revision: 186558

URL: http://llvm.org/viewvc/llvm-project?rev=186558&view=rev
Log:
Give 'hasPath' a longer but clearer name 'isPotentiallyReachable'. Also expand
the comment. No functionality change. This change broken out of
http://llvm-reviews.chandlerc.com/D996 .

Modified:
    llvm/trunk/lib/Analysis/AliasAnalysis.cpp

Modified: llvm/trunk/lib/Analysis/AliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/AliasAnalysis.cpp?rev=186558&r1=186557&r2=186558&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/AliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/AliasAnalysis.cpp Wed Jul 17 21:34:51 2013
@@ -361,9 +361,11 @@ AliasAnalysis::getModRefInfo(const Atomi
 }
 
 namespace {
-  // Conservatively return true. Return false, if there is a single path
-  // starting from "From" and the path does not reach "To".
-  static bool hasPath(const BasicBlock *From, const BasicBlock *To) {
+  /// Determine whether there is a path from From to To within a single
+  /// function. Returns false only if we can prove that once 'From' has been
+  /// executed then 'To' can not be executed. Conservatively returns true.
+  static bool isPotentiallyReachable(const BasicBlock *From,
+                                     const BasicBlock *To) {
     const unsigned MaxCheck = 5;
     const BasicBlock *Current = From;
     for (unsigned I = 0; I < MaxCheck; I++) {
@@ -400,7 +402,7 @@ namespace {
       // there is no need to explore the use if BeforeHere dominates use.
       // Check whether there is a path from I to BeforeHere.
       if (BeforeHere != I && DT->dominates(BeforeHere, I) &&
-          !hasPath(BB, BeforeHere->getParent()))
+          !isPotentiallyReachable(BB, BeforeHere->getParent()))
         return false;
       return true;
     }
@@ -412,7 +414,7 @@ namespace {
       if (BeforeHere != I && !DT->isReachableFromEntry(BB))
         return false;
       if (BeforeHere != I && DT->dominates(BeforeHere, I) &&
-          !hasPath(BB, BeforeHere->getParent()))
+          !isPotentiallyReachable(BB, BeforeHere->getParent()))
         return false;
       Captured = true;
       return true;