[PATCH] D86643: [LangRef] Memset/memcpy/memmove can take undef/poison pointer if the size is 0

[Juneyoung Lee via Phabricator via llvm-commits]

aqjune updated this revision to Diff 288067.
aqjune added a comment.

Updated wording about align 1


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86643/new/

https://reviews.llvm.org/D86643

Files:
  llvm/docs/LangRef.rst


Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -1157,10 +1157,11 @@
 ``align <n>`` or ``align(<n>)``
     This indicates that the pointer value may be assumed by the optimizer to
     have the specified alignment.  If the pointer value does not have the
-    specified alignment, behavior is undefined.
+    specified alignment, behavior is undefined. ``align 1`` has no effect on
+    non-byval, non-preallocated arguments.
 
     Note that this attribute has additional semantics when combined with the
-    ``byval`` attribute, which are documented there.
+    ``byval`` or ``preallocated`` attribute, which are documented there.
 
 .. _noalias:
 
@@ -12478,8 +12479,8 @@
 to be aligned to some boundary, this can be specified as an attribute on
 the argument.
 
-If "len" is 0, the pointers may be NULL or dangling. However, they must still
-be appropriately aligned.
+If "len" is 0, the pointers may be NULL, dangling, ``undef``, or ``poison``.
+However, they must still be appropriately aligned.
 
 .. _int_memcpy_inline:
 
@@ -12535,8 +12536,8 @@
 to be aligned to some boundary, this can be specified as an attribute on
 the argument.
 
-If "len" is 0, the pointers may be NULL or dangling. However, they must still
-be appropriately aligned.
+If "len" is 0, the pointers may be NULL, dangling, ``undef``, or ``poison``.
+However, they must still be appropriately aligned.
 
 The generated code is guaranteed not to call any external functions.
 
@@ -12595,8 +12596,8 @@
 aligned to some boundary, this can be specified as an attribute on
 the argument.
 
-If "len" is 0, the pointers may be NULL or dangling. However, they must still
-be appropriately aligned.
+If "len" is 0, the pointers may be NULL, dangling, ``undef``, or ``poison``.
+However, they must still be appropriately aligned.
 
 .. _int_memset:
 
@@ -12650,8 +12651,8 @@
 aligned to some boundary, this can be specified as an attribute on
 the argument.
 
-If "len" is 0, the pointers may be NULL or dangling. However, they must still
-be appropriately aligned.
+If "len" is 0, the pointers may be NULL, dangling, ``undef``, or ``poison``.
+However, they must still be appropriately aligned.
 
 '``llvm.sqrt.*``' Intrinsic
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^


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