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[Bug tree-optimization/37102] [4.3/4.4 Regression] out-of-SSA is broken
- From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 17 Sep 2008 14:25:05 -0000
- Subject: [Bug tree-optimization/37102] [4.3/4.4 Regression] out-of-SSA is broken
- References: <bug-37102-12544@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #12 from rguenth at gcc dot gnu dot org 2008-09-17 14:25 -------
Ok, so I think we should be fine if we ignore PHI nodes with zero-use results
during building the elimination graph - chained unused PHIs will have lifeness
computed for all but the PHI node with the zero-use result.
So, on the 4.3 branch the following fixes the failure for me:
Index: tree-outof-ssa.c
===================================================================
*** tree-outof-ssa.c (revision 140417)
--- tree-outof-ssa.c (working copy)
*************** eliminate_build (elim_graph g, basic_blo
*** 321,326 ****
--- 321,329 ----
for (phi = phi_nodes (B); phi; phi = PHI_CHAIN (phi))
{
+ if (has_zero_uses (PHI_RESULT (phi)))
+ continue;
+
T0 = var_to_partition_to_var (g->map, PHI_RESULT (phi));
/* Ignore results which are not in partitions. */
I am now giving this testing.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37102