S390: Refactor memrchr ifunc handling.

The ifunc handling for memrchr 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.

ChangeLog:

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

5 files changed, 13 insertions, 219 deletions

diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index d5a32fc309..260b514936 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,7 +1,3 @@
-ifeq ($(subdir),string)
-sysdep_routines += memrchr memrchr-vx memrchr-c
-endif
-
 ifeq ($(subdir),wcsmbs)
 sysdep_routines += wcslen wcslen-vx wcslen-c \
 		   wcsnlen wcsnlen-vx wcsnlen-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index b8917747f0..0f01b99691 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -45,6 +45,7 @@
 #include <ifunc-memchr.h>
 #include <ifunc-rawmemchr.h>
 #include <ifunc-memccpy.h>
+#include <ifunc-memrchr.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -411,6 +412,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_MEMCCPY_IFUNC  */
 
+#if HAVE_MEMRCHR_IFUNC
+    IFUNC_IMPL (i, name, memrchr,
+# if HAVE_MEMRCHR_Z13
+		IFUNC_IMPL_ADD (array, i, memrchr,
+				dl_hwcap & HWCAP_S390_VX, MEMRCHR_Z13)
+# endif
+# if HAVE_MEMRCHR_C
+		IFUNC_IMPL_ADD (array, i, memrchr, 1, MEMRCHR_C)
+# endif
+		)
+#endif /* HAVE_MEMRCHR_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -457,8 +470,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (wmemcmp);
 
-  IFUNC_VX_IMPL (memrchr);
-
 #endif /* HAVE_S390_VX_ASM_SUPPORT */
 
   return i;
diff --git a/sysdeps/s390/multiarch/memrchr-c.c b/sysdeps/s390/multiarch/memrchr-c.c
deleted file mode 100644
index 1e3c914a5d..0000000000
--- a/sysdeps/s390/multiarch/memrchr-c.c
+++ /dev/null
@@ -1,25 +0,0 @@
-/* Default memrchr 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 MEMRCHR  __memrchr_c
-
-# include <string.h>
-extern __typeof (__memrchr) __memrchr_c;
-# include <string/memrchr.c>
-#endif
diff --git a/sysdeps/s390/multiarch/memrchr-vx.S b/sysdeps/s390/multiarch/memrchr-vx.S
deleted file mode 100644
index 8e81f5ed75..0000000000
--- a/sysdeps/s390/multiarch/memrchr-vx.S
+++ /dev/null
@@ -1,160 +0,0 @@
-/* Vector optimized 32/64 bit S/390 version of memrchr.
-   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
-
-/* void *memrchr (const void *s, int c, size_t n)
-   Scans memory for character c backwards
-   and returns pointer to first c.
-
-   Register usage:
-   -r0=tmp
-   -r1=tmp
-   -r2=s
-   -r3=c
-   -r4=n
-   -r5=s in loop
-
-   -v16=part of s
-   -v17=index of found c
-   -v18=c replicated
-   -v20=permute pattern
-*/
-ENTRY(__memrchr_vx)
-	.machine "z13"
-	.machinemode "zarch_nohighgprs"
-
-# if !defined __s390x__
-	llgfr	%r4,%r4
-# endif /* !defined __s390x__ */
-	clgije	%r4,0,.Lnot_found
-
-	vlvgb	%v18,%r3,0	/* Generate vector which elements are all c.
-				   If c > 255, c will be truncated.  */
-	vrepb	%v18,%v18,0
-
-	llcr	%r3,%r3		/* char c_char = (char) c.  */
-
-	/* check byte n - 1.  */
-	llc	%r0,-1(%r4,%r2)
-	slgfi	%r4,1
-	clrje	%r0,%r3,.Lfound_end
-	jh	.Lnot_found	/* Return NULL if n is now 0.  */
-
-	larl	%r1,.Lpermute_mask /* Load permute mask.  */
-	vl	%v20,0(%r1)
-
-	/* check byte n - 2.  */
-	llc	%r0,-1(%r4,%r2)
-	slgfi	%r4,1
-	clrje	%r0,%r3,.Lfound_end
-	jh	.Lnot_found	/* Return NULL if n is now 0.  */
-
-	clgijhe	%r4,64,.Lloop64	/* If n >= 64 -> loop64.  */
-
-.Llt64:
-	/* Process n < 64 bytes.  */
-	clgijl	%r4,16,.Llt16	/* Jump away if n < 16.  */
-	aghi	%r4,-16
-	vl	%v16,0(%r4,%r2)
-	vfeebs	%v17,%v16,%v18
-	jno	.Lfound0
-	clgijl	%r4,16,.Llt16
-	aghi	%r4,-16
-	vl	%v16,0(%r4,%r2)
-	vfeebs	%v17,%v16,%v18
-	jno	.Lfound0
-	clgijl	%r4,16,.Llt16
-	aghi	%r4,-16
-	vl	%v16,0(%r4,%r2)
-	vfeebs	%v17,%v16,%v18
-	jno	.Lfound0
-.Llt16:
-	clgfi	%r4,0		/* if remaining bytes == 0, return NULL.  */
-	locghie	%r2,0
-	ber	%r14
-
-	aghi	%r4,-1		/* vll needs highest index.  */
-	vll	%v16,%r4,0(%r2)	/* Load remaining bytes.  */
-
-	/* Right-shift of v16 to mask bytes after highest index.  */
-	lhi	%r0,15
-	slr	%r0,%r4		/* Compute byte count for vector shift right.  */
-	sll	%r0,3		/* Convert to bit count.  */
-	vlvgb	%v17,%r0,7
-	vsrlb	%v16,%v16,%v17	/* Vector shift right by byte by number of bytes
-				   specified in bits 1-4 of byte 7 in v17.   */
-	j	.Lfound_permute
-
-.Lfound48:
-	aghi	%r4,16
-.Lfound32:
-	aghi	%r4,16
-.Lfound16:
-	aghi	%r4,16
-.Lfound0:
-	la	%r2,0(%r4,%r2)	/* Set pointer to start of v16.  */
-	lghi	%r4,15		/* Set highest index in v16 to last index.  */
-.Lfound_permute:
-	/* Search for a c in v16 in reversed byte order. v16 contains %r4 + 1
-	   bytes. If v16 was not fully loaded, the bytes are already
-	   right shifted, so that the bytes in v16 can simply be reversed.  */
-	vperm	%v16,%v16,%v16,%v20 /* Permute v16 to reversed order.  */
-	vfeeb	%v16,%v16,%v18	/* Find c in reversed v16.  */
-	vlgvb	%r1,%v16,7	/* Index of c or 16 if not found.  */
-
-	/* Return NULL if there is no c in loaded bytes. */
-	clrjh	%r1,%r4,.Lnot_found
-
-	slgr	%r4,%r1
-.Lfound_end:
-	la	%r2,0(%r4,%r2)	/* Return pointer to c.  */
-	br	%r14
-
-.Lnot_found:
-	lghi	%r2,0
-	br	%r14
-
-.Lpermute_mask:
-	.byte	0x0F,0x0E,0x0D,0x0C,0x0B,0x0A,0x09,0x08
-	.byte	0x07,0x06,0x05,0x04,0x03,0x02,0x01,0x00
-
-.Lloop64:
-	aghi	%r4,-64
-	vl	%v16,48(%r4,%r2) /* Load 16bytes of memory area.  */
-	vfeebs	%v17,%v16,%v18	/* Find c.  */
-	jno	.Lfound48	/* Jump away if c was found.  */
-	vl	%v16,32(%r4,%r2)
-	vfeebs	%v17,%v16,%v18
-	jno	.Lfound32
-	vl	%v16,16(%r4,%r2)
-	vfeebs	%v17,%v16,%v18
-	jno	.Lfound16
-	vl	%v16,0(%r4,%r2)
-	vfeebs	%v17,%v16,%v18
-	jno	.Lfound0
-
-	clgijhe	%r4,64,.Lloop64	/* If n >= 64 -> loop64.  */
-	j	.Llt64
-END(__memrchr_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
diff --git a/sysdeps/s390/multiarch/memrchr.c b/sysdeps/s390/multiarch/memrchr.c
deleted file mode 100644
index 43a44abcf6..0000000000
--- a/sysdeps/s390/multiarch/memrchr.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/* Multiple versions of memrchr.
-   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 <string.h>
-# include <ifunc-resolve.h>
-
-s390_vx_libc_ifunc (__memrchr)
-weak_alias (__memrchr, memrchr)
-
-#else
-# include <string/memrchr.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */