[Bug fortran/99839] ICE in inline_matmul_assign, at fortran/frontend-passes.c:4234

["anlauf at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99839

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
                 CC|                            |anlauf at gcc dot gnu.org,
                   |                            |tkoenig at gcc dot gnu.org
   Last reconfirmed|                            |2021-03-30
     Ever confirmed|0                           |1
           Priority|P3                          |P4

--- Comment #1 from anlauf at gcc dot gnu.org ---
This one is funny.  Simply punting on non-numeric and non-logical results
works around the ICE.

diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c
index 7d3eae67632..213530e46e1 100644
--- a/gcc/fortran/frontend-passes.c
+++ b/gcc/fortran/frontend-passes.c
@@ -4193,6 +4193,19 @@ inline_matmul_assign (gfc_code **c, int *walk_subtrees,
   if (m_case == none)
     return 0;

+  /* We only handle assignment to numeric or logical variables.  */
+  switch(expr1->ts.type)
+    {
+    case BT_INTEGER:
+    case BT_LOGICAL:
+    case BT_REAL:
+    case BT_COMPLEX:
+      break;
+
+    default:
+      return 0;
+    }
+
   ns = insert_block ();

   /* Assign the type of the zero expression for initializing the resulting

Adding Thomas, who knows the code better.