diff mbox

Don't prevent merging of bbs because of user labels (PR tree-optimization/50693)

Message ID 20111106194441.GC27375@tyan-ft48-01.lab.bos.redhat.com
State New
Headers show

Commit Message

Jakub Jelinek Nov. 6, 2011, 7:44 p.m. UTC 
On Sun, Nov 06, 2011 at 06:14:18PM +0100, Eric Botcazou wrote:
> > As has been suggested by Alexandre in the PR, this patch allows merging
> > basic blocks which couldn't be merged before because of user (non-forced)
> > labels at the beginning of the second basic blocks.
> > With this patch the user label is thrown away (for -g0 or -g
> > -fno-var-tracking-assignments) or turned into a debug bind stmt which
> > contains the label.
> 
> Do we really want to do that if !optimize?

You're right, at -O0 we don't do VTA and thus the user labels would be
dropped on the floor.

Fixed thusly, committed to trunk as obvious:

2011-11-06  Jakub Jelinek  <jakub@redhat.com>

	* tree-cfg.c (gimple_can_merge_blocks_p): For -O0 don't remove
	any user labels.



	Jakub
diff mbox

Patch

--- gcc/tree-cfg.c.jj	2011-11-04 18:01:25.000000000 +0100
+++ gcc/tree-cfg.c	2011-11-06 20:37:09.000000000 +0100
@@ -1454,8 +1454,8 @@  gimple_can_merge_blocks_p (basic_block a
 	break;
       lab = gimple_label_label (stmt);
 
-      /* Do not remove user forced labels.  */
-      if (!DECL_ARTIFICIAL (lab) && FORCED_LABEL (lab))
+      /* Do not remove user forced labels or for -O0 any user labels.  */
+      if (!DECL_ARTIFICIAL (lab) && (!optimize || FORCED_LABEL (lab)))
 	return false;
     }