This patch fixes an lto profiledbootstrap failure with -freorder-blocks-and-partition enabled.

This patch fixes an lto profiledbootstrap failure with
-freorder-blocks-and-partition enabled. Currently compgotos
is the only pass that goes into cfglayout mode after bb reordering,
which is undesireable (and in the case of -freorder-blocks-and-partition
can cause illegal partitioning) because of the optimizations performed
on the cfg when going into cfglayout mode. Moved compgoto before
bb reordering to avoid these problems.

2013-11-18  Teresa Johnson  <tejohnson@google.com>

	* gcc/cfgrtl.c (cfg_layout_initialize): Assert if we
	try to go into cfglayout after bb reordering.
	* gcc/passes.def: Move compgotos before bb reordering
	since it goes into cfglayout.

From-SVN: r204985

1 files changed, 9 insertions, 0 deletions

diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index c7ee7ee..1f99aa1df 100644
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -4204,6 +4204,15 @@ cfg_layout_initialize (unsigned int flags)
   rtx x;
   basic_block bb;
 
+  /* Once bb reordering is complete, cfg layout mode should not be re-entered.
+     Entering cfg layout mode will perform optimizations on the cfg that
+     could affect the bb layout negatively or even require fixups. An
+     example of the latter is if edge forwarding performed when optimizing
+     the cfg layout required moving a block from the hot to the cold section
+     under -freorder-blocks-and-partition. This would create an illegal
+     partitioning unless some manual fixup was performed.  */
+  gcc_assert (!crtl->bb_reorder_complete);
+
   initialize_original_copy_tables ();
 
   cfg_layout_rtl_register_cfg_hooks ();