File 0016-S390-Add-arch13-strstr-ifunc-variant.patch of Package glibc.22972
From d65ead17a0c11fc369225eb24ebf8c9a7132b2e8 Mon Sep 17 00:00:00 2001
From: Stefan Liebler <stli@linux.ibm.com>
Date: Fri, 22 Mar 2019 11:14:08 +0100
Subject: [PATCH 16/18] S390: Add arch13 strstr ifunc variant.
This patch introduces the new arch13 ifunc variant for strstr.
For needles longer than 9 charachters it is relying on the common-code
implementation. For shorter needles it is using the new vstrs instruction
which is able to search a substring within a vector register.
ChangeLog:
* sysdeps/s390/Makefile (sysdep_routines): Add strstr-arch13.
* sysdeps/s390/ifunc-strstr.h (HAVE_STRSTR_ARCH13, STRSTR_ARCH13,
STRSTR_Z13_ONLY_USED_AS_FALLBACK, HAVE_STRSTR_IFUNC_AND_ARCH13_SUPPORT):
New defines.
* sysdeps/s390/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add ifunc variant for arch13 strstr.
* sysdeps/s390/strstr-arch13.S: New file.
* sysdeps/s390/strstr-vx.c: Omit GI symbol for z13 strstr ifunc variant
if it is only used as fallback.
* sysdeps/s390/strstr.c (strstr): Add arch13 variant in ifunc selector.
(cherry picked from commit 6f47401bd5fc71209219779a0426170a9a7395b0)
---
sysdeps/s390/Makefile | 2 +-
sysdeps/s390/ifunc-strstr.h | 28 ++++-
sysdeps/s390/multiarch/ifunc-impl-list.c | 4 +
sysdeps/s390/strstr-arch13.S | 179 +++++++++++++++++++++++++++++++
sysdeps/s390/strstr-vx.c | 4 +-
sysdeps/s390/strstr.c | 8 +-
6 files changed, 219 insertions(+), 6 deletions(-)
create mode 100644 sysdeps/s390/strstr-arch13.S
Index: glibc-2.26/sysdeps/s390/Makefile
===================================================================
--- glibc-2.26.orig/sysdeps/s390/Makefile
+++ glibc-2.26/sysdeps/s390/Makefile
@@ -33,6 +33,6 @@ endif
ifeq ($(subdir),string)
sysdep_routines += mempcpy memcpy memcpy-z900 \
memmove memmove-c \
- strstr strstr-vx strstr-c \
+ strstr strstr-arch13 strstr-vx strstr-c \
memmem memmem-vx memmem-c
endif
Index: glibc-2.26/sysdeps/s390/ifunc-strstr.h
===================================================================
--- glibc-2.26.orig/sysdeps/s390/ifunc-strstr.h
+++ glibc-2.26/sysdeps/s390/ifunc-strstr.h
@@ -17,7 +17,7 @@
<http://www.gnu.org/licenses/>. */
#if defined USE_MULTIARCH && IS_IN (libc) \
- && ! defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+ && ! defined HAVE_S390_MIN_ARCH13_ZARCH_ASM_SUPPORT
# define HAVE_STRSTR_IFUNC 1
#else
# define HAVE_STRSTR_IFUNC 0
@@ -29,14 +29,32 @@
# define HAVE_STRSTR_IFUNC_AND_VX_SUPPORT 0
#endif
-#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+#ifdef HAVE_S390_ARCH13_ASM_SUPPORT
+# define HAVE_STRSTR_IFUNC_AND_ARCH13_SUPPORT HAVE_STRSTR_IFUNC
+#else
+# define HAVE_STRSTR_IFUNC_AND_ARCH13_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_ARCH13_ZARCH_ASM_SUPPORT
+# define STRSTR_DEFAULT STRSTR_ARCH13
+# define HAVE_STRSTR_C 0
+# define HAVE_STRSTR_Z13 1
+# define STRSTR_Z13_ONLY_USED_AS_FALLBACK 1
+# define HAVE_STRSTR_ARCH13 1
+#elif defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
# define STRSTR_DEFAULT STRSTR_Z13
# define HAVE_STRSTR_C 0
# define HAVE_STRSTR_Z13 1
+# define HAVE_STRSTR_ARCH13 HAVE_STRSTR_IFUNC_AND_ARCH13_SUPPORT
#else
# define STRSTR_DEFAULT STRSTR_C
# define HAVE_STRSTR_C 1
# define HAVE_STRSTR_Z13 HAVE_STRSTR_IFUNC_AND_VX_SUPPORT
+# define HAVE_STRSTR_ARCH13 HAVE_STRSTR_IFUNC_AND_ARCH13_SUPPORT
+#endif
+
+#ifndef STRSTR_Z13_ONLY_USED_AS_FALLBACK
+# define STRSTR_Z13_ONLY_USED_AS_FALLBACK 0
#endif
#if HAVE_STRSTR_C
@@ -50,3 +68,9 @@
#else
# define STRSTR_Z13 NULL
#endif
+
+#if HAVE_STRSTR_ARCH13
+# define STRSTR_ARCH13 __strstr_arch13
+#else
+# define STRSTR_ARCH13 NULL
+#endif
Index: glibc-2.26/sysdeps/s390/multiarch/ifunc-impl-list.c
===================================================================
--- glibc-2.26.orig/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ glibc-2.26/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -112,6 +112,10 @@ __libc_ifunc_impl_list (const char *name
#if HAVE_STRSTR_IFUNC
IFUNC_IMPL (i, name, strstr,
+# if HAVE_STRSTR_ARCH13
+ IFUNC_IMPL_ADD (array, i, strstr,
+ dl_hwcap & HWCAP_S390_VXRS_EXT2, STRSTR_ARCH13)
+# endif
# if HAVE_STRSTR_Z13
IFUNC_IMPL_ADD (array, i, strstr,
dl_hwcap & HWCAP_S390_VX, STRSTR_Z13)
Index: glibc-2.26/sysdeps/s390/strstr-arch13.S
===================================================================
--- /dev/null
+++ glibc-2.26/sysdeps/s390/strstr-arch13.S
@@ -0,0 +1,179 @@
+/* Vector optimized 32/64 bit S/390 version of strstr.
+ Copyright (C) 2019 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-strstr.h>
+#if HAVE_STRSTR_ARCH13
+# include "sysdep.h"
+# include "asm-syntax.h"
+ .text
+
+/* char *strstr (const char *haystack=r2, const char *needle=r3)
+ Locate a substring. */
+ENTRY(STRSTR_ARCH13)
+ .machine "arch13"
+ .machinemode "zarch_nohighgprs"
+ lcbb %r1,0(%r3),6
+ jo .Lneedle_on_bb /* Needle on block-boundary? */
+ vl %v18,0(%r3),6 /* Load needle. */
+ vfenezb %v19,%v18,%v18 /* v19[7] contains the length of needle. */
+.Lneedle_loaded:
+ vlgvb %r4,%v19,7 /* Get index of zero or 16 if not found. */
+ lghi %r5,17 /* See below: min-skip-partial-match-index. */
+ cgibe %r4,0,0(%r14) /* Test if needle is zero and return. */
+
+ /* The vstrs instruction is able to handle needles up to a length of 16,
+ but then we may have to load the next part of haystack with a
+ small offset. This will be slow - see examples:
+ haystack =mmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmm...mmmmmmmmmmmmmmmmmmma
+ needle = mmmmmmmmmmmmmma0
+ => needle_len=15; vstrs reports a partial match; haystack+=2
+ haystack =mmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmm...mmmmmmmmmmmmmmmmmmma
+ needle = mmmmmmmma0000000
+ => needle_len=9; vstrs reports a partial match; haystack+=8 */
+# if ! HAVE_STRSTR_Z13
+# error The arch13 variant of strstr needs the z13 variant of strstr!
+# endif
+ clgfi %r4,9
+ jh STRSTR_Z13
+
+ /* In case of a partial match, the vstrs instruction returns the index
+ of the partial match in a vector-register. Then we have to
+ reload the string at the "current-position plus this index" and run
+ vstrs again in order to determine if it was a full match or no match.
+ Transferring this index from vr to gr, compute the haystack-address
+ and loading with vl is quite slow as all instructions have data
+ dependencies. Thus we assume, that a partial match is always at the
+ first possible index and just load the next part of haystack from
+ there instead of waiting until the correct index is computed:
+ min-skip-partial-match-index = (16 - n_len) + 1 */
+ sgr %r5,%r4
+
+.Lloop:
+ lcbb %r1,0(%r2),6
+ jo .Lloop_haystack_on_bb /* Haystack on block-boundary? */
+ vl %v16,0(%r2) /* Load next part of haystack. */
+.Lloop_haystack_loaded:
+ /* Vector string search with zero search (cc=0 => no match). */
+ vstrs %v20,%v16,%v18,%v19,0,2
+ jne .Lloop_vstrs_nonzero_cc
+ lcbb %r1,16(%r2),6 /* Next part of haystack. */
+ jo .Lloop_haystack_on_bb16
+ vl %v16,16(%r2)
+ vstrs %v20,%v16,%v18,%v19,0,2
+ jne .Lloop_vstrs_nonzero_cc16
+ lcbb %r1,32(%r2),6 /* Next part of haystack. */
+ jo .Lloop_haystack_on_bb32
+ vl %v16,32(%r2)
+ vstrs %v20,%v16,%v18,%v19,0,2
+ jne .Lloop_vstrs_nonzero_cc32
+ lcbb %r1,48(%r2),6 /* Next part of haystack. */
+ jo .Lloop_haystack_on_bb48
+ vl %v16,48(%r2)
+ vstrs %v20,%v16,%v18,%v19,0,2
+ jne .Lloop_vstrs_nonzero_cc48
+ la %r2,64(%r2)
+ j .Lloop
+
+.Lloop_vstrs_nonzero_cc48:
+ la %r2,16(%r2)
+.Lloop_vstrs_nonzero_cc32:
+ la %r2,16(%r2)
+.Lloop_vstrs_nonzero_cc16:
+ la %r2,16(%r2)
+.Lloop_vstrs_nonzero_cc:
+ jh .Lend_match_found /* cc == 2 (full match) */
+ jl .Lend_no_match /* cc == 1 (no match, end of string) */
+ /* cc == 3 (partial match) See above: min-skip-partial-match-index! */
+ lcbb %r1,0(%r5,%r2),6
+ la %r2,0(%r5,%r2)
+ jo .Lloop_haystack_on_bb
+ vl %v16,0(%r2)
+ vstrs %v20,%v16,%v18,%v19,0,2
+.Lloop_vstrs_nonzero_cc_loop:
+ jh .Lend_match_found
+ jl .Lend_no_match
+ la %r2,0(%r5,%r2)
+ je .Lloop
+ lcbb %r1,0(%r2),6 /* Next part of haystack. */
+ jo .Lloop_haystack_on_bb
+ vl %v16,0(%r2)
+ vstrs %v20,%v16,%v18,%v19,0,2
+ jh .Lend_match_found
+ jl .Lend_no_match
+ la %r2,0(%r5,%r2)
+ je .Lloop
+ lcbb %r1,0(%r2),6 /* Next part of haystack. */
+ jo .Lloop_haystack_on_bb
+ vl %v16,0(%r2)
+ vstrs %v20,%v16,%v18,%v19,0,2
+ jh .Lend_match_found
+ jl .Lend_no_match
+ la %r2,0(%r5,%r2)
+ je .Lloop
+ lcbb %r1,0(%r2),6 /* Next part of haystack. */
+ jo .Lloop_haystack_on_bb
+ vl %v16,0(%r2)
+ vstrs %v20,%v16,%v18,%v19,0,2
+ j .Lloop_vstrs_nonzero_cc_loop
+
+.Lend_no_match:
+ lghi %r2,0
+ br %r14
+.Lend_match_found:
+ vlgvb %r4,%v20,7
+ la %r2,0(%r4,%r2)
+ br %r14
+
+.Lloop_haystack_on_bb48:
+ la %r2,16(%r2)
+.Lloop_haystack_on_bb32:
+ la %r2,16(%r2)
+.Lloop_haystack_on_bb16:
+ la %r2,16(%r2)
+.Lloop_haystack_on_bb:
+ /* Haystack located on page-boundary. */
+ ahi %r1,-1 /* vll needs highest index instead of count. */
+ vll %v16,%r1,0(%r2)
+ vlvgb %v21,%r1,7
+ vfenezb %v17,%v16,%v16 /* Search zero in loaded haystack bytes. */
+ veclb %v17,%v21 /* Zero index <= loaded byte index? */
+ jle .Lloop_haystack_loaded /* -> v16 contains full haystack. */
+ vl %v16,0(%r2) /* Load haystack beyond page boundary. */
+ j .Lloop_haystack_loaded
+
+.Lneedle_on_bb:
+ /* Needle located on page-boundary. */
+ ahi %r1,-1 /* vll needs highest index instead of count. */
+ vll %v18,%r1,0(%r3)
+ vlvgb %v21,%r1,7
+ vfenezb %v19,%v18,%v18 /* Search zero in loaded needle bytes. */
+ veclb %v19,%v21 /* Zero index <= max loaded byte index? */
+ jle .Lneedle_loaded /* -> v18 contains full needle. */
+ vl %v16,0(%r3) /* Load needle beyond page boundary. */
+ vfenezb %v19,%v18,%v18
+ j .Lneedle_loaded
+END(STRSTR_ARCH13)
+
+# if ! HAVE_STRSTR_IFUNC
+strong_alias (STRSTR_ARCH13, strstr)
+# endif
+
+# if STRSTR_Z13_ONLY_USED_AS_FALLBACK && defined SHARED && IS_IN (libc)
+strong_alias (STRSTR_ARCH13, __GI_strstr)
+# endif
+#endif
Index: glibc-2.26/sysdeps/s390/strstr-vx.c
===================================================================
--- glibc-2.26.orig/sysdeps/s390/strstr-vx.c
+++ glibc-2.26/sysdeps/s390/strstr-vx.c
@@ -19,11 +19,11 @@
#include <ifunc-strstr.h>
#if HAVE_STRSTR_Z13
-# if HAVE_STRSTR_IFUNC
+# if HAVE_STRSTR_IFUNC || STRSTR_Z13_ONLY_USED_AS_FALLBACK
# define STRSTR STRSTR_Z13
# if defined SHARED && IS_IN (libc)
# undef libc_hidden_builtin_def
-# if HAVE_STRSTR_C
+# if HAVE_STRSTR_C || STRSTR_Z13_ONLY_USED_AS_FALLBACK
# define libc_hidden_builtin_def(name)
# else
# define libc_hidden_builtin_def(name) \
Index: glibc-2.26/sysdeps/s390/strstr.c
===================================================================
--- glibc-2.26.orig/sysdeps/s390/strstr.c
+++ glibc-2.26/sysdeps/s390/strstr.c
@@ -32,8 +32,14 @@ extern __typeof (__redirect_strstr) STRS
extern __typeof (__redirect_strstr) STRSTR_Z13 attribute_hidden;
# endif
+# if HAVE_STRSTR_ARCH13
+extern __typeof (__redirect_strstr) STRSTR_ARCH13 attribute_hidden;
+# endif
+
s390_libc_ifunc_expr (__redirect_strstr, strstr,
- (HAVE_STRSTR_Z13 && (hwcap & HWCAP_S390_VX))
+ (HAVE_STRSTR_ARCH13 && (hwcap & HWCAP_S390_VXRS_EXT2))
+ ? STRSTR_ARCH13
+ : (HAVE_STRSTR_Z13 && (hwcap & HWCAP_S390_VX))
? STRSTR_Z13
: STRSTR_DEFAULT
)
