re PR fortran/48405 (Handle expressions in DO loops for front-end optimization)

2011-04-21  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/48405
	* frontend_passes (cfe_register_funcs): Remove workaround for DO
	loops.
	(gfc_code_walker):  Make sure the pointer to the current
	statement doen't change when other statements are inserted.

2011-04-21  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/48405
	* gfortran.dg/function_optimize_6.f90:  New test.

From-SVN: r172838

4 files changed, 140 insertions, 111 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 25ef329..bbe8624 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,11 @@
+2011-04-21  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/48405
+	* frontend_passes (cfe_register_funcs): Remove workaround for DO
+	loops.
+	(gfc_code_walker):  Make sure the pointer to the current
+	statement doen't change when other statements are inserted.
+
 2011-04-21  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/18918
diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c
index d70435d..fbe5d1c 100644
--- a/gcc/fortran/frontend-passes.c
+++ b/gcc/fortran/frontend-passes.c
@@ -140,12 +140,6 @@ cfe_register_funcs (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED,
 	  void *data ATTRIBUTE_UNUSED)
 {
 
-  /* FIXME - there is a bug in the insertion code for DO loops.  Bail
-     out here.  */
-
-  if ((*current_code)->op == EXEC_DO)
-    return 0;
-
   if ((*e)->expr_type != EXPR_FUNCTION)
     return 0;
 
@@ -956,31 +950,37 @@ gfc_code_walker (gfc_code **c, walk_code_fn_t codefn, walk_expr_fn_t exprfn,
 	{
 	  gfc_code *b;
 	  gfc_actual_arglist *a;
+	  gfc_code *co;
+
+	  /* There might be statement insertions before the current code,
+	     which must not affect the expression walker.  */
+
+	  co = *c;
 
-	  switch ((*c)->op)
+	  switch (co->op)
 	    {
 	    case EXEC_DO:
-	      WALK_SUBEXPR ((*c)->ext.iterator->var);
-	      WALK_SUBEXPR ((*c)->ext.iterator->start);
-	      WALK_SUBEXPR ((*c)->ext.iterator->end);
-	      WALK_SUBEXPR ((*c)->ext.iterator->step);
+	      WALK_SUBEXPR (co->ext.iterator->var);
+	      WALK_SUBEXPR (co->ext.iterator->start);
+	      WALK_SUBEXPR (co->ext.iterator->end);
+	      WALK_SUBEXPR (co->ext.iterator->step);
 	      break;
 
 	    case EXEC_CALL:
 	    case EXEC_ASSIGN_CALL:
-	      for (a = (*c)->ext.actual; a; a = a->next)
+	      for (a = co->ext.actual; a; a = a->next)
 		WALK_SUBEXPR (a->expr);
 	      break;
 
 	    case EXEC_CALL_PPC:
-	      WALK_SUBEXPR ((*c)->expr1);
-	      for (a = (*c)->ext.actual; a; a = a->next)
+	      WALK_SUBEXPR (co->expr1);
+	      for (a = co->ext.actual; a; a = a->next)
 		WALK_SUBEXPR (a->expr);
 	      break;
 
 	    case EXEC_SELECT:
-	      WALK_SUBEXPR ((*c)->expr1);
-	      for (b = (*c)->block; b; b = b->block)
+	      WALK_SUBEXPR (co->expr1);
+	      for (b = co->block; b; b = b->block)
 		{
 		  gfc_case *cp;
 		  for (cp = b->ext.block.case_list; cp; cp = cp->next)
@@ -996,7 +996,7 @@ gfc_code_walker (gfc_code **c, walk_code_fn_t codefn, walk_expr_fn_t exprfn,
 	    case EXEC_DEALLOCATE:
 	      {
 		gfc_alloc *a;
-		for (a = (*c)->ext.alloc.list; a; a = a->next)
+		for (a = co->ext.alloc.list; a; a = a->next)
 		  WALK_SUBEXPR (a->expr);
 		break;
 	      }
@@ -1004,7 +1004,7 @@ gfc_code_walker (gfc_code **c, walk_code_fn_t codefn, walk_expr_fn_t exprfn,
 	    case EXEC_FORALL:
 	      {
 		gfc_forall_iterator *fa;
-		for (fa = (*c)->ext.forall_iterator; fa; fa = fa->next)
+		for (fa = co->ext.forall_iterator; fa; fa = fa->next)
 		  {
 		    WALK_SUBEXPR (fa->var);
 		    WALK_SUBEXPR (fa->start);
@@ -1015,110 +1015,110 @@ gfc_code_walker (gfc_code **c, walk_code_fn_t codefn, walk_expr_fn_t exprfn,
 	      }
 
 	    case EXEC_OPEN:
-	      WALK_SUBEXPR ((*c)->ext.open->unit);
-	      WALK_SUBEXPR ((*c)->ext.open->file);
-	      WALK_SUBEXPR ((*c)->ext.open->status);
-	      WALK_SUBEXPR ((*c)->ext.open->access);
-	      WALK_SUBEXPR ((*c)->ext.open->form);
-	      WALK_SUBEXPR ((*c)->ext.open->recl);
-	      WALK_SUBEXPR ((*c)->ext.open->blank);
-	      WALK_SUBEXPR ((*c)->ext.open->position);
-	      WALK_SUBEXPR ((*c)->ext.open->action);
-	      WALK_SUBEXPR ((*c)->ext.open->delim);
-	      WALK_SUBEXPR ((*c)->ext.open->pad);
-	      WALK_SUBEXPR ((*c)->ext.open->iostat);
-	      WALK_SUBEXPR ((*c)->ext.open->iomsg);
-	      WALK_SUBEXPR ((*c)->ext.open->convert);
-	      WALK_SUBEXPR ((*c)->ext.open->decimal);
-	      WALK_SUBEXPR ((*c)->ext.open->encoding);
-	      WALK_SUBEXPR ((*c)->ext.open->round);
-	      WALK_SUBEXPR ((*c)->ext.open->sign);
-	      WALK_SUBEXPR ((*c)->ext.open->asynchronous);
-	      WALK_SUBEXPR ((*c)->ext.open->id);
-	      WALK_SUBEXPR ((*c)->ext.open->newunit);
+	      WALK_SUBEXPR (co->ext.open->unit);
+	      WALK_SUBEXPR (co->ext.open->file);
+	      WALK_SUBEXPR (co->ext.open->status);
+	      WALK_SUBEXPR (co->ext.open->access);
+	      WALK_SUBEXPR (co->ext.open->form);
+	      WALK_SUBEXPR (co->ext.open->recl);
+	      WALK_SUBEXPR (co->ext.open->blank);
+	      WALK_SUBEXPR (co->ext.open->position);
+	      WALK_SUBEXPR (co->ext.open->action);
+	      WALK_SUBEXPR (co->ext.open->delim);
+	      WALK_SUBEXPR (co->ext.open->pad);
+	      WALK_SUBEXPR (co->ext.open->iostat);
+	      WALK_SUBEXPR (co->ext.open->iomsg);
+	      WALK_SUBEXPR (co->ext.open->convert);
+	      WALK_SUBEXPR (co->ext.open->decimal);
+	      WALK_SUBEXPR (co->ext.open->encoding);
+	      WALK_SUBEXPR (co->ext.open->round);
+	      WALK_SUBEXPR (co->ext.open->sign);
+	      WALK_SUBEXPR (co->ext.open->asynchronous);
+	      WALK_SUBEXPR (co->ext.open->id);
+	      WALK_SUBEXPR (co->ext.open->newunit);
 	      break;
 
 	    case EXEC_CLOSE:
-	      WALK_SUBEXPR ((*c)->ext.close->unit);
-	      WALK_SUBEXPR ((*c)->ext.close->status);
-	      WALK_SUBEXPR ((*c)->ext.close->iostat);
-	      WALK_SUBEXPR ((*c)->ext.close->iomsg);
+	      WALK_SUBEXPR (co->ext.close->unit);
+	      WALK_SUBEXPR (co->ext.close->status);
+	      WALK_SUBEXPR (co->ext.close->iostat);
+	      WALK_SUBEXPR (co->ext.close->iomsg);
 	      break;
 
 	    case EXEC_BACKSPACE:
 	    case EXEC_ENDFILE:
 	    case EXEC_REWIND:
 	    case EXEC_FLUSH:
-	      WALK_SUBEXPR ((*c)->ext.filepos->unit);
-	      WALK_SUBEXPR ((*c)->ext.filepos->iostat);
-	      WALK_SUBEXPR ((*c)->ext.filepos->iomsg);
+	      WALK_SUBEXPR (co->ext.filepos->unit);
+	      WALK_SUBEXPR (co->ext.filepos->iostat);
+	      WALK_SUBEXPR (co->ext.filepos->iomsg);
 	      break;
 
 	    case EXEC_INQUIRE:
-	      WALK_SUBEXPR ((*c)->ext.inquire->unit);
-	      WALK_SUBEXPR ((*c)->ext.inquire->file);
-	      WALK_SUBEXPR ((*c)->ext.inquire->iomsg);
-	      WALK_SUBEXPR ((*c)->ext.inquire->iostat);
-	      WALK_SUBEXPR ((*c)->ext.inquire->exist);
-	      WALK_SUBEXPR ((*c)->ext.inquire->opened);
-	      WALK_SUBEXPR ((*c)->ext.inquire->number);
-	      WALK_SUBEXPR ((*c)->ext.inquire->named);
-	      WALK_SUBEXPR ((*c)->ext.inquire->name);
-	      WALK_SUBEXPR ((*c)->ext.inquire->access);
-	      WALK_SUBEXPR ((*c)->ext.inquire->sequential);
-	      WALK_SUBEXPR ((*c)->ext.inquire->direct);
-	      WALK_SUBEXPR ((*c)->ext.inquire->form);
-	      WALK_SUBEXPR ((*c)->ext.inquire->formatted);
-	      WALK_SUBEXPR ((*c)->ext.inquire->unformatted);
-	      WALK_SUBEXPR ((*c)->ext.inquire->recl);
-	      WALK_SUBEXPR ((*c)->ext.inquire->nextrec);
-	      WALK_SUBEXPR ((*c)->ext.inquire->blank);
-	      WALK_SUBEXPR ((*c)->ext.inquire->position);
-	      WALK_SUBEXPR ((*c)->ext.inquire->action);
-	      WALK_SUBEXPR ((*c)->ext.inquire->read);
-	      WALK_SUBEXPR ((*c)->ext.inquire->write);
-	      WALK_SUBEXPR ((*c)->ext.inquire->readwrite);
-	      WALK_SUBEXPR ((*c)->ext.inquire->delim);
-	      WALK_SUBEXPR ((*c)->ext.inquire->encoding);
-	      WALK_SUBEXPR ((*c)->ext.inquire->pad);
-	      WALK_SUBEXPR ((*c)->ext.inquire->iolength);
-	      WALK_SUBEXPR ((*c)->ext.inquire->convert);
-	      WALK_SUBEXPR ((*c)->ext.inquire->strm_pos);
-	      WALK_SUBEXPR ((*c)->ext.inquire->asynchronous);
-	      WALK_SUBEXPR ((*c)->ext.inquire->decimal);
-	      WALK_SUBEXPR ((*c)->ext.inquire->pending);
-	      WALK_SUBEXPR ((*c)->ext.inquire->id);
-	      WALK_SUBEXPR ((*c)->ext.inquire->sign);
-	      WALK_SUBEXPR ((*c)->ext.inquire->size);
-	      WALK_SUBEXPR ((*c)->ext.inquire->round);
+	      WALK_SUBEXPR (co->ext.inquire->unit);
+	      WALK_SUBEXPR (co->ext.inquire->file);
+	      WALK_SUBEXPR (co->ext.inquire->iomsg);
+	      WALK_SUBEXPR (co->ext.inquire->iostat);
+	      WALK_SUBEXPR (co->ext.inquire->exist);
+	      WALK_SUBEXPR (co->ext.inquire->opened);
+	      WALK_SUBEXPR (co->ext.inquire->number);
+	      WALK_SUBEXPR (co->ext.inquire->named);
+	      WALK_SUBEXPR (co->ext.inquire->name);
+	      WALK_SUBEXPR (co->ext.inquire->access);
+	      WALK_SUBEXPR (co->ext.inquire->sequential);
+	      WALK_SUBEXPR (co->ext.inquire->direct);
+	      WALK_SUBEXPR (co->ext.inquire->form);
+	      WALK_SUBEXPR (co->ext.inquire->formatted);
+	      WALK_SUBEXPR (co->ext.inquire->unformatted);
+	      WALK_SUBEXPR (co->ext.inquire->recl);
+	      WALK_SUBEXPR (co->ext.inquire->nextrec);
+	      WALK_SUBEXPR (co->ext.inquire->blank);
+	      WALK_SUBEXPR (co->ext.inquire->position);
+	      WALK_SUBEXPR (co->ext.inquire->action);
+	      WALK_SUBEXPR (co->ext.inquire->read);
+	      WALK_SUBEXPR (co->ext.inquire->write);
+	      WALK_SUBEXPR (co->ext.inquire->readwrite);
+	      WALK_SUBEXPR (co->ext.inquire->delim);
+	      WALK_SUBEXPR (co->ext.inquire->encoding);
+	      WALK_SUBEXPR (co->ext.inquire->pad);
+	      WALK_SUBEXPR (co->ext.inquire->iolength);
+	      WALK_SUBEXPR (co->ext.inquire->convert);
+	      WALK_SUBEXPR (co->ext.inquire->strm_pos);
+	      WALK_SUBEXPR (co->ext.inquire->asynchronous);
+	      WALK_SUBEXPR (co->ext.inquire->decimal);
+	      WALK_SUBEXPR (co->ext.inquire->pending);
+	      WALK_SUBEXPR (co->ext.inquire->id);
+	      WALK_SUBEXPR (co->ext.inquire->sign);
+	      WALK_SUBEXPR (co->ext.inquire->size);
+	      WALK_SUBEXPR (co->ext.inquire->round);
 	      break;
 
 	    case EXEC_WAIT:
-	      WALK_SUBEXPR ((*c)->ext.wait->unit);
-	      WALK_SUBEXPR ((*c)->ext.wait->iostat);
-	      WALK_SUBEXPR ((*c)->ext.wait->iomsg);
-	      WALK_SUBEXPR ((*c)->ext.wait->id);
+	      WALK_SUBEXPR (co->ext.wait->unit);
+	      WALK_SUBEXPR (co->ext.wait->iostat);
+	      WALK_SUBEXPR (co->ext.wait->iomsg);
+	      WALK_SUBEXPR (co->ext.wait->id);
 	      break;
 
 	    case EXEC_READ:
 	    case EXEC_WRITE:
-	      WALK_SUBEXPR ((*c)->ext.dt->io_unit);
-	      WALK_SUBEXPR ((*c)->ext.dt->format_expr);
-	      WALK_SUBEXPR ((*c)->ext.dt->rec);
-	      WALK_SUBEXPR ((*c)->ext.dt->advance);
-	      WALK_SUBEXPR ((*c)->ext.dt->iostat);
-	      WALK_SUBEXPR ((*c)->ext.dt->size);
-	      WALK_SUBEXPR ((*c)->ext.dt->iomsg);
-	      WALK_SUBEXPR ((*c)->ext.dt->id);
-	      WALK_SUBEXPR ((*c)->ext.dt->pos);
-	      WALK_SUBEXPR ((*c)->ext.dt->asynchronous);
-	      WALK_SUBEXPR ((*c)->ext.dt->blank);
-	      WALK_SUBEXPR ((*c)->ext.dt->decimal);
-	      WALK_SUBEXPR ((*c)->ext.dt->delim);
-	      WALK_SUBEXPR ((*c)->ext.dt->pad);
-	      WALK_SUBEXPR ((*c)->ext.dt->round);
-	      WALK_SUBEXPR ((*c)->ext.dt->sign);
-	      WALK_SUBEXPR ((*c)->ext.dt->extra_comma);
+	      WALK_SUBEXPR (co->ext.dt->io_unit);
+	      WALK_SUBEXPR (co->ext.dt->format_expr);
+	      WALK_SUBEXPR (co->ext.dt->rec);
+	      WALK_SUBEXPR (co->ext.dt->advance);
+	      WALK_SUBEXPR (co->ext.dt->iostat);
+	      WALK_SUBEXPR (co->ext.dt->size);
+	      WALK_SUBEXPR (co->ext.dt->iomsg);
+	      WALK_SUBEXPR (co->ext.dt->id);
+	      WALK_SUBEXPR (co->ext.dt->pos);
+	      WALK_SUBEXPR (co->ext.dt->asynchronous);
+	      WALK_SUBEXPR (co->ext.dt->blank);
+	      WALK_SUBEXPR (co->ext.dt->decimal);
+	      WALK_SUBEXPR (co->ext.dt->delim);
+	      WALK_SUBEXPR (co->ext.dt->pad);
+	      WALK_SUBEXPR (co->ext.dt->round);
+	      WALK_SUBEXPR (co->ext.dt->sign);
+	      WALK_SUBEXPR (co->ext.dt->extra_comma);
 	      break;
 
 	    case EXEC_OMP_DO:
@@ -1131,21 +1131,21 @@ gfc_code_walker (gfc_code **c, walk_code_fn_t codefn, walk_expr_fn_t exprfn,
 	    case EXEC_OMP_WORKSHARE:
 	    case EXEC_OMP_END_SINGLE:
 	    case EXEC_OMP_TASK:
-	      if ((*c)->ext.omp_clauses)
+	      if (co->ext.omp_clauses)
 		{
-		  WALK_SUBEXPR ((*c)->ext.omp_clauses->if_expr);
-		  WALK_SUBEXPR ((*c)->ext.omp_clauses->num_threads);
-		  WALK_SUBEXPR ((*c)->ext.omp_clauses->chunk_size);
+		  WALK_SUBEXPR (co->ext.omp_clauses->if_expr);
+		  WALK_SUBEXPR (co->ext.omp_clauses->num_threads);
+		  WALK_SUBEXPR (co->ext.omp_clauses->chunk_size);
 		}
 	      break;
 	    default:
 	      break;
 	    }
 
-	  WALK_SUBEXPR ((*c)->expr1);
-	  WALK_SUBEXPR ((*c)->expr2);
-	  WALK_SUBEXPR ((*c)->expr3);
-	  for (b = (*c)->block; b; b = b->block)
+	  WALK_SUBEXPR (co->expr1);
+	  WALK_SUBEXPR (co->expr2);
+	  WALK_SUBEXPR (co->expr3);
+	  for (b = co->block; b; b = b->block)
 	    {
 	      WALK_SUBEXPR (b->expr1);
 	      WALK_SUBEXPR (b->expr2);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0520b0f7..304ecb6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-04-21  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/48405
+	* gfortran.dg/function_optimize_6.f90:  New test.
+
 2011-04-21  Easwaran Raman  <eraman@google.com>
 
 	* gcc.dg/stack-layout-2.c: New test.
diff --git a/gcc/testsuite/gfortran.dg/function_optimize_6.f90 b/gcc/testsuite/gfortran.dg/function_optimize_6.f90
new file mode 100644
index 0000000..cda7ab0
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/function_optimize_6.f90
@@ -0,0 +1,16 @@
+! { dg-do compile }
+! { dg-options "-O -fdump-tree-original" }
+! PR 48405 - function elimnination in a DO loop should work.
+program main
+  interface
+     pure function mypure()
+       integer :: mypure
+     end function mypure
+  end interface
+  DO I=1,mypure() + mypure()
+  ENDDO
+END program main
+! { dg-final { scan-tree-dump-times "mypure" 1 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }
+
+