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Fix profile update in unrolling
- From: Jan Hubicka <hubicka at ucw dot cz>
- To: gcc-patches at gcc dot gnu dot org
- Date: Fri, 16 Jun 2017 19:47:03 +0200
- Subject: Fix profile update in unrolling
- Authentication-results: sourceware.org; auth=none
hi,
this patch make unroller to update profile slightly beter by updating outgoing
probabilities when exit is proved to be taken.
Bootstrapped/regtested x86_64-linux, will commit it later today.
Honza
* tree-ssa-loop-ivcanon.c (remove_exits_and_undefined_stmts): Update
profile.
(try_unroll_loop_completely): Fix reporting.
Index: tree-ssa-loop-ivcanon.c
===================================================================
--- tree-ssa-loop-ivcanon.c (revision 249244)
+++ tree-ssa-loop-ivcanon.c (working copy)
@@ -529,6 +529,8 @@ remove_exits_and_undefined_stmts (struct
}
if (!loop_exit_edge_p (loop, exit_edge))
exit_edge = EDGE_SUCC (bb, 1);
+ exit_edge->probability = REG_BR_PROB_BASE;
+ exit_edge->count = exit_edge->src->count;
gcc_checking_assert (loop_exit_edge_p (loop, exit_edge));
gcond *cond_stmt = as_a <gcond *> (elt->stmt);
if (exit_edge->flags & EDGE_TRUE_VALUE)
@@ -853,8 +855,9 @@ try_unroll_loop_completely (struct loop
loop->num);
return false;
}
- dump_printf_loc (report_flags, locus,
- "loop turned into non-loop; it never loops.\n");
+ if (!n_unroll)
+ dump_printf_loc (report_flags, locus,
+ "loop turned into non-loop; it never loops.\n");
initialize_original_copy_tables ();
auto_sbitmap wont_exit (n_unroll + 1);