Hello,
The attached patch moves the creation of anti-dep edge from a
branch to it's def from create_ddg_dep_from_intra_loop_link () to
add_cross_iteration_register_deps () due to the fact the edge is with
distance 1 and thus should be in the later function.
The edge was added to avoid creating reg-moves.
The patch was tested together with the rest of the patches in this series.
On ppc64-redhat-linux regtest as well as bootstrap with SMS flags
enabling SMS also on loops with stage count 1. Regtested on SPU.
On arm-linux-gnueabi regtseted on c,c++. Bootstrap c language with SMS
flags enabling SMS also on loops with stage count 1.
OK for mainline?
Thanks,
Revital
* ddg.c (create_ddg_dep_from_intra_loop_link): Remove the creation
of anti-dep edge from a branch.
(add_cross_iteration_register_deps): Create anti-dep edge from
a branch.
Index: ddg.c
===================================================================
--- ddg.c (revision 173785)
+++ ddg.c (working copy)
@@ -197,11 +197,6 @@ create_ddg_dep_from_intra_loop_link (ddg
}
}
- /* If a true dep edge enters the branch create an anti edge in the
- opposite direction to prevent the creation of reg-moves. */
- if ((DEP_TYPE (link) == REG_DEP_TRUE) && JUMP_P (dest_node->insn))
- create_ddg_dep_no_link (g, dest_node, src_node, ANTI_DEP, REG_DEP, 1);
-
latency = dep_cost (link);
e = create_ddg_edge (src_node, dest_node, t, dt, latency, distance);
add_edge_to_ddg (g, e);
@@ -306,8 +301,11 @@ add_cross_iteration_register_deps (ddg_p
gcc_assert (first_def_node);
+ /* Always create the edge if the use node is a branch in
+ order to prevent the creation of reg-moves. */
if (DF_REF_ID (last_def) != DF_REF_ID (first_def)
- || !flag_modulo_sched_allow_regmoves)
+ || !flag_modulo_sched_allow_regmoves
+ || (flag_modulo_sched_allow_regmoves && JUMP_P (use_node->insn)))
create_ddg_dep_no_link (g, use_node, first_def_node, ANTI_DEP,
REG_DEP, 1);
