S390: Refactor strspn ifunc handling.

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

1 files changed, 267 insertions, 0 deletions

diff --git a/sysdeps/s390/strspn-vx.S b/sysdeps/s390/strspn-vx.S
new file mode 100644
index 0000000000..ae5529b567
--- /dev/null
+++ b/sysdeps/s390/strspn-vx.S
@@ -0,0 +1,267 @@
+/* Vector optimized 32/64 bit S/390 version of strspn.
+   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-strspn.h>
+
+#if HAVE_STRSPN_Z13
+
+# include "sysdep.h"
+# include "asm-syntax.h"
+
+	.text
+
+/* size_t strspn (const char *s, const char * accept)
+   The strspn() function calculates the length of the initial segment
+   of s which consists entirely of characters in accept.
+
+   This method checks the length of accept string. If it fits entirely
+   in one vector register, a fast algorithm is used, which does not need
+   to check multiple parts of accept-string. Otherwise a slower full
+   check of accept-string is used.
+
+   register overview:
+   r3:  pointer to start of accept-string
+   r2:  pointer to start of search-string
+   r4:  loaded byte count of vl search-string
+   r0:  found byte index
+   r1:  current return len of s
+   v16: search-string
+   v17: accept-string
+   v18: temp-vreg
+
+   ONLY FOR SLOW:
+   v19: first accept-string
+   v20: zero for preparing acc-vector
+   v21: global mask; 1 indicates a match between
+	search-string-vreg and any accept-character
+   v22: current mask; 1 indicates a match between
+	search-string-vreg and any accept-character in current acc-vreg
+   v30, v31: for re-/storing registers r6, r8, r9
+   r5:  current len of accept-string
+   r6:	zero-index in search-string or 16 if no zero
+	or min(zero-index, loaded byte count)
+   r8:	>0, if former accept-string-part contains a zero,
+	otherwise =0;
+   r9: loaded byte count of vlbb accept-string
+*/
+ENTRY(STRSPN_Z13)
+	.machine "z13"
+	.machinemode "zarch_nohighgprs"
+
+	/*
+	  Check if accept-string fits in one vreg:
+	  ----------------------------------------
+	*/
+	vlbb	%v17,0(%r3),6	/* Load accept.  */
+	lcbb	%r4,0(%r3),6
+	jo	.Lcheck_onbb	/* Special case if accept lays
+				   on block-boundary.  */
+.Lcheck_notonbb:
+	vistrbs	%v17,%v17	/* Fill with zeros after first zero.  */
+	je	.Lfast		/* Zero found -> accept fits in one vreg.  */
+	j	.Lslow		/* No zero -> accept exceeds one vreg.  */
+
+.Lcheck_onbb:
+	/* Accept lays on block-boundary.  */
+	vfenezb	%v18,%v17,%v17	/* Search zero in loaded accept bytes.  */
+	vlgvb	%r0,%v18,7	/* Get index of zero or 16 if not found.  */
+	clrjl	%r0,%r4,.Lcheck_notonbb /* Zero index < loaded bytes count ->
+					   Accept fits in one vreg;
+					   Fill with zeros and proceed
+					   with FAST.  */
+	vl	%v17,0(%r3)	/* Load accept, which exceeds loaded bytes.  */
+	j	.Lcheck_notonbb /* Check if accept fits in one vreg.  */
+
+
+	/*
+	  Search s for accept in one vreg
+	  -------------------------------
+	*/
+.Lfast:
+	/* Complete accept-string is in v17 and remaining bytes are zero.  */
+
+	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.  */
+
+	vfaezbs	%v16,%v16,%v17,8 /* Find first element in v16
+				    unequal to any in v17
+				    or first zero element.  */
+	vlgvb	%r0,%v16,7	/* Load byte index of found element.  */
+	/* If found index is within loaded bytes (%r0 < %r1),
+	   return with found element index (=equal count).  */
+	clr	%r0,%r1
+	locgrl	%r2,%r0
+	blr	%r14
+
+	/* Align s to 16 byte.  */
+	risbgn	%r4,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
+	lghi	%r1,16		/* current_len = 16.  */
+	slr	%r1,%r4		/* Compute bytes to 16bytes boundary.  */
+
+.Lfast_loop:
+	vl	%v16,0(%r1,%r2)	/* Load search-string.  */
+	vfaezbs	%v16,%v16,%v17,8 /* Find first element in v16
+				    unequal to any in v17
+				    or first zero element.  */
+	jno	.Lfast_loop_found
+	vl	%v16,16(%r1,%r2)
+	vfaezbs	%v16,%v16,%v17,8
+	jno	.Lfast_loop_found16
+	vl	%v16,32(%r1,%r2)
+	vfaezbs	%v16,%v16,%v17,8
+	jno	.Lfast_loop_found32
+	vl	%v16,48(%r1,%r2)
+	vfaezbs	%v16,%v16,%v17,8
+	jno	.Lfast_loop_found48
+
+	aghi	%r1,64
+	j	.Lfast_loop	/* Loop if no element was unequal to accept
+				   and not zero.  */
+
+	/* Found unequal or zero element.  */
+.Lfast_loop_found48:
+	aghi	%r1,16
+.Lfast_loop_found32:
+	aghi	%r1,16
+.Lfast_loop_found16:
+	aghi	%r1,16
+.Lfast_loop_found:
+	vlgvb	%r0,%v16,7	/* Load byte index of found element.  */
+	algrk	%r2,%r1,%r0	/* And add it to current len.  */
+	br	%r14
+
+
+	/*
+	  Search s for accept in multiple vregs
+	  -------------------------------------
+	*/
+.Lslow:
+	/* Save registers.  */
+	vlvgg	%v30,%r6,0
+	vlvgp	%v31,%r8,%r9
+	lghi	%r1,0		/* current_len = 0.  */
+
+	/* Accept in v17 without zero.  */
+	vlr	%v19,%v17	/* Save first acc-part for a fast reload.  */
+	vzero	%v20		/* Zero for preparing acc-vector.  */
+
+	/* Align s to 16 byte.  */
+	risbg	%r0,%r2,60,128+63,0 /* Test if s is aligned and
+				     %r0 = bits 60-63 'and' 15  */
+	je	.Lslow_loop_str /* If s is aligned, loop aligned */
+	lghi	%r4,15
+	slr	%r4,%r0		/* Compute highest index to load (15-x).  */
+	vll	%v16,%r4,0(%r2) /* Load up to 16byte boundary (vll needs
+				   highest index, left bytes are 0).  */
+	ahi	%r4,1		/* Work with loaded byte count.  */
+	vzero	%v21		/* Zero out global mask.  */
+	lghi	%r5,0		/* Set current len of accept-string to zero.  */
+	vfenezb	%v18,%v16,%v16	/* Find zero in current string-part.  */
+	lghi	%r8,0		/* There is no zero in first accept-part.  */
+	vlgvb	%r6,%v18,7	/* Load byte index of zero or 16
+				   if there is no zero.  */
+	clr	%r4,%r6		/* cc==1 if loaded byte count < zero-index.  */
+	locrl	%r6,%r4		/* Load on cc==1.  */
+	j	.Lslow_loop_acc
+
+	/* Process s in 16byte aligned loop.  */
+.Lslow_next_str:
+	vlr	%v17,%v19	/* Load first part of accept (no zero).  */
+	algfr	%r1,%r4		/* Add loaded byte count to current len.  */
+.Lslow_loop_str:
+	vl	%v16,0(%r1,%r2)	/* Load search-string.  */
+	lghi	%r4,16		/* Loaded byte count is 16.  */
+	vzero	%v21		/* Zero out global mask.  */
+	lghi	%r5,0		/* Set current len of accept-string to zero.  */
+	vfenezb	%v18,%v16,%v16	/* Find zero in current string-part.  */
+	lghi	%r8,0		/* There is no zero in first accept-part.  */
+	vlgvb	%r6,%v18,7	/* Load byte index of zero or 16 if no zero.  */
+
+.Lslow_loop_acc:
+	vfaeb	%v22,%v16,%v17,4 /* Create matching-mask (1 in mask ->
+				    character matches any accepted character in
+				    this accept-string-part) IN=0, RT=1.  */
+	vo	%v21,%v21,%v22	/* global-mask = global- | matching-mask.  */
+	vfenezb	%v18,%v21,%v21	/* Find first zero in global-mask.  */
+	vlgvb	%r0,%v18,7	/* Get first found zero-index
+				   (= first mismatch).  */
+	clrjl	%r0,%r6,.Lslow_next_acc /* Mismatch-index < min(lbc,zero-index)
+					    -> Process this string-part
+					       with next acc-part.  */
+	clrjhe	%r0,%r4,.Lslow_next_str /* Found-index >= loaded byte count
+					   -> All loaded bytes are matching
+					      any accept-character
+					      and are not zero.  */
+	/* All bytes are matching any characters in accept-string
+	   and search-string is fully processed (found-index == zero-index)  */
+.Lslow_add_lbc_end:
+	algrk	%r2,%r1,%r0	/* Add matching characters to current_len.  */
+	/* Restore registers.  */
+	vlgvg	%r6,%v30,0
+	vlgvg	%r8,%v31,0
+	vlgvg	%r9,%v31,1
+	br	%r14
+
+
+
+.Lslow_next_acc:
+	clijh	%r8,0,.Lslow_add_lbc_end /* There was a zero in last acc-part
+					     -> Add found index to current len
+						and end.  */
+	vlbb	%v17,16(%r5,%r3),6 /* Load next accept part.  */
+	aghi	%r5,16		/* Add current_len of accept-string.  */
+	lcbb	%r9,0(%r5,%r3),6 /* Get loaded byte count of accept-string.  */
+	jo	.Lslow_next_acc_onbb /* Jump away if accept-string is
+					 on block-boundary.  */
+.Lslow_next_acc_notonbb:
+	vistrbs	%v17,%v17	/* Fill with zeros after first zero.  */
+	jo	.Lslow_loop_acc /* No zero found -> no preparation needed.  */
+
+.Lslow_next_acc_prepare_zero:
+	/* Zero in accept-part: fill zeros with first-accept-character.  */
+	vlgvb	%r8,%v17,0	/* Load first element of acc-part.  */
+	clije	%r8,0,.Lslow_add_lbc_end /* End if zero is first character
+					     in this part of accept-string.  */
+	/* r8>0 -> zero found in this acc-part.  */
+	vrepb	%v18,%v17,0	/* Replicate first char accross all chars.  */
+	vceqb	%v22,%v20,%v17	/* Create a mask (v22) of null chars
+				   by comparing with 0 (v20).  */
+	vsel	%v17,%v18,%v17,%v22 /* Replace null chars with first char.  */
+	j	.Lslow_loop_acc /* Accept part is prepared -> process.  */
+
+.Lslow_next_acc_onbb:
+	vfenezb	%v18,%v17,%v17	/* Find zero in loaded bytes of accept part.  */
+	vlgvb	%r8,%v18,7	/* Load byte index of zero.  */
+	clrjl	%r8,%r9,.Lslow_next_acc_notonbb /* Found a zero in loaded bytes
+						    -> Prepare vr.  */
+	vl	%v17,0(%r5,%r3)	/* Load over boundary ...  */
+	lghi	%r8,0		/* r8=0 -> no zero in this part of acc,
+				   Check for zero is in jump-target.  */
+	j	.Lslow_next_acc_notonbb /* ... and search for zero in
+					    fully loaded vreg again.  */
+END(STRSPN_Z13)
+
+# if ! HAVE_STRSPN_IFUNC
+strong_alias (STRSPN_Z13, strspn)
+# endif
+
+# if ! HAVE_STRSPN_C && defined SHARED && IS_IN (libc)
+strong_alias (STRSPN_Z13, __GI_strspn)
+# endif
+
+#endif /* HAVE_STRSPN_Z13  */