S390: Refactor strcat ifunc handling.

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

1 files changed, 170 insertions, 0 deletions

diff --git a/sysdeps/s390/strcat-vx.S b/sysdeps/s390/strcat-vx.S
new file mode 100644
index 0000000000..218e301f10
--- /dev/null
+++ b/sysdeps/s390/strcat-vx.S
@@ -0,0 +1,170 @@
+/* Vector optimized 32/64 bit S/390 version of strcat.
+   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-strcat.h>
+#if HAVE_STRCAT_Z13
+
+# include "sysdep.h"
+# include "asm-syntax.h"
+
+	.text
+
+/* char * strcat (const char *dest, const char *src)
+   Concatenate two strings.
+
+   Register usage:
+   -r0=saved dest pointer for return
+   -r1=tmp
+   -r2=dest
+   -r3=src
+   -r4=tmp
+   -r5=current_len
+   -v16=part of src
+   -v17=index of zero
+   -v18=part of src
+*/
+ENTRY(STRCAT_Z13)
+	.machine "z13"
+	.machinemode "zarch_nohighgprs"
+
+	lgr	%r0,%r2		/* Save destination pointer for return.  */
+
+	/* STRLEN
+	   r1 = loaded bytes (tmp)
+	   r4 = zero byte index (tmp)
+	   r2 = dst
+	*/
+	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.  */
+
+	vfenezb	%v16,%v16,%v16	/* Find element not equal with zero search.  */
+	vlgvb	%r5,%v16,7	/* Load zero index or 16 if not found.  */
+	clrjl	%r5,%r1,.Llen_end /* Found zero within loaded bytes, end.  */
+
+	/* Align s to 16 byte.  */
+	risbgn	%r1,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
+	lghi	%r5,16		/* current_len = 16.  */
+	slr	%r5,%r1		/* Compute bytes to 16bytes boundary.  */
+
+	/* Find zero in 16byte aligned loop.  */
+.Llen_loop:
+	vl	%v16,0(%r5,%r2)	/* Load s.  */
+	vfenezbs %v16,%v16,%v16	/* Find element not equal with zero search.  */
+	je	.Llen_found	/* Jump away if zero was found.  */
+	vl	%v16,16(%r5,%r2)
+	vfenezbs %v16,%v16,%v16
+	je	.Llen_found16
+	vl	%v16,32(%r5,%r2)
+	vfenezbs %v16,%v16,%v16
+	je	.Llen_found32
+	vl	%v16,48(%r5,%r2)
+	vfenezbs %v16,%v16,%v16
+	je	.Llen_found48
+
+	aghi	%r5,64
+	j	.Llen_loop	/* No zero -> loop.  */
+
+.Llen_found48:
+	aghi	%r5,16
+.Llen_found32:
+	aghi	%r5,16
+.Llen_found16:
+	aghi	%r5,16
+.Llen_found:
+	vlgvb	%r4,%v16,7	/* Load byte index of zero.  */
+	algr	%r5,%r4
+
+.Llen_end:
+	/* STRCPY
+	   %r1 = loaded bytes (tmp)
+	   %r4 = zero byte index (tmp)
+	   %r3 = curr src pointer
+	   %r2 = curr dst pointer
+	 */
+	la	%r2,0(%r5,%r2)	/* strcpy at end of dst-string.   */
+
+	vlbb	%v16,0(%r3),6	/* Load s until next 4k-byte boundary.  */
+	lcbb	%r1,0(%r3),6	/* Get bytes to 4k-byte boundary or 16.  */
+
+	vfenezb	%v17,%v16,%v16	/* Find element not equal with zero search.  */
+	vlgvb	%r5,%v17,7	/* Load zero index or 16 if not found.  */
+	clrjl	%r5,%r1,.Lcpy_found_align /* If found zero within loaded bytes,
+					     copy bytes before and return.  */
+
+	/* Align s to 16 byte.  */
+	risbgn	%r4,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
+	lghi	%r5,15		/* current_len = 15.  */
+	slr	%r5,%r4		/* Compute highest index to 16byte boundary.  */
+
+	vstl	%v16,%r5,0(%r2)	/* Copy loaded characters - no zero.  */
+	ahi	%r5,1		/* Start loop at next character.  */
+
+	/* Find zero in 16byte aligned loop.  */
+.Lcpy_loop:
+	vl	%v16,0(%r5,%r3)	/* Load s.  */
+	vfenezbs %v17,%v16,%v16	/* Find element not equal with zero search.  */
+	je	.Lcpy_found_v16_0 /* Jump away if zero was found.  */
+	vl	%v18,16(%r5,%r3)/* Load next part of s.  */
+	vst	%v16,0(%r5,%r2)	/* Store previous part without zero to dst.  */
+	vfenezbs %v17,%v18,%v18
+	je	.Lcpy_found_v18_16
+	vl	%v16,32(%r5,%r3)
+	vst	%v18,16(%r5,%r2)
+	vfenezbs %v17,%v16,%v16
+	je	.Lcpy_found_v16_32
+	vl	%v18,48(%r5,%r3)
+	vst	%v16,32(%r5,%r2)
+	vfenezbs %v17,%v18,%v18
+	je	.Lcpy_found_v18_48
+	vst	%v18,48(%r5,%r2)
+
+	aghi	%r5,64
+	j	.Lcpy_loop	/* No zero -> loop.  */
+
+.Lcpy_found_v16_32:
+	aghi	%r5,32
+.Lcpy_found_v16_0:
+	la	%r4,0(%r5,%r2)
+	vlgvb	%r1,%v17,7	/* Load byte index of zero.  */
+	vstl	%v16,%r1,0(%r4)	/* Copy characters including zero.  */
+	lgr	%r2,%r0		/* Load saved dest-ptr.  */
+	br	%r14
+
+.Lcpy_found_v18_48:
+	aghi	%r5,32
+.Lcpy_found_v18_16:
+	la	%r4,16(%r5,%r2)
+	vlgvb	%r1,%v17,7	/* Load byte index of zero.  */
+	vstl	%v18,%r1,0(%r4)	/* Copy characters including zero.  */
+	lgr	%r2,%r0		/* Load saved dest-ptr.  */
+	br	%r14
+
+.Lcpy_found_align:
+	vstl	%v16,%r5,0(%r2)	/* Copy characters including zero.  */
+	lgr	%r2,%r0		/* Load saved dest-ptr.  */
+	br	%r14
+END(STRCAT_Z13)
+
+# if ! HAVE_STRCAT_IFUNC
+strong_alias (STRCAT_Z13, strcat)
+# endif
+
+# if ! HAVE_STRCAT_C && defined SHARED && IS_IN (libc)
+strong_alias (STRCAT_Z13, __GI_strcat)
+# endif
+#endif