In scipy master (to be released as 0.14), scipy sparse matrices can now be indexed with 64 bit integers.

This means that we will probably need to use fused types for indptr and indices arrays whenever we deal with CSC or CSR datastructures in our Cython code base.

Edit: by @rth on Nov 2017 to add the status of support for 64 bit CSR indices in different parts of the code, as discussed in #2969 (comment)

• preprocessing_normalize[l1-False]
• preprocessing_normalize[l1-True]
• preprocessing_normalize[l2-False]
• preprocessing_normalize[l2-True]
• decomposition_truncatedsvd[randomized]
• decomposition_truncatedsvd[arpack]
• decomposition_nmf[cd]
• decomposition_nmf[mu]
• linear_model_logisticregression[liblinear-l1]
• linear_model_sgdclassifier[modified_huber-elasticnet]
• linear_model_sgdclassifier[squared_hinge-l1]
• linear_model_sgdclassifier[squared_hinge-l2]
• linear_model_sgdclassifier[squared_hinge-elasticnet]
• linear_model_sgdclassifier[perceptron-l1]
• linear_model_sgdclassifier[perceptron-l2]
• linear_model_sgdclassifier[perceptron-elasticnet]
• linear_model_sgdregressor[squared_loss-l1]
• linear_model_sgdregressor[squared_loss-l2]
• linear_model_sgdregressor[squared_loss-elasticnet]
• linear_model_sgdregressor[huber-l1]
• linear_model_sgdregressor[huber-l2]
• linear_model_sgdregressor[huber-elasticnet]
• linear_model_sgdregressor[epsilon_insensitive-l1]
• linear_model_sgdregressor[epsilon_insensitive-l2]
• linear_model_sgdregressor[epsilon_insensitive-elasticnet]
• linear_model_sgdregressor[squared_epsilon_insensitive-l1]
• linear_model_sgdregressor[squared_epsilon_insensitive-l2]
• linear_model_sgdregressor[squared_epsilon_insensitive-elasticnet]
• linear_model_estimator[linear_model.LinearRegression]
• linear_model_estimator[linear_model.ElasticNet]
• linear_model_estimator[svm.LinearSVC]
• linear_model_logisticregression[liblinear-l2]
• linear_model_sgdclassifier[log-l1]
• linear_model_sgdclassifier[log-l2]
• linear_model_sgdclassifier[log-elasticnet]
• linear_model_sgdclassifier[modified_huber-l1]
• linear_model_sgdclassifier[modified_huber-l2]
• linear_model_estimator[svm.SVC]
• linear_model_estimator[tree.DecisionTreeClassifier]
• linear_model_logisticregression[newton-cg-l2]
• linear_model_logisticregression[lbfgs-l2]
• linear_model_logisticregression[sag-l2]
• linear_model_sgdclassifier[hinge-l1]
• linear_model_sgdclassifier[hinge-l2]
• linear_model_sgdclassifier[hinge-elasticnet]