[llvm] [Legalizer] Cache extracted element when lowering G_SHUFFLE_VECTOR. (PR #163893)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-sve2-vla-2stage` running on `linaro-g4-02` while building `llvm` at step 12 "ninja check 2".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/199/builds/6774

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

```
Step 12 (ninja check 2) failure: stage 2 checked (failure)
******************** TEST 'libFuzzer-aarch64-default-Linux :: reduce_inputs.test' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
rm -rf /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C # RUN: at line 3
+ rm -rf /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C
mkdir -p /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C # RUN: at line 4
+ mkdir -p /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C
/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/lib/fuzzer  -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta  /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/ShrinkControlFlowSimpleTest.cpp -o /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest # RUN: at line 5
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/lib/fuzzer -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/ShrinkControlFlowSimpleTest.cpp -o /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest
/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/lib/fuzzer  -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta  /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/ShrinkControlFlowTest.cpp -o /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowTest # RUN: at line 6
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/lib/fuzzer -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/ShrinkControlFlowTest.cpp -o /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowTest
/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest  -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60   -runs=1000000 /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C 2>&1 | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/reduce_inputs.test # RUN: at line 7
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60 -runs=1000000 /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/reduce_inputs.test
/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -runs=0 /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C 2>&1 | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/reduce_inputs.test --check-prefix=COUNT # RUN: at line 11
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp-ShrinkControlFlowSimpleTest -runs=0 /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/compiler-rt/test/fuzzer/reduce_inputs.test --check-prefix=COUNT
/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/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: 30Mb
      ^

Input file: <stdin>
Check file: /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/llvm/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
            2: INFO: Seed: 2923922601 
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~
            3: INFO: Loaded 1 modules (6 inline 8-bit counters): 6 [0xb2b888606e98, 0xb2b888606e9e),  
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            4: INFO: Loaded 1 PC tables (6 PCs): 6 [0xb2b888606ea0,0xb2b888606f00),  
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            5: INFO: 3 files found in /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/fuzzer/AARCH64DefaultLinuxConfig/Output/reduce_inputs.test.tmp/C 
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            6: INFO: -max_len is not provided; libFuzzer will not generate inputs larger than 4096 bytes 
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            7: INFO: seed corpus: files: 3 min: 2b max: 3b total: 7b rss: 30Mb 
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...

```

</details>

https://github.com/llvm/llvm-project/pull/163893