[mlir] fix crash when scf utils work on llvm.func (#120688)

fixed #119378

Author: cxy-1993

mlir/lib/Dialect/SCF/Utils/Utils.cpp

@@ -130,7 +130,7 @@ FailureOr<func::FuncOp> mlir::outlineSingleBlockRegion(RewriterBase &rewriter,
 
   // Outline before current function.
   OpBuilder::InsertionGuard g(rewriter);
-  rewriter.setInsertionPoint(region.getParentOfType<func::FuncOp>());
+  rewriter.setInsertionPoint(region.getParentOfType<FunctionOpInterface>());
 
   SetVector<Value> captures;
   getUsedValuesDefinedAbove(region, captures);

mlir/test/Transforms/scf-if-utils.mlir

@@ -73,3 +73,30 @@ func.func @outline_empty_if_else(%cond: i1, %a: index, %b: memref<?xf32>, %c: i8
   }
   return
 }
+
+// -----
+
+// This test checks scf utils can work on llvm func.
+
+//      CHECK: func @outlined_then0() {
+// CHECK-NEXT:   return
+// CHECK-NEXT: }
+//      CHECK: func @outlined_else0(%{{.*}}: i1, %{{.*}}: i32) {
+// CHECK-NEXT:   "some_op"(%{{.*}}, %{{.*}}) : (i1, i32) -> ()
+// CHECK-NEXT:   return
+// CHECK-NEXT: }
+//      CHECK: llvm.func @llvm_func(%{{.*}}: i1, %{{.*}}: i32) {
+// CHECK-NEXT:   scf.if %{{.*}} {
+// CHECK-NEXT:     func.call @outlined_then0() : () -> ()
+// CHECK-NEXT:   } else {
+// CHECK-NEXT:     func.call @outlined_else0(%{{.*}}, %{{.*}}) : (i1, i32) -> ()
+// CHECK-NEXT:   }
+// CHECK-NEXT:   llvm.return
+// CHECK-NEXT: }
+llvm.func @llvm_func(%cond: i1, %a: i32) {
+  scf.if %cond {
+  } else {
+    "some_op"(%cond, %a) : (i1, i32) -> ()
+  }
+  llvm.return
+}

mlir/test/lib/Dialect/SCF/TestSCFUtils.cpp

@@ -79,6 +79,10 @@ struct TestSCFIfUtilsPass
   StringRef getDescription() const final { return "test scf.if utils"; }
   explicit TestSCFIfUtilsPass() = default;
 
+  void getDependentDialects(DialectRegistry &registry) const override {
+    registry.insert<func::FuncDialect>();
+  }
+
   void runOnOperation() override {
     int count = 0;
     getOperation().walk([&](scf::IfOp ifOp) {