From bca303165a67c44f0ca1f213381c78213c4342f6 Mon Sep 17 00:00:00 2001
From: ShenLiang <2282912238@qq.com>
Date: Fri, 31 Jul 2020 14:27:38 +0800
Subject: [PATCH] fix inverse bug (#25641)

* fix inverse bug, test=develop

* fix the untest, test=develop

* add singular checking, test=develop

* fix the utest, test=develop

* use memory::copy, test=develop

* fix bost_get, test=develop

* fix position, test=develop
---
 .../fluid/operators/math/matrix_inverse.cu.cc | 11 +++++
 .../fluid/tests/unittests/test_inverse_op.py  | 42 +++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/paddle/fluid/operators/math/matrix_inverse.cu.cc b/paddle/fluid/operators/math/matrix_inverse.cu.cc
index 8ea4e582ad1..614f89a048c 100644
--- a/paddle/fluid/operators/math/matrix_inverse.cu.cc
+++ b/paddle/fluid/operators/math/matrix_inverse.cu.cc
@@ -67,6 +67,8 @@ class MatrixInverseFunctor<platform::CUDADeviceContext, T> {
 
     auto blas = math::GetBlas<platform::CUDADeviceContext, T>(context);
 
+    std::vector<int> info;  // only for singular checking
+    info.resize(batch_size);
     // This functions in cuBLAS is intended to be used for matrices of small
     // sizes where the launch overhead is a significant factor.
     // TODO(Xreki): call function in cusolver for large matrices.
@@ -91,6 +93,15 @@ class MatrixInverseFunctor<platform::CUDADeviceContext, T> {
                         reinterpret_cast<const T**>(tmp_gpu_ptrs_data->ptr()),
                         gpu_pivot_ptr, gpu_inv_ptrs, gpu_info_ptr, batch_size);
     }
+    memory::Copy(platform::CPUPlace(), info.data(),
+                 BOOST_GET_CONST(platform::CUDAPlace, context.GetPlace()),
+                 gpu_info_ptr, sizeof(int) * batch_size, context.stream());
+    for (int i = 0; i < batch_size; ++i) {
+      PADDLE_ENFORCE_EQ(info[i], 0,
+                        platform::errors::PreconditionNotMet(
+                            "For batch [%d]: U(%d, %d) is zero, singular U.", i,
+                            info[i], info[i]));
+    }
   }
 };
 
diff --git a/python/paddle/fluid/tests/unittests/test_inverse_op.py b/python/paddle/fluid/tests/unittests/test_inverse_op.py
index 13cb2b1f8b1..3aecbe6e00b 100644
--- a/python/paddle/fluid/tests/unittests/test_inverse_op.py
+++ b/python/paddle/fluid/tests/unittests/test_inverse_op.py
@@ -140,5 +140,47 @@ class TestInverseAPIError(unittest.TestCase):
         self.assertRaises(ValueError, paddle.inverse, input)
 
 
+class TestInverseSingularAPI(unittest.TestCase):
+    def setUp(self):
+        self.places = [fluid.CPUPlace()]
+        if core.is_compiled_with_cuda():
+            self.places.append(fluid.CUDAPlace(0))
+
+    def check_static_result(self, place, with_out=False):
+        with fluid.program_guard(fluid.Program(), fluid.Program()):
+            input = fluid.data(name="input", shape=[4, 4], dtype="float64")
+            if with_out:
+                out = fluid.data(name="output", shape=[4, 4], dtype="float64")
+            else:
+                out = None
+            result = paddle.inverse(input=input, out=out)
+
+            input_np = np.zeros([4, 4]).astype("float64")
+
+            exe = fluid.Executor(place)
+            try:
+                fetches = exe.run(fluid.default_main_program(),
+                                  feed={"input": input_np},
+                                  fetch_list=[result])
+            except fluid.core.EnforceNotMet as ex:
+                print("The mat is singular")
+                pass
+
+    def test_static(self):
+        for place in self.places:
+            self.check_static_result(place=place)
+
+    def test_dygraph(self):
+        for place in self.places:
+            with fluid.dygraph.guard(place):
+                input_np = np.ones([4, 4]).astype("float64")
+                input = fluid.dygraph.to_variable(input_np)
+                try:
+                    result = paddle.inverse(input)
+                except fluid.core.EnforceNotMet as ex:
+                    print("The mat is singular")
+                    pass
+
+
 if __name__ == "__main__":
     unittest.main()
-- 
GitLab