From f2ea19ea2e7f426b0d2de973311464b3e0d3ad2b Mon Sep 17 00:00:00 2001
From: Renato Golin <renato.golin@linaro.org>
Date: Sat, 23 Feb 2013 13:25:41 +0000
Subject: Add global structure vectorization to docs

llvm-svn: 175965
---
 llvm/docs/Vectorizers.rst | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'llvm/docs/Vectorizers.rst')

diff --git a/llvm/docs/Vectorizers.rst b/llvm/docs/Vectorizers.rst
index 07486347e37..0894b1eb3f1 100644
--- a/llvm/docs/Vectorizers.rst
+++ b/llvm/docs/Vectorizers.rst
@@ -206,6 +206,25 @@ vectorization is profitable.
       A[i] += 4 * B[i];
   }
 
+Global Structures Alias Analysis
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Access to global structures can also be vectorized, with alias analysis being
+used to make sure accesses don't alias. Run-time checks can also be added on
+pointer access to structure members.
+
+Many variations are supported, but some that rely on undefined behaviour being
+ignored (as other compilers do) are still being left un-vectorized.
+
+.. code-block:: c++
+
+  struct { int A[100], K, B[100]; } Foo;
+
+  int foo() {
+    for (int i = 0; i < 100; ++i)
+      Foo.A[i] = Foo.B[i] + 100;
+  }
+
 Vectorization of function calls
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
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