[PATCH] D74935: [LangRef][AliasAnalysis] Clarify `noalias` affects only modified objects

Johannes Doerfert via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Sat Feb 22 15:11:39 PST 2020


jdoerfert updated this revision to Diff 246088.
jdoerfert added a comment.

Update language to memory locations instead of objects


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D74935/new/

https://reviews.llvm.org/D74935

Files:
  llvm/docs/LangRef.rst


Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -1107,14 +1107,16 @@
 .. _noalias:
 
 ``noalias``
-    This indicates that objects accessed via pointer values
+    This indicates that memory locations accessed via pointer values
     :ref:`based <pointeraliasing>` on the argument or return value are not also
     accessed, during the execution of the function, via pointer values not
-    *based* on the argument or return value. The attribute on a return value
-    also has additional semantics described below. The caller shares the
-    responsibility with the callee for ensuring that these requirements are met.
-    For further details, please see the discussion of the NoAlias response in
-    :ref:`alias analysis <Must, May, or No>`.
+    *based* on the argument or return value. This guarantee only holds for
+    memory locations that are *modified*, by any means, during the execution of
+    the function. The attribute on a return value also has additional semantics
+    described below. The caller shares the responsibility with the callee for
+    ensuring that these requirements are met.  For further details, please see
+    the discussion of the NoAlias response in :ref:`alias analysis <Must, May,
+    or No>`.
 
     Note that this definition of ``noalias`` is intentionally similar
     to the definition of ``restrict`` in C99 for function arguments.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D74935.246088.patch
Type: text/x-patch
Size: 1484 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200222/eac9a6b3/attachment.bin>


More information about the cfe-commits mailing list