[onert] Ease restriction on shape validation (#14950)

- Fix too strong shape restriction
- Add test case for rank > 4

ONE-DCO-1.0-Signed-off-by: Chunseok Lee <chunseok.lee@samsung.com>

Author: chunseoklee

runtime/onert/core/src/compiler/ShapeValidator.cc

@@ -563,9 +563,8 @@ void ShapeValidator::visit(const ir::operation::Gather &node)
   const auto &indices_shape = operands.at(indices_index).shape();
   const auto &ofm_shape = operands.at(ofm_index).shape();
 
-  OP_REQUIRES(ifm_shape.rank() <= 4);
-  OP_REQUIRES(indices_shape.rank() <= 3);
-  OP_REQUIRES(ofm_shape.rank() <= 4);
+  // Since gather implementation is general enough, we do not restrict max rank
+  OP_REQUIRES(ifm_shape.rank() + indices_shape.rank() - 1 == ofm_shape.rank());
 }
 
 void ShapeValidator::visit(const ir::operation::DepthToSpace &node)

runtime/tests/nnfw_api/src/GenModelTests/one_op_tests/Gather.test.cc

@@ -18,6 +18,32 @@
 
 #include "common.h"
 
+TEST_F(GenModelTest, OneOp_Gather_rank5)
+{
+  CircleGen cgen;
+
+  std::vector<int32_t> index_data{1};
+
+  auto index_buf = cgen.addBuffer(index_data);
+
+  int input = cgen.addTensor({{3, 1, 1, 2, 2}, circle::TensorType::TensorType_FLOAT32});
+  int indice = cgen.addTensor({{1}, circle::TensorType::TensorType_INT32, index_buf});
+  int output = cgen.addTensor({{1, 1, 1, 2, 2}, circle::TensorType::TensorType_FLOAT32});
+
+  cgen.addOperatorGather({{input, indice}, {output}}, 0 /*axis*/);
+  cgen.setInputsAndOutputs({input}, {output});
+
+  _context = std::make_unique<GenModelTestContext>(cgen.finish());
+
+  TestCaseData tc;
+  tc.addInput<float>({1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3});
+  tc.addOutput<float>({2, 2, 2, 2});
+  _context->addTestCase(tc);
+  _context->setBackends({"cpu"});
+
+  SUCCEED();
+}
+
 TEST_F(GenModelTest, OneOp_Gather_Q4_0)
 {
   CircleGen cgen;