Most callers of connect_infinite_loops_to_exit already do this but
the few that do not end up with extra exit edges. The following
makes that consistent, also matching the post-dominance DFS walk code.
Boostrapped and tested on x86_64-unknown-linux-gnu, queued for stage1.
2021-02-25 Richard Biener <rguent...@suse.de>
* cfganal.c (connect_infinite_loops_to_exit): First call
add_noreturn_fake_exit_edges.
* ipa-sra.c (process_scan_results): Do not call the now redundant
add_noreturn_fake_exit_edges.
* predict.c (tree_estimate_probability): Likewise.
(rebuild_frequencies): Likewise.
* store-motion.c (one_store_motion_pass): Likewise.
---
gcc/cfganal.c | 10 +++++++---
gcc/ipa-sra.c | 1 -
gcc/predict.c | 2 --
gcc/store-motion.c | 1 -
4 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/gcc/cfganal.c b/gcc/cfganal.c
index 2627c2ff457..cec5abe30f9 100644
--- a/gcc/cfganal.c
+++ b/gcc/cfganal.c
@@ -582,9 +582,9 @@ add_noreturn_fake_exit_edges (void)
make_single_succ_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FAKE);
}
-/* This function adds a fake edge between any infinite loops to the
- exit block. Some optimizations require a path from each node to
- the exit node.
+/* This function adds a fake edge between any noreturn block and
+ infinite loops to the exit block. Some optimizations require a path
+ from each node to the exit node.
See also Morgan, Figure 3.10, pp. 82-83.
@@ -596,6 +596,10 @@ add_noreturn_fake_exit_edges (void)
void
connect_infinite_loops_to_exit (void)
{
+ /* First add fake exits to noreturn blocks, this is required to
+ discover only truly infinite loops below. */
+ add_noreturn_fake_exit_edges ();
+
/* Perform depth-first search in the reverse graph to find nodes
reachable from the exit block. */
depth_first_search dfs;
diff --git a/gcc/ipa-sra.c b/gcc/ipa-sra.c
index 1571921cb48..7a89906cee6 100644
--- a/gcc/ipa-sra.c
+++ b/gcc/ipa-sra.c
@@ -2394,7 +2394,6 @@ process_scan_results (cgraph_node *node, struct function
*fun,
if (!pdoms_calculated)
{
gcc_checking_assert (cfun);
- add_noreturn_fake_exit_edges ();
connect_infinite_loops_to_exit ();
calculate_dominance_info (CDI_POST_DOMINATORS);
pdoms_calculated = true;
diff --git a/gcc/predict.c b/gcc/predict.c
index d0a8e5f8e04..0bf1748ffa8 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -3106,7 +3106,6 @@ tree_estimate_probability (bool dry_run)
{
basic_block bb;
- add_noreturn_fake_exit_edges ();
connect_infinite_loops_to_exit ();
/* We use loop_niter_by_eval, which requires that the loops have
preheaders. */
@@ -4291,7 +4290,6 @@ rebuild_frequencies (void)
if (profile_status_for_fn (cfun) == PROFILE_GUESSED)
{
loop_optimizer_init (0);
- add_noreturn_fake_exit_edges ();
mark_irreducible_loops ();
connect_infinite_loops_to_exit ();
estimate_bb_frequencies (true);
diff --git a/gcc/store-motion.c b/gcc/store-motion.c
index f0401cae272..3f6e003219d 100644
--- a/gcc/store-motion.c
+++ b/gcc/store-motion.c
@@ -1152,7 +1152,6 @@ one_store_motion_pass (void)
/* Now compute kill & transp vectors. */
build_store_vectors ();
- add_noreturn_fake_exit_edges ();
connect_infinite_loops_to_exit ();
edge_list = pre_edge_rev_lcm (num_stores, st_transp, st_avloc,
--
2.26.2
