From patchwork Fri May 2 19:11:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: R Vidya X-Patchwork-Id: 794 Return-Path: X-Original-To: siddhesh@wilcox.dreamhost.com Delivered-To: siddhesh@wilcox.dreamhost.com Received: from homiemail-mx20.g.dreamhost.com (mx2.sub5.homie.mail.dreamhost.com [208.113.200.128]) by wilcox.dreamhost.com (Postfix) with ESMTP id 75AFA360DF3 for ; Fri, 2 May 2014 12:11:15 -0700 (PDT) Received: by homiemail-mx20.g.dreamhost.com (Postfix, from userid 14307373) id 2253341527C03; Fri, 2 May 2014 12:11:15 -0700 (PDT) X-Original-To: glibc@patchwork.siddhesh.in Delivered-To: x14307373@homiemail-mx20.g.dreamhost.com Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by homiemail-mx20.g.dreamhost.com (Postfix) with ESMTPS id DED5C41527CCA for ; Fri, 2 May 2014 12:11:14 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:date:message-id; q=dns; s= default; b=KwAu1ecelgwXpG86jjPR1OACHAuPEkyHoyYqBXFqtNjMLhOFxFi26 Rldvb+kXAh5b9svDGQxfEQFaq8hPwb4GulI4l3YEVfLs73fqEIdP/sVTKTJFUgvg 3VTelXl1tHCiH2VTDghGDC0oslLEjDEXKl4Gkf8DRp9VFlkaONKaLE= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:date:message-id; s=default; bh=T0H/drOnNajpoUC4IvRdRax/GTY=; b=Fz3Fo+jOvOp/eCzLDHDHfs/dIZy3 IfA9MNk4KgbiUQSHrrAYiYe9czQY+oQ8/t0Xw4MlloxC4eCDJ1Nky5vgCg6k1oc9 1ybnXf3KH+32OfalLGFEgFIh7RjaeNRO6ay+FCZGSuSQAq9awiET/k/O2DSnGo+E zPvJt0ywbshGLlM= Received: (qmail 9768 invoked by alias); 2 May 2014 19:11:12 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 9756 invoked by uid 89); 2 May 2014 19:11:12 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL, BAYES_00, RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: e28smtp09.in.ibm.com From: vidya@linux.vnet.ibm.com To: libc-alpha@sourceware.org Cc: Vidya Ranganathan Subject: [PATCH] Optimization for strncpy and stpncpy on Power7 Date: Fri, 2 May 2014 15:11:05 -0400 Message-Id: <1399057865-9822-1-git-send-email-vidya@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14050219-2674-0000-0000-00000E1756D5 X-DH-Original-To: glibc@patchwork.siddhesh.in From: Vidya Ranganathan The optimization is achieved by following techniques: > data alignment [gain from aligned memory access on read/write] > prefetch data [gain from cache misses by anticipating load] > POWER7 gains performance with loop unrolling/unwinding [gain by reduction of branch penalty]. ChangeLog: 2014-04-27 Vidya Ranganathan * sysdeps/powerpc/powerpc64/power7/strncpy.S: New file: Optimization. * sysdeps/powerpc/powerpc64/multiarch/strncpy.c: New file: multiarch strncpy for PPC64. * sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c: New file * sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S: New file * sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strpcpy, stpncpy multiarch optimizations. * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c: (__libc_ifunc_impl_list): Likewise. * sysdeps/powerpc/powerpc64/power7/stpncpy.S: New file: Optimization. * sysdeps/powerpc/powerpc64/multiarch/stpncpy.c: New file: multiarch stpncpy for PPC64. * sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c: New file * sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S: New file Signed-off-by: Vidya Ranganathan --- sysdeps/powerpc/powerpc64/multiarch/Makefile | 3 +- .../powerpc/powerpc64/multiarch/ifunc-impl-list.c | 16 + .../powerpc/powerpc64/multiarch/stpncpy-power7.S | 44 +++ .../powerpc/powerpc64/multiarch/stpncpy-ppc64.c | 26 ++ sysdeps/powerpc/powerpc64/multiarch/stpncpy.c | 33 ++ .../powerpc/powerpc64/multiarch/strncpy-power7.S | 42 +++ .../powerpc/powerpc64/multiarch/strncpy-ppc64.c | 33 ++ sysdeps/powerpc/powerpc64/multiarch/strncpy.c | 35 +++ sysdeps/powerpc/powerpc64/power7/stpncpy.S | 24 ++ sysdeps/powerpc/powerpc64/power7/strncpy.S | 340 +++++++++++++++++++++ 10 files changed, 595 insertions(+), 1 deletion(-) create mode 100644 sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S create mode 100644 sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c create mode 100644 sysdeps/powerpc/powerpc64/multiarch/stpncpy.c create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strncpy.c create mode 100644 sysdeps/powerpc/powerpc64/power7/stpncpy.S create mode 100644 sysdeps/powerpc/powerpc64/power7/strncpy.S diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile index 8d367aa..35020a7 100644 --- a/sysdeps/powerpc/powerpc64/multiarch/Makefile +++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile @@ -16,7 +16,8 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \ strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \ strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \ strspn-power7 strspn-ppc64 strcspn-power7 strcspn-ppc64 \ - strpbrk-power7 strpbrk-ppc64 + strpbrk-power7 strpbrk-ppc64 strncpy-power7 strncpy-ppc64 \ + stpncpy-power7 stpncpy-ppc64 CFLAGS-strncase-power7.c += -mcpu=power7 -funroll-loops CFLAGS-strncase_l-power7.c += -mcpu=power7 -funroll-loops diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c index 91fabb0..d8578fb 100644 --- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c +++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c @@ -278,5 +278,21 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL_ADD (array, i, strpbrk, 1, __strpbrk_ppc)) + /* Support sysdeps/powerpc/powerpc64/multiarch/strncpy.c. */ + IFUNC_IMPL (i, name, strncpy, + IFUNC_IMPL_ADD (array, i, strncpy, + hwcap & PPC_FEATURE_HAS_VSX, + __strncpy_power7) + IFUNC_IMPL_ADD (array, i, strncpy, 1, + __strncpy_ppc)) + + /* Support sysdeps/powerpc/powerpc64/multiarch/stpncpy.c. */ + IFUNC_IMPL (i, name, stpncpy, + IFUNC_IMPL_ADD (array, i, stpncpy, + hwcap & PPC_FEATURE_HAS_VSX, + __stpncpy_power7) + IFUNC_IMPL_ADD (array, i, stpncpy, 1, + __stpncpy_ppc)) + return i; } diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S new file mode 100644 index 0000000..e29674f --- /dev/null +++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S @@ -0,0 +1,44 @@ +/* Optimized stpncpy implementation for POWER7. + Copyright (C) 2014 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 + . */ + +#include + +#define USE_AS_STPNCPY + +#undef EALIGN +#define EALIGN(name, alignt, words) \ + .section ".text"; \ + ENTRY_2(__stpncpy_power7) \ + .align ALIGNARG(alignt); \ + EALIGN_W_##words; \ + BODY_LABEL(__stpncpy_power7): \ + cfi_startproc; \ + LOCALENTRY(__stpncpy_power7) + +#undef END +#define END(name) \ + cfi_endproc; \ + TRACEBACK(__stpncpy_power7) \ + END_2(__stpncpy_power7) + +#undef libc_hidden_builtin_def +#define libc_hidden_builtin_def(name) + +#define MEMSET __memset_power7 + +#include diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c new file mode 100644 index 0000000..74f47a7 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-ppc64.c @@ -0,0 +1,26 @@ +/* Default stpncpy implementation for PowerPC64. + Copyright (C) 2014 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 + . */ + +#define STPNCPY __stpncpy_ppc +#ifdef SHARED +#undef libc_hidden_def +#define libc_hidden_def(name) \ + __hidden_ver1 (__stpncpy_ppc, __GI___stpncpy, __stpncpy_ppc); +#endif + +#include diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c b/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c new file mode 100644 index 0000000..dbf8521 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c @@ -0,0 +1,33 @@ +/* Multiple versions of stpncpy. PowerPC64 version. + Copyright (C) 2014 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 + . */ + +#ifndef NOT_IN_libc +# include +# include +# include "init-arch.h" + +extern __typeof (__stpncpy) __stpncpy_ppc attribute_hidden; +extern __typeof (__stpncpy) __stpncpy_power7 attribute_hidden; + +libc_ifunc (__stpncpy, + (hwcap & PPC_FEATURE_HAS_VSX) + ? __stpncpy_power7 + : __stpncpy_ppc); + +weak_alias (__stpncpy, stpncpy) +#endif diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S new file mode 100644 index 0000000..be349f9 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S @@ -0,0 +1,42 @@ +/* Optimized strncpy implementation for POWER7. + Copyright (C) 2014 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 + . */ + +#include + +#undef EALIGN +#define EALIGN(name, alignt, words) \ + .section ".text"; \ + ENTRY_2(__strncpy_power7) \ + .align ALIGNARG(alignt); \ + EALIGN_W_##words; \ + BODY_LABEL(__strncpy_power7): \ + cfi_startproc; \ + LOCALENTRY(__strncpy_power7) + +#undef END +#define END(name) \ + cfi_endproc; \ + TRACEBACK(__strncpy_power7) \ + END_2(__strncpy_power7) + +#undef libc_hidden_builtin_def +#define libc_hidden_builtin_def(name) + +#define MEMSET __memset_power7 + +#include diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c new file mode 100644 index 0000000..e3111d2 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/multiarch/strncpy-ppc64.c @@ -0,0 +1,33 @@ +/* Copyright (C) 2014 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 + . */ + +#include + +#define STRNCPY __strncpy_ppc +#undef weak_alias +#define weak_alias(name, aliasname) \ + extern __typeof (__strncpy_ppc) aliasname \ + __attribute__ ((weak, alias ("__strncpy_ppc"))); +#if !defined(NOT_IN_libc) && defined(SHARED) +# undef libc_hidden_builtin_def +# define libc_hidden_builtin_def(name) \ + __hidden_ver1(__strncpy_ppc, __GI_strncpy, __strncpy_ppc); +#endif + +extern __typeof (strncpy) __strncpy_ppc attribute_hidden; + +#include diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncpy.c b/sysdeps/powerpc/powerpc64/multiarch/strncpy.c new file mode 100644 index 0000000..818aba8 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/multiarch/strncpy.c @@ -0,0 +1,35 @@ +/* Multiple versions of strncpy. + Copyright (C) 2014 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 + . */ + +/* Define multiple versions only for definition in libc. */ +#ifndef NOT_IN_libc +# include +# include +# include "init-arch.h" + +extern __typeof (strncpy) __strncpy_ppc attribute_hidden; +extern __typeof (strncpy) __strncpy_power7 attribute_hidden; + +/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle + ifunc symbol properly. */ +libc_ifunc (strncpy, + (hwcap & PPC_FEATURE_HAS_VSX) + ? __strncpy_power7 + : __strncpy_ppc); + +#endif diff --git a/sysdeps/powerpc/powerpc64/power7/stpncpy.S b/sysdeps/powerpc/powerpc64/power7/stpncpy.S new file mode 100644 index 0000000..a539093 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/power7/stpncpy.S @@ -0,0 +1,24 @@ +/* Optimized stpncpy implementation for PowerPC64/POWER7. + Copyright (C) 2014 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 + . */ + +#define USE_AS_STPNCPY +#include + +weak_alias (__stpncpy, stpncpy) +libc_hidden_def (__stpncpy) +libc_hidden_builtin_def (stpncpy) diff --git a/sysdeps/powerpc/powerpc64/power7/strncpy.S b/sysdeps/powerpc/powerpc64/power7/strncpy.S new file mode 100644 index 0000000..dd28088 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/power7/strncpy.S @@ -0,0 +1,340 @@ +/* Copyright (C) 2014 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 + . */ + +#include + +/* Implements the functions + + char * [r3] strncpy (char *dst [r3], const char *src [r4], size_t n [r5]) + + AND + + char * [r3] stpncpy (char *dst [r3], const char *src [r4], size_t n [r5]) + + The algorithm is as follows: + > if src and dest are 8 byte aligned, perform double word copy + else + > copy byte by byte on unaligned addresses. + + The aligned comparison are made using cmpb instructions. */ + +/* The focus on optimization for performance improvements are as follows: + 1. data alignment [gain from aligned memory access on read/write] + 2. prefetch data [gain from cache misses by anticipating load] + 3. POWER7 gains performance with loop unrolling/unwinding + [gain by reduction of branch penalty]. */ + +#ifdef USE_AS_STPNCPY +# define FUNC_NAME __stpncpy +#else +# define FUNC_NAME strncpy +#endif + +#define FRAMESIZE (FRAME_MIN_SIZE+32) + +#ifndef MEMSET +/* For builds with no IFUNC support, local calls should be made to internal + GLIBC symbol (created by libc_hidden_builtin_def). */ +# ifdef SHARED +# define MEMSET __GI_memset +# else +# define MEMSET memset +# endif +#endif + + .machine power7 +EALIGN(FUNC_NAME, 4, 0) + CALL_MCOUNT 3 + + dcbt 0, r3 /* CPU pre-fetch dst to avoid cache miss */ + dcbt 0, r4 /* CPU pre-fetch src to avoid cache miss */ + + mflr r0 /* load link register LR to r0 */ + or r10, r3, r4 /* to verify source and destination */ + rldicl. r8, r10, 0, 61 /* is double word aligned .. ? */ + + std r19, -8(r1) /* save callers register , r19 */ + std r18, -16(r1) /* save callers register , r18 */ + std r0, 16(r1) /* store the link register */ + stdu r1, -FRAMESIZE(r1) /* create the stack frame */ + + mr r9, r3 /* save r3 into r9 for use */ + mr r18, r3 /* save r3 for retCode of strncpy */ + bne 0, L(byte_by_byte) + + + srdi r11, r5, 3 /* compute count for CTR ; count = n/8 */ + cmpldi cr7, r11, 3 /* if count > 4 ; perform unrolling 4 times */ + ble 7, L(update1) + + ld r10, 0(r4) /* load doubleWord from src */ + cmpb r8, r10, r8 /* compare src with NULL ,we read just now */ + cmpdi cr7, r8, 0 /* if cmpb returned NULL ; we continue */ + bne cr7, L(update3) + + std r10, 0(r3) /* copy doubleword at offset=0 */ + ld r10, 8(r4) /* load next doubleword from offset=8 */ + cmpb r8, r10, r8 /* compare src with NULL , we read just now */ + cmpdi cr7, r8, 0 /* if cmpb returned NULL ; we continue */ + bne 7,L(HopBy8) + + addi r8, r11, -4 + mr r7, r3 + srdi r8, r8, 2 + mr r6, r4 + addi r8, r8, 1 + li r12, 0 + mtctr r8 + b L(dwordCopy) + + .p2align 4 +L(dWordUnroll): + std r8, 16(r9) + ld r8, 24(r4) /* load dword,perform loop unrolling again */ + cmpb r10, r8, r10 + cmpdi cr7, r10, 0 + bne cr7, L(HopBy24) + + std r8, 24(r7) /* copy dword at offset=24 */ + addi r9, r9, 32 + addi r4, r4, 32 + bdz L(leftDwords) /* continue with loop on counter */ + + ld r3, 32(r6) + cmpb r8, r3, r10 + cmpdi cr7, r8, 0 + bne cr7, L(update2) + + std r3, 32(r7) + ld r10, 40(r6) + cmpb r8, r10, r8 + cmpdi cr7, r8, 0 + bne cr7, L(HopBy40) + + mr r6, r4 /* update values */ + mr r7, r9 + mr r11, r0 + mr r5, r19 + +L(dwordCopy): + std r10, 8(r9) /* copy dword at offset=8 */ + addi r19, r5, -32 + addi r0, r11, -4 + ld r8, 16(r4) + cmpb r10, r8, r12 + cmpdi cr7, r10, 0 + beq cr7, L(dWordUnroll) + + addi r9, r9, 16 /* increment dst by 16 */ + addi r4, r4, 16 /* increment src by 16 */ + addi r5, r5, -16 /* decrement length 'n' by 16 */ + addi r0, r11, -2 /* decrement loop counter */ + +L(dWordUnrollOFF): + ld r10, 0(r4) /* load first dword */ + li r8, 0 /* load mask */ + cmpb r8, r10, r8 + cmpdi cr7, r8, 0 + bne cr7, L(byte_by_byte) + mtctr r0 + li r7, 0 + b L(CopyDword) + + .p2align 4 +L(loadDWordandCompare): + ld r10, 0(r4) + cmpb r8, r10, r7 + cmpdi cr7, r8, 0 + bne cr7, L(byte_by_byte) + +L(CopyDword): + addi r9, r9, 8 + std r10, -8(r9) + addi r4, r4, 8 + addi r5, r5, -8 + bdnz L(loadDWordandCompare) + +L(byte_by_byte): + cmpldi cr7, r5, 3 + ble cr7, L(verifyByte) + srdi r10, r5, 2 + mr r19, r9 + mtctr r10 + b L(firstByteUnroll) + + .p2align 4 +L(bytes_unroll): + lbz r10, 1(r4) /* load byte from src */ + cmpdi cr7, r10, 0 /* compare for NULL */ + stb r10, 1(r19) /* store byte to dst */ + beq cr7, L(updtDestComputeN2ndByte) + + addi r4, r4, 4 /* advance src */ + + lbz r10, -2(r4) /* perform loop unrolling for byte r/w */ + cmpdi cr7, r10, 0 + stb r10, 2(r19) + beq cr7, L(updtDestComputeN3rdByte) + + lbz r10, -1(r4) /* perform loop unrolling for byte r/w */ + addi r19, r19, 4 + cmpdi cr7, r10, 0 + stb r10, -1(r19) + beq cr7, L(ComputeNByte) + + bdz L(update0) + +L(firstByteUnroll): + lbz r10, 0(r4) /* perform loop unrolling for byte r/w */ + cmpdi cr7, 10, 0 + stb r10, 0(r19) + bne cr7, L(bytes_unroll) + addi r19, r19, 1 + +L(ComputeNByte): + subf r9, r19, r9 /* compute 'n'n bytes to fill */ + add r8, r9, r5 + +L(zeroFill): + cmpdi cr7, r8, 0 /* compare if length is zero */ + beq cr7, L(update3return) + + mr r3, r19 /* fill buffer with */ + li r4, 0 /* zero fill buffer */ + mr r5, r8 /* how many bytes to fill buffer with */ + bl MEMSET /* call optimized memset */ + nop /* trigger CPU activity */ + +L(update3return): +#ifdef USE_AS_STPNCPY + addi r3, r19, -1 /* update return value */ +#endif + +L(hop2return): +#ifndef USE_AS_STPNCPY + mr r3, r18 /* set return value */ +#endif + addi r1, r1, FRAMESIZE /* restore stack pointer */ + ld r0, 16(r1) /* read the saved link register */ + ld r18, -16(r1) /* restore callers save register, r18 */ + ld r19, -8(r1) /* restore callers save register, r19 */ + mtlr r0 /* branch to link register */ + blr /* return */ + + .p2align 4 +L(update0): + mr r9, r19 + + .p2align 4 +L(verifyByte): + rldicl. r8, r5, 0, 62 +#ifdef USE_AS_STPNCPY + mr r3, r9 +#endif + beq cr0, L(hop2return) + mtctr r8 + addi r4, r4, -1 + mr r19, r9 + b L(oneBYone) + + .p2align 4 +L(proceed): + bdz L(done) + +L(oneBYone): + lbzu r10, 1(r4) /* copy byte */ + addi r19, r19, 1 + addi r8, r8, -1 + cmpdi cr7, r10, 0 + stb r10, -1(r19) + bne cr7, L(proceed) + b L(zeroFill) + + .p2align 4 +L(done): + addi r1, r1, FRAMESIZE /* restore stack pointer */ +#ifdef USE_AS_STPNCPY + mr r3, r19 /* set the return value */ +#else + mr r3, r18 /* set the return value */ +#endif + ld r0, 16(r1) /* read the saved link register */ + ld r18, -16(r1) /* restore callers save register, r18 */ + ld r19, -8(r1) /* restore callers save register, r19 */ + mtlr r0 /* branch to link register */ + blr /* return */ + +L(update1): + mr r0, r11 + mr r19, r5 + + .p2align 4 +L(leftDwords): + cmpdi cr7, r0, 0 + mr r5, r19 + bne cr7, L(dWordUnrollOFF) + b L(byte_by_byte) + + .p2align 4 +L(updtDestComputeN2ndByte): + addi r19, r19, 2 /* update dst by 2 */ + subf r9, r19, r9 /* compute distance covered */ + add r8, r9, r5 + b L(zeroFill) + + .p2align 4 +L(updtDestComputeN3rdByte): + addi r19, r19, 3 /* update dst by 3 */ + subf r9, r19, r9 /* compute distance covered */ + add r8, r9, r5 + b L(zeroFill) + + .p2align 4 +L(HopBy24): + addi r9, r9, 24 /* increment dst by 24 */ + addi r4, r4, 24 /* increment src by 24 */ + addi r5, r5, -24 /* decrement length 'n' by 24 */ + addi r0, r11, -3 /* decrement loop counter */ + b L(dWordUnrollOFF) + + .p2align 4 +L(update2): + mr r5, r19 + b L(dWordUnrollOFF) + + .p2align 4 +L(HopBy40): + addi r9, r7, 40 /* increment dst by 40 */ + addi r4, r6, 40 /* increment src by 40 */ + addi r5, r5, -40 /* decrement length 'n' by 40 */ + addi r0, r11, -5 /* decrement loop counter */ + b L(dWordUnrollOFF) + +L(update3): + mr r0, r11 + b L(dWordUnrollOFF) + +L(HopBy8): + addi r9, r3, 8 /* increment dst by 8 */ + addi r4, r4, 8 /* increment src by 8 */ + addi r5, r5, -8 /* decrement length 'n' by 8 */ + addi r0, r11, -1 /* decrement loop counter */ + b L(dWordUnrollOFF) +END(FUNC_NAME) +#ifndef USE_AS_STPNCPY +libc_hidden_builtin_def (strncpy) +#endif