Add missing cast to floating-point type:
* sopalin/src/variable_csc.c: In function ‘vcsc_add_node’:
* sopalin/src/variable_csc.c:138:13: error: non-floating-point argument in call to function ‘__builtin_isnan’
*              if (isnan(vcsc->values[COL-1][i*dof2 + ii])) {
See also:
https://bugs.gentoo.org/show_bug.cgi?id=580422

--- src/common/src/errors.h
+++ src/common/src/errors.h
@@ -140,7 +140,7 @@
  *   expr - The value to check.
  */
 #define CHECK_NAN(expr) {					\
-    ASSERT_DEBUG(!isnan(expr), DBG_SOPALIN_NAN);		\
+    ASSERT_DEBUG(!isnan(((double) expr)), DBG_SOPALIN_NAN);		\
     ASSERT_DEBUG(!isinf(expr), DBG_SOPALIN_INF);		\
   }
 #else
--- src/sopalin/src/variable_csc.c
+++ src/sopalin/src/variable_csc.c
@@ -135,7 +135,7 @@
 #endif
 
           for (ii = 0; ii < dof2; ii++) {
-            if (isnan(vcsc->values[COL-1][i*dof2 + ii])) {
+            if (isnan(((double) vcsc->values[COL-1][i*dof2 + ii]))) {
               vcsc->values[COL-1][i*dof2 + ii] = VALUE[ii];
             } else {
               vcsc->values[COL-1][i*dof2 + ii] = op(vcsc->values[COL-1][i*dof2 + ii],
@@ -252,7 +252,7 @@
                     vcsc->rows[COL_NODE][i]);
           }
 #endif
-          if (isnan(vcsc->values[COL_NODE][idx])) {
+          if (isnan(((double) vcsc->values[COL_NODE][idx]))) {
             vcsc->values[COL_NODE][idx] = VALUE;
           } else {
             vcsc->values[COL_NODE][idx] = op(vcsc->values[COL_NODE][idx],
@@ -660,7 +660,7 @@
           } else {
             INTS iterdof;
             for (iterdof = 0; iterdof < dof2; iterdof++) {
-              if (!isnan(vcsc->values[MYCOL-1][dof2*iter2+iterdof])) {
+              if (!isnan(((double) vcsc->values[MYCOL-1][dof2*iter2+iterdof]))) {
                 /* ignore NaN values from VCSC */
                 (*values_o)[dof2*iter3+iterdof] = op(
                   (*values_o)[dof2*iter3+iterdof],