/*
* Copyright (c) 2009
* MIPS Technologies, Inc., California.
*
* 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. Neither the name of the MIPS Technologies, Inc., nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, 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 THE MIPS TECHNOLOGIES, 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.
*/
/************************************************************************
*
* memcpy.S
* Version: "043009"
*
************************************************************************/
/************************************************************************
* Include files
************************************************************************/
#include "machine/asm.h"
/*
* This routine could be optimized for MIPS64. The current code only
* uses MIPS32 instructions.
*/
#if defined(__MIPSEB__)
# define LWHI lwl /* high part is left in big-endian */
# define SWHI swl /* high part is left in big-endian */
# define LWLO lwr /* low part is right in big-endian */
# define SWLO swr /* low part is right in big-endian */
#endif
#if defined(__MIPSEL__)
# define LWHI lwr /* high part is right in little-endian */
# define SWHI swr /* high part is right in little-endian */
# define LWLO lwl /* low part is left in big-endian */
# define SWLO swl /* low part is left in big-endian */
#endif
LEAF(memcpy,0)
.set noreorder
.set noat
/*
* Below we handle the case where memcpy is called with overlapping src and dst.
* Although memcpy is not required to handle this case, some parts of Android like Skia
* rely on such usage. We call memmove to handle such cases.
*/
subu t0,a0,a1
sra AT,t0,31
xor t1,t0,AT
subu t0,t1,AT
sltu AT,t0,a2
beq AT,zero,.Lmemcpy
la t9,memmove
jr t9
nop
.Lmemcpy:
slti AT,a2,8
bne AT,zero,.Llast8
move v0,a0 # memcpy returns the dst pointer
# Test if the src and dst are word-aligned, or can be made word-aligned
xor t8,a1,a0
andi t8,t8,0x3 # t8 is a0/a1 word-displacement
bne t8,zero,.Lunaligned
negu a3,a0
andi a3,a3,0x3 # we need to copy a3 bytes to make a0/a1 aligned
beq a3,zero,.Lchk16w # when a3=0 then the dst (a0) is word-aligned
subu a2,a2,a3 # now a2 is the remining bytes count
LWHI t8,0(a1)
addu a1,a1,a3
SWHI t8,0(a0)
addu a0,a0,a3
# Now the dst/src are mutually word-aligned with word-aligned addresses
.Lchk16w:
andi t8,a2,0x3f # any whole 64-byte chunks?
# t8 is the byte count after 64-byte chunks
beq a2,t8,.Lchk8w # if a2==t8, no 64-byte chunks
# There will be at most 1 32-byte chunk after it
subu a3,a2,t8 # subtract from a2 the reminder
# Here a3 counts bytes in 16w chunks
addu a3,a0,a3 # Now a3 is the final dst after 64-byte chunks
addu t0,a0,a2 # t0 is the "past the end" address
# When in the loop we exercise "pref 30,x(a0)", the a0+x should not be past
# the "t0-32" address
# This means: for x=128 the last "safe" a0 address is "t0-160"
# Alternatively, for x=64 the last "safe" a0 address is "t0-96"
# In the current version we will use "pref 30,128(a0)", so "t0-160" is the limit
subu t9,t0,160 # t9 is the "last safe pref 30,128(a0)" address
pref 0,0(a1) # bring the first line of src, addr 0
pref 0,32(a1) # bring the second line of src, addr 32
pref 0,64(a1) # bring the third line of src, addr 64
pref 30,32(a0) # safe, as we have at least 64 bytes ahead
# In case the a0 > t9 don't use "pref 30" at all
sgtu v1,a0,t9
bgtz v1,.Lloop16w # skip "pref 30,64(a0)" for too short arrays
nop
# otherwise, start with using pref30
pref 30,64(a0)
.Lloop16w:
pref 0,96(a1)
lw t0,0(a1)
bgtz v1,.Lskip_pref30_96 # skip "pref 30,96(a0)"
lw t1,4(a1)
pref 30,96(a0) # continue setting up the dest, addr 96
.Lskip_pref30_96:
lw t2,8(a1)
lw t3,12(a1)
lw t4,16(a1)
lw t5,20(a1)
lw t6,24(a1)
lw t7,28(a1)
pref 0,128(a1) # bring the next lines of src, addr 128
sw t0,0(a0)
sw t1,4(a0)
sw t2,8(a0)
sw t3,12(a0)
sw t4,16(a0)
sw t5,20(a0)
sw t6,24(a0)
sw t7,28(a0)
lw t0,32(a1)
bgtz v1,.Lskip_pref30_128 # skip "pref 30,128(a0)"
lw t1,36(a1)
pref 30,128(a0) # continue setting up the dest, addr 128
.Lskip_pref30_128:
lw t2,40(a1)
lw t3,44(a1)
lw t4,48(a1)
lw t5,52(a1)
lw t6,56(a1)
lw t7,60(a1)
pref 0, 160(a1) # bring the next lines of src, addr 160
sw t0,32(a0)
sw t1,36(a0)
sw t2,40(a0)
sw t3,44(a0)
sw t4,48(a0)
sw t5,52(a0)
sw t6,56(a0)
sw t7,60(a0)
addiu a0,a0,64 # adding 64 to dest
sgtu v1,a0,t9
bne a0,a3,.Lloop16w
addiu a1,a1,64 # adding 64 to src
move a2,t8
# Here we have src and dest word-aligned but less than 64-bytes to go
.Lchk8w:
pref 0, 0x0(a1)
andi t8,a2,0x1f # is there a 32-byte chunk?
# the t8 is the reminder count past 32-bytes
beq a2,t8,.Lchk1w # when a2=t8, no 32-byte chunk
nop
lw t0,0(a1)
lw t1,4(a1)
lw t2,8(a1)
lw t3,12(a1)
lw t4,16(a1)
lw t5,20(a1)
lw t6,24(a1)
lw t7,28(a1)
addiu a1,a1,32
sw t0,0(a0)
sw t1,4(a0)
sw t2,8(a0)
sw t3,12(a0)
sw t4,16(a0)
sw t5,20(a0)
sw t6,24(a0)
sw t7,28(a0)
addiu a0,a0,32
.Lchk1w:
andi a2,t8,0x3 # now a2 is the reminder past 1w chunks
beq a2,t8,.Llast8
subu a3,t8,a2 # a3 is count of bytes in 1w chunks
addu a3,a0,a3 # now a3 is the dst address past the 1w chunks
# copying in words (4-byte chunks)
.LwordCopy_loop:
lw t3,0(a1) # the first t3 may be equal t0 ... optimize?
addiu a1,a1,4
addiu a0,a0,4
bne a0,a3,.LwordCopy_loop
sw t3,-4(a0)
# For the last (<8) bytes
.Llast8:
blez a2,.Lleave
addu a3,a0,a2 # a3 is the last dst address
.Llast8loop:
lb v1,0(a1)
addiu a1,a1,1
addiu a0,a0,1
bne a0,a3,.Llast8loop
sb v1,-1(a0)
.Lleave:
j ra
nop
#
# UNALIGNED case
#
.Lunaligned:
# got here with a3="negu a0"
andi a3,a3,0x3 # test if the a0 is word aligned
beqz a3,.Lua_chk16w
subu a2,a2,a3 # bytes left after initial a3 bytes
LWHI v1,0(a1)
LWLO v1,3(a1)
addu a1,a1,a3 # a3 may be here 1, 2 or 3
SWHI v1,0(a0)
addu a0,a0,a3 # below the dst will be word aligned (NOTE1)
.Lua_chk16w:
andi t8,a2,0x3f # any whole 64-byte chunks?
# t8 is the byte count after 64-byte chunks
beq a2,t8,.Lua_chk8w # if a2==t8, no 64-byte chunks
# There will be at most 1 32-byte chunk after it
subu a3,a2,t8 # subtract from a2 the reminder
# Here a3 counts bytes in 16w chunks
addu a3,a0,a3 # Now a3 is the final dst after 64-byte chunks
addu t0,a0,a2 # t0 is the "past the end" address
subu t9,t0,160 # t9 is the "last safe pref 30,128(a0)" address
pref 0,0(a1) # bring the first line of src, addr 0
pref 0,32(a1) # bring the second line of src, addr 32
pref 0,64(a1) # bring the third line of src, addr 64
pref 30,32(a0) # safe, as we have at least 64 bytes ahead
# In case the a0 > t9 don't use "pref 30" at all
sgtu v1,a0,t9
bgtz v1,.Lua_loop16w # skip "pref 30,64(a0)" for too short arrays
nop
# otherwise, start with using pref30
pref 30,64(a0)
.Lua_loop16w:
pref 0,96(a1)
LWHI t0,0(a1)
LWLO t0,3(a1)
LWHI t1,4(a1)
bgtz v1,.Lua_skip_pref30_96
LWLO t1,7(a1)
pref 30,96(a0) # continue setting up the dest, addr 96
.Lua_skip_pref30_96:
LWHI t2,8(a1)
LWLO t2,11(a1)
LWHI t3,12(a1)
LWLO t3,15(a1)
LWHI t4,16(a1)
LWLO t4,19(a1)
LWHI t5,20(a1)
LWLO t5,23(a1)
LWHI t6,24(a1)
LWLO t6,27(a1)
LWHI t7,28(a1)
LWLO t7,31(a1)
pref 0,128(a1) # bring the next lines of src, addr 128
sw t0,0(a0)
sw t1,4(a0)
sw t2,8(a0)
sw t3,12(a0)
sw t4,16(a0)
sw t5,20(a0)
sw t6,24(a0)
sw t7,28(a0)
LWHI t0,32(a1)
LWLO t0,35(a1)
LWHI t1,36(a1)
bgtz v1,.Lua_skip_pref30_128
LWLO t1,39(a1)
pref 30,128(a0) # continue setting up the dest, addr 128
.Lua_skip_pref30_128:
LWHI t2,40(a1)
LWLO t2,43(a1)
LWHI t3,44(a1)
LWLO t3,47(a1)
LWHI t4,48(a1)
LWLO t4,51(a1)
LWHI t5,52(a1)
LWLO t5,55(a1)
LWHI t6,56(a1)
LWLO t6,59(a1)
LWHI t7,60(a1)
LWLO t7,63(a1)
pref 0, 160(a1) # bring the next lines of src, addr 160
sw t0,32(a0)
sw t1,36(a0)
sw t2,40(a0)
sw t3,44(a0)
sw t4,48(a0)
sw t5,52(a0)
sw t6,56(a0)
sw t7,60(a0)
addiu a0,a0,64 # adding 64 to dest
sgtu v1,a0,t9
bne a0,a3,.Lua_loop16w
addiu a1,a1,64 # adding 64 to src
move a2,t8
# Here we have src and dest word-aligned but less than 64-bytes to go
.Lua_chk8w:
pref 0, 0x0(a1)
andi t8,a2,0x1f # is there a 32-byte chunk?
# the t8 is the reminder count
beq a2,t8,.Lua_chk1w # when a2=t8, no 32-byte chunk
nop
LWHI t0,0(a1)
LWLO t0,3(a1)
LWHI t1,4(a1)
LWLO t1,7(a1)
LWHI t2,8(a1)
LWLO t2,11(a1)
LWHI t3,12(a1)
LWLO t3,15(a1)
LWHI t4,16(a1)
LWLO t4,19(a1)
LWHI t5,20(a1)
LWLO t5,23(a1)
LWHI t6,24(a1)
LWLO t6,27(a1)
LWHI t7,28(a1)
LWLO t7,31(a1)
addiu a1,a1,32
sw t0,0(a0)
sw t1,4(a0)
sw t2,8(a0)
sw t3,12(a0)
sw t4,16(a0)
sw t5,20(a0)
sw t6,24(a0)
sw t7,28(a0)
addiu a0,a0,32
.Lua_chk1w:
andi a2,t8,0x3 # now a2 is the reminder past 1w chunks
beq a2,t8,.Lua_smallCopy
subu a3,t8,a2 # a3 is count of bytes in 1w chunks
addu a3,a0,a3 # now a3 is the dst address past the 1w chunks
# copying in words (4-byte chunks)
.Lua_wordCopy_loop:
LWHI v1,0(a1)
LWLO v1,3(a1)
addiu a1,a1,4
addiu a0,a0,4 # note: dst=a0 is word aligned here, see NOTE1
bne a0,a3,.Lua_wordCopy_loop
sw v1,-4(a0)
# Now less than 4 bytes (value in a2) left to copy
.Lua_smallCopy:
beqz a2,.Lleave
addu a3,a0,a2 # a3 is the last dst address
.Lua_smallCopy_loop:
lb v1,0(a1)
addiu a1,a1,1
addiu a0,a0,1
bne a0,a3,.Lua_smallCopy_loop
sb v1,-1(a0)
j ra
nop
.set at
.set reorder
END(memcpy)
/************************************************************************
* Implementation : Static functions
************************************************************************/