Related: #111242

Description

mlir-opt --sccp crashes with an assertion failure in IntegerAttr::getInt() when processing a function containing an emitc.switch op whose condition has an unsigned integer type (e.g. ui32). The DeadCodeAnalysis pass invoked by SCCP calls SwitchOp::getEntrySuccessorRegions, which calls IntegerAttr::getInt() on the case value attributes to determine which branch is statically taken. However, getInt() asserts that the attribute type must be a signless integer or index — unsigned integer types such as ui32 satisfy neither condition, triggering the assertion.

Reproducer

module {
  func.func @f() {
    %0 = "emitc.constant"() {value = 1 : ui32} : () -> ui32
    emitc.switch %0 : ui32
    case 2 {
      emitc.yield
    }
    default {
      emitc.yield
    }
    return
  }
}

Command

mlir-opt --sccp reproduce.mlir

Expected behavior

--sccp either processes the file successfully or emits a diagnostic. It should not crash when emitc.switch uses an unsigned integer condition type.

Actual behavior

mlir-opt: mlir/lib/IR/BuiltinAttributes.cpp:367:
  int64_t mlir::IntegerAttr::getInt() const:
  Assertion `(getType().isIndex() || getType().isSignlessInteger()) && "must be signless integer"' failed.

Call chain

SCCP::runOnOperation
  → DataFlowSolver::initializeAndRun
    → DeadCodeAnalysis::visit
      → DeadCodeAnalysis::visitRegionBranchOperation
        → SwitchOp::getEntrySuccessorRegions   (EmitC.cpp:1569)
          → IntegerAttr::getInt()              ← assertion: not signless integer or index