<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/54355>54355</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
Performance issue using std::fill() on armv7-a clang 11.0.1
</td>
</tr>
<tr>
<th>Labels</th>
<td>
new issue
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
Reneg973
</td>
</tr>
</table>
<pre>
Using `std::fill` on a short array.
It generates the following asm:
`.LBB0_1:`
` add r3, r1, r2`
` add r2, r2, #2`
` cmp r2, #2048`
` strh r0, [r3]`
` bne .LBB0_1`
but could be optimized to be something like that:
`.LBB0_3: `
` strh r0, [r1], #2`
` cmp r1, r2`
` blo .LBB0_3`
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJx9k01v3CAQhn-NfRnF4sNe2wcfso0qVeqhqtRzhc3YpsVmBThR-us7ptlt2t0EIWDgYXh5Bb3Tz923YNYJsgMLUWfynuporKUY3AoKwux8BOW9ei4AMvaQsftPESZc0auIAeKMMDpr3dOeR4VlT5IwylF8Ph7Zd75PHdhlFl6K0jr1XmbiA3ieWvEuKV4YajMhb7LDcnrF7hQrm1tgiH5OIEtgdSQd1cMtsl8x9efrnJF-izC4zWroEdwpmsX8Qg3R7XFwC8Z5N8Wan0g-qXhtjaQp-K9cK7hWynelb5tw8eAdT3vrXl1KXpBcd1K3slV5NNFi9wX96Pyi1gHBhLAhbOnJ_PteRJOJNj0ZvzzWdwoGqwjivGAFzzdvuznGU9h3iI9UJxPnrS8Gt1Bg7eO5uzt59wOHSGE6LNCgKmVV5XPHh5KJRvJ2rLmsGG9lMzSsaWrdNGOJh9yqHm3oyKBMiBWf_uilMbmVm04wIZjkgh_YgcuiLtWgKVnLdD0ik1nJcFHGFruOwvkp912S1G9ToEVrQgx_F1UIZloR03GUX22R_kr3lX7G1NYyT2d3Sftvt1PsPw">