<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=http://email.email.llvm.org/c/eJzNVU2P3CgQ_TXuC7JlPmzg4MOkJ5O0NFGi2dXucUS3yzYZ20wApzP_fgv3x0ZRtFK0OYyEcGHgvecyvNq79qV5gGfv2uUQrZtJiPAcMn6TlbdZeZNVbwYz2hby_WLHtghDEb_FrLrNmBpiPK1kd9h6G4dlXxzchINx_Hp55Ij9GQ4Rh50dIeBTyrpiTGP0M2ycOFGv_a6fnbdzT-IA5MsCYRXpOpLV5f39Xx8ePz18vNvdv31MXcZRF0PCxJRnrJqKNPDmiK9xAwkAE4KNL8RDWMaYgO1M9t49wUzO-rYnZiT0QGwgwU0Qh7S0d6k_epf6AXdE_7Jqc2QC38MqEnkydnMlRtY4mEiOCe2UZ2hPDJ13U1qedxfJS4D0DXyb8bck7w4hv8z0MIM3ERL69edgfGqnIXtDLhnvWhNNTsVZV-6W-LzENT93cXq-ph6DMwNGLXQGk5KHaHrIaXHBIf-1aU3u3XnLScjR-BnTgjp_Yed1JmeCaS1zypiopWK1ErJStRSl4o_lNa8I_mH9tt0DuSSnJWcMcsTTSLajST_tx8nid6msqco1ZUoIxRVVitK6pCV9XSJZJXLKFRO8LCuqKl6qUgotX5fKktOcSoWJ1CmRErXyUsjyVamkUiu8U0yVSuPhlLXidSU0V69LZSV4Xgupa1VVQuBlklSL3ynxB9_ZkdaR2UWyzC14lDS36I5oeavvgffOJxuNMI7JLCeUvyX4bnDH5Jyd_Yb6j84_Ge8Qgth45vlzwG3Yzva8d6gM3TrZPuUk0dhkwcv8VHxfMrZbkonyb5hHsO8hxcfJ5pRu2oa3mmuzMUscnG_uYQ8tfH3YbRY_Nr9czmwIy1rPKrSAajM0ouuMpEwYSpXWTNM9UxrQuKQR8iDkZjR7GEODRTWVqd6lqlTdbv4_t21YySg6JsMeb3mhO8oroyuluOxk12ISYDJ2LBJO4Xy_8c0KuV_6gJOjDTH8O2lCsP0MsEpFhdHGcR18evcRx2T7R44R6RBxwbJ2rX_ncxI2q75mFfcPsPet_Q>52845</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [PGO] CS-PGO failure to merge profiles
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            pgo
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          LebedevRI
      </td>
    </tr>
</table>

<pre>
    Reproduction steps:
[halide-build.sh.txt](https://github.com/llvm/llvm-project/files/7765229/halide-build.sh.txt)

Ignoring the question of `LLVM_PROFILE_FILE="profile-%m.profraw"` seemingly resulting in broken files,
there is something going wrong when trying to merge the `*.profraw` that were produced
from `-fprofile-use=<> -fcs-profile-generate`:
```
+ llvm-profdata-14 merge -output=/tmp/halide/profile/default-stage-1.profdata /tmp/halide/profile/raw/stage-1
warning: /tmp/halide/profile/raw/stage-1/profile-242997-12246782684758674083_0.profraw: Merge IR generated profile with Clang generated profile.
warning: /tmp/halide/profile/raw/stage-1/profile-242618-9128448381881160101_0.profraw: Merge IR generated profile with Clang generated profile.
warning: /tmp/halide/profile/raw/stage-1/profile-242254-13824300518530807497_0.profraw: Merge IR generated profile with Clang generated profile.
warning: /tmp/halide/profile/raw/stage-1/profile-242031-17848391881700530470_0.profraw: Merge IR generated profile with Clang generated profile.
warning: /tmp/halide/profile/raw/stage-1/profile-241798-14280892247683654938_0.profraw: Merge IR generated profile with Clang generated profile.
warning: /tmp/halide/profile/raw/stage-1/profile-241543-64796855444297194_0.profraw: Merge IR generated profile with Clang generated profile.
```
I do not understand what that error is telling me, or how to fix/workaround it.
This is broken both in LLVM13 and in trunk.

CC @WenleiHe @wmi-11
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzNlV1v3SgQhn-Nzw3C4tPgC1-kJ83ukVK1yla7lxGOsc3GNlnAPc2_38HnY1dVValSLyIhPBiYeRibd1rfvTYP9iX4bn1Kzi8oJvsSC35TkNuC3BTy3Wgm11ncrm7qyjiW6Wsq5G3B9JjSaSW7gza4NK5t-eRnGEzTl8sDg--_7VOCYe8mG-GpVCUZq8H6nm-YOIXe-sOw-OCWAaXRon9WGzdI36OiIvf3f354_PTw8e5w__4xdwUHLgYBcyRcMDmXeRDMEV7DBhStncHZ9IqCjeuUsmO3oDb4Z7ugM9_-FBkCBotcRNHPNo156eBzfww-9yPsSOF1Y_NotmGwGyTEKdjNNTBETaNJ6Ji9nfJsu1OEPvg5L8f9BXmNNp-B7wv-HuH-KeLLzGAXG0yy2fv144B9aqche4cuGe87kwym4syF_Zpe1rTl5y7NL9fUg3GOAFZnewNJwTGZwWJaXvygH23aknt33nICOZqwQFqA8yd2XmcwE6yuFaaMiUppVmmhpK6UIJo_kmtewfmH7WyHB3RJTofOPtAR_ka0n0z-aN9Olr-KsqIa15RpITTXVGtKK0IJfVuQTApMuWaCEyKplpxookSt3hYl4RRTpSGRdU6kAlZOhCJvipKqWsOdYproGn5OVWleSVFz_bYopeC4EqqutJRCwGVStBa_EvEb3TmgzqPFJ7QunQ2AtHSgjiB5m-7ZEHzIMprsNGWxnAF_j-Dd6I9ZOXv3FfiPPjyb4MEFcukc5_MI26Cd5bn1QAZqnWWfcpTDuCzB6_Jc_r9k7PeoEOQvu0zW_W6zfZwdpnTXNbyreW12yaXJNlDbPv32EWoZ2v-BwUK9cdMKKn2V8_Ox424NU_PT5c7FuG71ToJEyN3YCKq5rFrDTadrSbSqmKkt6Xul-qo39W4yrZ1iBstlbPC5asnbnWsYYRT0kEEPd7ise8qlqaXWXPWq7-CIdgb4MhOUPgy70Gww7TpEmJxcTPG_SROjGxa7ZSD7N2safWjubWs7--XhsNvImw37X7fAmSA">