Crash in `iree-reduce` with complex tensors

### What happened? `iree-reduce` crashes in `reduceLinalgOnTensorsDelta` when it tries to replace a `linalg` op that produces a **complex**-typed tensor. The strategy builds a zero constant via `Builder::getZeroAttr(elementType)`, which returns a **null** attribute for `complex` (it only supports int/index/float). Creating an `arith.constant` from the null attribute aborts the process. Repro: `interesting.sh` ```bash #!/bin/bash # Interestingness oracle for iree-reduce. # # A reduced candidate is "interesting" (exit 0) only while it still contains the # complex-typed linalg.generic (identified by the complex.create in its body). # This keeps the reducer from deleting the op via an earlier strategy, so it # reaches reduceLinalgOnTensorsDelta with the complex op still present. grep -q "complex.create" "$1" ``` `complex_repro.mlir` ``` // Minimal reproducer for the iree-reduce crash in reduceLinalgOnTensorsDelta. // // The linalg.generic writes a complex<f32> tensor. When the reducer decides to // replace this op with a linalg.fill of a zero constant, it calls // Builder::getZeroAttr(complex<f32>), which returns a null attribute. Building // an arith.constant from that null attribute crashes ("Failed to infer result // type(s)"). // // The op survives the earlier reduction strategies because the interestingness // check (interesting.sh) requires "complex.create" to remain present, so the // reducer reaches reduceLinalgOnTensorsDelta with the complex op still in place. func.func @main(%arg0: tensor<4xf32>) -> tensor<4xcomplex<f32>> { %empty = tensor.empty() : tensor<4xcomplex<f32>> %0 = linalg.generic { indexing_maps = [affine_map<(d0) -> (d0)>, affine_map<(d0) -> (d0)>], iterator_types = ["parallel"] } ins(%arg0 : tensor<4xf32>) outs(%empty : tensor<4xcomplex<f32>>) { ^bb0(%in: f32, %out: complex<f32>): %c = complex.create %in, %in : complex<f32> linalg.yield %c : complex<f32> } -> tensor<4xcomplex<f32>> return %0 : tensor<4xcomplex<f32>> } ``` Run using: ```bash chmod +x interesting.sh iree-reduce ./interesting.sh ./complex_repro.mlir -o reduced.mlir ``` Crashes with: ``` LLVM ERROR: Failed to infer result type(s): "arith.constant"(...) {} : () -> ( ??? ) Please report issues to https://github.com/iree-org/iree/issues and include the crash backtrace. Stack dump: 0. Program arguments: ../../fix-undef-global-hoist/iree-compiler/tools/iree-reduce ./interesting.sh ./complex_repro.mlir -o reduced.mlir #0 0x00007aa82ee7cf5b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) fix-undef-global-hoist/iree/third_party/llvm-project/llvm/lib/Support/Unix/Signals.inc:881:13 #1 0x00007aa82ee7ab83 llvm::sys::RunSignalHandlers() fix-undef-global-hoist/iree/third_party/llvm-project/llvm/lib/Support/Signals.cpp:109:18 #2 0x00007aa82ee7de71 SignalHandler(int, siginfo_t*, void*) fix-undef-global-hoist/iree/third_party/llvm-project/llvm/lib/Support/Unix/Signals.inc:448:38 #3 0x00007aa828e45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330) #4 0x00007aa828e9eb2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76 #5 0x00007aa828e9eb2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10 #6 0x00007aa828e9eb2c pthread_kill ./nptl/pthread_kill.c:89:10 #7 0x00007aa828e4527e raise ./signal/../sysdeps/posix/raise.c:27:6 #8 0x00007aa828e288ff abort ./stdlib/abort.c:81:7 #9 0x00007aa82ee0850b llvm::report_fatal_error(llvm::Twine const&, bool) fix-undef-global-hoist/iree/third_party/llvm-project/llvm/lib/Support/ErrorHandling.cpp:137:5 #10 0x00007aa82ee0858e (fix-undef-global-hoist/iree-compiler/lib/libIREECompiler.so+0x580858e) #11 0x00007aa837dabc21 (fix-undef-global-hoist/iree-compiler/lib/libIREECompiler.so+0xe7abc21) #12 0x00007aa834c50cc1 llvm::SmallVectorTemplateCommon<mlir::Type, void>::begin() fix-undef-global-hoist/iree/third_party/llvm-project/llvm/include/llvm/ADT/SmallVector.h:276:45 #13 0x00007aa834c50cc1 llvm::SmallVectorTemplateCommon<mlir::Type, void>::end() fix-undef-global-hoist/iree/third_party/llvm-project/llvm/include/llvm/ADT/SmallVector.h:278:27 #14 0x00007aa834c50cc1 llvm::SmallVector<mlir::Type, 2u>::~SmallVector() fix-undef-global-hoist/iree/third_party/llvm-project/llvm/include/llvm/ADT/SmallVector.h:1242:46 #15 0x00007aa834c50cc1 mlir::arith::ConstantOp::build(mlir::OpBuilder&, mlir::OperationState&, mlir::TypedAttr) fix-undef-global-hoist/iree-compiler/llvm-project/tools/mlir/include/mlir/Dialect/Arith/IR/ArithOps.cpp.inc:4379:1 #16 0x00007aa834c131be mlir::arith::ConstantOp::create(mlir::OpBuilder&, mlir::Location, mlir::TypedAttr) fix-undef-global-hoist/iree-compiler/llvm-project/tools/mlir/include/mlir/Dialect/Arith/IR/ArithOps.cpp.inc:4384:55 #17 0x00007aa8337db6af mlir::Operation::getInlineOpResult(unsigned int) fix-undef-global-hoist/iree/third_party/llvm-project/mlir/include/mlir/IR/Operation.h:1035:61 #18 0x00007aa8337db6af mlir::Operation::getOpResultImpl(unsigned int) fix-undef-global-hoist/iree/third_party/llvm-project/mlir/include/mlir/IR/Operation.h:1045:14 #19 0x00007aa8337db6af mlir::Operation::getResult(unsigned int) fix-undef-global-hoist/iree/third_party/llvm-project/mlir/include/mlir/IR/Operation.h:432:54 #20 0x00007aa8337db6af mlir::OpTrait::OneTypedResult<mlir::Type>::Impl<mlir::arith::ConstantOp>::getResult() fix-undef-global-hoist/iree/third_party/llvm-project/mlir/include/mlir/IR/OpDefinition.h:708:33 #21 0x00007aa8337db6af mlir::OpTrait::OneTypedResult<mlir::Type>::Impl<mlir::arith::ConstantOp>::operator mlir::Value() fix-undef-global-hoist/iree/third_party/llvm-project/mlir/include/mlir/IR/OpDefinition.h:713:54 #22 0x00007aa8337db6af mlir::iree_compiler::Reducer::reduceLinalgOnTensorsDelta(mlir::iree_compiler::Reducer::ChunkManager&, mlir::iree_compiler::Reducer::WorkItem&) fix-undef-global-hoist/iree/compiler/src/iree/compiler/Reducer/Strategies/ReduceLinalgOnTensorsDelta.cpp:114:18 #23 0x00007aa834d464dd mlir::iree_compiler::Reducer::Delta::checkChunk(mlir::iree_compiler::Reducer::Chunk, llvm::function_ref<void (mlir::iree_compiler::Reducer::ChunkManager&, mlir::iree_compiler::Reducer::WorkItem&)>, llvm::ArrayRef<mlir::iree_compiler::Reducer::Chunk>, llvm::DenseSet<mlir::iree_compiler::Reducer::Chunk, llvm::DenseMapInfo<mlir::iree_compiler::Reducer::Chunk, void>>&) fix-undef-global-hoist/iree/compiler/src/iree/compiler/Reducer/Framework/Delta.cpp:39:8 #24 0x00007aa834d46aa7 llvm::LogicalResult::failed() const fix-undef-global-hoist/iree/third_party/llvm-project/llvm/include/llvm/Support/LogicalResult.h:43:43 #25 0x00007aa834d46aa7 llvm::failed(llvm::LogicalResult) fix-undef-global-hoist/iree/third_party/llvm-project/llvm/include/llvm/Support/LogicalResult.h:71:58 #26 0x00007aa834d46aa7 mlir::iree_compiler::Reducer::Delta::runDeltaPass(llvm::function_ref<void (mlir::iree_compiler::Reducer::ChunkManager&, mlir::iree_compiler::Reducer::WorkItem&)>, llvm::StringRef) fix-undef-global-hoist/iree/compiler/src/iree/compiler/Reducer/Framework/Delta.cpp:105:11 #27 0x00007aa82f5d68ea mlir::iree_compiler::Reducer::ireeRunReducingStrategies(mlir::OwningOpRef<mlir::Operation*>, mlir::iree_compiler::Reducer::ReducerConfig&) fix-undef-global-hoist/iree/compiler/src/iree/compiler/Reducer/iree_reduce_lib.cc:39:9 #28 0x00007aa82edba149 ireeReduceMainFromCL(int, char**, mlir::MLIRContext&) fix-undef-global-hoist/iree/compiler/src/iree/compiler/API/Internal/IREEReduceToolEntryPoint.cpp:102:26 #29 0x00007aa82edba149 ireeReduceRunMain fix-undef-global-hoist/iree/compiler/src/iree/compiler/API/Internal/IREEReduceToolEntryPoint.cpp:134:7 #30 0x00007aa828e2a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3 #31 0x00007aa828e2a28b call_init ./csu/../csu/libc-start.c:128:20 #32 0x00007aa828e2a28b __libc_start_main ./csu/../csu/libc-start.c:347:5 #33 0x00005a84cb2e26e5 _start (../../fix-undef-global-hoist/iree-compiler/tools/iree-reduce+0x16e5) ``` I have a local fix and will submit a PR. ### Steps to reproduce your issue `iree-reduce ./interesting.sh ./complex_repro.mlir -o reduced.mlir` ### What component(s) does this issue relate to? Other ### Version information Tested in 3.11 and latest: 2ce6926916ed5095aa922a3cfd105f967139dd82 ### Additional context _No response_