nuttx-update/libs/libc/machine/xtensa/arch_memcpy.S
anjiahao 603c87977f libc/machine:Add prefixes to libc functions implemented by arch
kasan does not instrument the assembly function,
so it is checked in advance before calling.
If Kasan is not turned on, the speed and space will
be almost unchanged under compiler optimization.

Signed-off-by: anjiahao <anjiahao@xiaomi.com>
2024-10-31 18:11:16 +08:00

286 lines
6.2 KiB
ArmAsm

/****************************************************************************
* libs/libc/machine/xtensa/arch_memcpy.S
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include "xtensa_asm.h"
#include <arch/chip/core-isa.h>
#include <arch/xtensa/xtensa_abi.h>
#include "libc.h"
#ifdef LIBC_BUILD_MEMCPY
/****************************************************************************
* Pre-processor Macros
****************************************************************************/
/* set to 1 when running on ISS (simulator) with the
lint or ferret client, or 0 to save a few cycles */
#define SIM_CHECKS_ALIGNMENT 0
/****************************************************************************
* Public Functions
****************************************************************************/
.section .text
.begin schedule
.literal_position
.local .Ldst1mod2
.local .Ldst2mod4
.local .Lbytecopy
.align 4
.global ARCH_LIBCFUN(memcpy)
.type ARCH_LIBCFUN(memcpy), @function
ARCH_LIBCFUN(memcpy):
ENTRY(16)
/* a2 = dst, a3 = src, a4 = len */
mov a5, a2 # copy dst so that a2 is return value
bbsi.l a2, 0, .Ldst1mod2
bbsi.l a2, 1, .Ldst2mod4
.Ldstaligned:
/* Get number of loop iterations with 16B per iteration. */
srli a7, a4, 4
/* Check if source is aligned. */
slli a8, a3, 30
bnez a8, .Lsrcunaligned
/* Destination and source are word-aligned, use word copy. */
#if XCHAL_HAVE_LOOPS
loopnez a7, 2f
#else
beqz a7, 2f
slli a8, a7, 4
add a8, a8, a3 # a8 = end of last 16B source chunk
#endif
1: l32i a6, a3, 0
l32i a7, a3, 4
s32i a6, a5, 0
l32i a6, a3, 8
s32i a7, a5, 4
l32i a7, a3, 12
s32i a6, a5, 8
addi a3, a3, 16
s32i a7, a5, 12
addi a5, a5, 16
#if !XCHAL_HAVE_LOOPS
bltu a3, a8, 1b
#endif
/* Copy any leftover pieces smaller than 16B. */
2: bbci.l a4, 3, 3f
/* Copy 8 bytes. */
l32i a6, a3, 0
l32i a7, a3, 4
addi a3, a3, 8
s32i a6, a5, 0
s32i a7, a5, 4
addi a5, a5, 8
3: bbsi.l a4, 2, 4f
bbsi.l a4, 1, 5f
bbsi.l a4, 0, 6f
RET(16)
# .align 4
/* Copy 4 bytes. */
4: l32i a6, a3, 0
addi a3, a3, 4
s32i a6, a5, 0
addi a5, a5, 4
bbsi.l a4, 1, 5f
bbsi.l a4, 0, 6f
RET(16)
/* Copy 2 bytes. */
5: l16ui a6, a3, 0
addi a3, a3, 2
s16i a6, a5, 0
addi a5, a5, 2
bbsi.l a4, 0, 6f
RET(16)
/* Copy 1 byte. */
6: l8ui a6, a3, 0
s8i a6, a5, 0
.Ldone:
RET(16)
/* Destination is aligned; source is unaligned. */
# .align 4
.Lsrcunaligned:
/* Avoid loading anything for zero-length copies. */
beqz a4, .Ldone
/* Copy 16 bytes per iteration for word-aligned dst and
unaligned src. */
ssa8 a3 # set shift amount from byte offset
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT
srli a11, a8, 30 # save unalignment offset for below
sub a3, a3, a11 # align a3
#endif
l32i a6, a3, 0 # load first word
#if XCHAL_HAVE_LOOPS
loopnez a7, 2f
#else
beqz a7, 2f
slli a10, a7, 4
add a10, a10, a3 # a10 = end of last 16B source chunk
#endif
1: l32i a7, a3, 4
l32i a8, a3, 8
src_b a6, a6, a7
s32i a6, a5, 0
l32i a9, a3, 12
src_b a7, a7, a8
s32i a7, a5, 4
l32i a6, a3, 16
src_b a8, a8, a9
s32i a8, a5, 8
addi a3, a3, 16
src_b a9, a9, a6
s32i a9, a5, 12
addi a5, a5, 16
#if !XCHAL_HAVE_LOOPS
bltu a3, a10, 1b
#endif
2: bbci.l a4, 3, 3f
/* Copy 8 bytes. */
l32i a7, a3, 4
l32i a8, a3, 8
src_b a6, a6, a7
s32i a6, a5, 0
addi a3, a3, 8
src_b a7, a7, a8
s32i a7, a5, 4
addi a5, a5, 8
mov a6, a8
3: bbci.l a4, 2, 4f
/* Copy 4 bytes. */
l32i a7, a3, 4
addi a3, a3, 4
src_b a6, a6, a7
s32i a6, a5, 0
addi a5, a5, 4
mov a6, a7
4:
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT
add a3, a3, a11 # readjust a3 with correct misalignment
#endif
bbsi.l a4, 1, 5f
bbsi.l a4, 0, 6f
RET(16)
/* Copy 2 bytes. */
5: l8ui a6, a3, 0
l8ui a7, a3, 1
addi a3, a3, 2
s8i a6, a5, 0
s8i a7, a5, 1
addi a5, a5, 2
bbsi.l a4, 0, 6f
RET(16)
/* Copy 1 byte. */
6: l8ui a6, a3, 0
s8i a6, a5, 0
RET(16)
# .align XCHAL_INST_FETCH_WIDTH
__memcpy_aux:
/* Skip bytes to get proper alignment for three-byte loop */
# .skip XCHAL_INST_FETCH_WIDTH - 3
.Lbytecopy:
#if XCHAL_HAVE_LOOPS
loopnez a4, 2f
#else
beqz a4, 2f
add a7, a3, a4 # a7 = end address for source
#endif
1: l8ui a6, a3, 0
addi a3, a3, 1
s8i a6, a5, 0
addi a5, a5, 1
#if !XCHAL_HAVE_LOOPS
bltu a3, a7, 1b
#endif
2: RET(16)
/* Destination is unaligned. */
# .align 4
.Ldst1mod2: # dst is only byte aligned
/* Do short copies byte-by-byte. */
bltui a4, 7, .Lbytecopy
/* Copy 1 byte. */
l8ui a6, a3, 0
addi a3, a3, 1
addi a4, a4, -1
s8i a6, a5, 0
addi a5, a5, 1
/* Return to main algorithm if dst is now aligned. */
bbci.l a5, 1, .Ldstaligned
.Ldst2mod4: # dst has 16-bit alignment
/* Do short copies byte-by-byte. */
bltui a4, 6, .Lbytecopy
/* Copy 2 bytes. */
l8ui a6, a3, 0
l8ui a7, a3, 1
addi a3, a3, 2
addi a4, a4, -2
s8i a6, a5, 0
s8i a7, a5, 1
addi a5, a5, 2
/* dst is now aligned; return to main algorithm. */
j .Ldstaligned
.end schedule
.size ARCH_LIBCFUN(memcpy), . - ARCH_LIBCFUN(memcpy)
#endif