Fix KnownFailure relative to gemm (and partially solves #415).

This does not change the logic of the Gemm optimizer, so #415 might still be needed in the future. This change: - apply the following optimization whether or not the transpose is inplace: T.dot(X,Y).T -> T.dot(Y.T, X.T). The latter form is expected by the Gemm optimizer. - removes the Warning class raised in test_blas.py:just_gemm, because it was caught silently, hiding the fact that another case was failing. A "Failure" is now thrown instead; - adds another test case for transposition; - makes the first case in test_blas.py:test_inplace0 expect a "gemm_no_inplace" instead of _dot22.

Fix KnownFailure relative to gemm (and partially solves #415).
a2ea8184 · Pascal Lamblin · 7c854bef · a2ea8184 · a2ea8184
--- a/theano/tensor/opt.py
+++ b/theano/tensor/opt.py
@@ -2824,10 +2824,21 @@ register_canonicalize(constant_folding, 'fast_compile')
 register_stabilize(constant_folding) # because
 register_specialize(constant_folding)

-
+## dot(x,y).T -> dot(y.T, x.T)
 inplace_matrix_transpose = T.DimShuffle([False,False], [1,0], inplace=True)
-local_transposed_dot = gof.PatternSub((inplace_matrix_transpose, (T.dot, 'x', 'y')),
-        (T.dot, (inplace_matrix_transpose, 'y'), (inplace_matrix_transpose, 'x')))
+matrix_transpose = T.DimShuffle([False,False], [1,0], inplace=False)
+# The transformation should be apply whether or not the transpose is inplace.
+# The newly-introduced transpositions are not inplace, this will be taken care
+# of in a later optimization phase.
+# First optimization: inplace
+local_transposed_dot_inplace = gof.PatternSub(
+        (inplace_matrix_transpose, (T.dot, 'x', 'y')),
+        (T.dot, (matrix_transpose, 'y'), (matrix_transpose, 'x')))
+register_canonicalize(local_transposed_dot_inplace, name='local_transposed_dot_inplace')
+# Second optimization: not inplace
+local_transposed_dot = gof.PatternSub(
+        (matrix_transpose, (T.dot, 'x', 'y')),
+        (T.dot, (matrix_transpose, 'y'), (matrix_transpose, 'x')))
 register_canonicalize(local_transposed_dot, name='local_transposed_dot')

 def _is_1(expr):

--- a/theano/tensor/tests/test_blas.py
+++ b/theano/tensor/tests/test_blas.py
@@ -309,9 +309,6 @@ def XYZab():
 class Failure(Exception):
    pass

-class Warning(Exception):
-    pass
-
 def just_gemm(i, o, ishapes = [(4,3), (3,5), (4,5), (), ()], max_graphlen=0):
    try:
        f = inplace_func(
@@ -320,14 +317,18 @@ def just_gemm(i, o, ishapes = [(4,3), (3,5), (4,5), (), ()], max_graphlen=0):
                mode='FAST_RUN')
        at_least_one_gemm = False
        for node in f.maker.env.nodes:
-            if node.op == T.dot: raise Warning('dot not changed to gemm_inplace in graph')
-            if node.op == _dot22: raise Warning('_dot22 not changed to gemm_inplace in graph')
-            if node.op == gemm_inplace: at_least_one_gemm = True
+            if node.op == T.dot:
+                raise Failure('dot not changed to gemm_inplace in graph')
+            if node.op == _dot22:
+                raise Failure('_dot22 not changed to gemm_inplace in graph')
+            if node.op == gemm_inplace:
+                at_least_one_gemm = True
        assert at_least_one_gemm
        g = inplace_func(i, o, mode=compile.Mode(linker='py', optimizer=None),
                allow_input_downcast=True)
        for node in g.maker.env.nodes:
-            if node.op == gemm_inplace: raise Exception('gemm_inplace in original graph')
+            if node.op == gemm_inplace:
+                raise Exception('gemm_inplace in original graph')

        graphlen = len(f.maker.env.toposort())
        if max_graphlen and (graphlen <= max_graphlen):
@@ -345,11 +346,6 @@ def just_gemm(i, o, ishapes = [(4,3), (3,5), (4,5), (), ()], max_graphlen=0):
        for node in f.maker.env.toposort():
            print 'GRAPH', node
        raise
-    except Warning, e:
-        #for node in f.maker.env.toposort():
-        #    print 'GRAPH', node
-        print 'WARNING:', e
-        #traceback.print_exc()


 def test_gemm_opt0():
@@ -366,6 +362,8 @@ def test_gemm_opt0():
    #with transposes (transposes should be pushed through dot in canonicalize)
    just_gemm([X,Y,Z,a,b], [b * Z.T - a * T.dot(Y.T,X.T)])
    just_gemm([X,Y,Z,a,b], [b * Z.T + a * b * T.dot(X,Y).T])
+    just_gemm([X,Y,Z,a,b], [b * Z + a * T.dot(X,Y).T],
+            ishapes=[(5,3), (3,4), (4,5), (), ()])

    #with N multiplications instead of just one
    just_gemm([X,Y,Z,a,b], [(b * b) * Z * a + (a * a) * T.dot(X,Y) * b])
@@ -390,7 +388,8 @@ def test_gemm_opt_double_gemm():
    i = [X,Y,Z,a,b, R, S, c]
    o = [a * T.dot(X,Y) + gemm_inplace(Z, b, S.T, R.T, 1.0)]
    try:
-        f = inplace_func([Param(ii, mutable=True) for ii in i],o, mode='FAST_RUN')
+        f = inplace_func([Param(ii, mutable=True) for ii in i],o,
+                mode='FAST_RUN')
        for node in f.maker.env.nodes:
            if node.op == T.dot: raise Failure('dot in graph')
            if node.op == _dot22: raise Failure('_dot22 in graph')
@@ -547,15 +546,15 @@ def test_inplace0():
    if (gemm_inplace in [n.op for n in f.maker.env.nodes]):
        print pp(f.maker.env.outputs[0])
        raise Failure('gemm_inplace in graph')
-    assert _dot22 in [n.op for n in f.maker.env.nodes]
+    assert gemm_no_inplace in [n.op for n in f.maker.env.nodes]

-    f = inplace_func([X,Y,Z,a,b, R, S, c],
-            [Z * (c*Z + a * T.dot(X,Y) + b * T.dot(R,S).T)], mode='FAST_RUN')
    # gemm_inplace should be inserted here, to work in-place on Z*c
+    f = inplace_func([X,Y,Z,a,b, R, S, c],
+            [Z * (c*Z + a * T.dot(X,Y) + b * T.dot(R,S).T)],
+            mode='FAST_RUN')
    if (not gemm_inplace in [n.op for n in f.maker.env.nodes]):
-        print pp(f.maker.env.outputs[0])
-        #raise Failure('no gemm_inplace in graph')
-        raise KnownFailureTest("gemm not always inserted, see #415")
+        theano.printing.debugprint(f)
+        raise Failure('no gemm_inplace in graph')

 def test_inplace1():
    X,Y,Z,a,b = XYZab()