[llvm] r369962 - Add a clarify comment for meaning of SafePointes [NFC]

[Philip Reames via llvm-commits]

Author: reames
Date: Mon Aug 26 13:48:35 2019
New Revision: 369962

URL: http://llvm.org/viewvc/llvm-project?rev=369962&view=rev
Log:
Add a clarify comment for meaning of SafePointes [NFC]

Extracted from D66688 as requested.


Modified:
    llvm/trunk/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp

Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp?rev=369962&r1=369961&r2=369962&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp Mon Aug 26 13:48:35 2019
@@ -924,7 +924,11 @@ bool LoopVectorizationLegality::canVecto
 
   assert(TheLoop->getNumBlocks() > 1 && "Single block loops are vectorizable");
 
-  // A list of pointers that we can safely read and write to.
+  // A list of pointers which are known to be dereferenceable within scope of
+  // the loop body for each iteration of the loop which executes.  That is,
+  // the memory pointed to can be dereferenced (with the access size implied by
+  // the value's type) unconditionally within the loop header without
+  // introducing a new fault.
   SmallPtrSet<Value *, 8> SafePointes;
 
   // Collect safe addresses.