From f06d9943f51fdb77b8c2841aa70258eb4dbf7f30 Mon Sep 17 00:00:00 2001
From: Chiyuan Zhang <pluskid@gmail.com>
Date: Tue, 6 Sep 2016 23:22:48 -0400
Subject: [PATCH] fix special handling of dot for SymbolicNode (#123)

---
 src/ndarray.jl                 |  3 +++
 src/symbolic-node.jl           | 12 ++++++++++--
 test/unittest/symbolic-node.jl | 17 ++++++++++++++++-
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/ndarray.jl b/src/ndarray.jl
index c3288dc323eb..2e2c806552f7 100644
--- a/src/ndarray.jl
+++ b/src/ndarray.jl
@@ -1036,6 +1036,9 @@ function _get_function_expressions(handle :: MX_handle, name)
     _use_vars.args[2:end] = flipdim(_use_vars.args[2:end], 1)
   end
 
+  # XXX: hacky way of solving the semantic difference of the axes parameter in Julia
+  # and in libmxnet.
+  # See https://github.com/dmlc/MXNet.jl/pull/123
   if name == :transpose
     transform = quote
       kwargs = Any[key != :axes ? (key, arg) : (key, reverse(map(i->length(arg)-i, arg))) for (key, arg) in kwargs]
diff --git a/src/symbolic-node.jl b/src/symbolic-node.jl
index 15ae1d7d0e2d..dfc54c3c3b1c 100644
--- a/src/symbolic-node.jl
+++ b/src/symbolic-node.jl
@@ -629,12 +629,20 @@ function _define_atomic_symbol_creator(hdr :: MX_handle)
     else
       name = ""
     end
+    
+    # XXX: hacky way of solving the problem that the arguments of `dot` should be swapped
+    # See https://github.com/dmlc/MXNet.jl/issues/55
+    if $func_name_s == "dot"
+      args = reverse(args)
+    end
 
-    if $func_name == :transpose
+    # XXX: hacky way of solving the semantic difference of the axes parameter in Julia
+    # and in libmxnet.
+    # See https://github.com/dmlc/MXNet.jl/pull/123
+    if $func_name_s == "transpose"
       kwargs = Any[key != :axes ? (key, arg) : (key, reverse(map(i->length(arg)-i, arg))) for (key, arg) in kwargs]
     end
 
-
     param_keys = String[]
     param_vals = String[]
     symbol_kws = Dict{Symbol, SymbolicNode}()
diff --git a/test/unittest/symbolic-node.jl b/test/unittest/symbolic-node.jl
index 388a74fe644b..d78b0775a983 100644
--- a/test/unittest/symbolic-node.jl
+++ b/test/unittest/symbolic-node.jl
@@ -2,7 +2,7 @@ module TestSymbolicNode
 using MXNet
 using Base.Test
 
-using ..Main: mlp2
+using ..Main: mlp2, reldiff
 
 ################################################################################
 # Test Implementations
@@ -112,6 +112,20 @@ function test_functions()
   typeof(mx.sum(data)) == mx.SymbolicNode
 end
 
+function test_dot()
+  info("SymbolicNode::dot")
+  x = mx.Variable(:x)
+  y = mx.Variable(:y)
+  z = mx.dot(x, y)
+  z_exec = mx.bind(z, context=mx.cpu(), 
+                   args=Dict(:x=>mx.ones((100, 2)), :y=>mx.ones((2, 200))))
+  mx.forward(z_exec)
+
+  ret = copy(z_exec.outputs[1])
+  @test size(ret) == (100, 200)
+  @test reldiff(ret, 2*ones(100, 200)) < 1e-6
+end
+
 ################################################################################
 # Run tests
 ################################################################################
@@ -123,5 +137,6 @@ test_infer_shape_error()
 test_saveload()
 test_attrs()
 test_functions()
+test_dot()
 
 end