[PATCH] Fix removal of ifunc (PR ipa/81214).

["Martin Liška" <mliska@suse.cz>]

[-- Attachment #1: Type: text/plain, Size: 882 bytes --]

Hello.

Following patch fixes the issue where we do not emit ifunc and resolver
for function that are not called in a compilation unit or and not
referenced.

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
i386.exp tests work on x86_64-linux-gnu.

Ready to be installed?
Martin

gcc/testsuite/ChangeLog:

2017-06-29  Martin Liska  <mliska@suse.cz>

	PR ipa/81214
	* gcc.target/i386/pr81214.c: New test.

gcc/ChangeLog:

2017-06-29  Martin Liska  <mliska@suse.cz>

	PR ipa/81214
	* multiple_target.c (create_dispatcher_calls): Make ifunc
	also for function that don't have calls or are not referenced.
---
 gcc/multiple_target.c                   | 64 ++++++++++++++++-----------------
 gcc/testsuite/gcc.target/i386/pr81214.c | 14 ++++++++
 2 files changed, 46 insertions(+), 32 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr81214.c



[-- Attachment #2: 0001-Fix-removal-of-ifunc-PR-ipa-81214.patch --]
[-- Type: text/x-patch, Size: 3101 bytes --]

diff --git a/gcc/multiple_target.c b/gcc/multiple_target.c
index eddc7d3744b..0d7cc3a2939 100644
--- a/gcc/multiple_target.c
+++ b/gcc/multiple_target.c
@@ -68,6 +68,38 @@ create_dispatcher_calls (struct cgraph_node *node)
       || !is_function_default_version (node->decl))
     return;
 
+  if (!targetm.has_ifunc_p ())
+    {
+      error_at (DECL_SOURCE_LOCATION (node->decl),
+		"the call requires ifunc, which is not"
+		" supported by this target");
+      return;
+    }
+  else if (!targetm.get_function_versions_dispatcher)
+    {
+      error_at (DECL_SOURCE_LOCATION (node->decl),
+		"target does not support function version dispatcher");
+      return;
+    }
+
+  tree idecl = targetm.get_function_versions_dispatcher (node->decl);
+  if (!idecl)
+    {
+      error_at (DECL_SOURCE_LOCATION (node->decl),
+		"default target_clones attribute was not set");
+      return;
+    }
+
+  cgraph_node *inode = cgraph_node::get (idecl);
+  gcc_assert (inode);
+  tree resolver_decl = targetm.generate_version_dispatcher_body (inode);
+
+  /* Update aliases.  */
+  inode->alias = true;
+  inode->alias_target = resolver_decl;
+  if (!inode->analyzed)
+    inode->resolve_alias (cgraph_node::get (resolver_decl));
+
   auto_vec<cgraph_edge *> edges_to_redirect;
   auto_vec<ipa_ref *> references_to_redirect;
 
@@ -80,38 +112,6 @@ create_dispatcher_calls (struct cgraph_node *node)
 
   if (!edges_to_redirect.is_empty () || !references_to_redirect.is_empty ())
     {
-      if (!targetm.has_ifunc_p ())
-	{
-	  error_at (DECL_SOURCE_LOCATION (node->decl),
-		    "the call requires ifunc, which is not"
-		    " supported by this target");
-	  return;
-	}
-      else if (!targetm.get_function_versions_dispatcher)
-	{
-	  error_at (DECL_SOURCE_LOCATION (node->decl),
-		    "target does not support function version dispatcher");
-	  return;
-	}
-
-      tree idecl = targetm.get_function_versions_dispatcher (node->decl);
-      if (!idecl)
-	{
-	  error_at (DECL_SOURCE_LOCATION (node->decl),
-		    "default target_clones attribute was not set");
-	  return;
-	}
-
-      cgraph_node *inode = cgraph_node::get (idecl);
-      gcc_assert (inode);
-      tree resolver_decl = targetm.generate_version_dispatcher_body (inode);
-
-      /* Update aliases.  */
-      inode->alias = true;
-      inode->alias_target = resolver_decl;
-      if (!inode->analyzed)
-	inode->resolve_alias (cgraph_node::get (resolver_decl));
-
       /* Redirect edges.  */
       unsigned i;
       cgraph_edge *e;
diff --git a/gcc/testsuite/gcc.target/i386/pr81214.c b/gcc/testsuite/gcc.target/i386/pr81214.c
new file mode 100644
index 00000000000..2584decdb3c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81214.c
@@ -0,0 +1,14 @@
+/* PR ipa/81214.  */
+/* { dg-do compile } */
+/* { dg-require-ifunc "" } */
+
+__attribute__((target_clones("avx","arch=slm","arch=core-avx2","default")))
+int
+foo ()
+{
+  return -2;
+}
+
+/* { dg-final { scan-assembler "\t.globl\tfoo" } } */
+/* { dg-final { scan-assembler "foo.resolver:" } } */
+/* { dg-final { scan-assembler "foo, @gnu_indirect_function" } } */