https://gcc.gnu.org/g:4e174ac8ee96a484be97313a90d2e831e978e27e
commit r14-10858-g4e174ac8ee96a484be97313a90d2e831e978e27e
Author: Yangyu Chen <c...@cyyself.name>
Date: Thu Oct 31 19:52:45 2024 +0000
Fix function multiversioning dispatcher link error with LTO
We forgot to apply DECL_EXTERNAL to __init_cpu_features_resolver decl. When
building with LTO, the linker cannot find the
__init_cpu_features_resolver.lto_priv* symbol, causing the link error.
This patch gets this fixed by adding DECL_EXTERNAL to the decl. To avoid
used
but never defined warning for this symbol, we also mark TREE_PUBLIC to the
decl.
We should also mark the decl having hidden visibility. And fix the
attribute in
the same way for __aarch64_cpu_features identifier.
Minimal steps to reproduce the bug:
echo '__attribute__((target_clones("default", "aes"))) void func1() { }' >
1.c
echo '__attribute__((target_clones("default", "aes"))) void func2() { }' >
2.c
echo 'void func1();void func2();int main(){func1();func2();return 0;}' >
main.c
gcc -flto -c 1.c 2.c
gcc -flto main.c 1.o 2.o
Fixes: 0cfde688e213 ("[aarch64] Add function multiversioning support")
Signed-off-by: Yangyu Chen <c...@cyyself.name>
gcc/ChangeLog:
* config/aarch64/aarch64.cc (dispatch_function_versions): Adding
DECL_EXTERNAL, TREE_PUBLIC and hidden DECL_VISIBILITY to
__init_cpu_features_resolver and __aarch64_cpu_features.
(cherry picked from commit 875279ff3ee3b4135401286b8378087a24fd0f8d)
Diff:
---
gcc/config/aarch64/aarch64.cc | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index e9bca8bbd08b..33a46c9eabec 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -20283,6 +20283,10 @@ dispatch_function_versions (tree dispatch_decl,
tree init_fn_id = get_identifier ("__init_cpu_features_resolver");
tree init_fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
init_fn_id, init_fn_type);
+ DECL_EXTERNAL (init_fn_decl) = 1;
+ TREE_PUBLIC (init_fn_decl) = 1;
+ DECL_VISIBILITY (init_fn_decl) = VISIBILITY_HIDDEN;
+ DECL_VISIBILITY_SPECIFIED (init_fn_decl) = 1;
tree arg1 = DECL_ARGUMENTS (dispatch_decl);
tree arg2 = TREE_CHAIN (arg1);
ifunc_cpu_init_stmt = gimple_build_call (init_fn_decl, 2, arg1, arg2);
@@ -20302,6 +20306,9 @@ dispatch_function_versions (tree dispatch_decl,
get_identifier ("__aarch64_cpu_features"),
global_type);
DECL_EXTERNAL (global_var) = 1;
+ TREE_PUBLIC (global_var) = 1;
+ DECL_VISIBILITY (global_var) = VISIBILITY_HIDDEN;
+ DECL_VISIBILITY_SPECIFIED (global_var) = 1;
tree mask_var = create_tmp_var (long_long_unsigned_type_node);
tree component_expr = build3 (COMPONENT_REF, long_long_unsigned_type_node,
