[llvm] [AMDGPU][True16][CodeGen] optimize codegen for mad-mix in true16 (PR #124995)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/17290

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
...
PASS: lit :: allow-retries.py (89915 of 89924)
PASS: lit :: discovery.py (89916 of 89924)
PASS: lit :: shtest-external-shell-kill.py (89917 of 89924)
PASS: lit :: googletest-timeout.py (89918 of 89924)
PASS: lit :: selecting.py (89919 of 89924)
PASS: lit :: shtest-timeout.py (89920 of 89924)
PASS: lit :: max-time.py (89921 of 89924)
PASS: lit :: shtest-shell.py (89922 of 89924)
PASS: lit :: shtest-define.py (89923 of 89924)
TIMEOUT: AddressSanitizer-x86_64-linux-dynamic :: TestCases/asan_lsan_deadlock.cpp (89924 of 89924)
******************** TEST 'AddressSanitizer-x86_64-linux-dynamic :: TestCases/asan_lsan_deadlock.cpp' FAILED ********************
Exit Code: -9
Timeout: Reached timeout of 900 seconds

Command Output (stderr):
--
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang  --driver-mode=g++ -fsanitize=address -mno-omit-leaf-frame-pointer -fno-omit-frame-pointer -fno-optimize-sibling-calls -gline-tables-only  -m64  -shared-libasan -O0 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/asan/TestCases/asan_lsan_deadlock.cpp -o /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/asan/X86_64LinuxDynamicConfig/TestCases/Output/asan_lsan_deadlock.cpp.tmp # RUN: at line 4
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang --driver-mode=g++ -fsanitize=address -mno-omit-leaf-frame-pointer -fno-omit-frame-pointer -fno-optimize-sibling-calls -gline-tables-only -m64 -shared-libasan -O0 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/asan/TestCases/asan_lsan_deadlock.cpp -o /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/asan/X86_64LinuxDynamicConfig/TestCases/Output/asan_lsan_deadlock.cpp.tmp
env ASAN_OPTIONS=detect_leaks=1 not  /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/asan/X86_64LinuxDynamicConfig/TestCases/Output/asan_lsan_deadlock.cpp.tmp 2>&1 | FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/asan/TestCases/asan_lsan_deadlock.cpp # RUN: at line 5
+ env ASAN_OPTIONS=detect_leaks=1 not /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/asan/X86_64LinuxDynamicConfig/TestCases/Output/asan_lsan_deadlock.cpp.tmp
+ FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/asan/TestCases/asan_lsan_deadlock.cpp

--

********************
********************
Timed Out Tests (1):
  AddressSanitizer-x86_64-linux-dynamic :: TestCases/asan_lsan_deadlock.cpp


Testing Time: 1171.22s

Total Discovered Tests: 124408
  Skipped          :     38 (0.03%)
  Unsupported      :   2646 (2.13%)
  Passed           : 121432 (97.61%)
  Expectedly Failed:    291 (0.23%)
  Timed Out        :      1 (0.00%)
FAILED: CMakeFiles/check-all /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/CMakeFiles/check-all 
cd /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build && /usr/bin/python3.8 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/llvm-lit --verbose --timeout=900 --param USE_Z3_SOLVER=0 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/utils/mlgo-utils /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/projects/cross-project-tests /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/tools/lld/test /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/tools/clang/tools/extra/include-cleaner/test /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/tools/clang/tools/extra/test /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/tools/clang/test @/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/lit.tests /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/utils/lit /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/test
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/124995