Patchwork x86-64: Implement strcspn/strpbrk/strspn IFUNC selectors in C

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Submitter H.J. Lu
Date June 12, 2017, 4:12 p.m.
Message ID <20170612161239.GF25262@gmail.com>
Download mbox | patch
Permalink /patch/20954/
State New
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Comments

H.J. Lu - June 12, 2017, 4:12 p.m.
Implement strcspn/strpbrk/strspn IFUNC selectors in C

All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register.  For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized.  Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for strcspn/strpbrk/strspn functions within libc.

Any comments?

H.J.
---
	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
	strcspn-sse2, strpbrk-sse2 and strspn-sse2.
	* sysdeps/x86_64/strcspn.S (STRPBRK_P): Removed.
	Check USE_AS_STRPBRK instead of STRPBRK_P.
	* sysdeps/x86_64/strpbrk.S (USE_AS_STRPBRK): New.
	* sysdeps/x86_64/multiarch/ifunc-sse4_2.h: New file.
	* sysdeps/x86_64/multiarch/strcspn-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/strcspn.c: Likewise.
	* sysdeps/x86_64/multiarch/strpbrk-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/strpbrk.c: Likewise.
	* sysdeps/x86_64/multiarch/strspn-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/strspn.c: Likewise.
	* sysdeps/x86_64/multiarch/strcspn.S: Removed.
	* sysdeps/x86_64/multiarch/strpbrk.S: Likewise.
	* sysdeps/x86_64/multiarch/strspn.S: Likewise.
	* sysdeps/x86_64/multiarch/strpbrk-c.c: Remove "#ifdef SHARED"
	and "#endif".
---
 sysdeps/x86_64/multiarch/Makefile                |  1 +
 sysdeps/x86_64/multiarch/ifunc-sse4_2.h          | 34 ++++++++++++
 sysdeps/x86_64/multiarch/strcspn-sse2.S          | 28 ++++++++++
 sysdeps/x86_64/multiarch/strcspn.S               | 69 ------------------------
 sysdeps/x86_64/multiarch/{strspn.S => strcspn.c} | 44 ++++++---------
 sysdeps/x86_64/multiarch/strpbrk-c.c             | 12 ++---
 sysdeps/x86_64/multiarch/strpbrk-sse2.S          | 29 ++++++++++
 sysdeps/x86_64/multiarch/strpbrk.S               |  5 --
 sysdeps/x86_64/multiarch/strpbrk.c               | 36 +++++++++++++
 sysdeps/x86_64/multiarch/strspn-sse2.S           | 28 ++++++++++
 sysdeps/x86_64/multiarch/strspn.c                | 36 +++++++++++++
 sysdeps/x86_64/strcspn.S                         |  5 +-
 sysdeps/x86_64/strpbrk.S                         |  1 +
 13 files changed, 213 insertions(+), 115 deletions(-)
 create mode 100644 sysdeps/x86_64/multiarch/ifunc-sse4_2.h
 create mode 100644 sysdeps/x86_64/multiarch/strcspn-sse2.S
 delete mode 100644 sysdeps/x86_64/multiarch/strcspn.S
 rename sysdeps/x86_64/multiarch/{strspn.S => strcspn.c} (57%)
 create mode 100644 sysdeps/x86_64/multiarch/strpbrk-sse2.S
 delete mode 100644 sysdeps/x86_64/multiarch/strpbrk.S
 create mode 100644 sysdeps/x86_64/multiarch/strpbrk.c
 create mode 100644 sysdeps/x86_64/multiarch/strspn-sse2.S
 create mode 100644 sysdeps/x86_64/multiarch/strspn.c
Adhemerval Zanella Netto - June 15, 2017, 3:35 p.m.
On 12/06/2017 13:12, H.J. Lu wrote:
> Implement strcspn/strpbrk/strspn IFUNC selectors in C
> 
> All internal calls within libc.so can use IFUNC on x86-64 since unlike
> x86, x86-64 supports PC-relative addressing to access the GOT entry so
> that it can call via PLT without using an extra register.  For libc.a,
> we can't use IFUNC for functions which are called before IFUNC has been
> initialized.  Use IFUNC internally reduces the icache footprint since
> libc.so and other codes in the process use the same implementations.
> This patch uses IFUNC for strcspn/strpbrk/strspn functions within libc.
> 
> Any comments?
> 
> H.J.
> ---
> 	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
> 	strcspn-sse2, strpbrk-sse2 and strspn-sse2.
> 	* sysdeps/x86_64/strcspn.S (STRPBRK_P): Removed.
> 	Check USE_AS_STRPBRK instead of STRPBRK_P.
> 	* sysdeps/x86_64/strpbrk.S (USE_AS_STRPBRK): New.
> 	* sysdeps/x86_64/multiarch/ifunc-sse4_2.h: New file.
> 	* sysdeps/x86_64/multiarch/strcspn-sse2.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strcspn.c: Likewise.
> 	* sysdeps/x86_64/multiarch/strpbrk-sse2.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strpbrk.c: Likewise.
> 	* sysdeps/x86_64/multiarch/strspn-sse2.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strspn.c: Likewise.
> 	* sysdeps/x86_64/multiarch/strcspn.S: Removed.
> 	* sysdeps/x86_64/multiarch/strpbrk.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strspn.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strpbrk-c.c: Remove "#ifdef SHARED"
> 	and "#endif".

LGTM.

Patch

diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
index 43443b3..2c54c5c 100644
--- a/sysdeps/x86_64/multiarch/Makefile
+++ b/sysdeps/x86_64/multiarch/Makefile
@@ -26,6 +26,7 @@  sysdep_routines += strncat-c stpncpy-c strncpy-c strcmp-ssse3 \
 		   strcat-sse2 \
 		   strcat-sse2-unaligned strncat-sse2-unaligned \
 		   strchr-sse2-no-bsf memcmp-ssse3 strstr-sse2-unaligned \
+		   strcspn-sse2 strpbrk-sse2 strspn-sse2 \
 		   strcspn-c strpbrk-c strspn-c varshift \
 		   memset-avx512-no-vzeroupper \
 		   memmove-sse2-unaligned-erms \
diff --git a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
new file mode 100644
index 0000000..a43265e
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
@@ -0,0 +1,34 @@ 
+/* Common definition for ifunc selections optimized with SSE2 and SSE4.2.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 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/>.  */
+
+#include <init-arch.h>
+
+extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden;
+
+static inline void *
+IFUNC_SELECTOR (void)
+{
+  const struct cpu_features* cpu_features = __get_cpu_features ();
+
+  if (CPU_FEATURES_CPU_P (cpu_features, SSE4_2))
+    return OPTIMIZE (sse42);
+
+  return OPTIMIZE (sse2);
+}
diff --git a/sysdeps/x86_64/multiarch/strcspn-sse2.S b/sysdeps/x86_64/multiarch/strcspn-sse2.S
new file mode 100644
index 0000000..72eb38b
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/strcspn-sse2.S
@@ -0,0 +1,28 @@ 
+/* strcspn optimized with SSE2.
+   Copyright (C) 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/>.  */
+
+#if IS_IN (libc)
+
+# include <sysdep.h>
+# define strcspn __strcspn_sse2
+
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(strcspn)
+#endif
+
+#include <sysdeps/x86_64/strcspn.S>
diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
deleted file mode 100644
index d102c7e..0000000
--- a/sysdeps/x86_64/multiarch/strcspn.S
+++ /dev/null
@@ -1,69 +0,0 @@ 
-/* Multiple versions of strcspn
-   All versions must be listed in ifunc-impl-list.c.
-   Copyright (C) 2009-2017 Free Software Foundation, Inc.
-   Contributed by Intel Corporation.
-   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 <config.h>
-#include <sysdep.h>
-#include <init-arch.h>
-
-#ifdef USE_AS_STRPBRK
-#define STRCSPN_SSE42	__strpbrk_sse42
-#define STRCSPN_SSE2	__strpbrk_sse2
-#define __GI_STRCSPN	__GI_strpbrk
-#else
-#ifndef STRCSPN
-#define STRCSPN		strcspn
-#define STRCSPN_SSE42	__strcspn_sse42
-#define STRCSPN_SSE2	__strcspn_sse2
-#define __GI_STRCSPN	__GI_strcspn
-#endif
-#endif
-
-/* Define multiple versions only for the definition in libc.  Don't
-   define multiple versions for strpbrk in static library since we
-   need strpbrk before the initialization happened.  */
-#if (defined SHARED || !defined USE_AS_STRPBRK) && IS_IN (libc)
-	.text
-ENTRY(STRCSPN)
-	.type	STRCSPN, @gnu_indirect_function
-	LOAD_RTLD_GLOBAL_RO_RDX
-	leaq	STRCSPN_SSE2(%rip), %rax
-	HAS_CPU_FEATURE (SSE4_2)
-	jz	2f
-	leaq	STRCSPN_SSE42(%rip), %rax
-2:	ret
-END(STRCSPN)
-
-# undef ENTRY
-# define ENTRY(name) \
-	.type STRCSPN_SSE2, @function; \
-	.globl STRCSPN_SSE2; \
-	.align 16; \
-	STRCSPN_SSE2: cfi_startproc; \
-	CALL_MCOUNT
-# undef END
-# define END(name) \
-	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
-#endif
-
-#ifdef USE_AS_STRPBRK
-#include "../strpbrk.S"
-#else
-#include "../strcspn.S"
-#endif
diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strcspn.c
similarity index 57%
rename from sysdeps/x86_64/multiarch/strspn.S
rename to sysdeps/x86_64/multiarch/strcspn.c
index adf7d9e..011f69a 100644
--- a/sysdeps/x86_64/multiarch/strspn.S
+++ b/sysdeps/x86_64/multiarch/strcspn.c
@@ -1,7 +1,6 @@ 
-/* Multiple versions of strspn
+/* Multiple versions of strcspn.
    All versions must be listed in ifunc-impl-list.c.
-   Copyright (C) 2009-2017 Free Software Foundation, Inc.
-   Contributed by Intel Corporation.
+   Copyright (C) 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
@@ -18,33 +17,20 @@ 
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <config.h>
-#include <sysdep.h>
-#include <init-arch.h>
-
 /* Define multiple versions only for the definition in libc.  */
 #if IS_IN (libc)
-	.text
-ENTRY(strspn)
-	.type	strspn, @gnu_indirect_function
-	LOAD_RTLD_GLOBAL_RO_RDX
-	leaq	__strspn_sse2(%rip), %rax
-	HAS_CPU_FEATURE (SSE4_2)
-	jz	2f
-	leaq	__strspn_sse42(%rip), %rax
-2:	ret
-END(strspn)
+# define _HAVE_STRING_ARCH_strcspn 1
+# define strcspn __redirect_strcspn
+# include <string.h>
+# undef strcspn
 
-# undef ENTRY
-# define ENTRY(name) \
-	.type __strspn_sse2, @function; \
-	.globl __strspn_sse2; \
-	.align 16; \
-	__strspn_sse2: cfi_startproc; \
-	CALL_MCOUNT
-# undef END
-# define END(name) \
-	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
-#endif
+# define SYMBOL_NAME strcspn
+# include "ifunc-sse4_2.h"
 
-#include "../strspn.S"
+libc_ifunc_redirected (__redirect_strcspn, strcspn, IFUNC_SELECTOR ());
+
+# ifdef SHARED
+__hidden_ver1 (strcspn, __GI_strcspn, __redirect_strcspn)
+  __attribute__ ((visibility ("hidden")));
+# endif
+#endif
diff --git a/sysdeps/x86_64/multiarch/strpbrk-c.c b/sysdeps/x86_64/multiarch/strpbrk-c.c
index bbf5c49..c58dcb5 100644
--- a/sysdeps/x86_64/multiarch/strpbrk-c.c
+++ b/sysdeps/x86_64/multiarch/strpbrk-c.c
@@ -1,8 +1,4 @@ 
-/* Don't define multiple versions for strpbrk in static library since we
-   need strpbrk before the initialization happened.  */
-#ifdef SHARED
-# define USE_AS_STRPBRK
-# define STRCSPN_SSE2 __strpbrk_sse2
-# define STRCSPN_SSE42 __strpbrk_sse42
-# include "strcspn-c.c"
-#endif
+#define USE_AS_STRPBRK
+#define STRCSPN_SSE2 __strpbrk_sse2
+#define STRCSPN_SSE42 __strpbrk_sse42
+#include "strcspn-c.c"
diff --git a/sysdeps/x86_64/multiarch/strpbrk-sse2.S b/sysdeps/x86_64/multiarch/strpbrk-sse2.S
new file mode 100644
index 0000000..d2efe7d
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/strpbrk-sse2.S
@@ -0,0 +1,29 @@ 
+/* strpbrk optimized with SSE2.
+   Copyright (C) 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/>.  */
+
+#if IS_IN (libc)
+
+# include <sysdep.h>
+# define strcspn __strpbrk_sse2
+
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(strpbrk)
+#endif
+
+#define USE_AS_STRPBRK
+#include <sysdeps/x86_64/strcspn.S>
diff --git a/sysdeps/x86_64/multiarch/strpbrk.S b/sysdeps/x86_64/multiarch/strpbrk.S
deleted file mode 100644
index 7201d63..0000000
--- a/sysdeps/x86_64/multiarch/strpbrk.S
+++ /dev/null
@@ -1,5 +0,0 @@ 
-/* Multiple versions of strpbrk
-   All versions must be listed in ifunc-impl-list.c.  */
-#define STRCSPN strpbrk
-#define USE_AS_STRPBRK
-#include "strcspn.S"
diff --git a/sysdeps/x86_64/multiarch/strpbrk.c b/sysdeps/x86_64/multiarch/strpbrk.c
new file mode 100644
index 0000000..65453df
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/strpbrk.c
@@ -0,0 +1,36 @@ 
+/* Multiple versions of strpbrk.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 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/>.  */
+
+/* Define multiple versions only for the definition in libc.  */
+#if IS_IN (libc)
+# define _HAVE_STRING_ARCH_strpbrk 1
+# define strpbrk __redirect_strpbrk
+# include <string.h>
+# undef strpbrk
+
+# define SYMBOL_NAME strpbrk
+# include "ifunc-sse4_2.h"
+
+libc_ifunc_redirected (__redirect_strpbrk, strpbrk, IFUNC_SELECTOR ());
+
+# ifdef SHARED
+__hidden_ver1 (strpbrk, __GI_strpbrk, __redirect_strpbrk)
+  __attribute__ ((visibility ("hidden")));
+# endif
+#endif
diff --git a/sysdeps/x86_64/multiarch/strspn-sse2.S b/sysdeps/x86_64/multiarch/strspn-sse2.S
new file mode 100644
index 0000000..9bc5bff
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/strspn-sse2.S
@@ -0,0 +1,28 @@ 
+/* strspn optimized with SSE2.
+   Copyright (C) 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/>.  */
+
+#if IS_IN (libc)
+
+# include <sysdep.h>
+# define strspn __strspn_sse2
+
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(strspn)
+#endif
+
+#include <sysdeps/x86_64/strspn.S>
diff --git a/sysdeps/x86_64/multiarch/strspn.c b/sysdeps/x86_64/multiarch/strspn.c
new file mode 100644
index 0000000..942e07a
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/strspn.c
@@ -0,0 +1,36 @@ 
+/* Multiple versions of strspn.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 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/>.  */
+
+/* Define multiple versions only for the definition in libc.  */
+#if IS_IN (libc)
+# define _HAVE_STRING_ARCH_strspn 1
+# define strspn __redirect_strspn
+# include <string.h>
+# undef strspn
+
+# define SYMBOL_NAME strspn
+# include "ifunc-sse4_2.h"
+
+libc_ifunc_redirected (__redirect_strspn, strspn, IFUNC_SELECTOR ());
+
+# ifdef SHARED
+__hidden_ver1 (strspn, __GI_strspn, __redirect_strspn)
+  __attribute__ ((visibility ("hidden")));
+# endif
+#endif
diff --git a/sysdeps/x86_64/strcspn.S b/sysdeps/x86_64/strcspn.S
index a1d1f7d..e450a1e 100644
--- a/sysdeps/x86_64/strcspn.S
+++ b/sysdeps/x86_64/strcspn.S
@@ -24,9 +24,6 @@ 
 #include <sysdep.h>
 #include "asm-syntax.h"
 
-/* BEWARE: `#ifdef strcspn' means that strcspn is redefined as `strpbrk' */
-#define STRPBRK_P (defined strcspn)
-
 	.text
 ENTRY (strcspn)
 
@@ -111,7 +108,7 @@  L(5):	incq %rax
 
 L(4):	addq $256, %rsp		/* remove skipset */
 	cfi_adjust_cfa_offset(-256)
-#if STRPBRK_P
+#ifdef USE_AS_STRPBRK
 	xorl %edx,%edx
 	orb %cl, %cl		/* was last character NUL? */
 	cmovzq %rdx, %rax	/* Yes:	return NULL */
diff --git a/sysdeps/x86_64/strpbrk.S b/sysdeps/x86_64/strpbrk.S
index 9b97ada..21888a5 100644
--- a/sysdeps/x86_64/strpbrk.S
+++ b/sysdeps/x86_64/strpbrk.S
@@ -1,2 +1,3 @@ 
 #define strcspn strpbrk
+#define USE_AS_STRPBRK
 #include <sysdeps/x86_64/strcspn.S>