[PATCH] D86189: [LangRef] State that storing an aggregate fills padding with undef

[Juneyoung Lee via Phabricator via llvm-commits]

aqjune updated this revision to Diff 286732.
aqjune added a comment.

Mention that load ignores padding of aggregate.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86189/new/

https://reviews.llvm.org/D86189

Files:
  llvm/docs/LangRef.rst


Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -9238,6 +9238,9 @@
 value of a type like ``i20`` with a size that is not an integral number
 of bytes, the result is undefined if the value was not originally
 written using a store of the same type.
+If the value being loaded is of aggregate type, the bytes that correspond to
+padding is not read, because it is impossible to observe padding from the
+loaded aggregate value.
 
 Examples:
 """""""""
@@ -9327,6 +9330,8 @@
 value of a type like ``i20`` with a size that is not an integral number
 of bytes, it is unspecified what happens to the extra bits that do not
 belong to the type, but they will typically be overwritten.
+If ``<value>`` is of aggregate type, padding is filled with
+:ref:`undef <undefvalues>`.
 
 Example:
 """"""""


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