Framework to test IFUNC implementations on target

ChangeLog

@@ -1,5 +1,19 @@
 2012-10-11  H.J. Lu  <hongjiu.lu@intel.com>
 
+	* Rules [$(multi-arch) = no] (tests): Filter out $(tests-ifunc).
+	[$(multi-arch) = no] (xtests): Filter out $(xtests-ifunc).
+	* include/ifunc-impl-list.h: New file.
+	* misc/ifunc-impl-list.c: Likewise.
+	* misc/Makefile (routines): Add ifunc-impl-list.
+	* misc/Versions (GLIBC_PRIVATE): Add __libc_ifunc_impl_list.
+	* string/test-string.h: Include <ifunc-impl-list.h>.
+	[TEST_IFUNC && TEST_NAME] (func_list, func_count, impl_count,
+	impl_array): New variables.
+	(FOR_EACH_IMPL): Support func_list if TEST_IFUNC and TEST_NAME
+	are defined.
+	(test_init): Call __libc_ifunc_impl_list to initialize
+	func_list if TEST_IFUNC and TEST_NAME are defined.
+
 	* string/Makefile (strop-tests): Add bcopy and bzero.
 	* string/test-bcopy.c: New file.
 	* string/test-bzero.c: Likewise.

Rules

@@ -84,6 +84,11 @@ common-generated += dummy.o dummy.c
 # This makes all the auxiliary and test programs.
 
 .PHONY: others tests
+ifeq ($(multi-arch),no)
+tests := $(filter-out $(tests-ifunc), $(tests))
+xtests := $(filter-out $(xtests-ifunc), $(xtests))
+endif
+
 ifeq ($(build-programs),yes)
 others: $(addprefix $(objpfx),$(others) $(sysdep-others) $(extra-objs))
 else

include/ifunc-impl-list.h

@@ -0,0 +1,56 @@
+/* Internal header file for __libc_supported_implementations.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _IFUNC_IMPL_LIST_H
+#define _IFUNC_IMPL_LIST_H	1
+
+#include <stdbool.h>
+#include <stddef.h>
+
+struct libc_ifunc_impl
+{
+  /* The name of function to be tested.  */
+  const char *name;
+  /* The address of function to be tested.  */
+  void (*fn) (void);
+  /* True if this implementation is usable on this machine.  */
+  bool usable;
+};
+
+/* Add an IFUNC implementation, IMPL, for function FUNC, to ARRAY with
+   USABLE at index I and advance I by one.  */
+#define IFUNC_IMPL_ADD(array, i, func, usable, impl) \
+  extern __typeof (func) impl attribute_hidden; \
+  (array)[i++] = (struct libc_ifunc_impl) { #impl, (void (*) (void)) impl, (usable) };
+
+/* Return the number of IFUNC implementations, N, for function FUNC if
+   string NAME matches FUNC.  */
+#define IFUNC_IMPL(n, name, func, ...) \
+  if (strcmp (name, #func) == 0) \
+    { \
+      __VA_ARGS__; \
+      return n; \
+    }
+
+/* Fill ARRAY of MAX elements with IFUNC implementations for function
+   NAME and return the number of valid entries.  */
+extern size_t __libc_ifunc_impl_list (const char *name,
+				      struct libc_ifunc_impl *array,
+				      size_t max);
+
+#endif /* ifunc-impl-list.h */

misc/Makefile

@@ -65,7 +65,7 @@ routines := brk sbrk sstk ioctl \
 	    getloadavg getclktck \
 	    fgetxattr flistxattr fremovexattr fsetxattr getxattr \
 	    listxattr lgetxattr llistxattr lremovexattr lsetxattr \
-	    removexattr setxattr getauxval
+	    removexattr setxattr getauxval ifunc-impl-list
 
 generated := tst-error1.mtrace tst-error1-mem
 

misc/Versions

@@ -151,5 +151,6 @@ libc {
   }
   GLIBC_PRIVATE {
     __madvise;
+    __libc_ifunc_impl_list;
   }
 }

misc/ifunc-impl-list.c

@@ -0,0 +1,32 @@
+/* Enumerate available IFUNC implementations of a function.  Stub version.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <ifunc-impl-list.h>
+
+/* Fill ARRAY of MAX elements with IFUNC implementations for function
+   NAME supported on target machine and return the number of valid
+   entries.  */
+
+size_t
+__libc_ifunc_impl_list
+  (const char *name __attribute__ ((unused)),
+   struct libc_ifunc_impl *array __attribute__ ((unused)),
+   size_t max __attribute__ ((unused)))
+{
+  return 0;
+}

string/test-string.h

@@ -50,6 +50,7 @@ extern impl_t __start_impls[], __stop_impls[];
 #include <error.h>
 #include <errno.h>
 #include <time.h>
+#include <ifunc-impl-list.h>
 #define GL(x) _##x
 #define GLRO(x) _##x
 #include <hp-timing.h>
@@ -106,9 +107,57 @@ size_t iterations = 100000;
 #define CALL(impl, ...)	\
   (* (proto_t) (impl)->fn) (__VA_ARGS__)
 
-#define FOR_EACH_IMPL(impl, notall) \
+#if defined TEST_IFUNC && defined TEST_NAME
+/* Increase size of FUNC_LIST if assert is triggered at run-time.  */
+static struct libc_ifunc_impl func_list[32];
+static int func_count;
+static int impl_count = -1;
+static impl_t *impl_array;
+
+# define FOR_EACH_IMPL(impl, notall) \
+  impl_t *impl;								\
+  int count;								\
+  if (impl_count == -1)							\
+    {									\
+      impl_count = 0;							\
+      if (func_count != 0)						\
+	{								\
+	  int f;							\
+	  impl_t *skip = NULL, *a;					\
+	  for (impl = __start_impls; impl < __stop_impls; ++impl)	\
+	    if (strcmp (impl->name, TEST_NAME) == 0)			\
+	      skip = impl;						\
+	    else							\
+	      impl_count++;						\
+	  a = impl_array = malloc ((impl_count + func_count) *		\
+				   sizeof (impl_t));			\
+	  for (impl = __start_impls; impl < __stop_impls; ++impl)	\
+	    if (impl != skip)						\
+	      *a++ = *impl;						\
+	  for (f = 0; f < func_count; f++)				\
+	    if (func_list[f].usable)					\
+	      {								\
+		a->name = func_list[f].name;				\
+		a->fn = func_list[f].fn;				\
+		a->test = 1;						\
+		a++;							\
+	      }								\
+	  impl_count = a - impl_array;					\
+	}								\
+      else								\
+        {								\
+	  impl_count = __stop_impls - __start_impls;			\
+	  impl_array = __start_impls;					\
+        }								\
+    }									\
+  impl = impl_array;							\
+  for (count = 0; count < impl_count; ++count, ++impl)			\
+    if (!notall || impl->test)
+#else
+# define FOR_EACH_IMPL(impl, notall) \
   for (impl_t *impl = __start_impls; impl < __stop_impls; ++impl)	\
     if (!notall || impl->test)
+#endif
 
 #define HP_TIMING_BEST(best_time, start, end)	\
   do									\
@@ -127,6 +176,12 @@ size_t iterations = 100000;
 static void
 test_init (void)
 {
+#if defined TEST_IFUNC && defined TEST_NAME
+  func_count = __libc_ifunc_impl_list (TEST_NAME, func_list,
+				       (sizeof func_list
+					/ sizeof func_list[0]));
+#endif
+
   page_size = 2 * getpagesize ();
 #ifdef MIN_PAGE_SIZE
   if (page_size < MIN_PAGE_SIZE)