From cdbd6be420394ca8982d5bd884f28437f75a1484 Mon Sep 17 00:00:00 2001
From: Ivan Yashchuk <ivan.yashchuk@aalto.fi>
Date: Tue, 20 Aug 2019 13:38:50 +0300
Subject: [PATCH] Added early return for empty arrays in cuda qr kernel

---
 chainerx_cc/chainerx/cuda/cuda_device/linalg.cu | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/chainerx_cc/chainerx/cuda/cuda_device/linalg.cu b/chainerx_cc/chainerx/cuda/cuda_device/linalg.cu
index e29ab6a7f2e6..f6937c75e9c9 100644
--- a/chainerx_cc/chainerx/cuda/cuda_device/linalg.cu
+++ b/chainerx_cc/chainerx/cuda/cuda_device/linalg.cu
@@ -337,6 +337,12 @@ void QrImpl(const Array& a, const Array& q, const Array& r, const Array& tau, Qr
     int64_t k = std::min(m, n);
     int64_t lda = std::max(int64_t{1}, m);
 
+    // Older versions of cuSOLVER (<10.1) might not work well with zero sized arrays
+    // therefore it's better to return earlier
+    if (a.shape().GetTotalSize() == 0 && mode != QrMode::kComplete) {
+        return;
+    }
+
     // cuSOLVER does not return correct result in this case
     if (mode == QrMode::kComplete && n == 0) {
         device.backend().CallKernel<IdentityKernel>(q);