Where the alloca'd space actually lives in ram is undefined, and attempting to
authorNick Lewycky <nicholas@mxc.ca>
Wed, 29 Feb 2012 08:26:44 +0000 (08:26 +0000)
committerNick Lewycky <nicholas@mxc.ca>
Wed, 29 Feb 2012 08:26:44 +0000 (08:26 +0000)
pin it down is undefined behaviour.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151710 91177308-0d34-0410-b5e6-96231b3b80d8

docs/LangRef.html

index 5d3c7458c2d85d7ad1bafa8bd26d12a7c518afa3..29ac260fd0ed7c506fae62fca36724919f4ca323 100644 (file)
@@ -4859,7 +4859,12 @@ IfUnequal:
    variables that must have an address available.  When the function returns
    (either with the <tt><a href="#i_ret">ret</a></tt>
    or <tt><a href="#i_resume">resume</a></tt> instructions), the memory is
-   reclaimed.  Allocating zero bytes is legal, but the result is undefined.</p>
+   reclaimed.  Allocating zero bytes is legal, but the result is undefined.
+   The order in which memory is allocated (ie., which way the stack grows) is
+   not specified, and relational comparisons involving '<tt>alloca</tt>'s are
+   undefined.</p>
+
+<p>
 
 <h5>Example:</h5>
 <pre>