platform_bionic/libc/arch-riscv64/string/strnlen_v.S
Elliott Hughes aefe999d92 string/memory functions: avoid qemu bugs/performance issues.
Use V on real hardware, but GC on qemu.

Change-Id: I419546d94555540e14a14dcc52bd99413cbbcfa1
2023-11-15 15:49:57 -08:00

89 lines
3.6 KiB
ArmAsm

/*
* Copyright (C) 2023 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Copyright (c) 2023 SiFive, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the company may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY SIFIVE INC ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL SIFIVE INC BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <private/bionic_asm.h>
#define pStr a0
#define pCopyStr a2
#define iRetValue a0
#define iMaxlen a1
#define iCurrentVL a3
#define iEndOffset a4
#define ELEM_LMUL_SETTING m1
#define vStr v0
#define vMaskEnd v8
ENTRY(strnlen_v)
mv pCopyStr, pStr
mv iRetValue, iMaxlen
L(strnlen_loop):
beqz iMaxlen, L(end_strnlen_loop)
vsetvli zero, iMaxlen, e8, ELEM_LMUL_SETTING, ta, ma
vle8ff.v vStr, (pCopyStr)
vmseq.vi vMaskEnd, vStr, 0
vfirst.m iEndOffset, vMaskEnd /* first occurrence of \0 */
csrr iCurrentVL, vl
add pCopyStr, pCopyStr, iCurrentVL
sub iMaxlen, iMaxlen, iCurrentVL
bltz iEndOffset, L(strnlen_loop)
add iMaxlen, iMaxlen, iCurrentVL
sub iRetValue, iRetValue, iMaxlen
add iRetValue, iRetValue, iEndOffset
L(end_strnlen_loop):
ret
END(strnlen_v)