From: Josef Melcr <josef.melcr@suse.com>
Date: Thu, 20 Nov 2025 22:57:57 +0000 (+0100)
Subject: ipa: Remove LTO requirement for builtin callback carriers.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f9c01c47f8e5451e41a5df78f044d7b1e7b3d5d6;p=thirdparty%2Fgcc.git

ipa: Remove LTO requirement for builtin callback carriers.

Due to the if statement in ipa_compute_jump_functions_for_bb, callback
edges were never constructed for builtin functions unless LTO was
enabled.  This patch corrects this behavior, allowing GCC to optimize
callbacks more broadly.  It also extends our testing capabilities.

gcc/ChangeLog:

	* attr-callback.cc (callback_edge_callee_has_attr): New
	function.
	* attr-callback.h (callback_edge_callee_has_attr): New function
	decl.
	* ipa-prop.cc (ipa_compute_jump_functions_for_bb): Don't skip
	callback carriers when calculating jump functions.

libgomp/ChangeLog:

	* testsuite/libgomp.c/ipcp-cb-spec1.c: Remove LTO requirement.
	* testsuite/libgomp.c/ipcp-cb-spec2.c: Likewise.
	* testsuite/libgomp.c/ipcp-cb1.c: Likewise.

Signed-off-by: Josef Melcr <josef.melcr@suse.com>
---

diff --git a/gcc/attr-callback.cc b/gcc/attr-callback.cc
index 04b5ad0ef11..f116f0472f3 100644
--- a/gcc/attr-callback.cc
+++ b/gcc/attr-callback.cc
@@ -83,6 +83,15 @@ callback_special_case_attr (tree decl)
   gcc_unreachable ();
 }
 
+/* Returns TRUE if the callee of E has a callback attribute.  */
+bool
+callback_edge_callee_has_attr (cgraph_edge *e)
+{
+  return lookup_attribute (CALLBACK_ATTR_IDENT,
+			   DECL_ATTRIBUTES (e->callee->decl))
+	 || callback_is_special_cased (e->callee->decl, e->call_stmt);
+}
+
 /* Given an instance of callback attribute, return the 0-based
    index of the called function in question.  */
 int
diff --git a/gcc/attr-callback.h b/gcc/attr-callback.h
index b0b08438afb..39a4fe8ac94 100644
--- a/gcc/attr-callback.h
+++ b/gcc/attr-callback.h
@@ -43,6 +43,9 @@ bool callback_is_special_cased (tree decl, gcall *stmt);
 /* Returns an attribute for a special cased function.  */
 tree callback_special_case_attr (tree decl);
 
+/* Returns TRUE if the callee of E has a callback attribute.  */
+bool callback_edge_callee_has_attr (cgraph_edge *e);
+
 /* Given an instance of callback attribute, return the 0-based
    index of the called function in question.  */
 int callback_get_fn_index (tree cb_attr);
diff --git a/gcc/ipa-prop.cc b/gcc/ipa-prop.cc
index 1e4b6d4548d..2debbe10de3 100644
--- a/gcc/ipa-prop.cc
+++ b/gcc/ipa-prop.cc
@@ -2698,7 +2698,8 @@ ipa_compute_jump_functions_for_bb (struct ipa_func_body_info *fbi, basic_block b
 	  /* We do not need to bother analyzing calls to unknown functions
 	     unless they may become known during lto/whopr.  */
 	  if (!callee->definition && !flag_lto
-	      && !gimple_call_fnspec (cs->call_stmt).known_p ())
+	      && !gimple_call_fnspec (cs->call_stmt).known_p ()
+	      && !callback_edge_callee_has_attr (cs))
 	    continue;
 	}
       ipa_compute_jump_functions_for_edge (fbi, cs);
diff --git a/libgomp/testsuite/libgomp.c/ipcp-cb-spec1.c b/libgomp/testsuite/libgomp.c/ipcp-cb-spec1.c
index a85e62300f9..ff82f4c2f29 100644
--- a/libgomp/testsuite/libgomp.c/ipcp-cb-spec1.c
+++ b/libgomp/testsuite/libgomp.c/ipcp-cb-spec1.c
@@ -1,9 +1,8 @@
 /* Test that GOMP_task is special cased when cpyfn is NULL.  */
 
 /* { dg-do run } */
-/* { dg-options "-O3 -fopenmp -flto -std=gnu99 -fdump-ipa-cp-details" } */
+/* { dg-options "-O3 -fopenmp -std=gnu99 -fdump-ipa-cp-details" } */
 /* { dg-require-effective-target fopenmp } */
-/* { dg-require-effective-target lto } */
 
 void test(int c) {
   for (int i = 0; i < c; i++)
@@ -16,4 +15,4 @@ int main() {
   return 0;
 }
 
-/* { dg-final { scan-wpa-ipa-dump "Creating a specialized node of main._omp_fn" "cp" } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of main._omp_fn" "cp" } } */
diff --git a/libgomp/testsuite/libgomp.c/ipcp-cb-spec2.c b/libgomp/testsuite/libgomp.c/ipcp-cb-spec2.c
index 01d7425c99f..30894d7d748 100644
--- a/libgomp/testsuite/libgomp.c/ipcp-cb-spec2.c
+++ b/libgomp/testsuite/libgomp.c/ipcp-cb-spec2.c
@@ -2,9 +2,8 @@
    NULL.  */
 
 /* { dg-do run } */
-/* { dg-options "-O3 -fopenmp -flto -std=gnu99 -fdump-ipa-cp-details" } */
+/* { dg-options "-O3 -fopenmp -std=gnu99 -fdump-ipa-cp-details" } */
 /* { dg-require-effective-target fopenmp } */
-/* { dg-require-effective-target lto } */
 
 void test(int *a) {
   for (int i = 0; i < 100; i++) {
diff --git a/libgomp/testsuite/libgomp.c/ipcp-cb1.c b/libgomp/testsuite/libgomp.c/ipcp-cb1.c
index 3418b5dedab..e390f04d8cf 100644
--- a/libgomp/testsuite/libgomp.c/ipcp-cb1.c
+++ b/libgomp/testsuite/libgomp.c/ipcp-cb1.c
@@ -2,9 +2,8 @@
    This tests the underlying callback attribute and its related edges.  */
 
 /* { dg-do run } */
-/* { dg-options "-O3 -fopenmp -flto -std=gnu99 -fdump-ipa-cp-details" } */
+/* { dg-options "-O3 -fopenmp -std=gnu99 -fdump-ipa-cp-details" } */
 /* { dg-require-effective-target fopenmp } */
-/* { dg-require-effective-target lto } */
 
 int a[100];
 void test(int c) {
@@ -21,5 +20,5 @@ int main() {
   return a[5] - 5;
 }
 
-/* { dg-final { scan-wpa-ipa-dump "Creating a specialized node of test._omp_fn" "cp" } } */
-/* { dg-final { scan-wpa-ipa-dump "Aggregate replacements: 0\\\[0]=100\\(by_ref\\)" "cp" } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of test._omp_fn" "cp" } } */
+/* { dg-final { scan-ipa-dump "Aggregate replacements: 0\\\[0]=100\\(by_ref\\)" "cp" } } */