[llvm] [RegAlloc] Relax the split constrain on MBB prolog (PR #168259)

Fri Nov 28 15:38:00 PST 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-hip-vega20` running on `hip-vega20-0` while building `llvm` at step 3 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/123/builds/31426

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 3 (annotate) failure: '../llvm-zorg/zorg/buildbot/builders/annotated/hip-build.sh --jobs=' (failure)
...
[59/61] Linking CXX executable External/HIP/cmath-hip-7.0.2
[60/61] Building CXX object External/HIP/CMakeFiles/TheNextWeek-hip-7.0.2.dir/workload/ray-tracing/TheNextWeek/main.cc.o
[61/61] Linking CXX executable External/HIP/TheNextWeek-hip-7.0.2
+ build_step 'Testing HIP test-suite'
+ echo '@@@BUILD_STEP Testing HIP test-suite@@@'
+ ninja check-hip-simple
@@@BUILD_STEP Testing HIP test-suite@@@
[0/1] cd /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP && /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/llvm/bin/llvm-lit -sv array-hip-7.0.2.test empty-hip-7.0.2.test with-fopenmp-hip-7.0.2.test saxpy-hip-7.0.2.test memmove-hip-7.0.2.test memset-hip-7.0.2.test split-kernel-args-hip-7.0.2.test builtin-logb-scalbn-hip-7.0.2.test TheNextWeek-hip-7.0.2.test algorithm-hip-7.0.2.test cmath-hip-7.0.2.test complex-hip-7.0.2.test math_h-hip-7.0.2.test new-hip-7.0.2.test blender.test
-- Testing: 15 tests, 15 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90
FAIL: test-suite :: External/HIP/blender.test (15 of 15)
******************** TEST 'test-suite :: External/HIP/blender.test' FAILED ********************

/home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/tools/timeit-target --timeout 7200 --limit-core 0 --limit-cpu 7200 --limit-file-size 209715200 --limit-rss-size 838860800 --append-exitstatus --redirect-output /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP/Output/blender.test.out --redirect-input /dev/null --summary /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP/Output/blender.test.time /bin/bash test_blender.sh
/bin/bash verify_blender.sh /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP/Output/blender.test.out
Begin Blender test.
TEST_SUITE_HIP_ROOT=/opt/botworker/llvm/External/hip
Render /opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo_release.blend
Blender 4.1.1 (hash e1743a0317bc built 2024-04-15 23:47:45)
Read blend: "/opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo_release.blend"
Could not open as Ogawa file from provided streams.
Unable to open /opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.002", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.003", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.004", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.001", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
Could not open as Ogawa file from provided streams.
Unable to open /opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.002", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.003", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.001", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.004", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
I1128 23:34:51.795140 2091859 device.cpp:39] HIPEW initialization succeeded
I1128 23:34:51.798669 2091859 device.cpp:45] Found HIPCC hipcc
I1128 23:34:51.884619 2091859 device.cpp:207] Device has compute preemption or is not used for display.
I1128 23:34:51.884635 2091859 device.cpp:211] Added device "" with id "HIP__0000:83:00".
I1128 23:34:51.884714 2091859 device.cpp:568] Mapped host memory limit set to 1,009,924,165,632 bytes. (940.56G)
I1128 23:34:51.884985 2091859 device_impl.cpp:63] Using AVX2 CPU kernels.
Fra:1 Mem:524.00M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Eyepiece_rim
Fra:1 Mem:524.00M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Rivets.006
Fra:1 Mem:524.05M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Rivets.024
Fra:1 Mem:524.13M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_Cables.004
Fra:1 Mem:533.53M (Peak 533.53M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_Connectors.001
Fra:1 Mem:533.89M (Peak 533.89M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_Connectors.004
Fra:1 Mem:534.18M (Peak 534.18M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | Cylinder.120
Fra:1 Mem:534.10M (Peak 534.18M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Head_additional
Fra:1 Mem:534.24M (Peak 534.24M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Head_glowy_bits
Step 12 (Testing HIP test-suite) failure: Testing HIP test-suite (failure)
@@@BUILD_STEP Testing HIP test-suite@@@
[0/1] cd /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP && /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/llvm/bin/llvm-lit -sv array-hip-7.0.2.test empty-hip-7.0.2.test with-fopenmp-hip-7.0.2.test saxpy-hip-7.0.2.test memmove-hip-7.0.2.test memset-hip-7.0.2.test split-kernel-args-hip-7.0.2.test builtin-logb-scalbn-hip-7.0.2.test TheNextWeek-hip-7.0.2.test algorithm-hip-7.0.2.test cmath-hip-7.0.2.test complex-hip-7.0.2.test math_h-hip-7.0.2.test new-hip-7.0.2.test blender.test
-- Testing: 15 tests, 15 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90
FAIL: test-suite :: External/HIP/blender.test (15 of 15)
******************** TEST 'test-suite :: External/HIP/blender.test' FAILED ********************

/home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/tools/timeit-target --timeout 7200 --limit-core 0 --limit-cpu 7200 --limit-file-size 209715200 --limit-rss-size 838860800 --append-exitstatus --redirect-output /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP/Output/blender.test.out --redirect-input /dev/null --summary /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP/Output/blender.test.time /bin/bash test_blender.sh
/bin/bash verify_blender.sh /home/botworker/bbot/clang-hip-vega20/botworker/clang-hip-vega20/test-suite-build/External/HIP/Output/blender.test.out
Begin Blender test.
TEST_SUITE_HIP_ROOT=/opt/botworker/llvm/External/hip
Render /opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo_release.blend
Blender 4.1.1 (hash e1743a0317bc built 2024-04-15 23:47:45)
Read blend: "/opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo_release.blend"
Could not open as Ogawa file from provided streams.
Unable to open /opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.002", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.003", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.004", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.001", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
Could not open as Ogawa file from provided streams.
Unable to open /opt/botworker/llvm/External/hip/Blender_Scenes/290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.002", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.003", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.001", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
WARN (bke.modifier): source/blender/blenkernel/intern/modifier.cc:425 BKE_modifier_set_error: Object: "GEO-flag.004", Modifier: "MeshSequenceCache", Could not create reader for file //290skydemo2_flags.abc
I1128 23:34:51.795140 2091859 device.cpp:39] HIPEW initialization succeeded
I1128 23:34:51.798669 2091859 device.cpp:45] Found HIPCC hipcc
I1128 23:34:51.884619 2091859 device.cpp:207] Device has compute preemption or is not used for display.
I1128 23:34:51.884635 2091859 device.cpp:211] Added device "" with id "HIP__0000:83:00".
I1128 23:34:51.884714 2091859 device.cpp:568] Mapped host memory limit set to 1,009,924,165,632 bytes. (940.56G)
I1128 23:34:51.884985 2091859 device_impl.cpp:63] Using AVX2 CPU kernels.
Fra:1 Mem:524.00M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Eyepiece_rim
Fra:1 Mem:524.00M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Rivets.006
Fra:1 Mem:524.05M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Rivets.024
Fra:1 Mem:524.13M (Peak 524.70M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_Cables.004
Fra:1 Mem:533.53M (Peak 533.53M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_Connectors.001
Fra:1 Mem:533.89M (Peak 533.89M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_Connectors.004
Fra:1 Mem:534.18M (Peak 534.18M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | Cylinder.120
Fra:1 Mem:534.10M (Peak 534.18M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Head_additional
Fra:1 Mem:534.24M (Peak 534.24M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Head_glowy_bits
Fra:1 Mem:535.83M (Peak 535.84M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Head_greeble.003
Fra:1 Mem:536.16M (Peak 536.16M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_Wires
Fra:1 Mem:536.88M (Peak 536.97M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Head_greeble.008
Fra:1 Mem:537.30M (Peak 537.30M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Head_plates
Fra:1 Mem:537.96M (Peak 537.96M) | Time:00:00.48 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Pistons.001
Fra:1 Mem:538.91M (Peak 538.91M) | Time:00:00.49 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Pistons.005
Fra:1 Mem:541.14M (Peak 541.14M) | Time:00:00.49 | Mem:0.00M, Peak:0.00M | Scene, View Layer | Synchronizing object | GEO-Curve_wires

```

</details>

https://github.com/llvm/llvm-project/pull/168259