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38 KiB

Backport of:
commit f06a4faf8a2b4d046eb40e94b47948cc47d79902
Author: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
Date: Wed Dec 31 11:47:41 2014 -0500
powerpc: Optimized st{r,p}ncpy for POWER8/PPC64
This patch adds an optimized POWER8 st{r,p}ncpy using unaligned accesses.
It shows 10%-80% improvement over the optimized POWER7 one that uses
only aligned accesses, specially on unaligned inputs.
The algorithm first read and check 16 bytes (if inputs do not cross a 4K
page size). The it realign source to 16-bytes and issue a 16 bytes read
and compare loop to speedup null byte checks for large strings. Also,
different from POWER7 optimization, the null pad is done inline in the
implementation using possible unaligned accesses, instead of realying on
a memset call. Special case is added for page cross reads.
ChangeLog:
2015-01-13 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
* sysdeps/powerpc/powerpc64/multiarch/Makefile [sysdep_routines]:
Add strncpy-power8 and stpncpy-power8 objects.
* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add __strncpy_power8 and stpncpy_power8
implementations.
* sysdeps/powerpc/powerpc64/multiarch/stpncpy-power8.S: New file.
* sysdeps/powerpc/powerpc64/multiarch/stpncpy.c (__stpncpy): Add
__stpncpy_power8 implementation.
* sysdeps/powerpc/powerpc64/multiarch/strncpy-power8.S: New file.
* sysdeps/powerpc/powerpc64/multiarch/strncpy.c (strncpy): Add
__strncpy_power8 implementation.
* sysdeps/powerpc/powerpc64/power8/stpncpy.S: New file.
* sysdeps/powerpc/powerpc64/power8/strncpy.S: New file.
* NEWS: Update.
and its dependency:
commit f360f94a05570045be615649e9a411cefba2e210
Author: Vidya Ranganathan <vidya@linux.vnet.ibm.com>
Date: Mon May 5 19:10:45 2014 -0500
PowerPC: strncpy/stpncpy optimization for PPC64/POWER7
The optimization is achieved by following techniques:
> data alignment [gain from aligned memory access on read/write]
> POWER7 gains performance with loop unrolling/unwinding
[gain by reduction of branch penalty].
> zero padding done by calling optimized memset
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 74ae710..ef39917 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -8,6 +8,8 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
stpcpy-power8 stpcpy-power7 stpcpy-ppc64 \
strcat-power8 strcat-power7 strcat-ppc64 \
strcpy-power8 strcpy-power7 strcpy-ppc64 \
+ stpncpy-power8 stpncpy-power7 stpncpy-ppc64 \
+ strncpy-power8 strncpy-power7 strncpy-ppc64
strncat-power7 \
rawmemchr-ppc64 strlen-power7 strlen-ppc64 strnlen-power7 \
strnlen-ppc64 strcasecmp-power7 strcasecmp_l-power7 \
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index 4e5bb17..23bf5dc 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -255,5 +255,27 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, wcscpy, 1,
__wcscpy_ppc))
+ /* Support sysdeps/powerpc/powerpc64/multiarch/strncpy.c. */
+ IFUNC_IMPL (i, name, strncpy,
+ IFUNC_IMPL_ADD (array, i, strncpy,
+ hwcap2 & PPC_FEATURE2_ARCH_2_07,
+ __strncpy_power8)
+ IFUNC_IMPL_ADD (array, i, strncpy,
+ hwcap & PPC_FEATURE_HAS_VSX,
+ __strncpy_power7)
+ IFUNC_IMPL_ADD (array, i, strncpy, 1,
+ __strncpy_ppc))
+
+ /* Support sysdeps/powerpc/powerpc64/multiarch/stpncpy.c. */
+ IFUNC_IMPL (i, name, stpncpy,
+ IFUNC_IMPL_ADD (array, i, stpncpy,
+ hwcap2 & PPC_FEATURE2_ARCH_2_07,
+ __stpncpy_power8)
+ IFUNC_IMPL_ADD (array, i, stpncpy,
+ hwcap & PPC_FEATURE_HAS_VSX,
+ __stpncpy_power7)
+ IFUNC_IMPL_ADD (array, i, stpncpy, 1,
+ __stpncpy_ppc))
+
return i;
}
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S
new file mode 100644
index 0000000..e29674f
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S
@@ -0,0 +1,44 @@
+/* Optimized stpncpy implementation for POWER7.
+ Copyright (C) 2014 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 <sysdep.h>
+
+#define USE_AS_STPNCPY
+
+#undef EALIGN
+#define EALIGN(name, alignt, words) \
+ .section ".text"; \
+ ENTRY_2(__stpncpy_power7) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__stpncpy_power7): \
+ cfi_startproc; \
+ LOCALENTRY(__stpncpy_power7)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__stpncpy_power7) \
+ END_2(__stpncpy_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#define MEMSET __memset_power7
+
+#include <sysdeps/powerpc/powerpc64/power7/stpncpy.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power8.S b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power8.S
new file mode 100644
index 0000000..d5d835d
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power8.S
@@ -0,0 +1,39 @@
+/* Optimized stpncpy implementation for POWER8.
+ Copyright (C) 2015 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 <sysdep.h>
+
+#define USE_AS_STPNCPY
+
+#undef EALIGN
+#define EALIGN(name, alignt, words) \
+ .section ".text"; \
+ ENTRY_2(__stpncpy_power8) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__stpncpy_power8): \
+ cfi_startproc; \
+ LOCALENTRY(__stpncpy_power8)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__stpncpy_power8) \
+ END_2(__stpncpy_power8)
+
+#include <sysdeps/powerpc/powerpc64/power8/stpncpy.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c
new file mode 100644
index 0000000..74f47a7
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c
@@ -0,0 +1,26 @@
+/* Default stpncpy implementation for PowerPC64.
+ Copyright (C) 2014 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/>. */
+
+#define STPNCPY __stpncpy_ppc
+#ifdef SHARED
+#undef libc_hidden_def
+#define libc_hidden_def(name) \
+ __hidden_ver1 (__stpncpy_ppc, __GI___stpncpy, __stpncpy_ppc);
+#endif
+
+#include <string/stpncpy.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c b/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c
new file mode 100644
index 0000000..3ee50e5
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c
@@ -0,0 +1,36 @@
+/* Multiple versions of stpncpy. PowerPC64 version.
+ Copyright (C) 2014 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 NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (__stpncpy) __stpncpy_ppc attribute_hidden;
+extern __typeof (__stpncpy) __stpncpy_power7 attribute_hidden;
+extern __typeof (__stpncpy) __stpncpy_power8 attribute_hidden;
+
+libc_ifunc (__stpncpy,
+ (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+ ? __stpncpy_power8 :
+ (hwcap & PPC_FEATURE_HAS_VSX)
+ ? __stpncpy_power7
+ : __stpncpy_ppc);
+
+weak_alias (__stpncpy, stpncpy)
+#endif
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S
new file mode 100644
index 0000000..be349f9
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S
@@ -0,0 +1,42 @@
+/* Optimized strncpy implementation for POWER7.
+ Copyright (C) 2014 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 <sysdep.h>
+
+#undef EALIGN
+#define EALIGN(name, alignt, words) \
+ .section ".text"; \
+ ENTRY_2(__strncpy_power7) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__strncpy_power7): \
+ cfi_startproc; \
+ LOCALENTRY(__strncpy_power7)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strncpy_power7) \
+ END_2(__strncpy_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#define MEMSET __memset_power7
+
+#include <sysdeps/powerpc/powerpc64/power7/strncpy.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncpy-power8.S b/sysdeps/powerpc/powerpc64/multiarch/strncpy-power8.S
new file mode 100644
index 0000000..ed906a4
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strncpy-power8.S
@@ -0,0 +1,40 @@
+/* Optimized strncpy implementation for POWER8.
+ Copyright (C) 2015 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 <sysdep.h>
+
+#undef EALIGN
+#define EALIGN(name, alignt, words) \
+ .section ".text"; \
+ ENTRY_2(__strncpy_power8) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__strncpy_power8): \
+ cfi_startproc; \
+ LOCALENTRY(__strncpy_power8)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strncpy_power8) \
+ END_2(__strncpy_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/strncpy.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c
new file mode 100644
index 0000000..e3111d2
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c
@@ -0,0 +1,33 @@
+/* Copyright (C) 2014 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 <string.h>
+
+#define STRNCPY __strncpy_ppc
+#undef weak_alias
+#define weak_alias(name, aliasname) \
+ extern __typeof (__strncpy_ppc) aliasname \
+ __attribute__ ((weak, alias ("__strncpy_ppc")));
+#if !defined(NOT_IN_libc) && defined(SHARED)
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name) \
+ __hidden_ver1(__strncpy_ppc, __GI_strncpy, __strncpy_ppc);
+#endif
+
+extern __typeof (strncpy) __strncpy_ppc attribute_hidden;
+
+#include <string/strncpy.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncpy.c b/sysdeps/powerpc/powerpc64/multiarch/strncpy.c
new file mode 100644
index 0000000..19927bc
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strncpy.c
@@ -0,0 +1,38 @@
+/* Multiple versions of strncpy.
+ Copyright (C) 2014 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/ >. */
+
+/* Define multiple versions only for definition in libc. */
+#ifndef NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strncpy) __strncpy_ppc attribute_hidden;
+extern __typeof (strncpy) __strncpy_power7 attribute_hidden;
+extern __typeof (strncpy) __strncpy_power8 attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+ ifunc symbol properly. */
+libc_ifunc (strncpy,
+ (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+ ? __strncpy_power8 :
+ (hwcap & PPC_FEATURE_HAS_VSX)
+ ? __strncpy_power7
+ : __strncpy_ppc);
+
+#endif
diff --git a/sysdeps/powerpc/powerpc64/power7/stpncpy.S b/sysdeps/powerpc/powerpc64/power7/stpncpy.S
new file mode 100644
index 0000000..a539093
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power7/stpncpy.S
@@ -0,0 +1,24 @@
+/* Optimized stpncpy implementation for PowerPC64/POWER7.
+ Copyright (C) 2014 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/>. */
+
+#define USE_AS_STPNCPY
+#include <sysdeps/powerpc/powerpc64/power7/strncpy.S>
+
+weak_alias (__stpncpy, stpncpy)
+libc_hidden_def (__stpncpy)
+libc_hidden_builtin_def (stpncpy)
diff --git a/sysdeps/powerpc/powerpc64/power7/strncpy.S b/sysdeps/powerpc/powerpc64/power7/strncpy.S
new file mode 100644
index 0000000..51860df
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power7/strncpy.S
@@ -0,0 +1,338 @@
+/* Copyright (C) 2014 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 <sysdep.h>
+
+/* Implements the functions
+
+ char * [r3] strncpy (char *dst [r3], const char *src [r4], size_t n [r5])
+
+ AND
+
+ char * [r3] stpncpy (char *dst [r3], const char *src [r4], size_t n [r5])
+
+ The algorithm is as follows:
+ > if src and dest are 8 byte aligned, perform double word copy
+ else
+ > copy byte by byte on unaligned addresses.
+
+ The aligned comparison are made using cmpb instructions. */
+
+/* The focus on optimization for performance improvements are as follows:
+ 1. data alignment [gain from aligned memory access on read/write]
+ 2. POWER7 gains performance with loop unrolling/unwinding
+ [gain by reduction of branch penalty].
+ 3. The final pad with null bytes is done by calling an optimized
+ memset. */
+
+#ifdef USE_AS_STPNCPY
+# define FUNC_NAME __stpncpy
+#else
+# define FUNC_NAME strncpy
+#endif
+
+#define FRAMESIZE (FRAME_MIN_SIZE+32)
+
+#ifndef MEMSET
+/* For builds with no IFUNC support, local calls should be made to internal
+ GLIBC symbol (created by libc_hidden_builtin_def). */
+# ifdef SHARED
+# define MEMSET __GI_memset
+# else
+# define MEMSET memset
+# endif
+#endif
+
+ .machine power7
+EALIGN(FUNC_NAME, 4, 0)
+ CALL_MCOUNT 3
+
+ mflr r0 /* load link register LR to r0 */
+ or r10, r3, r4 /* to verify source and destination */
+ rldicl. r8, r10, 0, 61 /* is double word aligned .. ? */
+
+ std r19, -8(r1) /* save callers register , r19 */
+ std r18, -16(r1) /* save callers register , r18 */
+ std r0, 16(r1) /* store the link register */
+ stdu r1, -FRAMESIZE(r1) /* create the stack frame */
+
+ mr r9, r3 /* save r3 into r9 for use */
+ mr r18, r3 /* save r3 for retCode of strncpy */
+ bne 0, L(byte_by_byte)
+
+
+ srdi r11, r5, 3 /* compute count for CTR ; count = n/8 */
+ cmpldi cr7, r11, 3 /* if count > 4 ; perform unrolling 4 times */
+ ble 7, L(update1)
+
+ ld r10, 0(r4) /* load doubleWord from src */
+ cmpb r8, r10, r8 /* compare src with NULL ,we read just now */
+ cmpdi cr7, r8, 0 /* if cmpb returned NULL ; we continue */
+ bne cr7, L(update3)
+
+ std r10, 0(r3) /* copy doubleword at offset=0 */
+ ld r10, 8(r4) /* load next doubleword from offset=8 */
+ cmpb r8, r10, r8 /* compare src with NULL , we read just now */
+ cmpdi cr7, r8, 0 /* if cmpb returned NULL ; we continue */
+ bne 7,L(HopBy8)
+
+ addi r8, r11, -4
+ mr r7, r3
+ srdi r8, r8, 2
+ mr r6, r4
+ addi r8, r8, 1
+ li r12, 0
+ mtctr r8
+ b L(dwordCopy)
+
+ .p2align 4
+L(dWordUnroll):
+ std r8, 16(r9)
+ ld r8, 24(r4) /* load dword,perform loop unrolling again */
+ cmpb r10, r8, r10
+ cmpdi cr7, r10, 0
+ bne cr7, L(HopBy24)
+
+ std r8, 24(r7) /* copy dword at offset=24 */
+ addi r9, r9, 32
+ addi r4, r4, 32
+ bdz L(leftDwords) /* continue with loop on counter */
+
+ ld r3, 32(r6)
+ cmpb r8, r3, r10
+ cmpdi cr7, r8, 0
+ bne cr7, L(update2)
+
+ std r3, 32(r7)
+ ld r10, 40(r6)
+ cmpb r8, r10, r8
+ cmpdi cr7, r8, 0
+ bne cr7, L(HopBy40)
+
+ mr r6, r4 /* update values */
+ mr r7, r9
+ mr r11, r0
+ mr r5, r19
+
+L(dwordCopy):
+ std r10, 8(r9) /* copy dword at offset=8 */
+ addi r19, r5, -32
+ addi r0, r11, -4
+ ld r8, 16(r4)
+ cmpb r10, r8, r12
+ cmpdi cr7, r10, 0
+ beq cr7, L(dWordUnroll)
+
+ addi r9, r9, 16 /* increment dst by 16 */
+ addi r4, r4, 16 /* increment src by 16 */
+ addi r5, r5, -16 /* decrement length 'n' by 16 */
+ addi r0, r11, -2 /* decrement loop counter */
+
+L(dWordUnrollOFF):
+ ld r10, 0(r4) /* load first dword */
+ li r8, 0 /* load mask */
+ cmpb r8, r10, r8
+ cmpdi cr7, r8, 0
+ bne cr7, L(byte_by_byte)
+ mtctr r0
+ li r7, 0
+ b L(CopyDword)
+
+ .p2align 4
+L(loadDWordandCompare):
+ ld r10, 0(r4)
+ cmpb r8, r10, r7
+ cmpdi cr7, r8, 0
+ bne cr7, L(byte_by_byte)
+
+L(CopyDword):
+ addi r9, r9, 8
+ std r10, -8(r9)
+ addi r4, r4, 8
+ addi r5, r5, -8
+ bdnz L(loadDWordandCompare)
+
+L(byte_by_byte):
+ cmpldi cr7, r5, 3
+ ble cr7, L(verifyByte)
+ srdi r10, r5, 2
+ mr r19, r9
+ mtctr r10
+ b L(firstByteUnroll)
+
+ .p2align 4
+L(bytes_unroll):
+ lbz r10, 1(r4) /* load byte from src */
+ cmpdi cr7, r10, 0 /* compare for NULL */
+ stb r10, 1(r19) /* store byte to dst */
+ beq cr7, L(updtDestComputeN2ndByte)
+
+ addi r4, r4, 4 /* advance src */
+
+ lbz r10, -2(r4) /* perform loop unrolling for byte r/w */
+ cmpdi cr7, r10, 0
+ stb r10, 2(r19)
+ beq cr7, L(updtDestComputeN3rdByte)
+
+ lbz r10, -1(r4) /* perform loop unrolling for byte r/w */
+ addi r19, r19, 4
+ cmpdi cr7, r10, 0
+ stb r10, -1(r19)
+ beq cr7, L(ComputeNByte)
+
+ bdz L(update0)
+
+L(firstByteUnroll):
+ lbz r10, 0(r4) /* perform loop unrolling for byte r/w */
+ cmpdi cr7, 10, 0
+ stb r10, 0(r19)
+ bne cr7, L(bytes_unroll)
+ addi r19, r19, 1
+
+L(ComputeNByte):
+ subf r9, r19, r9 /* compute 'n'n bytes to fill */
+ add r8, r9, r5
+
+L(zeroFill):
+ cmpdi cr7, r8, 0 /* compare if length is zero */
+ beq cr7, L(update3return)
+
+ mr r3, r19 /* fill buffer with */
+ li r4, 0 /* zero fill buffer */
+ mr r5, r8 /* how many bytes to fill buffer with */
+ bl MEMSET /* call optimized memset */
+ nop
+
+L(update3return):
+#ifdef USE_AS_STPNCPY
+ addi r3, r19, -1 /* update return value */
+#endif
+
+L(hop2return):
+#ifndef USE_AS_STPNCPY
+ mr r3, r18 /* set return value */
+#endif
+ addi r1, r1, FRAMESIZE /* restore stack pointer */
+ ld r0, 16(r1) /* read the saved link register */
+ ld r18, -16(r1) /* restore callers save register, r18 */
+ ld r19, -8(r1) /* restore callers save register, r19 */
+ mtlr r0 /* branch to link register */
+ blr /* return */
+
+ .p2align 4
+L(update0):
+ mr r9, r19
+
+ .p2align 4
+L(verifyByte):
+ rldicl. r8, r5, 0, 62
+#ifdef USE_AS_STPNCPY
+ mr r3, r9
+#endif
+ beq cr0, L(hop2return)
+ mtctr r8
+ addi r4, r4, -1
+ mr r19, r9
+ b L(oneBYone)
+
+ .p2align 4
+L(proceed):
+ bdz L(done)
+
+L(oneBYone):
+ lbzu r10, 1(r4) /* copy byte */
+ addi r19, r19, 1
+ addi r8, r8, -1
+ cmpdi cr7, r10, 0
+ stb r10, -1(r19)
+ bne cr7, L(proceed)
+ b L(zeroFill)
+
+ .p2align 4
+L(done):
+ addi r1, r1, FRAMESIZE /* restore stack pointer */
+#ifdef USE_AS_STPNCPY
+ mr r3, r19 /* set the return value */
+#else
+ mr r3, r18 /* set the return value */
+#endif
+ ld r0, 16(r1) /* read the saved link register */
+ ld r18, -16(r1) /* restore callers save register, r18 */
+ ld r19, -8(r1) /* restore callers save register, r19 */
+ mtlr r0 /* branch to link register */
+ blr /* return */
+
+L(update1):
+ mr r0, r11
+ mr r19, r5
+
+ .p2align 4
+L(leftDwords):
+ cmpdi cr7, r0, 0
+ mr r5, r19
+ bne cr7, L(dWordUnrollOFF)
+ b L(byte_by_byte)
+
+ .p2align 4
+L(updtDestComputeN2ndByte):
+ addi r19, r19, 2 /* update dst by 2 */
+ subf r9, r19, r9 /* compute distance covered */
+ add r8, r9, r5
+ b L(zeroFill)
+
+ .p2align 4
+L(updtDestComputeN3rdByte):
+ addi r19, r19, 3 /* update dst by 3 */
+ subf r9, r19, r9 /* compute distance covered */
+ add r8, r9, r5
+ b L(zeroFill)
+
+ .p2align 4
+L(HopBy24):
+ addi r9, r9, 24 /* increment dst by 24 */
+ addi r4, r4, 24 /* increment src by 24 */
+ addi r5, r5, -24 /* decrement length 'n' by 24 */
+ addi r0, r11, -3 /* decrement loop counter */
+ b L(dWordUnrollOFF)
+
+ .p2align 4
+L(update2):
+ mr r5, r19
+ b L(dWordUnrollOFF)
+
+ .p2align 4
+L(HopBy40):
+ addi r9, r7, 40 /* increment dst by 40 */
+ addi r4, r6, 40 /* increment src by 40 */
+ addi r5, r5, -40 /* decrement length 'n' by 40 */
+ addi r0, r11, -5 /* decrement loop counter */
+ b L(dWordUnrollOFF)
+
+L(update3):
+ mr r0, r11
+ b L(dWordUnrollOFF)
+
+L(HopBy8):
+ addi r9, r3, 8 /* increment dst by 8 */
+ addi r4, r4, 8 /* increment src by 8 */
+ addi r5, r5, -8 /* decrement length 'n' by 8 */
+ addi r0, r11, -1 /* decrement loop counter */
+ b L(dWordUnrollOFF)
+END(FUNC_NAME)
+#ifndef USE_AS_STPNCPY
+libc_hidden_builtin_def (strncpy)
+#endif
diff --git a/sysdeps/powerpc/powerpc64/power8/stpncpy.S b/sysdeps/powerpc/powerpc64/power8/stpncpy.S
new file mode 100644
index 0000000..76a1466
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power8/stpncpy.S
@@ -0,0 +1,20 @@
+/* Optimized stpncpy implementation for PowerPC64/POWER8.
+ Copyright (C) 2015 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/>. */
+
+#define USE_AS_STPNCPY
+#include <sysdeps/powerpc/powerpc64/power8/strncpy.S>
diff --git a/sysdeps/powerpc/powerpc64/power8/strncpy.S b/sysdeps/powerpc/powerpc64/power8/strncpy.S
new file mode 100644
index 0000000..5fda953
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power8/strncpy.S
@@ -0,0 +1,424 @@
+/* Optimized strncpy/stpncpy implementation for PowerPC64/POWER8.
+ Copyright (C) 2015 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 <sysdep.h>
+
+#ifdef USE_AS_STPNCPY
+# define FUNC_NAME __stpncpy
+#else
+# define FUNC_NAME strncpy
+#endif
+
+/* Implements the function
+
+ char * [r3] strncpy (char *dest [r3], const char *src [r4], size_t n [r5])
+
+ or
+
+ char * [r3] stpncpy (char *dest [r3], const char *src [r4], size_t n [r5])
+
+ if USE_AS_STPCPY is defined.
+
+ The implementation uses unaligned doubleword access to avoid specialized
+ code paths depending of data alignment. Although recent powerpc64 uses
+ 64K as default, the page cross handling assumes minimum page size of
+ 4k. */
+
+ .machine power7
+EALIGN (FUNC_NAME, 4, 0)
+
+ /* Check if the [src]+15 will cross a 4K page by checking if the bit
+ indicating the page size changes. Basically:
+
+ uint64_t srcin = (uint64_t)src;
+ uint64_t ob = srcin & 4096UL;
+ uint64_t nb = (srcin+15UL) & 4096UL;
+ if (ob ^ nb)
+ goto pagecross; */
+
+ addi r10,r4,16
+ rlwinm r9,r4,0,19,19
+
+ /* Since it is a leaf function, save some non-volatile registers on the
+ protected/red zone. */
+ std r26,-48(r1)
+ std r27,-40(r1)
+
+ rlwinm r8,r10,0,19,19
+
+ std r28,-32(r1)
+ std r29,-24(r1)
+
+ cmpld r7,r9,r8
+
+ std r30,-16(r1)
+ std r31,-8(r1)
+
+ beq cr7,L(unaligned_lt_16)
+ rldicl r9,r4,0,61
+ subfic r8,r9,8
+ cmpld cr7,r5,r8
+ bgt cr7,L(pagecross)
+
+ /* At this points there is 1 to 15 bytes to check and write. Since it could
+ be either from first unaligned 16 bytes access or from bulk copy, the code
+ uses an unrolled byte read/write instead of trying to analyze the cmpb
+ results. */
+L(short_path):
+ mr r9,r3
+L(short_path_1):
+ cmpdi cr7,r5,0
+ beq cr7,L(short_path_loop_end_1)
+L(short_path_2):
+ lbz r10,0(r4)
+ cmpdi cr7,r10,0
+ stb r10,0(r9)
+ beq cr7,L(zero_pad_start_1)
+ cmpdi cr0,r5,1
+ addi r8,r9,1
+ addi r6,r5,-1
+ beq cr0,L(short_path_loop_end_0)
+ lbz r10,1(r4)
+ cmpdi cr7,r10,0
+ stb r10,1(r9)
+ beq cr7,L(zero_pad_start_prepare_1)
+ addi r10,r5,-3
+ b L(short_path_loop_1)
+
+ .align 4
+L(short_path_loop):
+ lbz r8,0(r4)
+ addi r7,r10,-2
+ cmpdi cr5,r8,0
+ stb r8,0(r9)
+ beq cr5,L(zero_pad_start_1)
+ beq r7,L(short_path_loop_end_0)
+ lbz r8,1(r4)
+ cmpdi cr7,r8,0
+ stb r8,1(r9)
+ beq cr7,L(zero_pad_start)
+ mr r10,r7
+L(short_path_loop_1):
+ addic. r5,r5,-2
+ addi r9,r9,2
+ cmpdi cr7,r10,0
+ addi r4,r4,2
+ addi r6,r9,1
+ bne cr0,L(short_path_loop)
+#ifdef USE_AS_STPNCPY
+ mr r3,r9
+ b L(short_path_loop_end)
+#endif
+
+L(short_path_loop_end_0):
+#ifdef USE_AS_STPNCPY
+ addi r3,r9,1
+ b L(short_path_loop_end)
+#endif
+L(short_path_loop_end_1):
+#ifdef USE_AS_STPNCPY
+ mr r3,r9
+#endif
+L(short_path_loop_end):
+ /* Restore non-volatile registers. */
+ ld r26,-48(r1)
+ ld r27,-40(r1)
+ ld r28,-32(r1)
+ ld r29,-24(r1)
+ ld r30,-16(r1)
+ ld r31,-8(r1)
+ blr
+
+ /* This code pads the remainder dest with NULL bytes. The algorithm
+ calculate the remanining size and issues a doubleword unrolled
+ loops followed by a byte a byte set. */
+ .align 4
+L(zero_pad_start):
+ mr r5,r10
+ mr r9,r6
+L(zero_pad_start_1):
+ srdi. r8,r5,r3
+ mr r10,r9
+#ifdef USE_AS_STPNCPY
+ mr r3,r9
+#endif
+ beq- cr0,L(zero_pad_loop_b_start)
+ cmpldi cr7,r8,1
+ li cr7,0
+ std r7,0(r9)
+ beq cr7,L(zero_pad_loop_b_prepare)
+ addic. r8,r8,-2
+ addi r10,r9,r16
+ std r7,8(r9)
+ beq cr0,L(zero_pad_loop_dw_2)
+ std r7,16(r9)
+ li r9,0
+ b L(zero_pad_loop_dw_1)
+
+ .align 4
+L(zero_pad_loop_dw):
+ addi r10,r10,16
+ std r9,-8(r10)
+ beq cr0,L(zero_pad_loop_dw_2)
+ std r9,0(r10)
+L(zero_pad_loop_dw_1):
+ cmpldi cr7,r8,1
+ std r9,0(r10)
+ addic. r8,r8,-2
+ bne cr7,L(zero_pad_loop_dw)
+ addi r10,r10,8
+L(zero_pad_loop_dw_2):
+ rldicl r5,r5,0,61
+L(zero_pad_loop_b_start):
+ cmpdi cr7,r5,0
+ addi r5,r5,-1
+ addi r9,r10,-1
+ add r10,r10,5
+ subf r10,r9,r10
+ li r8,0
+ beq- cr7,L(short_path_loop_end)
+
+ /* Write remaining 1-8 bytes. */
+ .align 4
+ addi r9,r9,1
+ mtocrf 0x1,r10
+ bf 29,4f
+ stw r8,0(r9)
+ addi r9,r9,4
+
+ .align 4
+4: bf 30,2f
+ sth r8,0(r9)
+ addi r9,r9,2
+
+ .align 4
+2: bf 31,1f
+ stb r8,0(r9)
+
+ /* Restore non-volatile registers. */
+1: ld r26,-48(r1)
+ ld r27,-40(r1)
+ ld r28,-32(r1)
+ ld r29,-24(r1)
+ ld r30,-16(r1)
+ ld r31,-8(r1)
+ blr
+
+ /* The common case where [src]+16 will not cross a 4K page boundary.
+ In this case the code fast check the first 16 bytes by using doubleword
+ read/compares and update destiny if neither total size or null byte
+ is found in destiny. */
+ .align 4
+L(unaligned_lt_16):
+ cmpldi cr7,r5,7
+ ble cr7,L(short_path)
+ ld r7,0(r4)
+ li r8,0
+ cmpb r8,r7,r8
+ cmpdi cr7,r8,0
+ bne cr7,L(short_path_prepare_2)
+ addi r6,r5,-8
+ std r7,0(r3)
+ addi r9,r3,r8
+ cmpldi cr7,r6,7
+ addi r7,r4,8
+ ble cr7,L(short_path_prepare_1_1)
+ ld r4,8(r4)
+ cmpb r8,r4,r8
+ cmpdi cr7,r8,0
+ bne cr7,L(short_path_prepare_2_1)
+ std r4,8(r3)
+ addi r29,r3,16
+ addi r5,r5,-16
+ /* Neither the null byte was found or total length was reached,
+ align to 16 bytes and issue a bulk copy/compare. */
+ b L(align_to_16b)
+
+ /* In the case of 4k page boundary cross, the algorithm first align
+ the address to a doubleword, calculate a mask based on alignment
+ to ignore the bytes and continue using doubleword. */
+ .align 4
+L(pagecross):
+ rldicr r11,r4,0,59 /* Align the address to 8 bytes boundary. */
+ li r6,-1 /* MASK = 0xffffffffffffffffUL. */
+ sldi r9,r9,3 /* Calculate padding. */
+ ld r7,0(r11) /* Load doubleword from memory. */
+#ifdef __LITTLE_ENDIAN__
+ sld r9,r6,r9 /* MASK = MASK << padding. */
+#else
+ srd r9,r6,r9 /* MASK = MASK >> padding. */
+#endif
+ orc r9,r7,r9 /* Mask bits that are not part of the
+ string. */
+ li cr7,0
+ cmpb r9,r9,r7 /* Check for null bytes in DWORD1. */
+ cmpdi cr7,r9,0
+ bne cr7,L(short_path_prepare_2)
+ subf r8,r8,r5 /* Adjust total length. */
+ cmpldi cr7,r8,8 /* Check if length was reached. */
+ ble cr7,L(short_path_prepare_2)
+
+ /* For next checks we have aligned address, so we check for more
+ three doublewords to make sure we can read 16 unaligned bytes
+ to start the bulk copy with 16 aligned addresses. */
+ ld cr7,8(r11)
+ cmpb r9,r7,r9
+ cmpdi cr7,r9,0
+ bne cr7,L(short_path_prepare_2)
+ addi cr7,r8,-8
+ cmpldi cr7,r7,8
+ ble cr7,L(short_path_prepare_2)
+ ld cr7,16(r11)
+ cmpb r9,r7,r9
+ cmpdi cr7,r9,0
+ bne cr7,L(short_path_prepare_2)
+ addi r8,r8,-16
+ cmpldi r7,r8,8
+ ble cr7,L(short_path_prepare_2)
+ ld r8,24(r11)
+ cmpb r9,r8,r9
+ cmpdi r7,r9,0
+ bne cr7,L(short_path_prepare_2)
+
+ /* No null byte found in the 32 bytes readed and length not reached,
+ read source again using unaligned loads and store them. */
+ ld r9,0(r4)
+ addi r29,r3,16
+ addi r5,r5,-16
+ std r9,0(r3)
+ ld r9,8(r4)
+ std r9,8(r3)
+
+ /* Align source to 16 bytes and adjust destiny and size. */
+L(align_to_16b):
+ rldicl r9,r10,0,60
+ rldicr r28,r10,0,59
+ add r12,r5,r9
+ subf r29,r9,r29
+
+ /* The bulk read/compare/copy loads two doublewords, compare and merge
+ in a single register for speed. This is an attempt to speed up the
+ null-checking process for bigger strings. */
+
+ cmpldi cr7,r12,15
+ ble cr7,L(short_path_prepare_1_2)
+
+ /* Main loop for large sizes, unrolled 2 times to get better use of
+ pipeline. */
+ ld r8,0(28)
+ ld r10,8(28)
+ li r9,0
+ cmpb r7,r8,r9
+ cmpb r9,r10,r9
+ or. r6,r9,r7
+ bne cr0,L(short_path_prepare_2_3)
+ addi r5,r12,-16
+ addi r4,r28,16
+ std r8,0(r29)
+ std r10,8(r29)
+ cmpldi cr7,r5,15
+ addi r9,r29,16
+ ble cr7,L(short_path_1)
+ mr r11,r28
+ mr r6,r29
+ li r30,0
+ subfic r26,r4,48
+ subfic r27,r9,48
+
+ b L(loop_16b)
+
+ .align 4
+L(loop_start):
+ ld r31,0(r11)
+ ld r10,8(r11)
+ cmpb r0,r31,r7
+ cmpb r8,r10,r7
+ or. r7,r0,r8
+ addi r5,r5,-32
+ cmpldi cr7,r5,15
+ add r4,r4,r26
+ add r9,r9,r27
+ bne cr0,L(short_path_prepare_2_2)
+ add r4,r28,r4
+ std r31,0(r6)
+ add r9,r29,r9
+ std r10,8(r6)
+ ble cr7,L(short_path_1)
+
+L(loop_16b):
+ ld r10,16(r11)
+ ld r0,24(r11)
+ cmpb r8,r10,r30
+ cmpb r7,r0,r30
+ or. r7,r8,r7
+ addi r12,r12,-32
+ cmpldi r7,r12,15
+ addi r11,r11,32
+ bne cr0,L(short_path_2)
+ std r10,16(r6)
+ addi r6,r6,32
+ std r0,-8(r6)
+ bgt cr7,L(loop_start)
+
+ mr r5,r12
+ mr r4,r11
+ mr r9,r6
+ b L(short_path_1)
+
+ .align 4
+L(short_path_prepare_1_1):
+ mr r5,r6
+ mr r4,r7
+ b L(short_path_1)
+L(short_path_prepare_1_2):
+ mr r5,r12
+ mr r4,r28
+ mr r9,r29
+ b L(short_path_1)
+L(short_path_prepare_2):
+ mr r9,r3
+ b L(short_path_2)
+L(short_path_prepare_2_1):
+ mr r5,r6
+ mr r4,r7
+ b L(short_path_2)
+L(short_path_prepare_2_2):
+ mr r5,r12
+ mr r4,r11
+ mr r9,r6
+ b L(short_path_2)
+L(short_path_prepare_2_3):
+ mr r5,r12
+ mr r4,r28
+ mr r9,r29
+ b L(short_path_2)
+L(zero_pad_loop_b_prepare):
+ addi r10,r9,8
+ rldicl r5,r5,0,61
+ b L(zero_pad_loop_b_start)
+L(zero_pad_start_prepare_1):
+ mr r5,r6
+ mr r9,r8
+ b L(zero_pad_start_1)
+END (FUNC_NAME)
+
+#ifdef USE_AS_STPNCPY
+libc_hidden_def (__stpncpy)
+#else
+libc_hidden_builtin_def (strncpy)
+#endif