!46884 issue:I5C2X7 Mul doc refresh

Merge pull request !46884 from zhangzhaoju/master_mul

docs/api/api_python/mindspore/Tensor/mindspore.Tensor.mul.rst

@@ -0,0 +1,6 @@
+mindspore.Tensor.mul
+==========================
+
+.. py:method:: mindspore.Tensor.mul(value)
+
+    详情请参考 :func:`mindspore.ops.mul`。

mindspore/ccsrc/plugin/device/cpu/kernel/cpu_kernel.cc

@@ -658,6 +658,12 @@ void GetBroadCastIndex(const std::vector<size_t> &unaligned_input_shape, const s
                         << " and output shape is " << output_shape;
     }
   }
+
+  // while input address is null, whose shape like (4, 0, 5), then the output size is zero
+  if (output_size < 1) {
+    return;
+  }
+
   // Get the flatten input indices according to "logical_shape" and "physical_shape".
   size_t offset = 1;
   size_t stride = 1;
@@ -665,7 +671,7 @@ void GetBroadCastIndex(const std::vector<size_t> &unaligned_input_shape, const s
   (*index_list)[0] = 0;  // First element is set to 0.
   for (size_t i = 0; i < size; ++i) {
     size_t increment = (logical_shape[i] == physical_shape[i] ? stride : 0);
-    for (size_t j = 0; j < (physical_shape[i] - 1) * offset; ++j) {
+    for (size_t j = 0; j + offset < physical_shape[i] * offset; ++j) {
       (*index_list)[offset + j] = (*index_list)[j] + increment;
     }
     offset *= physical_shape[i];

mindspore/python/mindspore/ops/operations/math_ops.py

@@ -2078,6 +2078,17 @@ class Mul(_MathBinaryOp):
         [ 4. 10. 18.]
     """
 
+    # Let x/y using same sig_dtype to enable implicit conversion for compatibility
+    __mindspore_signature__ = (
+        sig.make_sig('x', rw=sig.sig_rw.RW_READ, dtype=sig.sig_dtype.T),
+        sig.make_sig('y', rw=sig.sig_rw.RW_READ, dtype=sig.sig_dtype.T)
+    )
+
+    @prim_attr_register
+    def __init__(self):
+        """Initialize Xdivy."""
+        self.init_prim_io_names(inputs=['x', 'y'], outputs=['output'])
+
     @staticmethod
     def _infer_specified_mul_value(x, y):
         """Calculate min/max value for output of Mul op"""