Make gpugemv and gpugemm work correctly when the back-end don't support inplace.

theano/sandbox/gpuarray/blas.py

@@ -28,12 +28,16 @@ class GpuGemv(BlasOp, Gemv):
         A = as_gpuarray_variable(A)
         x = as_gpuarray_variable(x)
         y = as_gpuarray_variable(y)
+        assert A.dtype == x.dtype == y.dtype == alpha.dtype == beta.dtype
         return Apply(self, [y, alpha, A, x, beta], [y.type()])
 
     def perform(self, node, inputs, out_storage):
         y, alpha, A, x, beta = inputs
-        out_storage[0][0] = blas.gemv(alpha, A, x, beta, y, trans=False,
-                                      overwrite_y=self.inplace)
+        inplace = self.inplace
+        if inplace and y.strides[0] < 0:
+            inplace = False
+        out_storage[0][0] = blas.gemv(alpha, A, x, beta, y,
+                                      overwrite_y=inplace)
 
     def c_code(self, node, name, inp, out, sub):
         vars = dict(out=out[0], y=inp[0], alpha=inp[1], A=inp[2], x=inp[3],
@@ -64,7 +68,7 @@ class GpuGemv(BlasOp, Gemv):
         if config.gpuarray.sync:
             code += """
             GpuArray_sync(&%(out)s->ga);
-            """
+            """ % vars
         return code
 
     def c_code_cache_version(self):
@@ -80,12 +84,16 @@ class GpuGemm(BlasOp, Gemm):
         A = as_gpuarray_variable(A)
         B = as_gpuarray_variable(B)
         C = as_gpuarray_variable(C)
+        assert A.dtype == B.dtype == C.dtype == alpha.dtype == beta.dtype
         return Apply(self, [C, alpha, A, B, beta], [C.type()])
 
     def perform(self, node, inputs, outputs):
         C, alpha, A, B, beta = inputs
+        inplace = self.inplace
+        if inplace and not C.flags.forc:
+            inplace = False
         outputs[0][0] = blas.gemm(alpha, A, B, beta, C,
-                                  overwrite_c=self.inplace)
+                                  overwrite_c=inplace)
 
     def c_code(self, node, name, inp, out, sub):
         vars = dict(out=out[0], C=inp[0], alpha=inp[1], A=inp[2], B=inp[3],
@@ -116,7 +124,7 @@ class GpuGemm(BlasOp, Gemm):
         if config.gpuarray.sync:
             code += """
             GpuArray_sync(&%(out)s->ga);
-            """
+            """ % vars
         return code
 
     def c_code_cache_version(self):