re PR fortran/48412 (CP2K miscompiled due to some Fortran frontend pass)

2011-04-04  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/48412
	* frontend-passes (cfe_expr_0):  Reverse the order of going
	through the loops.

2011-04-04  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/48412
	* function_optimize_4.f90:  New test.

From-SVN: r171952

gcc/fortran/ChangeLog

+2011-04-04  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/48412
+	* frontend-passes (cfe_expr_0):  Reverse the order of going
+	through the loops.
+
 2011-04-04  Tobias Burnus  <burnus@net-b.de>
 	    Mikael Morin  <mikael.morin@sfr.fr>
 

gcc/fortran/frontend-passes.c

@@ -295,16 +295,16 @@ cfe_expr_0 (gfc_expr **e, int *walk_subtrees,
 
   gfc_expr_walker (e, cfe_register_funcs, NULL);
 
-  /* Walk backwards through all the functions to make sure we
-     catch the leaf functions first.  */
-  for (i=expr_count-1; i>=1; i--)
+  /* Walk through all the functions.  */
+
+  for (i=1; i<expr_count; i++)
     {
       /* Skip if the function has been replaced by a variable already.  */
       if ((*(expr_array[i]))->expr_type == EXPR_VARIABLE)
 	continue;
 
       newvar = NULL;
-      for (j=i-1; j>=0; j--)
+      for (j=0; j<i; j++)
 	{
 	  if (gfc_dep_compare_functions(*(expr_array[i]),
 					*(expr_array[j]), true)	== 0)

gcc/testsuite/ChangeLog

+2011-04-04  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/48412
+	* function_optimize_4.f90:  New test.
+
 2011-04-04  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/18918

gcc/testsuite/gfortran.dg/function_optimize_4.f90

+! { dg-do run }
+! { dg-options "-O" }
+! PR 48412 - function elimination got temporary varibles in the wrong order.
+! Test case contributed by Joost VandeVondele.
+
+INTEGER FUNCTION S1(m,ma,lx)
+INTEGER :: m,ma,lx
+
+IF (((m < 0).AND.(MODULO(ABS(ma-lx),2) == 1)).OR.&
+    ((m > 0).AND.(MODULO(ABS(ma-lx),2) == 0))) THEN
+   S1=1
+ELSE
+   S1=0
+ENDIF
+
+END FUNCTION
+
+INTEGER :: s1
+IF (S1(1,2,1).NE.0) CALL ABORT()
+END