re PR fortran/83900 (ICE in gfc_simplify_matmul, at fortran/simplify.c:4593)

2018-01-20  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/83900
    * simplify.c (gfc_simplify_matmul): Set return type correctly.

2018-01-20  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/83900
	* gfortran.dg/matmul_18.f90: New test.

From-SVN: r256919

gcc/fortran/ChangeLog

+2018-01-20  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/83900
+    * simplify.c (gfc_simplify_matmul): Set return type correctly.
+
 2018-01-19  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/83900

gcc/fortran/simplify.c

@@ -4590,9 +4590,23 @@ gfc_simplify_matmul (gfc_expr *matrix_a, gfc_expr *matrix_b)
       || !is_constant_array_expr (matrix_b))
     return NULL;
 
-  result = gfc_get_array_expr (matrix_a->ts.type,
-			       matrix_a->ts.kind,
-			       &matrix_a->where);
+  /* MATMUL should do mixed-mode arithmetic.  Set the result type.  */
+  if (matrix_a->ts.type != matrix_b->ts.type)
+    {
+      gfc_expr e;
+      e.expr_type = EXPR_OP;
+      gfc_clear_ts (&e.ts);
+      e.value.op.op = INTRINSIC_NONE;
+      e.value.op.op1 = matrix_a;
+      e.value.op.op2 = matrix_b;
+      gfc_type_convert_binary (&e, 1);
+      result = gfc_get_array_expr (e.ts.type, e.ts.kind, &matrix_a->where);
+    }
+  else
+    {
+      result = gfc_get_array_expr (matrix_a->ts.type, matrix_a->ts.kind,
+				   &matrix_a->where);
+    }
 
   if (matrix_a->rank == 1 && matrix_b->rank == 2)
     {

gcc/testsuite/ChangeLog

+2018-01-20  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/83900
+	* gfortran.dg/matmul_18.f90: New test.
+
 2018-01-20  Richard Sandiford  <richard.sandiford@linaro.org>
 
 	PR tree-optimization/83940

gcc/testsuite/gfortran.dg/matmul_18.f90

+! { dg-do run }
+program p
+   integer, parameter :: a(3,2) = 1
+   real, parameter :: b(2,3) = 2
+   real d(3,3)
+   d = 4
+   if (any(d /= matmul(a,b))) call abort
+end