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| author | Duncan Sands <baldrick@free.fr> | 2009-03-22 11:33:16 +0000 |
|---|---|---|
| committer | Duncan Sands <baldrick@free.fr> | 2009-03-22 11:33:16 +0000 |
| commit | 19527c6ef371c6a09743bf91d4bee36b32241b12 (patch) | |
| tree | d3c1b2396d2767357a601caddd5b897e6ea1ce2e /docs/LangRef.html | |
| parent | ad20d3825ea2ce02e502901679a1305158b6d7b2 (diff) | |
| download | external_llvm-19527c6ef371c6a09743bf91d4bee36b32241b12.zip external_llvm-19527c6ef371c6a09743bf91d4bee36b32241b12.tar.gz external_llvm-19527c6ef371c6a09743bf91d4bee36b32241b12.tar.bz2 | |
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
Diffstat (limited to 'docs/LangRef.html')
| -rw-r--r-- | docs/LangRef.html | 17 |
1 files changed, 15 insertions, 2 deletions
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 @@ alignment may produce less efficient code. An alignment of 1 is always 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 @@ safe. </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> |