<html>
<head>
<base href="http://llvm.org/bugs/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [ARM Backend] Folding SP Update should depends on frame-pointer elimination"
href="http://llvm.org/bugs/show_bug.cgi?id=18160">18160</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[ARM Backend] Folding SP Update should depends on frame-pointer elimination
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>zhaoshiz@codeaurora.org
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu, t.p.northover@gmail.com
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=11679" name="attach_11679" title="LLVM-IR test case">attachment 11679</a> <a href="attachment.cgi?id=11679&action=edit" title="LLVM-IR test case">[details]</a></span>
LLVM-IR test case
Currently there're two frontend flags controls fp-elim:
-fomit-frame-pointer
-momit-leaf-frame-pointer
An example:
0: e92d48f0 push {r4, r5, r6, r7, fp, lr}
<span class="quote">> 4: e28db010 add fp, sp, #16
> 8: ed2d8b02 vpush {d8}
> c: e24dd018 sub sp, sp, #24</span >
...
140: e24bd018 sub sp, fp, #24
144: ecbd8b02 vpop {d8}
148: e8bd88f0 pop {r4, r5, r6, r7, fp, pc}
when SP-update-folding is enabled without fp-elim, the above ASM becomes:
0: e92d48f0 push {r4, r5, r6, r7, fp, lr}
<span class="quote">> 4: e28db028 add fp, sp, #40 ; 0x28
> 8: ed2d5b08 vpush {d5-d8}</span >
...
13c: e24bd018 sub sp, fp, #24
140: ecbd8b02 vpop {d8}
144: e8bd88f0 pop {r4, r5, r6, r7, fp, pc}
We can make fp-elim part of Oz or have SP-update-folding check for fp-elim
attributes along with MinSize.
p.s.: Tim, this should be the last one, :)</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>