[llvm] [LV] Ignore some costs when loop gets fully unrolled (PR #106699)

Mon Dec 9 12:54:37 PST 2024

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-x86_64-debian-fast` running on `gribozavr4` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/56/builds/14076

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
17.214 [881/51/5129] Copying llvm_bitwriter.mli to build area
17.214 [881/50/5130] Copying bitwriter_ocaml.c to build area
17.218 [880/50/5131] Linking CXX static library lib/libLLVMExecutionEngine.a
17.220 [879/50/5132] Linking CXX static library lib/libLLVMCGData.a
17.222 [879/49/5133] Linking CXX static library lib/libLLVMSandboxIR.a
17.223 [879/48/5134] Linking CXX static library lib/libLLVMMCJIT.a
17.262 [879/47/5135] Building OCaml stub object file analysis_ocaml.o
17.263 [878/47/5136] Linking CXX static library lib/libLLVMTransformUtils.a
17.265 [868/56/5137] Building OCaml stub object file bitwriter_ocaml.o
17.267 [867/56/5138] Building CXX object lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o
FAILED: lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/1/clang-x86_64-debian-fast/llvm.obj/lib/Transforms/Vectorize -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Transforms/Vectorize -I/b/1/clang-x86_64-debian-fast/llvm.obj/include -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include -std=c++11 -Wdocumentation -Wno-documentation-deprecated-sync -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o -MF lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o.d -o lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o -c /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:117:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/IR/MDBuilder.h:64:14: warning: parameter 'Do' not found in the function declaration [-Wdocumentation]
  /// @param Do these weights come from __builtin_expect*
             ^~
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/IR/MDBuilder.h:64:14: note: did you mean 'IsExpected'?
  /// @param Do these weights come from __builtin_expect*
             ^~
             IsExpected
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/IR/MDBuilder.h:78:14: warning: parameter 'Do' not found in the function declaration [-Wdocumentation]
  /// @param Do these weights come from __builtin_expect*
             ^~
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/IR/MDBuilder.h:78:14: note: did you mean 'IsExpected'?
  /// @param Do these weights come from __builtin_expect*
             ^~
             IsExpected
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:2699:49: error: reference to local binding 'IV' declared in enclosing function 'addFullyUnrolledInstructionsToIgnore'
               [&](const User *U) { return U == IV || U == Cmp; }))
                                                ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:2694:21: note: 'IV' declared here
  for (const auto &[IV, IndDesc] : IL) {
                    ^
2 warnings and 1 error generated.
17.267 [867/55/5139] Copying llvm_transform_utils.ml to build area
17.267 [867/54/5140] Copying llvm_transform_utils.mli to build area
17.267 [867/53/5141] Copying transform_utils_ocaml.c to build area
17.269 [867/52/5142] Linking CXX static library lib/libLLVMFrontendOffloading.a
17.270 [867/51/5143] Linking CXX static library lib/libLLVMAggressiveInstCombine.a
17.270 [867/50/5144] Linking CXX static library lib/libLLVMHipStdPar.a
17.272 [867/49/5145] Linking CXX static library lib/libLLVMLinker.a
17.274 [867/48/5146] Linking CXX static library lib/libLLVMObjCARCOpts.a
17.278 [867/47/5147] Linking CXX executable bin/llvm-size
17.280 [867/46/5148] Linking CXX executable bin/llvm-debuginfod-find
17.289 [867/45/5149] Linking CXX static library lib/libLLVMInstCombine.a
17.292 [867/44/5150] Linking CXX static library lib/libLLVMInstrumentation.a
17.305 [867/43/5151] Building OCaml library llvm_analysis
17.312 [867/42/5152] Building OCaml library llvm_bitwriter
17.320 [867/41/5153] Building OCaml stub object file target_ocaml.o

```

</details>

https://github.com/llvm/llvm-project/pull/106699