[mlir][Interfaces] Split successor inputs from region successor #175815

matthias-springer · 2026-01-13T19:14:53Z

This commit simplifies the design of the RegionBranchOpInterface. The property of being a successor input is now independent of the region branch point.

There is a new API for querying successor inputs: RegionBranchOpInterface::getSuccessorInputs(RegionSuccessor). Note that this function does not take a RegionBranchPoint as parameter.

The RegionSuccessor API is now also simpler: it no longer stores successor inputs. A region successor is simply Region *, wrapped around a convenience API.

Note: This commit is mostly mechanical. Analyses / transformations that build on top of the RegionBranchOpInterface (e.g., visitNonControlFlowArguments API) can likely be simplified in follow-up commits.

Note for LLVM integration: Split RegionBranchOpInterface::getSuccessorRegion implementations into two functions: getSuccessorRegion and `getSuccessorInputs. (There are many examples in this commit.)

RFC: https://discourse.llvm.org/t/rfc-simplify-regionbranchopinterface-separate-successor-inputs-from-region-successor/89420/7

github-actions · 2026-01-14T10:23:05Z

🐧 Linux x64 Test Results

121197 tests passed
4756 tests skipped

✅ The build succeeded and all tests passed.

zero9178

LGTM, but please give it a few days for others to review as well

linuxlonelyeagle · 2026-01-14T17:38:23Z

mlir/lib/Analysis/DataFlow/SparseAnalysis.cpp

-                branch->getResults().slice(firstIndex, inputs.size())),
-            lattices, firstIndex);
+            branch, RegionSuccessor::parent(),
+            branch->getResults().slice(firstIndex, inputs.size()), lattices,


Could we avoid adding an extra argument to visitNonControlFlowArgumentsImpl?"Since this PR implements getSuccessorInputs, I think we could potentially leverage it in the subsequent call.

Maybe. I am trying to do that here: #175978. But I don't know that part of the code base well enough. I'm not sure if that's safe.

This PR is already large enough, so I wanted to limit the changes to the "mechanical" ones, for which we can for sure say that they are correct. Then improve that API (and maybe others) in a follow-up commit.

I see, thanks. I've approved it.😉

linuxlonelyeagle

LGTM.

llvm-ci · 2026-01-16T09:28:30Z

LLVM Buildbot has detected a new failure on builder openmp-offload-sles-build-only running on rocm-worker-hw-04-sles while building clang,flang,mlir at step 5 "compile-openmp".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/140/builds/37130

Here is the relevant piece of the build log for the reference

Step 5 (compile-openmp) failure: build (failure)
...
           ~~~~~~~^~~~~~~~~~~~~~~~
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Target/Wasm/TranslateFromWasm.cpp: In instantiation of ‘constexpr bool {anonymous}::isValueOneOf(std::byte, {anonymous}::ByteSequence<allowedFlags ...>) [with std::byte ...allowedFlags = {(std::byte)11, (std::byte)5}]’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Target/Wasm/TranslateFromWasm.cpp:965:21:   required from ‘llvm::FailureOr<{anonymous}::ExpressionParser::ParseResultWithInfo> {anonymous}::ExpressionParser::parse(mlir::OpBuilder&, {anonymous}::ByteSequence<allowedFlags ...>) [with std::byte ...ExpressionParseEnd = {(std::byte)11, (std::byte)5}]’
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Target/Wasm/TranslateFromWasm.cpp:403:10:   required from ‘llvm::FailureOr<std::byte> {anonymous}::ExpressionParser::parseBlockContent(mlir::OpBuilder&, mlir::Block*, mlir::TypeRange, mlir::Location, mlir::wasmssa::LabelLevelOpInterface, FilterT) [with FilterT = {anonymous}::ByteSequence<(std::byte)11, (std::byte)5>]’
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Target/Wasm/TranslateFromWasm.cpp:1057:57:   required from here
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Target/Wasm/TranslateFromWasm.cpp:108:18: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses]
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Target/Wasm/TranslateFromWasm.cpp:108:18: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses]
At global scope:
cc1plus: warning: unrecognized command line option ‘-Wno-deprecated-copy’
18.172 [3824/32/3859] Building CXX object tools/mlir/lib/Dialect/SCF/IR/CMakeFiles/obj.MLIRSCFDialect.dir/SCF.cpp.o
FAILED: tools/mlir/lib/Dialect/SCF/IR/CMakeFiles/obj.MLIRSCFDialect.dir/SCF.cpp.o 
ccache /usr/bin/c++ -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Itools/mlir/lib/Dialect/SCF/IR -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR -Itools/mlir/include -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/include -Iinclude -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-array-bounds -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -Wundef -Wno-unused-but-set-parameter -Wno-deprecated-copy -O3 -DNDEBUG -UNDEBUG -fno-exceptions -funwind-tables -fno-rtti -std=c++1z -MD -MT tools/mlir/lib/Dialect/SCF/IR/CMakeFiles/obj.MLIRSCFDialect.dir/SCF.cpp.o -MF tools/mlir/lib/Dialect/SCF/IR/CMakeFiles/obj.MLIRSCFDialect.dir/SCF.cpp.o.d -o tools/mlir/lib/Dialect/SCF/IR/CMakeFiles/obj.MLIRSCFDialect.dir/SCF.cpp.o -c /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp: In member function ‘mlir::ValueRange mlir::scf::ExecuteRegionOp::getSuccessorInputs(mlir::RegionSuccessor)’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp:314:31: error: operands to ?: have different types ‘mlir::Operation::result_range {aka mlir::ResultRange}’ and ‘mlir::ValueRange’
   return successor.isParent() ? getOperation()->getResults() : ValueRange();
          ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp:314:31: note:   and each type can be converted to the other
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp: In member function ‘mlir::ValueRange mlir::scf::IfOp::getSuccessorInputs(mlir::RegionSuccessor)’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp:2140:31: error: operands to ?: have different types ‘mlir::Operation::result_range {aka mlir::ResultRange}’ and ‘mlir::ValueRange’
   return successor.isParent() ? getOperation()->getResults() : ValueRange();
          ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp:2140:31: note:   and each type can be converted to the other
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp: In member function ‘mlir::ValueRange mlir::scf::IndexSwitchOp::getSuccessorInputs(mlir::RegionSuccessor)’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp:3878:31: error: operands to ?: have different types ‘mlir::Operation::result_range {aka mlir::ResultRange}’ and ‘mlir::ValueRange’
   return successor.isParent() ? getOperation()->getResults() : ValueRange();
          ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/mlir/lib/Dialect/SCF/IR/SCF.cpp:3878:31: note:   and each type can be converted to the other
At global scope:
cc1plus: warning: unrecognized command line option ‘-Wno-deprecated-copy’
18.173 [3824/31/3860] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
In file included from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/LTO/LTO.h:25:0,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/LTO/LTO.cpp:13:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/IR/ModuleSummaryIndex.h: In member function ‘llvm::TypeIdSummary& llvm::ModuleSummaryIndex::getOrInsertTypeIdSummary(llvm::StringRef)’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/IR/ModuleSummaryIndex.h:1930:33: warning: unused variable ‘GUID’ [-Wunused-variable]
     for (auto &[GUID, TypeIdPair] : make_range(TidIter))
                                 ^
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/IR/ModuleSummaryIndex.h: In member function ‘const llvm::TypeIdSummary* llvm::ModuleSummaryIndex::getTypeIdSummary(llvm::StringRef) const’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/IR/ModuleSummaryIndex.h:1944:39: warning: unused variable ‘GUID’ [-Wunused-variable]
     for (const auto &[GUID, TypeIdPair] : make_range(TidIter))
                                       ^
In file included from /usr/include/c++/7/cassert:44:0,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/ProfileData/InstrProf.h:40,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/Analysis/IndirectCallPromotionAnalysis.h:16,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/Transforms/IPO/MemProfContextDisambiguation.h:18,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/lib/LTO/LTO.cpp:60:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/ProfileData/InstrProf.h: In member function ‘llvm::ArrayRef<llvm::InstrProfValueSiteRecord> llvm::InstrProfRecord::getValueSitesForKind(uint32_t) const’:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/ProfileData/InstrProf.h:1027:23: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
     assert(IPVK_First <= ValueKind && ValueKind <= IPVK_Last &&
            ~~~~~~~~~~~^~~~

Fix this build error, which is reported by some compilers after #175815: ``` error: operands to ?: have different types ‘mlir::Operation::result_range {aka mlir::ResultRange}’ and ‘mlir::ValueRange’ return successor.isParent() ? getOperation()->getResults() : ValueRange(); ```

…#175815) This commit simplifies the design of the `RegionBranchOpInterface`. The property of being a successor input is now independent of the region branch point. There is a new API for querying successor inputs: `RegionBranchOpInterface::getSuccessorInputs(RegionSuccessor)`. Note that this function does **not** take a `RegionBranchPoint` as parameter. The `RegionSuccessor` API is now also simpler: it no longer stores successor inputs. A region successor is simply `Region *`, wrapped around a convenience API. Note: This commit is mostly mechanical. Analyses / transformations that build on top of the `RegionBranchOpInterface` (e.g., `visitNonControlFlowArguments` API) can likely be simplified in follow-up commits. Note for LLVM integration: Split `RegionBranchOpInterface::getSuccessorRegion` implementations into two functions: `getSuccessorRegion` and `getSuccessorInputs. (There are many examples in this commit.) RFC: https://discourse.llvm.org/t/rfc-simplify-regionbranchopinterface-separate-successor-inputs-from-region-successor/89420/7

Fix this build error, which is reported by some compilers after llvm#175815: ``` error: operands to ?: have different types ‘mlir::Operation::result_range {aka mlir::ResultRange}’ and ‘mlir::ValueRange’ return successor.isParent() ? getOperation()->getResults() : ValueRange(); ```

…#175815) This commit simplifies the design of the `RegionBranchOpInterface`. The property of being a successor input is now independent of the region branch point. There is a new API for querying successor inputs: `RegionBranchOpInterface::getSuccessorInputs(RegionSuccessor)`. Note that this function does **not** take a `RegionBranchPoint` as parameter. The `RegionSuccessor` API is now also simpler: it no longer stores successor inputs. A region successor is simply `Region *`, wrapped around a convenience API. Note: This commit is mostly mechanical. Analyses / transformations that build on top of the `RegionBranchOpInterface` (e.g., `visitNonControlFlowArguments` API) can likely be simplified in follow-up commits. Note for LLVM integration: Split `RegionBranchOpInterface::getSuccessorRegion` implementations into two functions: `getSuccessorRegion` and `getSuccessorInputs. (There are many examples in this commit.) RFC: https://discourse.llvm.org/t/rfc-simplify-regionbranchopinterface-separate-successor-inputs-from-region-successor/89420/7

Fix this build error, which is reported by some compilers after llvm#175815: ``` error: operands to ?: have different types ‘mlir::Operation::result_range {aka mlir::ResultRange}’ and ‘mlir::ValueRange’ return successor.isParent() ? getOperation()->getResults() : ValueRange(); ```

Integrate llvm at 3ca2a5fc0b84762f0e7d8a0e613fd69f7e344219 This includes the **RegionBranchOpInterface** related changes from llvm/llvm-project#175815

This reverts commit 8ca6c8f13398c5bbe961e9bc874d6b3de398e5e8. Also uses `visitNonControlFlowArguments` new API since llvm/llvm-project#175815

…#175815) This commit simplifies the design of the `RegionBranchOpInterface`. The property of being a successor input is now independent of the region branch point. There is a new API for querying successor inputs: `RegionBranchOpInterface::getSuccessorInputs(RegionSuccessor)`. Note that this function does **not** take a `RegionBranchPoint` as parameter. The `RegionSuccessor` API is now also simpler: it no longer stores successor inputs. A region successor is simply `Region *`, wrapped around a convenience API. Note: This commit is mostly mechanical. Analyses / transformations that build on top of the `RegionBranchOpInterface` (e.g., `visitNonControlFlowArguments` API) can likely be simplified in follow-up commits. Note for LLVM integration: Split `RegionBranchOpInterface::getSuccessorRegion` implementations into two functions: `getSuccessorRegion` and `getSuccessorInputs. (There are many examples in this commit.) RFC: https://discourse.llvm.org/t/rfc-simplify-regionbranchopinterface-separate-successor-inputs-from-region-successor/89420/7

Fix this build error, which is reported by some compilers after llvm#175815: ``` error: operands to ?: have different types ‘mlir::Operation::result_range {aka mlir::ResultRange}’ and ‘mlir::ValueRange’ return successor.isParent() ? getOperation()->getResults() : ValueRange(); ```

This reverts commit 8ca6c8f13398c5bbe961e9bc874d6b3de398e5e8. Also uses `visitNonControlFlowArguments` new API since llvm/llvm-project#175815 Signed-off-by: Keshav Vinayak Jha <[email protected]>

matthias-springer force-pushed the users/matthias-springer/split_successor_inputs branch from 4976ae4 to 792ea47 Compare January 13, 2026 19:18

Base automatically changed from users/matthias-springer/region_successor to main January 14, 2026 09:57

matthias-springer force-pushed the users/matthias-springer/split_successor_inputs branch from 792ea47 to 6feec83 Compare January 14, 2026 09:58

matthias-springer force-pushed the users/matthias-springer/split_successor_inputs branch 3 times, most recently from 6b144e4 to 072b98c Compare January 14, 2026 11:12

matthias-springer marked this pull request as ready for review January 14, 2026 11:13

matthias-springer requested review from PeimingLiu, aartbik, fabianmcg, ftynse, nicolasvasilache, rolfmorel and yinying-lisa-li as code owners January 14, 2026 11:13

matthias-springer requested a review from zero9178 January 14, 2026 11:13

llvmbot added mlir:gpu mlir:affine mlir:sparse Sparse compiler in MLIR mlir flang Flang issues not falling into any other category mlir:bufferization Bufferization infrastructure mlir:memref mlir:scf mlir:async mlir:emitc mlir:openacc mlir:shape flang:fir-hlfir openacc labels Jan 14, 2026

matthias-springer requested a review from andykaylor as a code owner January 14, 2026 11:27

llvmbot added the ClangIR Anything related to the ClangIR project label Jan 14, 2026

matthias-springer force-pushed the users/matthias-springer/split_successor_inputs branch from f09ea5a to cc13c77 Compare January 14, 2026 11:28

matthias-springer requested review from rengolin and removed request for yinying-lisa-li January 14, 2026 11:36

zero9178 approved these changes Jan 14, 2026

View reviewed changes

matthias-springer force-pushed the users/matthias-springer/split_successor_inputs branch from cc13c77 to bf8c119 Compare January 14, 2026 14:38

matthias-springer mentioned this pull request Jan 14, 2026

[mlir][Analysis][NFC] Clean up visitNonControlFlowArguments #175978

Closed

linuxlonelyeagle reviewed Jan 14, 2026

View reviewed changes

linuxlonelyeagle approved these changes Jan 14, 2026

View reviewed changes

[mlir][Interfaces] Split successor inputs from region successor

3b1d7ed

matthias-springer force-pushed the users/matthias-springer/split_successor_inputs branch from bf8c119 to 3b1d7ed Compare January 16, 2026 07:55

matthias-springer merged commit f764337 into main Jan 16, 2026
12 checks passed

matthias-springer deleted the users/matthias-springer/split_successor_inputs branch January 16, 2026 09:16

matthias-springer added a commit that referenced this pull request Jan 16, 2026

[mlir] Fix build after #175815

5b3d64f

matthias-springer mentioned this pull request Jan 16, 2026

[mlir] Fix build after #175815 #176332

Merged

pravg-amd mentioned this pull request Jan 20, 2026

Integrate LLVM at 3ca2a5fc0b84762f0e7d8a0e613fd69f7e344219 llvm/torch-mlir#4435

Merged

amd-eochoalo mentioned this pull request Jan 22, 2026

Reapply "LLVM Integrate@6cc18a8e4338 (#23226)" iree-org/iree#23236

Merged

matthias-springer mentioned this pull request Jan 23, 2026

[mlir][interface] Add getNonSuccessorInputs API to RegionBranchOpInterface #175212

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[mlir][Interfaces] Split successor inputs from region successor #175815

[mlir][Interfaces] Split successor inputs from region successor #175815

Uh oh!

matthias-springer commented Jan 13, 2026 •

edited

Loading

Uh oh!

github-actions bot commented Jan 14, 2026 •

edited

Loading

Uh oh!

zero9178 left a comment

Uh oh!

linuxlonelyeagle Jan 14, 2026

Uh oh!

matthias-springer Jan 14, 2026 •

edited

Loading

Uh oh!

linuxlonelyeagle Jan 14, 2026

Uh oh!

linuxlonelyeagle left a comment

Uh oh!

Uh oh!

llvm-ci commented Jan 16, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

[mlir][Interfaces] Split successor inputs from region successor #175815

[mlir][Interfaces] Split successor inputs from region successor #175815

Uh oh!

Conversation

matthias-springer commented Jan 13, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions bot commented Jan 14, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

🐧 Linux x64 Test Results

Uh oh!

zero9178 left a comment

Choose a reason for hiding this comment

Uh oh!

linuxlonelyeagle Jan 14, 2026

Choose a reason for hiding this comment

Uh oh!

matthias-springer Jan 14, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

linuxlonelyeagle Jan 14, 2026

Choose a reason for hiding this comment

Uh oh!

linuxlonelyeagle left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

llvm-ci commented Jan 16, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

matthias-springer commented Jan 13, 2026 •

edited

Loading

github-actions bot commented Jan 14, 2026 •

edited

Loading

matthias-springer Jan 14, 2026 •

edited

Loading