<html>
<head>
<base href="https://bugs.llvm.org/">
</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 - Optimize pass struct by value to tail call"
href="https://bugs.llvm.org/show_bug.cgi?id=38862">38862</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Optimize pass struct by value to tail call
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>david.bolvansky@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>struct A {
int x[64];
};
void structByValue(A s);
void callStructByValue(A s) {
structByValue(s);
}
Clang:
callStructByValue(A): # @callStructByValue(A)
sub rsp, 264
lea rsi, [rsp + 272]
mov ecx, 32
mov rdi, rsp
rep movsq
call structByValue(A)
add rsp, 264
ret
GCC:
callStructByValue(A):
jmp structByValue(A)
If I change code to:
struct A {
int *x;
};
Clang tail calls it too.</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>