<html>
    <head>
      <base href="https://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 --- - use lvx instead of lxvd2x and xxswapd when address is assumed to be aligned"
   href="https://llvm.org/bugs/show_bug.cgi?id=30730">30730</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>use lvx instead of lxvd2x and xxswapd when address is assumed to be aligned
          </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>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>Backend: PowerPC
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>echristo@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Power9 has a little endian load here that it can use for unaligned addresses,
but for power8 this is still important.

---

#include <altivec.h>

struct S {
  vector int v;
  vector int f() const;
};

vector int S::f() const {
  return v;
}
---

AltiVec code:

        .text
        .abiversion 2
        .file   "aligned_load.cc"
        .globl  _ZNK1S1fEv
        .p2align        4
        .type   _ZNK1S1fEv,@function
_ZNK1S1fEv:                             # @_ZNK1S1fEv
.Lfunc_begin0:
# BB#0:
        lvx 2, 0, 3
        blr
        .long   0
        .quad   0
.Lfunc_end0:
        .size   _ZNK1S1fEv, .Lfunc_end0-.Lfunc_begin0

---
VSX code


        .text
        .abiversion 2
        .file   "aligned_load.cc"
        .globl  _ZNK1S1fEv
        .p2align        4
        .type   _ZNK1S1fEv,@function
_ZNK1S1fEv:                             # @_ZNK1S1fEv
.Lfunc_begin0:
# BB#0:
        lxvd2x 0, 0, 3
        xxswapd  34, 0
                                        # kill: %V2<def> %V2<kill> %VSH2<kill>
        blr
        .long   0
        .quad   0
.Lfunc_end0:
        .size   _ZNK1S1fEv, .Lfunc_end0-.Lfunc_begin0</pre>
        </div>
      </p>
      <hr>
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