Add some explanations of how apint loads and stores
work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67471 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LangRef.html b/docs/LangRef.html
index 94f3c3d..cac8fc7 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -3486,7 +3486,13 @@
safe.
</p>
<h5>Semantics:</h5>
-<p>The location of memory pointed to is loaded.</p>
+<p>The location of memory pointed to is loaded. If the value being loaded
+is of scalar type then the number of bytes read does not exceed the minimum
+number of bytes needed to hold all bits of the type. For example, loading an
+<tt>i24</tt> reads at most three bytes. When loading a value of a type like
+<tt>i20</tt> 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.</p>
<h5>Examples:</h5>
<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
<a
@@ -3525,7 +3531,14 @@
</p>
<h5>Semantics:</h5>
<p>The contents of memory are updated to contain '<tt><value></tt>'
-at the location specified by the '<tt><pointer></tt>' operand.</p>
+at the location specified by the '<tt><pointer></tt>' operand.
+If '<tt><value></tt>' is of scalar type then the number of bytes
+written does not exceed the minimum number of bytes needed to hold all
+bits of the type. For example, storing an <tt>i24</tt> writes at most
+three bytes. When writing a value of a type like <tt>i20</tt> 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.</p>
<h5>Example:</h5>
<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
store i32 3, i32* %ptr <i>; yields {void}</i>