Some minor changes to the PowerPC target_clones support:
1) I added a warning if target_clones was used and the compiler whas configured
with an older glibc where __builtin_cpu_supports always returns 0;
2) I reworked how the ifunc resolver function is generated, and always made it
a static function;
3) I added an executable target_clones test, and I made both clone tests
dependent on GCC being configured with a new glibc.
I have done a full bootstrap and make check test on a little endian power8
system, and there were no regressions. I did the bootstrap using the Advance
Toolchain 10.0-3 libraries, and verified that the 2 clone tests were run.
Are these patches ok to apply to the trunk?
[gcc]
2017-06-28 Michael Meissner <meiss...@linux.vnet.ibm.com>
* config/rs6000/rs6000.c
(rs6000_get_function_versions_dispatcher): Add warning if the
compiler is not configured to use at least GLIBC version 2.23.
(make_resolver_func): Make resolver function private and not a
COMDAT function. Create the name with clone_function_name instead
of make_unique_name.
[gcc/testsuite]
2017-06-28 Michael Meissner <meiss...@linux.vnet.ibm.com>
* gcc.target/powerpc/clone2.c: New runtime test for
target_clones.
* gcc.target/powerpc/clone1.c: Add check to make sure the
__builtin_cpu_supports function is fully supported.
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c
(.../svn+ssh://meiss...@gcc.gnu.org/svn/gcc/trunk/gcc/config/rs6000)
(revision 249737)
+++ gcc/config/rs6000/rs6000.c (.../gcc/config/rs6000) (working copy)
@@ -37266,6 +37266,11 @@ rs6000_get_function_versions_dispatcher
default_node = default_version_info->this_node;
+#ifndef TARGET_LIBC_PROVIDES_HWCAP_IN_TCB
+ warning_at (DECL_SOURCE_LOCATION (default_node->decl), 0,
+ "target_clone needs at least glibc 2.23");
+#endif
+
if (targetm.has_ifunc_p ())
{
struct cgraph_function_version_info *it_v = NULL;
@@ -37311,29 +37316,24 @@ make_resolver_func (const tree default_d
const tree dispatch_decl,
basic_block *empty_bb)
{
- /* IFUNC's have to be globally visible. So, if the default_decl is
- not, then the name of the IFUNC should be made unique. */
- bool is_uniq = (TREE_PUBLIC (default_decl) == 0);
-
/* Append the filename to the resolver function if the versions are
not externally visible. This is because the resolver function has
to be externally visible for the loader to find it. So, appending
the filename will prevent conflicts with a resolver function from
another module which is based on the same version name. */
- char *resolver_name = make_unique_name (default_decl, "resolver", is_uniq);
+ tree decl_name = clone_function_name (default_decl, "resolver");
+ const char *resolver_name = IDENTIFIER_POINTER (decl_name);
/* The resolver function should return a (void *). */
tree type = build_function_type_list (ptr_type_node, NULL_TREE);
tree decl = build_fn_decl (resolver_name, type);
- tree decl_name = get_identifier (resolver_name);
SET_DECL_ASSEMBLER_NAME (decl, decl_name);
DECL_NAME (decl) = decl_name;
TREE_USED (decl) = 1;
DECL_ARTIFICIAL (decl) = 1;
DECL_IGNORED_P (decl) = 0;
- /* IFUNC resolvers have to be externally visible. */
- TREE_PUBLIC (decl) = 1;
+ TREE_PUBLIC (decl) = 0;
DECL_UNINLINABLE (decl) = 1;
/* Resolver is not external, body is generated. */
@@ -37344,15 +37344,6 @@ make_resolver_func (const tree default_d
DECL_INITIAL (decl) = make_node (BLOCK);
DECL_STATIC_CONSTRUCTOR (decl) = 0;
- if (DECL_COMDAT_GROUP (default_decl) || TREE_PUBLIC (default_decl))
- {
- /* In this case, each translation unit with a call to this
- versioned function will put out a resolver. Ensure it
- is comdat to keep just one copy. */
- DECL_COMDAT (decl) = 1;
- make_decl_one_only (decl, DECL_ASSEMBLER_NAME (decl));
- }
-
/* Build result decl and add to function_decl. */
tree t = build_decl (UNKNOWN_LOCATION, RESULT_DECL, NULL_TREE,
ptr_type_node);
DECL_ARTIFICIAL (t) = 1;
@@ -37374,7 +37365,7 @@ make_resolver_func (const tree default_d
= make_attribute ("ifunc", resolver_name, DECL_ATTRIBUTES (dispatch_decl));
cgraph_node::create_same_body_alias (dispatch_decl, decl);
- XDELETEVEC (resolver_name);
+
return decl;
}
Index: gcc/testsuite/gcc.target/powerpc/clone2.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/clone2.c
(.../svn+ssh://meiss...@gcc.gnu.org/svn/gcc/trunk/gcc/testsuite/gcc.target/powerpc)
(revision 0)
+++ gcc/testsuite/gcc.target/powerpc/clone2.c
(.../gcc/testsuite/gcc.target/powerpc) (revision 249738)
@@ -0,0 +1,31 @@
+/* { dg-do run { target { powerpc*-*-linux* } } } */
+/* { dg-options "-mvsx -O2" } */
+/* { dg-require-effective-target powerpc_p9vector_ok } */
+/* { dg-require-effective-target ppc_cpu_supports_hw } */
+
+#include <stddef.h>
+#include <stdlib.h>
+
+/* Power9 (aka, ISA 3.0) has a MODSD instruction to do modulus, while Power8
+ (aka, ISA 2.07) has to do modulus with divide and multiply. Make sure that
+ the basic support for target_clones runs.
+
+ Restrict ourselves to Linux, since IFUNC might not be supported in other
+ operating systems. */
+
+__attribute__((__target_clones__("cpu=power9,default")))
+long mod_func (long a, long b)
+{
+ return a % b;
+}
+
+#define X 53L
+#define Y 7L
+int
+main (void)
+{
+ if (mod_func (X, Y) != (X % Y))
+ abort ();
+
+ return 0;
+}
Index: gcc/testsuite/gcc.target/powerpc/clone1.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/clone1.c
(.../svn+ssh://meiss...@gcc.gnu.org/svn/gcc/trunk/gcc/testsuite/gcc.target/powerpc)
(revision 249737)
+++ gcc/testsuite/gcc.target/powerpc/clone1.c
(.../gcc/testsuite/gcc.target/powerpc) (working copy)
@@ -2,6 +2,7 @@
/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } {
"-mcpu=power8" } } */
/* { dg-options "-mcpu=power8 -O2" } */
/* { dg-require-effective-target powerpc_p9vector_ok } */
+/* { dg-require-effective-target ppc_cpu_supports_hw } */
/* Power9 (aka, ISA 3.0) has a MODSD instruction to do modulus, while Power8
(aka, ISA 2.07) has to do modulus with divide and multiply. Make sure
