newlib-cygwin/newlib/libc/machine/xtensa/strcpy.S

275 lines
6.5 KiB
ArmAsm

/* ANSI C standard library function strcpy.
Copyright (c) 2001-2008 Tensilica Inc.
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
#include "xtensa-asm.h"
.text
.begin schedule
.align 4
.literal_position
.global strcpy
.type strcpy, @function
strcpy:
leaf_entry sp, 16
/* a2 = dst, a3 = src */
mov a10, a2 // leave dst in return value register
movi a4, MASK0
movi a5, MASK1
movi a6, MASK2
movi a7, MASK3
bbsi.l a3, 0, .Lsrc1mod2
bbsi.l a3, 1, .Lsrc2mod4
.Lsrcaligned:
/* Check if the destination is aligned. */
movi a8, 3
bnone a10, a8, .Laligned
j .Ldstunaligned
.Lsrc1mod2: // src address is odd
l8ui a8, a3, 0 // get byte 0
addi a3, a3, 1 // advance src pointer
s8i a8, a10, 0 // store byte 0
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
beqz a8, 1f // if byte 0 is zero
addi a10, a10, 1 // advance dst pointer
bbci.l a3, 1, .Lsrcaligned // if src is now word-aligned
.Lsrc2mod4: // src address is 2 mod 4
l8ui a8, a3, 0 // get byte 0
/* 1-cycle interlock */
s8i a8, a10, 0 // store byte 0
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
beqz a8, 1f // if byte 0 is zero
l8ui a8, a3, 1 // get byte 0
addi a3, a3, 2 // advance src pointer
s8i a8, a10, 1 // store byte 0
addi a10, a10, 2 // advance dst pointer
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
bnez a8, .Lsrcaligned
1: leaf_return
/* dst is word-aligned; src is word-aligned. */
.align 4
#if XCHAL_HAVE_LOOPS
#if XCHAL_HAVE_DENSITY
/* (2 mod 4) alignment for loop instruction */
#else
/* (1 mod 4) alignment for loop instruction */
.byte 0
.byte 0
#endif
.Laligned:
#if XCHAL_HAVE_DENSITY
_movi.n a8, 0 // set up for the maximum loop count
#else
_movi a8, 0 // set up for the maximum loop count
#endif
loop a8, .Lz3 // loop forever (almost anyway)
l32i a8, a3, 0 // get word from src
addi a3, a3, 4 // advance src pointer
bnone a8, a4, .Lz0 // if byte 0 is zero
bnone a8, a5, .Lz1 // if byte 1 is zero
bnone a8, a6, .Lz2 // if byte 2 is zero
s32i a8, a10, 0 // store word to dst
#if XTENSA_ESP32_PSRAM_CACHE_FIX
l32i a8, a10, 0
s32i a8, a10, 0
#endif
bnone a8, a7, .Lz3 // if byte 3 is zero
addi a10, a10, 4 // advance dst pointer
#else /* !XCHAL_HAVE_LOOPS */
1: addi a10, a10, 4 // advance dst pointer
.Laligned:
l32i a8, a3, 0 // get word from src
addi a3, a3, 4 // advance src pointer
bnone a8, a4, .Lz0 // if byte 0 is zero
bnone a8, a5, .Lz1 // if byte 1 is zero
bnone a8, a6, .Lz2 // if byte 2 is zero
s32i a8, a10, 0 // store word to dst
#if XTENSA_ESP32_PSRAM_CACHE_FIX
l32i a8, a10, 0
s32i a8, a10, 0
#endif
bany a8, a7, 1b // if byte 3 is zero
#endif /* !XCHAL_HAVE_LOOPS */
.Lz3: /* Byte 3 is zero. */
leaf_return
.Lz0: /* Byte 0 is zero. */
#ifdef __XTENSA_EB__
movi a8, 0
#endif
s8i a8, a10, 0
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
leaf_return
.Lz1: /* Byte 1 is zero. */
#ifdef __XTENSA_EB__
extui a8, a8, 16, 16
#endif
s16i a8, a10, 0
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
leaf_return
.Lz2: /* Byte 2 is zero. */
#ifdef __XTENSA_EB__
extui a8, a8, 16, 16
#endif
s16i a8, a10, 0
movi a8, 0
s8i a8, a10, 2
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
leaf_return
#if 1
/* For now just use byte copy loop for the unaligned destination case. */
.align 4
#if XCHAL_HAVE_LOOPS
#if XCHAL_HAVE_DENSITY
/* (2 mod 4) alignment for loop instruction */
#else
/* (1 mod 4) alignment for loop instruction */
.byte 0
.byte 0
#endif
#endif
.Ldstunaligned:
#if XCHAL_HAVE_LOOPS
#if XCHAL_HAVE_DENSITY
_movi.n a8, 0 // set up for the maximum loop count
#else
_movi a8, 0 // set up for the maximum loop count
#endif
loop a8, 2f // loop forever (almost anyway)
#endif
1: l8ui a8, a3, 0
addi a3, a3, 1
s8i a8, a10, 0
addi a10, a10, 1
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
#if XCHAL_HAVE_LOOPS
beqz a8, 2f
#else
bnez a8, 1b
#endif
2: leaf_return
#else /* 0 */
/* This code is not functional yet. */
.Ldstunaligned:
l32i a9, a2, 0 // load word from dst
#ifdef __XTENSA_EB__
ssa8b a9 // rotate by dst alignment so that
src a9, a9, a9 // shift in loop will put back in place
ssa8l a9 // shift left by byte*8
#else
ssa8l a9 // rotate by dst alignment so that
src a9, a9, a9 // shift in loop will put back in place
ssa8b a9 // shift left by 32-byte*8
#endif
/* dst is word-aligned; src is unaligned. */
.Ldstunalignedloop:
l32i a8, a3, 0 // get word from src
/* 1-cycle interlock */
bnone a8, a4, .Lu0 // if byte 0 is zero
bnone a8, a5, .Lu1 // if byte 1 is zero
bnone a8, a6, .Lu2 // if byte 2 is zero
src a9, a8, a9 // combine last word and this word
s32i a9, a10, 0 // store word to dst
bnone a8, a7, .Lu3 // if byte 3 is nonzero, iterate
l32i a9, a3, 4 // get word from src
addi a3, a3, 8 // advance src pointer
bnone a9, a4, .Lu4 // if byte 0 is zero
bnone a9, a5, .Lu5 // if byte 1 is zero
bnone a9, a6, .Lu6 // if byte 2 is zero
src a8, a9, a8 // combine last word and this word
s32i a8, a10, 4 // store word to dst
addi a10, a10, 8 // advance dst pointer
bany a8, a7, .Ldstunalignedloop // if byte 3 is nonzero, iterate
/* Byte 7 is zero. */
.Lu7: leaf_return
.Lu0: /* Byte 0 is zero. */
#ifdef __XTENSA_EB__
movi a8, 0
#endif
s8i a8, a10, 0
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
leaf_return
.Lu1: /* Byte 1 is zero. */
#ifdef __XTENSA_EB__
extui a8, a8, 16, 16
#endif
s16i a8, a10, 0
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
leaf_return
.Lu2: /* Byte 2 is zero. */
s16i a8, a10, 0
movi a8, 0
s8i a8, a10, 2
#if XTENSA_ESP32_PSRAM_CACHE_FIX
memw
#endif
leaf_return
#endif /* 0 */
.end schedule
.size strcpy, . - strcpy