forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
553 lines
12 KiB
553 lines
12 KiB
/* |
|
* arch/xtensa/lib/hal/memcopy.S -- Core HAL library functions |
|
* xthal_memcpy and xthal_bcopy |
|
* |
|
* This file is subject to the terms and conditions of the GNU General Public |
|
* License. See the file "COPYING" in the main directory of this archive |
|
* for more details. |
|
* |
|
* Copyright (C) 2002 - 2012 Tensilica Inc. |
|
*/ |
|
|
|
#include <linux/linkage.h> |
|
#include <asm/asmmacro.h> |
|
#include <asm/core.h> |
|
|
|
/* |
|
* void *memcpy(void *dst, const void *src, size_t len); |
|
* |
|
* This function is intended to do the same thing as the standard |
|
* library function memcpy() for most cases. |
|
* However, where the source and/or destination references |
|
* an instruction RAM or ROM or a data RAM or ROM, that |
|
* source and/or destination will always be accessed with |
|
* 32-bit load and store instructions (as required for these |
|
* types of devices). |
|
* |
|
* !!!!!!! XTFIXME: |
|
* !!!!!!! Handling of IRAM/IROM has not yet |
|
* !!!!!!! been implemented. |
|
* |
|
* The (general case) algorithm is as follows: |
|
* If destination is unaligned, align it by conditionally |
|
* copying 1 and 2 bytes. |
|
* If source is aligned, |
|
* do 16 bytes with a loop, and then finish up with |
|
* 8, 4, 2, and 1 byte copies conditional on the length; |
|
* else (if source is unaligned), |
|
* do the same, but use SRC to align the source data. |
|
* This code tries to use fall-through branches for the common |
|
* case of aligned source and destination and multiple |
|
* of 4 (or 8) length. |
|
* |
|
* Register use: |
|
* a0/ return address |
|
* a1/ stack pointer |
|
* a2/ return value |
|
* a3/ src |
|
* a4/ length |
|
* a5/ dst |
|
* a6/ tmp |
|
* a7/ tmp |
|
* a8/ tmp |
|
* a9/ tmp |
|
* a10/ tmp |
|
* a11/ tmp |
|
*/ |
|
|
|
.text |
|
|
|
/* |
|
* Byte by byte copy |
|
*/ |
|
.align 4 |
|
.byte 0 # 1 mod 4 alignment for LOOPNEZ |
|
# (0 mod 4 alignment for LBEG) |
|
.Lbytecopy: |
|
#if XCHAL_HAVE_LOOPS |
|
loopnez a4, .Lbytecopydone |
|
#else /* !XCHAL_HAVE_LOOPS */ |
|
beqz a4, .Lbytecopydone |
|
add a7, a3, a4 # a7 = end address for source |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Lnextbyte: |
|
l8ui a6, a3, 0 |
|
addi a3, a3, 1 |
|
s8i a6, a5, 0 |
|
addi a5, a5, 1 |
|
#if !XCHAL_HAVE_LOOPS |
|
bne a3, a7, .Lnextbyte # continue loop if $a3:src != $a7:src_end |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Lbytecopydone: |
|
abi_ret_default |
|
|
|
/* |
|
* Destination is unaligned |
|
*/ |
|
|
|
.align 4 |
|
.Ldst1mod2: # dst is only byte aligned |
|
_bltui a4, 7, .Lbytecopy # do short copies byte by byte |
|
|
|
# copy 1 byte |
|
l8ui a6, a3, 0 |
|
addi a3, a3, 1 |
|
addi a4, a4, -1 |
|
s8i a6, a5, 0 |
|
addi a5, a5, 1 |
|
_bbci.l a5, 1, .Ldstaligned # if dst is now aligned, then |
|
# return to main algorithm |
|
.Ldst2mod4: # dst 16-bit aligned |
|
# copy 2 bytes |
|
_bltui a4, 6, .Lbytecopy # do short copies byte by byte |
|
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 |
|
j .Ldstaligned # dst is now aligned, return to main algorithm |
|
|
|
ENTRY(__memcpy) |
|
WEAK(memcpy) |
|
|
|
abi_entry_default |
|
# a2/ dst, a3/ src, a4/ len |
|
mov a5, a2 # copy dst so that a2 is return value |
|
.Lcommon: |
|
_bbsi.l a2, 0, .Ldst1mod2 # if dst is 1 mod 2 |
|
_bbsi.l a2, 1, .Ldst2mod4 # if dst is 2 mod 4 |
|
.Ldstaligned: # return here from .Ldst?mod? once dst is aligned |
|
srli a7, a4, 4 # number of loop iterations with 16B |
|
# per iteration |
|
movi a8, 3 # if source is not aligned, |
|
_bany a3, a8, .Lsrcunaligned # then use shifting copy |
|
/* |
|
* Destination and source are word-aligned, use word copy. |
|
*/ |
|
# copy 16 bytes per iteration for word-aligned dst and word-aligned src |
|
#if XCHAL_HAVE_LOOPS |
|
loopnez a7, .Loop1done |
|
#else /* !XCHAL_HAVE_LOOPS */ |
|
beqz a7, .Loop1done |
|
slli a8, a7, 4 |
|
add a8, a8, a3 # a8 = end of last 16B source chunk |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Loop1: |
|
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 |
|
bne a3, a8, .Loop1 # continue loop if a3:src != a8:src_end |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Loop1done: |
|
bbci.l a4, 3, .L2 |
|
# 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 |
|
.L2: |
|
bbsi.l a4, 2, .L3 |
|
bbsi.l a4, 1, .L4 |
|
bbsi.l a4, 0, .L5 |
|
abi_ret_default |
|
.L3: |
|
# copy 4 bytes |
|
l32i a6, a3, 0 |
|
addi a3, a3, 4 |
|
s32i a6, a5, 0 |
|
addi a5, a5, 4 |
|
bbsi.l a4, 1, .L4 |
|
bbsi.l a4, 0, .L5 |
|
abi_ret_default |
|
.L4: |
|
# copy 2 bytes |
|
l16ui a6, a3, 0 |
|
addi a3, a3, 2 |
|
s16i a6, a5, 0 |
|
addi a5, a5, 2 |
|
bbsi.l a4, 0, .L5 |
|
abi_ret_default |
|
.L5: |
|
# copy 1 byte |
|
l8ui a6, a3, 0 |
|
s8i a6, a5, 0 |
|
abi_ret_default |
|
|
|
/* |
|
* Destination is aligned, Source is unaligned |
|
*/ |
|
|
|
.align 4 |
|
.Lsrcunaligned: |
|
_beqz a4, .Ldone # avoid loading anything for zero-length copies |
|
# copy 16 bytes per iteration for word-aligned dst and unaligned src |
|
__ssa8 a3 # set shift amount from byte offset |
|
|
|
/* 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 1 |
|
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
|
and a11, a3, a8 # 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, .Loop2done |
|
#else /* !XCHAL_HAVE_LOOPS */ |
|
beqz a7, .Loop2done |
|
slli a10, a7, 4 |
|
add a10, a10, a3 # a10 = end of last 16B source chunk |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Loop2: |
|
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 |
|
bne a3, a10, .Loop2 # continue loop if a3:src != a10:src_end |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Loop2done: |
|
bbci.l a4, 3, .L12 |
|
# 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 |
|
.L12: |
|
bbci.l a4, 2, .L13 |
|
# 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 |
|
.L13: |
|
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
|
add a3, a3, a11 # readjust a3 with correct misalignment |
|
#endif |
|
bbsi.l a4, 1, .L14 |
|
bbsi.l a4, 0, .L15 |
|
.Ldone: abi_ret_default |
|
.L14: |
|
# copy 2 bytes |
|
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, .L15 |
|
abi_ret_default |
|
.L15: |
|
# copy 1 byte |
|
l8ui a6, a3, 0 |
|
s8i a6, a5, 0 |
|
abi_ret_default |
|
|
|
ENDPROC(__memcpy) |
|
|
|
/* |
|
* void bcopy(const void *src, void *dest, size_t n); |
|
*/ |
|
|
|
ENTRY(bcopy) |
|
|
|
abi_entry_default |
|
# a2=src, a3=dst, a4=len |
|
mov a5, a3 |
|
mov a3, a2 |
|
mov a2, a5 |
|
j .Lmovecommon # go to common code for memmove+bcopy |
|
|
|
ENDPROC(bcopy) |
|
|
|
/* |
|
* void *memmove(void *dst, const void *src, size_t len); |
|
* |
|
* This function is intended to do the same thing as the standard |
|
* library function memmove() for most cases. |
|
* However, where the source and/or destination references |
|
* an instruction RAM or ROM or a data RAM or ROM, that |
|
* source and/or destination will always be accessed with |
|
* 32-bit load and store instructions (as required for these |
|
* types of devices). |
|
* |
|
* !!!!!!! XTFIXME: |
|
* !!!!!!! Handling of IRAM/IROM has not yet |
|
* !!!!!!! been implemented. |
|
* |
|
* The (general case) algorithm is as follows: |
|
* If end of source doesn't overlap destination then use memcpy. |
|
* Otherwise do memcpy backwards. |
|
* |
|
* Register use: |
|
* a0/ return address |
|
* a1/ stack pointer |
|
* a2/ return value |
|
* a3/ src |
|
* a4/ length |
|
* a5/ dst |
|
* a6/ tmp |
|
* a7/ tmp |
|
* a8/ tmp |
|
* a9/ tmp |
|
* a10/ tmp |
|
* a11/ tmp |
|
*/ |
|
|
|
/* |
|
* Byte by byte copy |
|
*/ |
|
.align 4 |
|
.byte 0 # 1 mod 4 alignment for LOOPNEZ |
|
# (0 mod 4 alignment for LBEG) |
|
.Lbackbytecopy: |
|
#if XCHAL_HAVE_LOOPS |
|
loopnez a4, .Lbackbytecopydone |
|
#else /* !XCHAL_HAVE_LOOPS */ |
|
beqz a4, .Lbackbytecopydone |
|
sub a7, a3, a4 # a7 = start address for source |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Lbacknextbyte: |
|
addi a3, a3, -1 |
|
l8ui a6, a3, 0 |
|
addi a5, a5, -1 |
|
s8i a6, a5, 0 |
|
#if !XCHAL_HAVE_LOOPS |
|
bne a3, a7, .Lbacknextbyte # continue loop if |
|
# $a3:src != $a7:src_start |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.Lbackbytecopydone: |
|
abi_ret_default |
|
|
|
/* |
|
* Destination is unaligned |
|
*/ |
|
|
|
.align 4 |
|
.Lbackdst1mod2: # dst is only byte aligned |
|
_bltui a4, 7, .Lbackbytecopy # do short copies byte by byte |
|
|
|
# copy 1 byte |
|
addi a3, a3, -1 |
|
l8ui a6, a3, 0 |
|
addi a5, a5, -1 |
|
s8i a6, a5, 0 |
|
addi a4, a4, -1 |
|
_bbci.l a5, 1, .Lbackdstaligned # if dst is now aligned, then |
|
# return to main algorithm |
|
.Lbackdst2mod4: # dst 16-bit aligned |
|
# copy 2 bytes |
|
_bltui a4, 6, .Lbackbytecopy # do short copies byte by byte |
|
addi a3, a3, -2 |
|
l8ui a6, a3, 0 |
|
l8ui a7, a3, 1 |
|
addi a5, a5, -2 |
|
s8i a6, a5, 0 |
|
s8i a7, a5, 1 |
|
addi a4, a4, -2 |
|
j .Lbackdstaligned # dst is now aligned, |
|
# return to main algorithm |
|
|
|
ENTRY(__memmove) |
|
WEAK(memmove) |
|
|
|
abi_entry_default |
|
# a2/ dst, a3/ src, a4/ len |
|
mov a5, a2 # copy dst so that a2 is return value |
|
.Lmovecommon: |
|
sub a6, a5, a3 |
|
bgeu a6, a4, .Lcommon |
|
|
|
add a5, a5, a4 |
|
add a3, a3, a4 |
|
|
|
_bbsi.l a5, 0, .Lbackdst1mod2 # if dst is 1 mod 2 |
|
_bbsi.l a5, 1, .Lbackdst2mod4 # if dst is 2 mod 4 |
|
.Lbackdstaligned: # return here from .Lbackdst?mod? once dst is aligned |
|
srli a7, a4, 4 # number of loop iterations with 16B |
|
# per iteration |
|
movi a8, 3 # if source is not aligned, |
|
_bany a3, a8, .Lbacksrcunaligned # then use shifting copy |
|
/* |
|
* Destination and source are word-aligned, use word copy. |
|
*/ |
|
# copy 16 bytes per iteration for word-aligned dst and word-aligned src |
|
#if XCHAL_HAVE_LOOPS |
|
loopnez a7, .backLoop1done |
|
#else /* !XCHAL_HAVE_LOOPS */ |
|
beqz a7, .backLoop1done |
|
slli a8, a7, 4 |
|
sub a8, a3, a8 # a8 = start of first 16B source chunk |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.backLoop1: |
|
addi a3, a3, -16 |
|
l32i a7, a3, 12 |
|
l32i a6, a3, 8 |
|
addi a5, a5, -16 |
|
s32i a7, a5, 12 |
|
l32i a7, a3, 4 |
|
s32i a6, a5, 8 |
|
l32i a6, a3, 0 |
|
s32i a7, a5, 4 |
|
s32i a6, a5, 0 |
|
#if !XCHAL_HAVE_LOOPS |
|
bne a3, a8, .backLoop1 # continue loop if a3:src != a8:src_start |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.backLoop1done: |
|
bbci.l a4, 3, .Lback2 |
|
# copy 8 bytes |
|
addi a3, a3, -8 |
|
l32i a6, a3, 0 |
|
l32i a7, a3, 4 |
|
addi a5, a5, -8 |
|
s32i a6, a5, 0 |
|
s32i a7, a5, 4 |
|
.Lback2: |
|
bbsi.l a4, 2, .Lback3 |
|
bbsi.l a4, 1, .Lback4 |
|
bbsi.l a4, 0, .Lback5 |
|
abi_ret_default |
|
.Lback3: |
|
# copy 4 bytes |
|
addi a3, a3, -4 |
|
l32i a6, a3, 0 |
|
addi a5, a5, -4 |
|
s32i a6, a5, 0 |
|
bbsi.l a4, 1, .Lback4 |
|
bbsi.l a4, 0, .Lback5 |
|
abi_ret_default |
|
.Lback4: |
|
# copy 2 bytes |
|
addi a3, a3, -2 |
|
l16ui a6, a3, 0 |
|
addi a5, a5, -2 |
|
s16i a6, a5, 0 |
|
bbsi.l a4, 0, .Lback5 |
|
abi_ret_default |
|
.Lback5: |
|
# copy 1 byte |
|
addi a3, a3, -1 |
|
l8ui a6, a3, 0 |
|
addi a5, a5, -1 |
|
s8i a6, a5, 0 |
|
abi_ret_default |
|
|
|
/* |
|
* Destination is aligned, Source is unaligned |
|
*/ |
|
|
|
.align 4 |
|
.Lbacksrcunaligned: |
|
_beqz a4, .Lbackdone # avoid loading anything for zero-length copies |
|
# copy 16 bytes per iteration for word-aligned dst and unaligned src |
|
__ssa8 a3 # set shift amount from byte offset |
|
#define SIM_CHECKS_ALIGNMENT 1 /* set to 1 when running on ISS with |
|
* the lint or ferret client, or 0 |
|
* to save a few cycles */ |
|
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
|
and a11, a3, a8 # 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, .backLoop2done |
|
#else /* !XCHAL_HAVE_LOOPS */ |
|
beqz a7, .backLoop2done |
|
slli a10, a7, 4 |
|
sub a10, a3, a10 # a10 = start of first 16B source chunk |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.backLoop2: |
|
addi a3, a3, -16 |
|
l32i a7, a3, 12 |
|
l32i a8, a3, 8 |
|
addi a5, a5, -16 |
|
__src_b a6, a7, a6 |
|
s32i a6, a5, 12 |
|
l32i a9, a3, 4 |
|
__src_b a7, a8, a7 |
|
s32i a7, a5, 8 |
|
l32i a6, a3, 0 |
|
__src_b a8, a9, a8 |
|
s32i a8, a5, 4 |
|
__src_b a9, a6, a9 |
|
s32i a9, a5, 0 |
|
#if !XCHAL_HAVE_LOOPS |
|
bne a3, a10, .backLoop2 # continue loop if a3:src != a10:src_start |
|
#endif /* !XCHAL_HAVE_LOOPS */ |
|
.backLoop2done: |
|
bbci.l a4, 3, .Lback12 |
|
# copy 8 bytes |
|
addi a3, a3, -8 |
|
l32i a7, a3, 4 |
|
l32i a8, a3, 0 |
|
addi a5, a5, -8 |
|
__src_b a6, a7, a6 |
|
s32i a6, a5, 4 |
|
__src_b a7, a8, a7 |
|
s32i a7, a5, 0 |
|
mov a6, a8 |
|
.Lback12: |
|
bbci.l a4, 2, .Lback13 |
|
# copy 4 bytes |
|
addi a3, a3, -4 |
|
l32i a7, a3, 0 |
|
addi a5, a5, -4 |
|
__src_b a6, a7, a6 |
|
s32i a6, a5, 0 |
|
mov a6, a7 |
|
.Lback13: |
|
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
|
add a3, a3, a11 # readjust a3 with correct misalignment |
|
#endif |
|
bbsi.l a4, 1, .Lback14 |
|
bbsi.l a4, 0, .Lback15 |
|
.Lbackdone: |
|
abi_ret_default |
|
.Lback14: |
|
# copy 2 bytes |
|
addi a3, a3, -2 |
|
l8ui a6, a3, 0 |
|
l8ui a7, a3, 1 |
|
addi a5, a5, -2 |
|
s8i a6, a5, 0 |
|
s8i a7, a5, 1 |
|
bbsi.l a4, 0, .Lback15 |
|
abi_ret_default |
|
.Lback15: |
|
# copy 1 byte |
|
addi a3, a3, -1 |
|
addi a5, a5, -1 |
|
l8ui a6, a3, 0 |
|
s8i a6, a5, 0 |
|
abi_ret_default |
|
|
|
ENDPROC(__memmove)
|
|
|