[llvm] [GlobalISel] Combine G_MERGE_VALUES of x and zero (PR #116283)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `sanitizer-x86_64-linux-bootstrap-asan` running on `sanitizer-buildbot2` while building `llvm` at step 2 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/52/builds/3759

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

```
Step 2 (annotate) failure: 'python ../sanitizer_buildbot/sanitizers/zorg/buildbot/builders/sanitizers/buildbot_selector.py' (failure)
...
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using lld-link: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/lld-link
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld64.lld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using wasm-ld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld.lld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld.lld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using lld-link: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/lld-link
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld64.lld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using wasm-ld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/main.py:72: note: The test suite configuration requested an individual test timeout of 0 seconds but a timeout of 900 seconds was requested on the command line. Forcing timeout to be 900 seconds.
-- Testing: 87236 of 87237 tests, 88 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
FAIL: lld :: ELF/lto/devirt_vcall_vis_localize.ll (85847 of 87236)
******************** TEST 'lld :: ELF/lto/devirt_vcall_vis_localize.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 5: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/devirt_vcall_vis_localize.ll
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/devirt_vcall_vis_localize.ll
RUN: at line 6: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/Inputs/devirt_vcall_vis_shared_def.ll
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/Inputs/devirt_vcall_vis_shared_def.ll
RUN: at line 7: echo '{ global: _start; local: *; };' > /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp.ver
+ echo '{ global: _start; local: *; };'
RUN: at line 9: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld.lld /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp.out --save-temps --lto-whole-program-visibility -shared    -mllvm -pass-remarks=. 2>&1 | /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/count 0
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld.lld /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp.out --save-temps --lto-whole-program-visibility -shared -mllvm -pass-remarks=.
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/count 0
Expected 0 lines, got 1.

--

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 
Slowest Tests:
--------------------------------------------------------------------------
231.75s: LLVM :: CodeGen/AMDGPU/sched-group-barrier-pipeline-solver.mir
114.64s: Clang :: Driver/fsanitize.c
101.56s: Clang :: Preprocessor/riscv-target-features.c
90.94s: Clang :: Analysis/a_flaky_crash.cpp
87.47s: Clang :: OpenMP/target_defaultmap_codegen_01.cpp
86.36s: Clang :: Driver/arm-cortex-cpus-2.c
86.27s: Clang :: OpenMP/target_update_codegen.cpp
85.26s: Clang :: Driver/arm-cortex-cpus-1.c
82.25s: Clang :: Analysis/runtime-regression.c
72.73s: Clang :: Preprocessor/arm-target-features.c
72.71s: Clang :: Preprocessor/aarch64-target-features.c
64.45s: Clang :: Preprocessor/predefined-arch-macros.c
62.67s: Clang :: CodeGen/AArch64/sve-intrinsics/acle_sve_reinterpret.c
61.50s: LLVM :: CodeGen/AMDGPU/memintrinsic-unroll.ll
58.02s: LLVM :: CodeGen/RISCV/attributes.ll
57.08s: Clang :: Driver/linux-ld.c
Step 10 (stage2/asan check) failure: stage2/asan check (failure)
...
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using lld-link: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/lld-link
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld64.lld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using wasm-ld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld.lld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld.lld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using lld-link: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/lld-link
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld64.lld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using wasm-ld: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/utils/lit/lit/main.py:72: note: The test suite configuration requested an individual test timeout of 0 seconds but a timeout of 900 seconds was requested on the command line. Forcing timeout to be 900 seconds.
-- Testing: 87236 of 87237 tests, 88 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
FAIL: lld :: ELF/lto/devirt_vcall_vis_localize.ll (85847 of 87236)
******************** TEST 'lld :: ELF/lto/devirt_vcall_vis_localize.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 5: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/devirt_vcall_vis_localize.ll
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/devirt_vcall_vis_localize.ll
RUN: at line 6: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/Inputs/devirt_vcall_vis_shared_def.ll
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/opt --thinlto-bc -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/lld/test/ELF/lto/Inputs/devirt_vcall_vis_shared_def.ll
RUN: at line 7: echo '{ global: _start; local: *; };' > /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp.ver
+ echo '{ global: _start; local: *; };'
RUN: at line 9: /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld.lld /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp.out --save-temps --lto-whole-program-visibility -shared    -mllvm -pass-remarks=. 2>&1 | /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/count 0
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/ld.lld /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp1.o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp2.o -o /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/tools/lld/test/ELF/lto/Output/devirt_vcall_vis_localize.ll.tmp.out --save-temps --lto-whole-program-visibility -shared -mllvm -pass-remarks=.
+ /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/count 0
Expected 0 lines, got 1.

--

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 
Slowest Tests:
--------------------------------------------------------------------------
231.75s: LLVM :: CodeGen/AMDGPU/sched-group-barrier-pipeline-solver.mir
114.64s: Clang :: Driver/fsanitize.c
101.56s: Clang :: Preprocessor/riscv-target-features.c
90.94s: Clang :: Analysis/a_flaky_crash.cpp
87.47s: Clang :: OpenMP/target_defaultmap_codegen_01.cpp
86.36s: Clang :: Driver/arm-cortex-cpus-2.c
86.27s: Clang :: OpenMP/target_update_codegen.cpp
85.26s: Clang :: Driver/arm-cortex-cpus-1.c
82.25s: Clang :: Analysis/runtime-regression.c
72.73s: Clang :: Preprocessor/arm-target-features.c
72.71s: Clang :: Preprocessor/aarch64-target-features.c
64.45s: Clang :: Preprocessor/predefined-arch-macros.c
62.67s: Clang :: CodeGen/AArch64/sve-intrinsics/acle_sve_reinterpret.c
61.50s: LLVM :: CodeGen/AMDGPU/memintrinsic-unroll.ll
58.02s: LLVM :: CodeGen/RISCV/attributes.ll
57.08s: Clang :: Driver/linux-ld.c

```

</details>

https://github.com/llvm/llvm-project/pull/116283