From ec5cab790eb93c48adc9dcd9a1fa0eeb0adb6253 Mon Sep 17 00:00:00 2001
From: Carl-Martin Pfeiler <carl-martin.pfeiler@ipp.mpg.de>
Date: Fri, 24 Jan 2025 14:20:46 +0100
Subject: [PATCH] mxp: Test .view(...).view(...)

---
 tests/test_mxp.cxx | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/tests/test_mxp.cxx b/tests/test_mxp.cxx
index 945cbeb4..d95e7696 100644
--- a/tests/test_mxp.cxx
+++ b/tests/test_mxp.cxx
@@ -742,6 +742,48 @@ TEST(mxp, view_slice_2D)
   }
 }
 
+TEST(mxp, view_view_axaxaxpy)
+{
+  const int nx{3};
+  const int ny{5};
+  const float x_init{exp2f(-23)};
+  const float y_init{1.f};
+  const float a{1.f / 3.f};
+
+  EXPECT_NE(y_init, y_init + x_init);
+
+  const std::vector<float> x(nx, x_init);
+  /* */ std::vector<float> y(ny, y_init);
+
+  const auto gt_x = gt::adapt<1>(x.data(), x.size());
+  /* */ auto gt_y = gt::adapt<1>(y.data(), y.size());
+
+  using gt::placeholders::_s;
+
+  gt_y.view(_s(1, -1)).view(_s(1, -1)) =
+    gt_y.view(_s(1, -1)).view(_s(1, -1)) + a * gt_x.view(_s(1, -1)) +
+    a * gt_x.view(_s(1, -1)) + a * gt_x.view(_s(1, -1));
+
+  EXPECT_EQ(y[0], y_init);
+  EXPECT_EQ(y[1], y_init);
+  EXPECT_EQ(y[2], y_init);
+  EXPECT_EQ(y[3], y_init);
+  EXPECT_EQ(y[4], y_init);
+
+  const auto mxp_x = mxp::adapt<1, double>(x.data(), x.size());
+  /* */ auto mxp_y = mxp::adapt<1, double>(y.data(), y.size());
+
+  mxp_y.view(_s(1, -1)).view(_s(1, -1)) =
+    mxp_y.view(_s(1, -1)).view(_s(1, -1)) + a * mxp_x.view(_s(1, -1)) +
+    a * mxp_x.view(_s(1, -1)) + a * mxp_x.view(_s(1, -1));
+
+  EXPECT_EQ(y[0], y_init);
+  EXPECT_EQ(y[1], y_init);
+  EXPECT_EQ(y[2], y_init + x_init);
+  EXPECT_EQ(y[3], y_init);
+  EXPECT_EQ(y[4], y_init);
+}
+
 TEST(mxp, view_complex_axaxaxpy)
 {
   using complex32_t = gt::complex<float>;