re PR fortran/56342 (MATMUL with PARAMETER: Simplification usually doesn't work)

2017-10-27  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/56342
	* simplify.c (is_constant_array_expr): If the expression is
	a parameter array, call gfc_simplify_expr.

2017-10-27  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/56342
	* gfortran.dg/matmul_const.f90: New test.

From-SVN: r254157

gcc/fortran/ChangeLog

+2017-10-27  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/56342
+	* simplify.c (is_constant_array_expr): If the expression is
+	a parameter array, call gfc_simplify_expr.
+
 2017-10-25  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>
 
 	* match.c (gfc_match_type_is): Fix typo in error message.

gcc/fortran/simplify.c

@@ -227,7 +227,8 @@ convert_boz (gfc_expr *x, int kind)
 }
 
 
-/* Test that the expression is an constant array.  */
+/* Test that the expression is an constant array, simplifying if
+   we are dealing with a parameter array.  */
 
 static bool
 is_constant_array_expr (gfc_expr *e)
@@ -237,6 +238,10 @@ is_constant_array_expr (gfc_expr *e)
   if (e == NULL)
     return true;
 
+  if (e->expr_type == EXPR_VARIABLE && e->rank > 0
+      && e->symtree->n.sym->attr.flavor == FL_PARAMETER)
+    gfc_simplify_expr (e, 1);
+
   if (e->expr_type != EXPR_ARRAY || !gfc_is_constant_expr (e))
     return false;
 

gcc/testsuite/ChangeLog

+2017-10-27  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/56342
+	* gfortran.dg/matmul_const.f90: New test.
+
 2017-10-25  Jan Hubicka  <hubicka@ucw.cz>
 
 	* gcc.target/i386/pr70021.c: Add -mtune=skylake.

gcc/testsuite/gfortran.dg/matmul_const.f90

+! { dg-do  run }
+! { dg-additional-options "-fno-frontend-optimize -fdump-tree-original" }
+program main
+  integer, parameter :: A(3,2) = reshape([1,2,3,4,5,6],[3,2])
+  integer, parameter :: B(2,3) = reshape([1,1,1,1,1,1],[2,3])
+  character (len=30) :: line
+  write (unit=line,fmt='(9i3)') matmul(A,B)
+  if (line /= '  5  7  9  5  7  9  5  7  9') call abort
+end program main
+!  dg-final { scan-tree-dump-times "matmul_i4" 0 "original" } }