[llvm] [SimplifyCFG] Simplify nested branches (PR #97067)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `sanitizer-x86_64-linux` running on `sanitizer-buildbot1` while building `llvm` at step 2 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/66/builds/806

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-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/i386-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m32', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-Wthread-safety', '-Wthread-safety-reference', '-Wthread-safety-beta', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-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: 9980 tests, 80 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.
FAIL: libFuzzer-x86_64-static-libcxx-Linux :: reduce_inputs.test (1564 of 9980)
******************** TEST 'libFuzzer-x86_64-static-libcxx-Linux :: reduce_inputs.test' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 3: rm -rf /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
+ rm -rf /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
RUN: at line 4: mkdir -p /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
+ mkdir -p /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
RUN: at line 5: /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowSimpleTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest
+ /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowSimpleTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest
RUN: at line 6: /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowTest
+ /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowTest
RUN: at line 7: /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest  -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60   -runs=1000000 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C 2>&1 | FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test
+ FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test
+ /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60 -runs=1000000 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
RUN: at line 11: /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -runs=0 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C 2>&1 | FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test --check-prefix=COUNT
+ /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -runs=0 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
+ FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test --check-prefix=COUNT
/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test:12:8: error: COUNT: expected string not found in input
COUNT: seed corpus: files: 4
       ^
<stdin>:1:1: note: scanning from here
INFO: Running with entropic power schedule (0xFF, 100).
^
<stdin>:7:7: note: possible intended match here
INFO: seed corpus: files: 3 min: 2b max: 3b total: 7b rss: 31Mb
      ^

Input file: <stdin>
Check file: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test

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

Input was:
<<<<<<
            1: INFO: Running with entropic power schedule (0xFF, 100). 
check:12'0     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
Step 9 (test compiler-rt gcc) failure: test compiler-rt gcc (failure)
...
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/i386-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m32', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-Wthread-safety', '-Wthread-safety-reference', '-Wthread-safety-beta', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/lit.common.cfg.py:60: warning: Path reported by clang does not exist: "/b/sanitizer-x86_64-linux/build/build_gcc/lib/clang/19/lib/x86_64-unknown-linux-gnu". This path was found by running ['/b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang', '--target=x86_64-unknown-linux-gnu', '-m64', '-print-runtime-dir'].
llvm-lit: /b/sanitizer-x86_64-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: 9980 tests, 80 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.
FAIL: libFuzzer-x86_64-static-libcxx-Linux :: reduce_inputs.test (1564 of 9980)
******************** TEST 'libFuzzer-x86_64-static-libcxx-Linux :: reduce_inputs.test' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 3: rm -rf /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
+ rm -rf /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
RUN: at line 4: mkdir -p /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
+ mkdir -p /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
RUN: at line 5: /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowSimpleTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest
+ /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowSimpleTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest
RUN: at line 6: /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowTest
+ /b/sanitizer-x86_64-linux/build/build_gcc/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/fuzzer -m64 /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/ShrinkControlFlowTest.cpp -o /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowTest
RUN: at line 7: /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest  -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60   -runs=1000000 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C 2>&1 | FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test
+ FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test
+ /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60 -runs=1000000 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
RUN: at line 11: /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -runs=0 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C 2>&1 | FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test --check-prefix=COUNT
+ /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -runs=0 /b/sanitizer-x86_64-linux/build/build_gcc/runtimes/runtimes-bins/compiler-rt/test/fuzzer/X86_64StaticLibcxxLinuxConfig/Output/reduce_inputs.test.tmp/C
+ FileCheck /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test --check-prefix=COUNT
/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test:12:8: error: COUNT: expected string not found in input
COUNT: seed corpus: files: 4
       ^
<stdin>:1:1: note: scanning from here
INFO: Running with entropic power schedule (0xFF, 100).
^
<stdin>:7:7: note: possible intended match here
INFO: seed corpus: files: 3 min: 2b max: 3b total: 7b rss: 31Mb
      ^

Input file: <stdin>
Check file: /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/test/fuzzer/reduce_inputs.test

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

Input was:
<<<<<<
            1: INFO: Running with entropic power schedule (0xFF, 100). 
check:12'0     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found

```

https://github.com/llvm/llvm-project/pull/97067