[llvm] [DAGCombiner] Don't let scalarizeBinOpOfSplats create illegal scalar MULHS/MULHU (PR #104518)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `sanitizer-ppc64le-linux` running on `ppc64le-sanitizer` while building `llvm` at step 2 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/72/builds/2317

Here is the relevant piece of the build log for the reference:
```
Step 2 (annotate) failure: 'python ../sanitizer_buildbot/sanitizers/zorg/buildbot/builders/sanitizers/buildbot_selector.py' (failure)
...
PASS: ThreadSanitizer-powerpc64le :: ignore_lib4.cpp (2438 of 2485)
PASS: ThreadSanitizer-powerpc64le :: mutex_cycle2.c (2439 of 2485)
PASS: SanitizerCommon-tsan-powerpc64le-Linux :: Linux/signal_name.c (2440 of 2485)
PASS: ThreadSanitizer-powerpc64le :: Linux/fork_multithreaded4.cpp (2441 of 2485)
PASS: MemorySanitizer-POWERPC64LE :: poison_in_signal.cpp (2442 of 2485)
PASS: ThreadSanitizer-powerpc64le :: mutex_cycle_long.c (2443 of 2485)
PASS: ThreadSanitizer-powerpc64le :: simple_stack.c (2444 of 2485)
PASS: SanitizerCommon-lsan-powerpc64le-Linux :: max_allocation_size.cpp (2445 of 2485)
PASS: MemorySanitizer-POWERPC64LE :: recover-dso.cpp (2446 of 2485)
PASS: XRay-powerpc64le-linux :: TestCases/Posix/fdr-reinit.cpp (2447 of 2485)
FAIL: ThreadSanitizer-powerpc64le :: signal_thread.cpp (2448 of 2485)
******************** TEST 'ThreadSanitizer-powerpc64le :: signal_thread.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/./bin/clang  --driver-mode=g++ -fsanitize=thread -Wall  -m64 -fno-function-sections   -gline-tables-only -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -std=c++11 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -nostdinc++ -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/tsan/libcxx_tsan_powerpc64le/include/c++/v1 -O1 /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp -o /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp &&  /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp 2>&1 | FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/./bin/clang --driver-mode=g++ -fsanitize=thread -Wall -m64 -fno-function-sections -gline-tables-only -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -std=c++11 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -nostdinc++ -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/tsan/libcxx_tsan_powerpc64le/include/c++/v1 -O1 /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp -o /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp
+ FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp
/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:51:15: error: CHECK-NOT: excluded string found in input
// CHECK-NOT: WARNING: ThreadSanitizer:
              ^
<stdin>:2:1: note: found here
WARNING: ThreadSanitizer: signal handler spoils errno (pid=1968576)
^~~~~~~~~~~~~~~~~~~~~~~~~

Input file: <stdin>
Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp

-dump-input=help explains the following input dump.

Input was:
<<<<<<
        1: ================== 
        2: WARNING: ThreadSanitizer: signal handler spoils errno (pid=1968576) 
not:51     !~~~~~~~~~~~~~~~~~~~~~~~~                                            error: no match expected
        3:  Signal 27 handler invoked at: 
        4:  #0 handler(int) /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:14 (signal_thread.cpp.tmp+0x101ee0) 
        5:  #1 main /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:43:5 (signal_thread.cpp.tmp+0x101e00) 
        6:  
        7: SUMMARY: ThreadSanitizer: signal handler spoils errno /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:14 in handler(int) 
        8: ================== 
        9: DONE 
       10: ThreadSanitizer: reported 1 warnings 
>>>>>>

--

Step 9 (test compiler-rt debug) failure: test compiler-rt debug (failure)
...
PASS: ThreadSanitizer-powerpc64le :: ignore_lib4.cpp (2438 of 2485)
PASS: ThreadSanitizer-powerpc64le :: mutex_cycle2.c (2439 of 2485)
PASS: SanitizerCommon-tsan-powerpc64le-Linux :: Linux/signal_name.c (2440 of 2485)
PASS: ThreadSanitizer-powerpc64le :: Linux/fork_multithreaded4.cpp (2441 of 2485)
PASS: MemorySanitizer-POWERPC64LE :: poison_in_signal.cpp (2442 of 2485)
PASS: ThreadSanitizer-powerpc64le :: mutex_cycle_long.c (2443 of 2485)
PASS: ThreadSanitizer-powerpc64le :: simple_stack.c (2444 of 2485)
PASS: SanitizerCommon-lsan-powerpc64le-Linux :: max_allocation_size.cpp (2445 of 2485)
PASS: MemorySanitizer-POWERPC64LE :: recover-dso.cpp (2446 of 2485)
PASS: XRay-powerpc64le-linux :: TestCases/Posix/fdr-reinit.cpp (2447 of 2485)
FAIL: ThreadSanitizer-powerpc64le :: signal_thread.cpp (2448 of 2485)
******************** TEST 'ThreadSanitizer-powerpc64le :: signal_thread.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/./bin/clang  --driver-mode=g++ -fsanitize=thread -Wall  -m64 -fno-function-sections   -gline-tables-only -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -std=c++11 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -nostdinc++ -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/tsan/libcxx_tsan_powerpc64le/include/c++/v1 -O1 /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp -o /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp &&  /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp 2>&1 | FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/./bin/clang --driver-mode=g++ -fsanitize=thread -Wall -m64 -fno-function-sections -gline-tables-only -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -std=c++11 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/../ -nostdinc++ -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/tsan/libcxx_tsan_powerpc64le/include/c++/v1 -O1 /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp -o /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/build_default/runtimes/runtimes-bins/compiler-rt/test/tsan/POWERPC64LEConfig/Output/signal_thread.cpp.tmp
+ FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp
/home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:51:15: error: CHECK-NOT: excluded string found in input
// CHECK-NOT: WARNING: ThreadSanitizer:
              ^
<stdin>:2:1: note: found here
WARNING: ThreadSanitizer: signal handler spoils errno (pid=1968576)
^~~~~~~~~~~~~~~~~~~~~~~~~

Input file: <stdin>
Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp

-dump-input=help explains the following input dump.

Input was:
<<<<<<
        1: ================== 
        2: WARNING: ThreadSanitizer: signal handler spoils errno (pid=1968576) 
not:51     !~~~~~~~~~~~~~~~~~~~~~~~~                                            error: no match expected
        3:  Signal 27 handler invoked at: 
        4:  #0 handler(int) /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:14 (signal_thread.cpp.tmp+0x101ee0) 
        5:  #1 main /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:43:5 (signal_thread.cpp.tmp+0x101e00) 
        6:  
        7: SUMMARY: ThreadSanitizer: signal handler spoils errno /home/buildbots/llvm-external-buildbots/workers/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm-project/compiler-rt/test/tsan/signal_thread.cpp:14 in handler(int) 
        8: ================== 
        9: DONE 
       10: ThreadSanitizer: reported 1 warnings 
>>>>>>

--


```

https://github.com/llvm/llvm-project/pull/104518