BUG: linalg: make umath_linalg to track errors from all inner loop iterations

This ensures that the FP invalid flag always reflects the return code
from LAPACK. Fixes a bug in 63a8aef81 where umath_linalg raises a
warning only if the error occurs in the last iteration of the ufunc
inner loop.

2 files changed, 47 insertions, 51 deletions

diff --git a/numpy/linalg/tests/test_linalg.py b/numpy/linalg/tests/test_linalg.py
index 0a6f8f4ca..af9bf884d 100644
--- a/numpy/linalg/tests/test_linalg.py
+++ b/numpy/linalg/tests/test_linalg.py
@@ -654,5 +654,18 @@ def test_byteorder_check():
             assert_array_equal(res, routine(sw_arr))
 
 
+def test_generalized_raise_multiloop():
+    # It should raise an error even if the error doesn't occur in the
+    # last iteration of the ufunc inner loop
+
+    invertible = np.array([[1, 2], [3, 4]])
+    non_invertible = np.array([[1, 1], [1, 1]])
+
+    x = np.zeros([4, 4, 2, 2])[1::2]
+    x[...] = invertible
+    x[0,0] = non_invertible
+
+    assert_raises(np.linalg.LinAlgError, np.linalg.inv, x)
+
 if __name__ == "__main__":
     run_module_suite()
diff --git a/numpy/linalg/umath_linalg.c.src b/numpy/linalg/umath_linalg.c.src
index c9d55f635..eadbde8e7 100644
--- a/numpy/linalg/umath_linalg.c.src
+++ b/numpy/linalg/umath_linalg.c.src
@@ -374,10 +374,23 @@ offset_ptr(void* ptr, ptrdiff_t offset)
     return (void*)((npy_uint8*)ptr + offset);
 }
 
+static inline int
+get_fp_invalid_and_clear()
+{
+    int status;
+    status = PyUFunc_getfperr();
+    return !!(status & UFUNC_FPE_INVALID);
+}
+
 static inline void
-clear_fp_errors()
+set_fp_invalid_or_clear(int error_occurred)
 {
-    PyUFunc_getfperr();
+    if (error_occurred) {
+        npy_set_floatstatus_invalid();
+    }
+    else {
+        PyUFunc_getfperr();
+    }
 }
 
 /*
@@ -862,10 +875,6 @@ nan_@TYPE@_matrix(void *dst_in, const LINEARIZE_DATA_t* data)
         }
         dst += data->row_strides/sizeof(@typ@);
     }
-
-    /* if this function gets called, the module generates nans */
-    /* set the fpe status to invalid to notify that nans were generated */
-    npy_set_floatstatus_invalid();
 }
 
 static inline void
@@ -1786,7 +1795,7 @@ static inline void
     size_t outer_dim = *dimensions++;
     size_t op_count = (JOBZ=='N')?2:3;
     EIGH_PARAMS_t eigh_params;
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
 
     for (iter=0; iter < op_count; ++iter) {
         outer_steps[iter] = (ptrdiff_t) steps[iter];
@@ -1843,10 +1852,7 @@ static inline void
         release_@lapack_func@(&eigh_params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 /**end repeat**/
 
@@ -1973,7 +1979,7 @@ static void
 {
     GESV_PARAMS_t params;
     fortran_int n, nrhs;
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
     INIT_OUTER_LOOP_3
 
     n = (fortran_int)dimensions[0];
@@ -2001,10 +2007,7 @@ static void
         release_@lapack_func@(&params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 
 static void
@@ -2012,7 +2015,7 @@ static void
               void *NPY_UNUSED(func))
 {
     GESV_PARAMS_t params;
-    int error_occurred;
+    int error_occurred = get_fp_invalid_and_clear();
     fortran_int n;
     INIT_OUTER_LOOP_3
 
@@ -2039,10 +2042,7 @@ static void
         release_@lapack_func@(&params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 
 static void
@@ -2051,7 +2051,7 @@ static void
 {
     GESV_PARAMS_t params;
     fortran_int n;
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
     INIT_OUTER_LOOP_2
 
     n = (fortran_int)dimensions[0];
@@ -2076,11 +2076,9 @@ static void
         release_@lapack_func@(&params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
+
 /**end repeat**/
 
 
@@ -2150,7 +2148,7 @@ static void
 @TYPE@_cholesky(char uplo, char **args, npy_intp *dimensions, npy_intp *steps)
 {
     POTR_PARAMS_t params;
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
     fortran_int n;
     INIT_OUTER_LOOP_2
 
@@ -2175,10 +2173,7 @@ static void
         release_@lapack_func@(&params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 
 static void
@@ -2592,7 +2587,7 @@ static inline void
     size_t iter;
     size_t outer_dim = *dimensions++;
     size_t op_count = 2;
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
     GEEV_PARAMS_t geev_params;
 
     STACK_TRACE;
@@ -2668,10 +2663,7 @@ static inline void
         release_@lapack_func@(&geev_params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 
 static void
@@ -3038,7 +3030,7 @@ static inline void
                    npy_intp* steps)
 {
     ptrdiff_t outer_steps[3];
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
     size_t iter;
     size_t outer_dim = *dimensions++;
     size_t op_count = (JOBZ=='N')?2:4;
@@ -3110,10 +3102,7 @@ static inline void
         release_@lapack_func@(&params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 /**end repeat*/
 
@@ -3519,7 +3508,7 @@ static void
                 )
 {
     POTRS_PARAMS_t params;
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
     fortran_int n, nrhs;
     INIT_OUTER_LOOP_3
 
@@ -3553,10 +3542,7 @@ static void
         release_@lapack_func@(&params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 
 static void
@@ -3679,7 +3665,7 @@ static inline void
              npy_intp *steps)
 {
     POTRI_PARAMS_t params;
-    int error_occurred = 0;
+    int error_occurred = get_fp_invalid_and_clear();
     fortran_int n;
     INIT_OUTER_LOOP_2
 
@@ -3706,10 +3692,7 @@ static inline void
         release_@potri@(&params);
     }
 
-    if (!error_occurred) {
-        /* lapack success, clear FP error status */
-        clear_fp_errors();
-    }
+    set_fp_invalid_or_clear(error_occurred);
 }
 
 static void