<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/60477>60477</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            update_llc_test_checks not commoning functions with identical output
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
            nhaehnle,
            mtrofin,
            JanekvO
      </td>
    </tr>

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

<pre>
    I recently tried to use update_llc_test_checks on llvm/test/CodeGen/AMDGPU/llvm.is.fpclass.f16.ll. Some of the functions have identical output between the SelectionDAG and GlobalISel run lines, and previously had merged check lines. This appears to no longer be the case. e.g.

```
-; GFX8CHECK-LABEL: sgpr_isnan_f16:
-; GFX8CHECK: ; %bb.0:
-; GFX8CHECK-NEXT:    s_load_dword s2, s[0:1], 0x2c
-; GFX8CHECK-NEXT:    s_load_dwordx2 s[0:1], s[0:1], 0x24
-; GFX8CHECK-NEXT: s_waitcnt lgkmcnt(0)
-; GFX8CHECK-NEXT:    v_cmp_class_f16_e64 s[2:3], s2, 3
-; GFX8CHECK-NEXT:    v_mov_b32_e32 v0, s0
-; GFX8CHECK-NEXT: v_cndmask_b32_e64 v2, 0, -1, s[2:3]
-; GFX8CHECK-NEXT:    v_mov_b32_e32 v1, s1
-; GFX8CHECK-NEXT:    flat_store_dword v[0:1], v2
-; GFX8CHECK-NEXT:    s_endpgm

+; GFX8SELDAG-LABEL: sgpr_isnan_f16:
+; GFX8SELDAG:       ; %bb.0:
+; GFX8SELDAG-NEXT:    s_load_dword s2, s[0:1], 0x2c
+; GFX8SELDAG-NEXT:    s_load_dwordx2 s[0:1], s[0:1], 0x24
+; GFX8SELDAG-NEXT:    s_waitcnt lgkmcnt(0)
+; GFX8SELDAG-NEXT: v_cmp_class_f16_e64 s[2:3], s2, 3
+; GFX8SELDAG-NEXT:    v_mov_b32_e32 v0, s0
+; GFX8SELDAG-NEXT:    v_cndmask_b32_e64 v2, 0, -1, s[2:3]
+; GFX8SELDAG-NEXT:    v_mov_b32_e32 v1, s1
+; GFX8SELDAG-NEXT: flat_store_dword v[0:1], v2
+; GFX8SELDAG-NEXT:    s_endpgm
+;
+; GFX8GLISEL-LABEL: sgpr_isnan_f16:
+; GFX8GLISEL:       ; %bb.0:
+; GFX8GLISEL-NEXT:    s_load_dword s2, s[0:1], 0x2c
+; GFX8GLISEL-NEXT: s_load_dwordx2 s[0:1], s[0:1], 0x24
+; GFX8GLISEL-NEXT:    s_waitcnt lgkmcnt(0)
+; GFX8GLISEL-NEXT:    v_cmp_class_f16_e64 s[2:3], s2, 3
+; GFX8GLISEL-NEXT:    v_mov_b32_e32 v0, s0
+; GFX8GLISEL-NEXT: v_cndmask_b32_e64 v2, 0, -1, s[2:3]
+; GFX8GLISEL-NEXT:    v_mov_b32_e32 v1, s1
+; GFX8GLISEL-NEXT:    flat_store_dword v[0:1], v2
+; GFX8GLISEL-NEXT:    s_endpgm
```

It's possible this test was manually hacked around before, it was missing the "Assertions have been autogenerated" comment.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJysll9vozgXxj-Nc3MUBIeEthdcpE2Tt-92_0idleYO2fgA3hob2YbMfPsVNJ3ZTtKm6YxUURnOc_zY5xfp4d6r2hDlbHnNEE3DqTGaGCLDG4bYBmcrZb6t_88NPQ5_juvlesb70FiXc-fJtDNh5df8DhyVZIL-CsEpkhAs9J6g7yQPVGhdFoF8KMqGykcP1oDWQ8twM75luLmxkrZkGG5Wv6-3f_3NcDMWRMpHVVdq7n1UJVmkdQQPtiWwFYSGoOpNGZQ1Hho-EChJJqiSa7B96PoAgsKOyEy1D6RpKl6vtsCNhK22guu7B9LgegNaGfIMb6ZvnaNB2d7rr9BwCS25miRM7p8KI_jUKA-864g7Px7XWNDW1ORA0LRhyT1FQFEdsXjN4tX-mcX7v2k5Z-k1bDefL2_-d3vz2_x-dX17z9IV-LpzhfKGm6JKMpaujpWPheMLhkshoviVqvkft58_jaUA4AttuSzkzjoJfpwueLa8HqUJW67HdfwFy3PafMGDFkdaLt5s6YsdV6E0AXT92JYmMLyMGV6d8jEUZdsVEx_jNRWULabNkaWr9NnMdMr0dKvWDoVIsaAUYYgn6fEhPauGojSy5f7xSZYtYJj2mrTz5Pkmvpk5z8GTPjmlqjQPhQ_W0X6qww-XP-DpaZKRXd2-wBSvn-sfbu_Xq-1JNA8U--4ARxk93OCjmL6701mknuj6Fq-vS8_m9U0XbyF7QvgBcM-x8oLd14XvZvfEMF7gO5UeyLb3dw-39-dA_KR4N8T7DX4BxD90-hUEHzP3ToIPpT8D8bFu74L4B-HPEnzSx2sEHwo_AvGxebyA-GVIeHreBYYXHjrrvRJ6zBjKw5ifYMc9tNz0XE95pXwkCdzZ3kgQVFlHow21r1PeK1NPCYUhrrwn958IJca4xPtgazLkeCDJEKG0bUsmRDOZp_IqveIzypPsYpkulpgmsyZf4lLIKiUhMEsvBYpMJEhSiLjCjDCZqRxjTGOMMUkXMV5GolpcJWUmMb6sxMXVgi1iarnS0ZT7rKtnyvue8ixeXFzMNBek_XNcpR1MH_d51OWjZi762rNFrJUP_nuXoIKm_JUcamyYzmbNeCXf0-ROheYgTc56p_MmhM6Pv3_cMNzUKjS9iErb7gPr_t-8c_YfKsdkOxn1DDfTQf4NAAD__0JhOX0">