PR middle-end/39157

	* Makefile.in (loop-invariant.o): Depend on $(PARAMS_H).
	* params.h (LOOP_INVARIANT_MAX_BBS_IN_LOOP): Define.
	* params.def (loop-invariant-max-bbs-in-loop): New parameter.
	* opts.c (decode_options): Set loop-invariant-max-bbs-in-loop
	parameter to 1000 for -O1 by default.
	* doc/invoke.texi (loop-invariant-max-bbs-in-loop): Document new
	parameter.
	* loop-invariant.c: Include params.h.
	(move_loop_invariants): Don't call move_single_loop_invariants on
	very large loops.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@144320 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 7 insertions, 2 deletions

diff --git a/gcc/loop-invariant.c b/gcc/loop-invariant.c
index 8b8345fe5fd..82e18297e20 100644
--- a/gcc/loop-invariant.c
+++ b/gcc/loop-invariant.c
@@ -1,5 +1,6 @@
 /* RTL-level loop invariant motion.
-   Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
+   Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -52,6 +53,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "df.h"
 #include "hashtab.h"
 #include "except.h"
+#include "params.h"
 
 /* The data stored for the loop.  */
 
@@ -1345,7 +1347,10 @@ move_loop_invariants (void)
   /* Process the loops, innermost first.  */
   FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
     {
-      move_single_loop_invariants (loop);
+      /* move_single_loop_invariants for very large loops
+	 is time consuming and might need a lot of memory.  */
+      if (loop->num_nodes <= (unsigned) LOOP_INVARIANT_MAX_BBS_IN_LOOP)
+	move_single_loop_invariants (loop);
     }
 
   FOR_EACH_LOOP (li, loop, 0)