[llvm] [InstCombine] Check for undef first before freeze (PR #96769)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `sanitizer-aarch64-linux` running on `sanitizer-buildbot7` while building `llvm` at step 2 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/51/builds/1272

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)
...
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:60: note: linux feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:36: note: lsan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:48: note: msan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:60: note: linux feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:36: note: lsan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:48: note: msan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:60: note: linux feature available
llvm-lit: /b/sanitizer-aarch64-linux/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: 5483 tests, 48 workers --
Testing:  0.. 10.. 20.. 30
FAIL: LeakSanitizer-AddressSanitizer-aarch64 :: TestCases/use_registers.cpp (1767 of 5483)
******************** TEST 'LeakSanitizer-AddressSanitizer-aarch64 :: TestCases/use_registers.cpp' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Test alloc: 0x51a000000080 

=================================================================
==2075034==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 1337 byte(s) in 1 object(s) allocated from:
    #0 0xb77f22a5b6f8 in malloc /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:68:3
    #1 0xb77f22b84cfc in registers_thread_func /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp:16:13
    #2 0xb77f22a58f64 in asan_thread_start(void*) /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/asan/asan_interceptors.cpp:239:28
    #3 0xfa2849c3ba48  (/lib/aarch64-linux-gnu/libc.so.6+0xeba48) (BuildId: 3119d7bcf68a34e21742cd08095272de601d373f)

Objects leaked above:
0x51a000000080 (1337 bytes)

SUMMARY: AddressSanitizer: 1337 byte(s) leaked in 1 allocation(s).

--
Command Output (stderr):
--
RUN: at line 2: /b/sanitizer-aarch64-linux/build/build_default/./bin/clang  --driver-mode=g++ -O0   -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   -gline-tables-only -fsanitize=address -I/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/../ -pthread /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp -o /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp
+ /b/sanitizer-aarch64-linux/build/build_default/./bin/clang --driver-mode=g++ -O0 -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -gline-tables-only -fsanitize=address -I/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/../ -pthread /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp -o /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp
RUN: at line 3: env LSAN_OPTIONS=:detect_leaks=1:"report_objects=1:use_stacks=0:use_registers=0" not  /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp 2>&1 | FileCheck /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp
+ env LSAN_OPTIONS=:detect_leaks=1:report_objects=1:use_stacks=0:use_registers=0 not /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp
+ FileCheck /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp
RUN: at line 4: env LSAN_OPTIONS=:detect_leaks=1:"report_objects=1:use_stacks=0:use_registers=1"  /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp 2>&1
+ env LSAN_OPTIONS=:detect_leaks=1:report_objects=1:use_stacks=0:use_registers=1 /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp

--

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 

2 warning(s) in tests
Step 9 (test compiler-rt symbolizer) failure: test compiler-rt symbolizer (failure)
...
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:60: note: linux feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:36: note: lsan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:48: note: msan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:60: note: linux feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:36: note: lsan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:48: note: msan feature available
llvm-lit: /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/fuzzer/lit.cfg.py:60: note: linux feature available
llvm-lit: /b/sanitizer-aarch64-linux/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: 5483 tests, 48 workers --
Testing:  0.. 10.. 20.. 30
FAIL: LeakSanitizer-AddressSanitizer-aarch64 :: TestCases/use_registers.cpp (1767 of 5483)
******************** TEST 'LeakSanitizer-AddressSanitizer-aarch64 :: TestCases/use_registers.cpp' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Test alloc: 0x51a000000080 

=================================================================
==2075034==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 1337 byte(s) in 1 object(s) allocated from:
    #0 0xb77f22a5b6f8 in malloc /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:68:3
    #1 0xb77f22b84cfc in registers_thread_func /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp:16:13
    #2 0xb77f22a58f64 in asan_thread_start(void*) /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/asan/asan_interceptors.cpp:239:28
    #3 0xfa2849c3ba48  (/lib/aarch64-linux-gnu/libc.so.6+0xeba48) (BuildId: 3119d7bcf68a34e21742cd08095272de601d373f)

Objects leaked above:
0x51a000000080 (1337 bytes)

SUMMARY: AddressSanitizer: 1337 byte(s) leaked in 1 allocation(s).

--
Command Output (stderr):
--
RUN: at line 2: /b/sanitizer-aarch64-linux/build/build_default/./bin/clang  --driver-mode=g++ -O0   -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   -gline-tables-only -fsanitize=address -I/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/../ -pthread /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp -o /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp
+ /b/sanitizer-aarch64-linux/build/build_default/./bin/clang --driver-mode=g++ -O0 -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -gline-tables-only -fsanitize=address -I/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/../ -pthread /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp -o /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp
RUN: at line 3: env LSAN_OPTIONS=:detect_leaks=1:"report_objects=1:use_stacks=0:use_registers=0" not  /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp 2>&1 | FileCheck /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp
+ env LSAN_OPTIONS=:detect_leaks=1:report_objects=1:use_stacks=0:use_registers=0 not /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp
+ FileCheck /b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/test/lsan/TestCases/use_registers.cpp
RUN: at line 4: env LSAN_OPTIONS=:detect_leaks=1:"report_objects=1:use_stacks=0:use_registers=1"  /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp 2>&1
+ env LSAN_OPTIONS=:detect_leaks=1:report_objects=1:use_stacks=0:use_registers=1 /b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/test/lsan/AARCH64AsanConfig/TestCases/Output/use_registers.cpp.tmp

--

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..

2 warning(s) in tests

```

https://github.com/llvm/llvm-project/pull/96769