AutoFDO early inlining can inline all direct calls to a local
function while speculative call promotion keeps the function
address-taken. The function consequently remains in the call graph
with no direct callers, triggering the -ftoplevel-reorder checking
assertion in IPA-CP.
Ordinary IPA devirtualization does not normally produce this state at
IPA-CP: it creates speculative edges before IPA-CP, but those edges are
inlined only by the later IPA inliner. IPA-CP therefore still sees a
direct caller. AutoFDO instead performs speculative inlining early, so
only its IPA_REF_ADDR may remain by the time IPA-CP runs.
When AutoFDO inlining is enabled, recognize zero-caller functions that
cannot be removed after their direct calls disappear and initialize
their lattices as variable. Preserve the assertion for removable
locals and non-AutoFDO compilation.
gcc/ChangeLog:
* ipa-cp.cc (initialize_node_lattices): Handle zero-caller local
functions left after AutoFDO early inlining.
Regression tested on aarch64-linux-gnu with no new regressions
Signed-off-by: Kugan Vivekanandarajah <[email protected]>
---
gcc/ipa-cp.cc | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
index c1b1f6201fd3..d68952ec8711 100644
--- a/gcc/ipa-cp.cc
+++ b/gcc/ipa-cp.cc
@@ -1443,7 +1443,18 @@ initialize_node_lattices (struct cgraph_node *node)
NULL, true);
else if (caller_count == 0)
{
- gcc_checking_assert (!opt_for_fn (node->decl, flag_toplevel_reorder));
+ /* With -ftoplevel-reorder, a local body with no direct callers
+ should already have been removed. AutoFDO early-inline of a
+ speculative call expands via gimple_ic (&target), so after all
+ direct call edges are inlined the local can remain address-taken
+ with unknown indirect uses; treat that as VARIABLE. Ordinary
+ IPA devirtualization does not need this exception: it creates
+ speculative edges before IPA-CP, but inlines them only later, so
+ IPA-CP still sees a direct caller. */
+ if (!(flag_auto_profile && flag_auto_profile_inlining
+ && !node->can_remove_if_no_direct_calls_p (false)))
+ gcc_checking_assert
+ (!opt_for_fn (node->decl, flag_toplevel_reorder));
variable = true;
}
}
--
2.34.1
