Fix Get Item Problem. Warning: This change has not passed a completely check.

python/jittor/src/ops/getitem_op.cc

@@ -572,6 +572,8 @@ void GetitemOp::jit_run() {
                 index_t(vp@d[0 @for(j,0,VD,@if((VS@d>>j)&1, + i@{j+FOV} * vs@d@@s@j,))])
             , ??? ))))));
         )
+        @for(d, 0, IDIM, if (iid@d < 0) iid@d += ishape@d;
+        )
         auto iid = 0 @for(d, 0, IDIM,  + iid@d * istride@d);
         op[oid] = ip[iid];
     }

python/jittor/test/test_getitem_simple.py

@@ -0,0 +1,48 @@
+# ***************************************************************
+# Copyright (c) 2023 Jittor. All Rights Reserved. 
+# Maintainers: Dun Liang <[email protected]>. 
+# This file is subject to the terms and conditions defined in
+# file 'LICENSE.txt', which is part of this source code package.
+# ***************************************************************
+import unittest
+import jittor as jt
+import numpy as np
+
+class TestGetItemSimple(unittest.TestCase):
+    def test_get_by_pos_int(self):
+        a = jt.array([-2,3,4,-5,-6])
+        b = a[3]
+        b.sync()
+        assert b.item() == -5
+    def test_get_by_neg_int(self):
+        a = jt.array([-2,3,4,-5,-6])
+        b = a[-3]
+        b.sync()
+        assert b.item() == 4
+    def test_get_slice(self):
+        a = jt.array([-2,3,4,-5,-6])
+        b = a[-1:-3:-1].numpy().tolist()
+        assert len(b) == 2
+        assert b[0] == -6
+        assert b[1] == -5
+    def test_get_by_list(self):
+        a = jt.array([-2,3,4,-5,-6])
+        b = a[[-1, -3, 1]].numpy().tolist()
+        assert len(b) == 3
+        assert b[0] == -6
+        assert b[1] == 4
+        assert b[2] == 3
+    def test_multidim_by_points(self):
+        a = jt.arange(24).reshape(2, 3, 4)
+        b = jt.array([0, 1, 0])
+        c = jt.array([0, -1, 1])
+        d = jt.array([-2, 0, 3])
+        e = a[(b, c, d)].numpy().tolist()
+        assert len(e) == 3
+        assert e[0] == 2
+        assert e[1] == 20
+        assert e[2] == 7
+
+if __name__ == "__main__":
+    jt.flags.use_cuda = True
+    unittest.main()