arm: Implement memcpy ifunc selection in C

This patch refactor ARM memcpy ifunc selector to a C implementation.
No functional change is expected, including ifunc resolution rules.

It also adds some cleanup:

  - Internal memcpy hidden definition (__GI_memcpy) is now a hidden
    symbol.

  - No need to create hidden definition for the ifunc variants.

Checked on armv7-linux-gnueabihf and with a build for arm-linux-gnueabi,
arm-linux-gnueabihf with and without multiarch support and with both
GCC 7.1 and GCC mainline.  I also checked with the some possible
multiarch different configurations that trigger different memcpy
buids (__ARM_NEON__ && !__SOFT_FP__, !__ARM_NEON__ && !__SOFT_FP__, and
!__ARM_NEON__ && __SOFT_FP__).

	* sysdeps/arm/arm-ifunc.h: New file.
	* sysdeps/arm/armv7/multiarch/ifunc-memcpy.h: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy.c: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy_arm.S: Likewise.
	* sysdeps/arm/armv7/multiarch/rtld-memcpy.S: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy_neon.S [!__ARM_NEON__]
	(__memcpy_neon): Avoid create hidden alias.
	* sysdeps/arm/armv7/multiarch/memcpy_vfp.S [!__ARM_NEON_]
	(__memcpy_vfp): Likewise.
	* sysdeps/arm/armv7/multiarch/Makefile [$(subdir) = string]
	(sysdep_routines): Add memcpy_arm.
	* sysdeps/arm/armv7/multiarch/memcpy.S: Remove file.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/sysdeps/arm/arm-ifunc.h b/sysdeps/arm/arm-ifunc.h
new file mode 100644
index 0000000..52cb533
--- /dev/null
+++ b/sysdeps/arm/arm-ifunc.h
@@ -0,0 +1,33 @@
+/* Common definition for ifunc resolvers.  Linux/ARM version.
+   This file is part of the GNU C Library.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+
+   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 <sysdep.h>
+#include <ifunc-init.h>
+
+#define INIT_ARCH()
+
+#define arm_libc_ifunc_redirected(redirected_name, name, expr)	\
+  __ifunc (redirected_name, name, expr(hwcap), int hwcap, INIT_ARCH)
+
+#if defined SHARED
+# define arm_libc_ifunc_hidden_def(redirect_name, name) \
+  __hidden_ver1 (name, __GI_##name, redirect_name) \
+    __attribute__ ((visibility ("hidden")))
+#else
+# define arm_libc_ifunc_hidden_def(redirect_name, name)
+#endif