glibc/sysdeps/s390/mempcpy.S

/* CPU specific mempcpy without multiarch - 32/64 bit S/390 version.
   Copyright (C) 2016-2017 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/>.  */

/* mempcpy is implemented in memcpy.S.  */
S390: Implement mempcpy with help of memcpy. [BZ #19765] There exist optimized memcpy functions on s390, but no optimized mempcpy. This patch adds mempcpy entry points in memcpy.S files, which use the memcpy implementation. Now mempcpy itself is also an IFUNC function as memcpy is and the variants are listed in ifunc-impl-list.c. The s390 string.h does not define _HAVE_STRING_ARCH_mempcpy. Instead mempcpy string/string.h inlines memcpy() + n. If n is constant and small enough, GCC emits instructions like mvi or mvc and avoids the function call to memcpy. If n is not constant, then memcpy is called and n is added afterwards. If _HAVE_STRING_ARCH_mempcpy would be defined, mempcpy would be called in every case. According to PR70140 "Inefficient expansion of __builtin_mempcpy" (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70140) GCC should handle a call to mempcpy in the same way as memcpy. Then either the mempcpy macro in string/string.h has to be removed or _HAVE_STRING_ARCH_mempcpy has to be defined for S390. ChangeLog: [BZ #19765] * sysdeps/s390/mempcpy.S: New File. * sysdeps/s390/multiarch/mempcpy.c: Likewise. * sysdeps/s390/multiarch/Makefile (sysdep_routines): Add mempcpy. * sysdeps/s390/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add mempcpy variants. * sysdeps/s390/s390-32/memcpy.S: Add mempcpy entry point. (memcpy): Adjust to be usable from mempcpy entry point. (__memcpy_mvcle): Likewise. * sysdeps/s390/s390-64/memcpy.S: Likewise. * sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Add entry points ____mempcpy_z196, ____mempcpy_z10 and add __GI_ symbols for mempcpy. (__memcpy_z196): Adjust to be usable from mempcpy entry point. (__memcpy_z10): Likewise. * sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Likewise. 2016-05-24 08:39:13 +00:00			`/* CPU specific mempcpy without multiarch - 32/64 bit S/390 version.`
Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00			`Copyright (C) 2016-2017 Free Software Foundation, Inc.`
S390: Implement mempcpy with help of memcpy. [BZ #19765] There exist optimized memcpy functions on s390, but no optimized mempcpy. This patch adds mempcpy entry points in memcpy.S files, which use the memcpy implementation. Now mempcpy itself is also an IFUNC function as memcpy is and the variants are listed in ifunc-impl-list.c. The s390 string.h does not define _HAVE_STRING_ARCH_mempcpy. Instead mempcpy string/string.h inlines memcpy() + n. If n is constant and small enough, GCC emits instructions like mvi or mvc and avoids the function call to memcpy. If n is not constant, then memcpy is called and n is added afterwards. If _HAVE_STRING_ARCH_mempcpy would be defined, mempcpy would be called in every case. According to PR70140 "Inefficient expansion of __builtin_mempcpy" (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70140) GCC should handle a call to mempcpy in the same way as memcpy. Then either the mempcpy macro in string/string.h has to be removed or _HAVE_STRING_ARCH_mempcpy has to be defined for S390. ChangeLog: [BZ #19765] * sysdeps/s390/mempcpy.S: New File. * sysdeps/s390/multiarch/mempcpy.c: Likewise. * sysdeps/s390/multiarch/Makefile (sysdep_routines): Add mempcpy. * sysdeps/s390/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add mempcpy variants. * sysdeps/s390/s390-32/memcpy.S: Add mempcpy entry point. (memcpy): Adjust to be usable from mempcpy entry point. (__memcpy_mvcle): Likewise. * sysdeps/s390/s390-64/memcpy.S: Likewise. * sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Add entry points ____mempcpy_z196, ____mempcpy_z10 and add __GI_ symbols for mempcpy. (__memcpy_z196): Adjust to be usable from mempcpy entry point. (__memcpy_z10): Likewise. * sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Likewise. 2016-05-24 08:39:13 +00:00			`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/>. */`

			`/* mempcpy is implemented in memcpy.S. */`