just by skipping alpha*matrix multiplication when alpha == 1.0.

All tests succeed (with blas.ldflags empty) for:
* test_abstract_conv.py in theano/tensor/nnet/tests/
* test_blas.py and test_blas_scipy.py in theano/tensor/tests/

I have modified theano/tensor/tests/test_blas_c.py
to skip all tests that involves either gemv or ger functions.
* Before the modifications, this file executed 44 tests and 34 were skipped.
* After  the modifications, this file executes 44 tests and 29 are skipped.

# $ theano-cache purge && THEANO_FLAGS=blas.ldflags= nosetests --verbose theano/tensor/tests/test_blas_c.py

PS: I also tried to execute test_corr.py in
theano/tensor/nnet/tests/test_corr.py after removing ldflags checking,
but I get many errors in many of the tests (theano outputs not matches ref outputs).
So for the moment I have let this file and I will continue investigations tomorrow.