[Bug tree-optimization/54146] Very slow compile with attribute((flatten))

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54146

--- Comment #24 from Steven Bosscher <steven at gcc dot gnu.org> 2012-08-06 
20:55:37 UTC ---
(In reply to comment #23)
> Created attachment 27953 [details]

Needs this extra bit:

diff -u ira.c ira.c
--- ira.c       (working copy)
+++ ira.c       (working copy)
@@ -3539,7 +3539,8 @@
   *p = NULL;

   for (i = 0; i < (unsigned int) max_regno; i++)
-    sbitmap_free (live_subregs[i]);
+    if (live_subregs[i] != NULL)
+      sbitmap_free (live_subregs[i]);
   free (live_subregs);
   BITMAP_FREE (live_subregs_used);
   BITMAP_FREE (live_relevant_regs);


With that, reload time goes down to ~14s, down from ~124s.