[llvm] [Utils] Consolidate `LockstepReverseIterator` into own header (NFC) (PR #116657)

Fri Feb 21 13:42:30 PST 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-nvptx-nvidia-ubuntu` running on `as-builder-7` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/180/builds/13363

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:176:33:   required from ‘bool llvm::VPlanPatternMatch::Recipe_match<Ops_t, Opcode, Commutative, RecipeTys>::match(const llvm::VPRecipeBase*) const [with Ops_t = std::tuple<>; unsigned int Opcode = 0; bool Commutative = false; RecipeTys = {llvm::VPCanonicalIVPHIRecipe}]’
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:147:25:   required from ‘bool llvm::VPlanPatternMatch::Recipe_match<Ops_t, Opcode, Commutative, RecipeTys>::match(const llvm::VPValue*) const [with Ops_t = std::tuple<>; unsigned int Opcode = 0; bool Commutative = false; RecipeTys = {llvm::VPCanonicalIVPHIRecipe}]’
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:171:45:   required from ‘llvm::VPlanPatternMatch::Recipe_match<std::tuple<llvm::VPlanPatternMatch::Recipe_match<std::tuple<>, 0, false, llvm::VPCanonicalIVPHIRecipe>, llvm::VPlanPatternMatch::specific_intval<0> >, 0, false, llvm::VPScalarIVStepsRecipe>::match(const llvm::VPRecipeBase*) const::<lambda(auto:26, unsigned int)> [with auto:26 = llvm::VPlanPatternMatch::Recipe_match<std::tuple<>, 0, false, llvm::VPCanonicalIVPHIRecipe>]’
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:200:14:   required from ‘bool llvm::VPlanPatternMatch::Recipe_match<Ops_t, Opcode, Commutative, RecipeTys>::all_of_tuple_elements(std::index_sequence<Idx ...>, Fn) const [with Fn = llvm::VPlanPatternMatch::Recipe_match<std::tuple<llvm::VPlanPatternMatch::Recipe_match<std::tuple<>, 0, false, llvm::VPCanonicalIVPHIRecipe>, llvm::VPlanPatternMatch::specific_intval<0> >, 0, false, llvm::VPScalarIVStepsRecipe>::match(const llvm::VPRecipeBase*) const::<lambda(auto:26, unsigned int)>; long unsigned int ...Is = {0, 1}; Ops_t = std::tuple<llvm::VPlanPatternMatch::Recipe_match<std::tuple<>, 0, false, llvm::VPCanonicalIVPHIRecipe>, llvm::VPlanPatternMatch::specific_intval<0> >; unsigned int Opcode = 0; bool Commutative = false; RecipeTys = {llvm::VPScalarIVStepsRecipe}; std::index_sequence<Idx ...> = std::integer_sequence<long unsigned int, 0, 1>]’
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:170:30:   required from ‘bool llvm::VPlanPatternMatch::Recipe_match<Ops_t, Opcode, Commutative, RecipeTys>::match(const llvm::VPRecipeBase*) const [with Ops_t = std::tuple<llvm::VPlanPatternMatch::Recipe_match<std::tuple<>, 0, false, llvm::VPCanonicalIVPHIRecipe>, llvm::VPlanPatternMatch::specific_intval<0> >; unsigned int Opcode = 0; bool Commutative = false; RecipeTys = {llvm::VPScalarIVStepsRecipe}]’
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:147:25:   required from ‘bool llvm::VPlanPatternMatch::Recipe_match<Ops_t, Opcode, Commutative, RecipeTys>::match(const llvm::VPValue*) const [with Ops_t = std::tuple<llvm::VPlanPatternMatch::Recipe_match<std::tuple<>, 0, false, llvm::VPCanonicalIVPHIRecipe>, llvm::VPlanPatternMatch::specific_intval<0> >; unsigned int Opcode = 0; bool Commutative = false; RecipeTys = {llvm::VPScalarIVStepsRecipe}]’
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:29:17:   required from ‘bool llvm::VPlanPatternMatch::match(Val*, const Pattern&) [with Val = llvm::VPValue; Pattern = llvm::VPlanPatternMatch::Recipe_match<std::tuple<llvm::VPlanPatternMatch::Recipe_match<std::tuple<>, 0, false, llvm::VPCanonicalIVPHIRecipe>, llvm::VPlanPatternMatch::specific_intval<0> >, 0, false, llvm::VPScalarIVStepsRecipe>]’
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanUtils.cpp:65:18:   required from here
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h:199:61: warning: parameter ‘P’ set but not used [-Wunused-but-set-parameter]
50.187 [688/6/2022] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SimplifyCFG.cpp.o
FAILED: lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SimplifyCFG.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/c++ -DGTEST_HAS_RTTI=0 -DLLVM_EXPORTS -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/build/lib/Transforms/Utils -I/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils -I/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/build/include -I/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -fPIC  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SimplifyCFG.cpp.o -MF lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SimplifyCFG.cpp.o.d -o lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SimplifyCFG.cpp.o -c /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp: In function ‘bool sinkCommonCodeFromPredecessors(llvm::BasicBlock*, llvm::DomTreeUpdater*)’:
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2503:3: error: reference to ‘LockstepReverseIterator’ is ambiguous
 2503 |   LockstepReverseIterator<true> LRI(UnconditionalPreds);
      |   ^~~~~~~~~~~~~~~~~~~~~~~
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:1787:7: note: candidates are: ‘class {anonymous}::LockstepReverseIterator’
 1787 | class LockstepReverseIterator {
      |       ^~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:77:
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/include/llvm/Transforms/Utils/LockstepReverseIterator.h:41:7: note:                 ‘template<bool EarlyFailure> class llvm::LockstepReverseIterator’
   41 | class LockstepReverseIterator
      |       ^~~~~~~~~~~~~~~~~~~~~~~
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2503:33: error: ‘LRI’ was not declared in this scope
 2503 |   LockstepReverseIterator<true> LRI(UnconditionalPreds);
      |                                 ^~~
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2533:44: error: reference to ‘LockstepReverseIterator’ is ambiguous
 2533 |     auto ProfitableToSinkInstruction = [&](LockstepReverseIterator<true> &LRI) {
      |                                            ^~~~~~~~~~~~~~~~~~~~~~~
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:1787:7: note: candidates are: ‘class {anonymous}::LockstepReverseIterator’
 1787 | class LockstepReverseIterator {
      |       ^~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:77:
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/include/llvm/Transforms/Utils/LockstepReverseIterator.h:41:7: note:                 ‘template<bool EarlyFailure> class llvm::LockstepReverseIterator’
   41 | class LockstepReverseIterator
      |       ^~~~~~~~~~~~~~~~~~~~~~~
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2533:44: error: ‘LockstepReverseIterator’ has not been declared
 2533 |     auto ProfitableToSinkInstruction = [&](LockstepReverseIterator<true> &LRI) {
      |                                            ^~~~~~~~~~~~~~~~~~~~~~~
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2533:67: error: expected ‘,’ or ‘...’ before ‘<’ token
 2533 |     auto ProfitableToSinkInstruction = [&](LockstepReverseIterator<true> &LRI) {
      |                                                                   ^
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp: At global scope:
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2206:13: warning: ‘bool canSinkInstructions(llvm::ArrayRef<llvm::Instruction*>, llvm::DenseMap<const llvm::Use*, llvm::SmallVector<llvm::Value*, 4> >&)’ defined but not used [-Wunused-function]
 2206 | static bool canSinkInstructions(
      |             ^~~~~~~~~~~~~~~~~~~
53.658 [688/4/2024] Building CXX object lib/MC/MCParser/CMakeFiles/LLVMMCParser.dir/AsmParser.cpp.o
60.316 [688/2/2026] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
60.464 [688/1/2027] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/AsmPrinter.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/116657