So maybe this patch adding a comment on calculate_dominance_info is more
adapted.
ChangeLog:
2011-05-17 Pierre Vittet<pier...@pvittet.com>
* dominance.c (calculate_dominance_info): Add comment
precising when to free with free_dominance_info
contributor number: 634276
Index: gcc/dominance.c
===================================================================
--- gcc/dominance.c (revision 173830)
+++ gcc/dominance.c (working copy)
@@ -628,8 +628,15 @@ compute_dom_fast_query (enum cdi_direction dir)
}
/* The main entry point into this module. DIR is set depending on whether
- we want to compute dominators or postdominators. */
+ we want to compute dominators or postdominators.
+ We try to keep dominance info alive as long as possible (to avoid
+ recomputing it often). It has to be freed with free_dominance_info when CFG
+ transformation makes it invalide.
+
+ post_dominance info is less often used, and should be freed after each use.
+*/
+
void
calculate_dominance_info (enum cdi_direction dir)
{
