S390: Refactor strchrnul ifunc handling.

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

1 files changed, 101 insertions, 0 deletions

diff --git a/sysdeps/s390/strchrnul-vx.S b/sysdeps/s390/strchrnul-vx.S
new file mode 100644
index 0000000..0cd587b
--- /dev/null
+++ b/sysdeps/s390/strchrnul-vx.S
@@ -0,0 +1,101 @@
+/* Vector optimized 32/64 bit S/390 version of strchrnul.
+   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/>.  */
+
+#include <ifunc-strchrnul.h>
+
+#if HAVE_STRCHRNUL_Z13
+
+# include "sysdep.h"
+# include "asm-syntax.h"
+
+	.text
+
+/* char *strchrnul (const char *s, int c)
+   Returns pointer to first c or to \0 if c not found.
+
+   Register usage:
+   -r1=tmp
+   -r2=s and return pointer
+   -r3=c
+   -r4=tmp
+   -r5=current_len
+   -v16=part of s
+   -v18=vector with c replicated in every byte
+*/
+ENTRY(STRCHRNUL_Z13)
+	.machine "z13"
+	.machinemode "zarch_nohighgprs"
+
+	vlbb	%v16,0(%r2),6	/* Load s until next 4k-byte boundary.  */
+	lcbb	%r1,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */
+
+	lghi	%r5,0		/* current_len = 0.  */
+
+	vlvgb	%v18,%r3,0	/* Generate vector which elements are all c.
+				   If c > 255, c will be truncated.  */
+	vrepb	%v18,%v18,0
+
+	vfeezbs	%v16,%v16,%v18	/* Find element equal with zero search.  */
+	vlgvb	%r4,%v16,7	/* Load byte index of character or zero.  */
+	clrjl	%r4,%r1,.Lfound /* Return if c/zero is in loaded bytes.  */
+
+	/* Align s to 16 byte.  */
+	risbgn	%r4,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
+	lghi	%r5,16		/* current_len = 16.  */
+	slr	%r5,%r4		/* Compute bytes to 16bytes boundary.  */
+
+	/* Find c/zero in 16byte aligned loop */
+.Lloop:
+	vl	%v16,0(%r5,%r2) /* Load s */
+	vfeezbs	%v16,%v16,%v18	/* Find element equal with zero search.  */
+	jno	.Lfound		/* Found c/zero (cc=0|1|2).  */
+	vl	%v16,16(%r5,%r2)
+	vfeezbs	%v16,%v16,%v18
+	jno	.Lfound16
+	vl	%v16,32(%r5,%r2)
+	vfeezbs	%v16,%v16,%v18
+	jno	.Lfound32
+	vl	%v16,48(%r5,%r2)
+	vfeezbs	%v16,%v16,%v18
+	jno	.Lfound48
+
+	aghi	%r5,64
+	j	.Lloop		/* No character and no zero -> loop.  */
+
+	/* Found character or zero */
+.Lfound48:
+	aghi	%r5,16
+.Lfound32:
+	aghi	%r5,16
+.Lfound16:
+	aghi	%r5,16
+.Lfound:
+	vlgvb	%r1,%v16,7	/* Load byte index of character.  */
+	algr	%r5,%r1
+	la	%r2,0(%r5,%r2)	/* Return pointer to character.  */
+
+.Lend:
+	br	%r14
+END(STRCHRNUL_Z13)
+
+# if ! HAVE_STRCHRNUL_IFUNC
+strong_alias (STRCHRNUL_Z13, __strchrnul)
+weak_alias (__strchrnul, strchrnul)
+# endif
+
+#endif /* HAVE_STRCHRNUL_Z13  */