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authorDavid Greene <greened@obbligato.org>2010-02-16 20:50:18 +0000
committerDavid Greene <greened@obbligato.org>2010-02-16 20:50:18 +0000
commit8939b0d8a930729cd8d9c06dd4afd08de93260d2 (patch)
treedae31b5f9f2e13fc81011349b9e34ffcd6b722e2 /docs
parent713bc585ef5f60129c950f69392cefa85b9aaac1 (diff)
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Add support for emitting non-temporal stores for DAGs marked
non-temporal. Fix from r96241 for botched encoding of MOVNTDQ. Add documentation for !nontemporal metadata. Add a simpler movnt testcase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96386 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
-rw-r--r--docs/LangRef.html28
1 files changed, 23 insertions, 5 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html
index b337b6a..7620838 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -4074,8 +4074,9 @@ Instruction</a> </div>
<h5>Syntax:</h5>
<pre>
- &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
- &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
+ &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>]
+ &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>]
+ !<index> = !{ i32 1 }
</pre>
<h5>Overview:</h5>
@@ -4088,7 +4089,7 @@ Instruction</a> </div>
marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
number or order of execution of this <tt>load</tt> with other
volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
- instructions. </p>
+ instructions.</p>
<p>The optional constant "align" argument specifies the alignment of the
operation (that is, the alignment of the memory address). A value of 0 or an
@@ -4098,6 +4099,14 @@ Instruction</a> </div>
alignment results in an undefined behavior. Underestimating the alignment may
produce less efficient code. An alignment of 1 is always safe.</p>
+<p>The optional !nontemporal metadata must reference a single metatadata
+ name <index> corresponding to a metadata node with one i32 entry of
+ value 1. The existance of the !nontemporal metatadata on the
+ instruction tells the optimizer and code generator that this load is
+ not expected to be reused in the cache. The code generator may
+ select special instructions to save cache bandwidth, such as the
+ MOVNT intruction on x86.</p>
+
<h5>Semantics:</h5>
<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
@@ -4124,8 +4133,8 @@ Instruction</a> </div>
<h5>Syntax:</h5>
<pre>
- store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
- volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
+ store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
+ volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
</pre>
<h5>Overview:</h5>
@@ -4150,6 +4159,15 @@ Instruction</a> </div>
alignment results in an undefined behavior. Underestimating the alignment may
produce less efficient code. An alignment of 1 is always safe.</p>
+<p>The optional !nontemporal metadata must reference a single metatadata
+ name <index> corresponding to a metadata node with one i32 entry of
+ value 1. The existance of the !nontemporal metatadata on the
+ instruction tells the optimizer and code generator that this load is
+ not expected to be reused in the cache. The code generator may
+ select special instructions to save cache bandwidth, such as the
+ MOVNT intruction on x86.</p>
+
+
<h5>Semantics:</h5>
<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If