S390: Refactor strncmp ifunc handling.

The ifunc handling for strncmp is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strncmp variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strncmp variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strncmp.
	* sysdeps/s390/multiarch/strncmp-c.c: Move to ...
	* sysdeps/s390/strncmp-c.c: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strncmp-vx.S: Move to ...
	* sysdeps/s390/strncmp-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strncmp.c: Move to ...
	* sysdeps/s390/strncmp.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strncmp.h: New file.

5 files changed, 14 insertions, 199 deletions

diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 97421a4996..381376bf9f 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),string)
-sysdep_routines += strncmp strncmp-vx strncmp-c \
-		   strchr strchr-vx strchr-c \
+sysdep_routines += strchr strchr-vx strchr-c \
 		   strchrnul strchrnul-vx strchrnul-c \
 		   strrchr strrchr-vx strrchr-c \
 		   strspn strspn-vx strspn-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 44637c431b..d982de5788 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -35,6 +35,7 @@
 #include <ifunc-strcat.h>
 #include <ifunc-strncat.h>
 #include <ifunc-strcmp.h>
+#include <ifunc-strncmp.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -281,6 +282,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_STRCMP_IFUNC  */
 
+#if HAVE_STRNCMP_IFUNC
+    IFUNC_IMPL (i, name, strncmp,
+# if HAVE_STRNCMP_Z13
+		IFUNC_IMPL_ADD (array, i, strncmp,
+				dl_hwcap & HWCAP_S390_VX, STRNCMP_Z13)
+# endif
+# if HAVE_STRNCMP_C
+		IFUNC_IMPL_ADD (array, i, strncmp, 1, STRNCMP_C)
+# endif
+		)
+#endif /* HAVE_STRNCMP_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -307,7 +320,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (wcscmp);
 
-  IFUNC_VX_IMPL (strncmp);
   IFUNC_VX_IMPL (wcsncmp);
 
   IFUNC_VX_IMPL (strchr);
diff --git a/sysdeps/s390/multiarch/strncmp-c.c b/sysdeps/s390/multiarch/strncmp-c.c
deleted file mode 100644
index e54277ec1b..0000000000
--- a/sysdeps/s390/multiarch/strncmp-c.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/* Default strncmp implementation for S/390.
-   Copyright (C) 2015-2018 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 defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
-# define STRNCMP  __strncmp_c
-# ifdef SHARED
-#  undef libc_hidden_builtin_def
-#  define libc_hidden_builtin_def(name)			\
-  __hidden_ver1 (__strncmp_c, __GI_strncmp, __strncmp_c);
-# endif /* SHARED */
-
-# include <string/strncmp.c>
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
diff --git a/sysdeps/s390/multiarch/strncmp-vx.S b/sysdeps/s390/multiarch/strncmp-vx.S
deleted file mode 100644
index 168fd657da..0000000000
--- a/sysdeps/s390/multiarch/strncmp-vx.S
+++ /dev/null
@@ -1,137 +0,0 @@
-/* Vector optimized 32/64 bit S/390 version of strncmp.
-   Copyright (C) 2015-2018 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 defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
-
-# include "sysdep.h"
-# include "asm-syntax.h"
-
-	.text
-
-/* int strncmp (const char *s1, const char *s2, size_t n)
-   Compare at most n characters of two strings.
-
-   Register usage:
-   -r0=tmp
-   -r1=tmp
-   -r2=s1
-   -r3=s2
-   -r4=n
-   -r5=current_len
-   -v16=part of s1
-   -v17=part of s2
-   -v18=index of unequal
-*/
-ENTRY(__strncmp_vx)
-	.machine "z13"
-	.machinemode "zarch_nohighgprs"
-
-# if !defined __s390x__
-	llgfr	%r4,%r4
-# endif /* !defined __s390x__ */
-
-	clgije	%r4,0,.Lend_equal /* Nothing to do if n == 0,  */
-	lghi	%r5,0		/* current_len = 0.  */
-
-.Lloop:
-	vlbb	%v16,0(%r5,%r2),6 /* Load s1 to block boundary.  */
-	vlbb	%v17,0(%r5,%r3),6 /* Load s2 to block boundary.  */
-	lcbb	%r0,0(%r5,%r2),6 /* Get loaded byte count of s1.  */
-	jo	.Llt16_1	/* Jump away if vr is not fully loaded.  */
-	lcbb	%r1,0(%r5,%r3),6 /* Get loaded byte count of s2.  */
-	jo	.Llt16_2	/* Jump away if vr is not fully loaded.  */
-	aghi	%r5,16		/* Both vrs are fully loaded.  */
-	clgrjhe	%r5,%r4,.Llastcmp /* If current_len >= n ->last compare.  */
-	vfenezbs %v18,%v16,%v17	/* Compare not equal with zero search.  */
-	jno	.Lfound
-
-	vlbb	%v16,0(%r5,%r2),6
-	vlbb	%v17,0(%r5,%r3),6
-	lcbb	%r0,0(%r5,%r2),6
-	jo	.Llt16_1
-	lcbb	%r1,0(%r5,%r3),6
-	jo	.Llt16_2
-	aghi	%r5,16
-	clgrjhe	%r5,%r4,.Llastcmp
-	vfenezbs %v18,%v16,%v17
-	jno	.Lfound
-
-	vlbb	%v16,0(%r5,%r2),6
-	vlbb	%v17,0(%r5,%r3),6
-	lcbb	%r0,0(%r5,%r2),6
-	jo	.Llt16_1
-	lcbb	%r1,0(%r5,%r3),6
-	jo	.Llt16_2
-	aghi	%r5,16
-	clgrjhe	%r5,%r4,.Llastcmp
-	vfenezbs %v18,%v16,%v17
-	jno	.Lfound
-
-	vlbb	%v16,0(%r5,%r2),6
-	vlbb	%v17,0(%r5,%r3),6
-	lcbb	%r0,0(%r5,%r2),6
-	jo	.Llt16_1
-	lcbb	%r1,0(%r5,%r3),6
-	jo	.Llt16_2
-	aghi	%r5,16
-	clgrjhe	%r5,%r4,.Llastcmp
-	vfenezbs %v18,%v16,%v17
-	jno	.Lfound
-	j	.Lloop
-
-.Llt16_1:
-	lcbb	%r1,0(%r5,%r3),6 /* Get loaded byte count ofs2.  */
-.Llt16_2:
-	clr	%r0,%r1		/* Compare logical.  */
-	locrh	%r0,%r1		/* Compute minimum of bytes loaded.  */
-	algfr	%r5,%r0		/* Add smallest loaded bytes to current_len.  */
-	clgrj	%r5,%r4,10,.Llastcmp /* If current_len >= n ->last compare.  */
-	vfenezbs %v18,%v16,%v17	/* Compare not equal with zero search.  */
-	vlgvb	%r1,%v18,7	/* Get not equal index or 16 if all equal.  */
-	clrjl	%r1,%r0,.Lfound /* Jump away if miscompare is within
-				    loaded bytes (index < loaded-bytes) */
-	j	.Lloop
-
-.Llastcmp:
-	/* Use comparision result only if located within first n characters.
-	   %r0: loaded byte count in vreg;
-	   %r5: current_len;
-	   %r4: n;
-	   (current_len - n): [0...16[
-	   First ignored match index: loaded bytes - (current_len-n): ]0...16]
-	*/
-	slgr	%r5,%r4		/* %r5 = current_len - n.  */
-	slr	%r0,%r5		/* %r0 = first ignored match index.  */
-	vfenezbs %v18,%v16,%v17	/* Compare not equal with zero search.  */
-	vlgvb	%r1,%v18,7	/* Get not equal index or 16 if all equal.  */
-	clrjl	%r1,%r0,.Lfound /* Jump away if miscompare is within
-				    loaded bytes and below n bytes.  */
-	j	.Lend_equal	/* Miscompare after n-bytes -> end equal.  */
-
-.Lfound:
-	/* Difference or end of string.  */
-	je	.Lend_equal
-	lghi	%r2,1
-	lghi	%r1,-1
-	locgrl	%r2,%r1
-	br	%r14
-.Lend_equal:
-	lghi	%r2,0
-	br	%r14
-END(__strncmp_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
diff --git a/sysdeps/s390/multiarch/strncmp.c b/sysdeps/s390/multiarch/strncmp.c
deleted file mode 100644
index 0ec472c3b0..0000000000
--- a/sysdeps/s390/multiarch/strncmp.c
+++ /dev/null
@@ -1,31 +0,0 @@
-/* Multiple versions of strncmp.
-   Copyright (C) 2015-2018 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 defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
-# define strncmp __redirect_strncmp
-/* Omit the strncmp inline definitions because it would redefine strncmp.  */
-# define __NO_STRING_INLINES
-# include <string.h>
-# undef strncmp
-# include <ifunc-resolve.h>
-
-s390_vx_libc_ifunc2_redirected (__redirect_strncmp, __strncmp, strncmp)
-
-#else
-# include <string/strncmp.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */