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/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <machine/asm.h>
RCSID("$NetBSD: memcpy_neon.S,v 1.1 2013/01/03 09:34:44 matt Exp $")
.text
ENTRY(memcpy)
teq r2, #0 /* 0 length? */
cmpne r0, r1 /* if not, does src == dst? */
RETc(eq) /* yes, (to either) return */
mov r3, r0 /* keep r0 unchanged */
#if 0
cmp r2, #16 /* copy less than 8 bytes? */
bge .Ldst_aligner /* nope, do it the long way */
1: ldrb ip, [r1], #1 /* load a byte from src */
subs r2, r2, #1 /* and more to transfer? */
strb ip, [r3], #1 /* save it to dst */
bne 1b /* yes, do next byte */
RET /* return */
#endif
.Ldst_aligner:
tst r3, #7 /* is dst pointer word aligned? */
beq .Lsrc_aligner /* yes, check src pointer */
/*
* Until the dst pointer is word aligned, read src and dst byte by
* byte until it is aligned or we've copied everything.
*/
ldrb ip, [r1], #1 /* load a byte from src */
strb ip, [r3], #1 /* save the byte to dst */
subs r2, r2, #1 /* end of transfer? */
bne .Ldst_aligner /* no, try next byte */
RET /* yes, we're done! */
.Lsrc_aligner:
push {r4-r5} /* save some registers */
add r4, r2, r3 /* keep a pointer to the end of src */
ands r5, r1, #7 /* get misalignment of src pointer */
beq .Lcongruent_main /* aligned, do it the fast way */
vdup.8 d1, r5 /* set offset for table */
rsb r5, r5, #8 /* calculate leftover of each word */
bic r1, r1, #7 /* dword align src pointer */
vldr d0, .Ltbl_value /* load table value */
vadd.u8 d0, d0, d1 /* add offset to it */
vld1.64 {d1}, [r1:64]! /* load a dword from src */
cmp r2, r5 /* do we already have enough? */
bgt .Lincongruent /* no, so read more */
.Lincongruent_finish:
vtbl.8 d0, {d1-d2}, d0 /* merge last dwords */
cmp r2, #8 /* room for a full dword? */
#ifdef __ARMEB__
vrev64.32 d0, d0 /* word swap to LE */
#endif
blt .Lfinish /* no, write final partial dword */
vst1.32 {d0}, [r3:64] /* yes, write final full dword */
b .Ldone /* and we're done! */
.Lincongruent:
vld1.64 {d2}, [r1:64]! /* load a dword */
cmp r2, #8 /* can we write a full dword? */
blt .Lincongruent_finish /* no, finish it. */
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vst1.64 {d1}, [r3:64]! /* store a dword */
subs r2, r2, #8 /* have we written everything? */
beq .Ldone /* yes, we're done! */
vmov d1, d2 /* prepare for next dword */
tst r3, #63 /* are we 64-byte aligned? */
bne .Lincongruent /* no, load next dword */
/*
* We are now 64-byte aligneds so all writes should fill one or more
* cachelines. Even if d1 has 7 bytes cached, to write 32 bytes we
* still need to read 4 dwords (3 full dwords and 1 dword for that
* last byte).
*/
cmp r2, #32 /* can we write 4 more dwords? */
blt .Lincongruent_dword /* no, handle dword by dword */
vld1.64 {d2-d5}, [r1:64]! /* read 4 dwords */
cmp r2, #64 /* can we write 4 more dwords? */
blt .Lincongruent_4dword /* no, handle it */
1: vld1.64 {d7-d10}, [r1:64]! /* read 4 dwords */
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vtbl.8 d2, {d2-d3}, d0 /* reorder */
vtbl.8 d3, {d3-d4}, d0 /* reorder */
vtbl.8 d4, {d4-d5}, d0 /* reorder */
vst1.64 {d1-d4}, [r3:64]! /* write 4 dwords */
vmov d6, d5 /* move out of the way the load */
cmp r2, #96 /* have 8+4 dwords to write? */
blt 2f /* no more data, skip the load */
vld1.64 {d2-d5}, [r1:64]! /* more data, load 4 dwords */
2: vtbl.8 d6, {d6-d7}, d0 /* reorder */
vtbl.8 d7, {d7-d8}, d0 /* reorder */
vtbl.8 d8, {d8-d9}, d0 /* reorder */
vtbl.8 d9, {d9-d10}, d0 /* reorder */
vst1.64 {d6-d9}, [r3:64]! /* write 4 dwords */
subs r2, r2, #64
beq .Ldone
vmov d1, d10
cmp r2, #64
bge 1b
/*
* we have leftovers in d1 and new untranslated date in d2-d5.
*/
.Lincongruent_4dword:
cmp r2, #32
blt .Lincongruent_dword
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vtbl.8 d2, {d2-d3}, d0 /* reorder */
vtbl.8 d3, {d3-d4}, d0 /* reorder */
vtbl.8 d4, {d4-d5}, d0 /* reorder */
vst1.64 {d1-d4}, [r3:64]! /* write 4 dwords */
vmov d1, d5 /* move leftovers */
subs r2, r2, #32
beq .Ldone
.Lincongruent_dword:
#if 0
cmp r2, r5 /* enough in leftovers? */
ble .Lincongruent_finish /* yes, finish it. */
vld1.64 {d2}, [r1:64]! /* load a dword */
cmp r2, #8 /* can we write a full dword? */
blt .Lincongruent_finish /* no, finish it. */
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vst1.64 {d1}, [r3:64]! /* store a dword */
subs r2, r2, #8 /* have we written everything? */
beq .Ldone /* yes, we're done! */
b .Lincongruent_dword /* and go get it */
#else
cmp r2, r5 /* are the bytes we have enough? */
ble .Lincongruent_finish /* yes, finish it. */
mov ip, r2 /* get remaining count */
bic ip, ip, #7 /* truncate to a dword */
rsb ip, ip, #32 /* subtract from 32 */
ands r2, r2, #7 /* count mod 8 */
add pc, pc, ip, lsl #1 /* and jump! */
nop
vld1.64 {d2}, [r1:64]! /* load a dword */
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vst1.64 {d1}, [r3:64]! /* store a dword */
vmov d1, d2 /* prepare for next dword */
vld1.64 {d2}, [r1:64]! /* load a dword */
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vst1.64 {d1}, [r3:64]! /* store a dword */
vmov d1, d2 /* prepare for next dword */
vld1.64 {d2}, [r1:64]! /* load a dword */
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vst1.64 {d1}, [r3:64]! /* store a dword */
vmov d1, d2 /* prepare for next dword */
vld1.64 {d2}, [r1:64]! /* load a dword */
vtbl.8 d1, {d1-d2}, d0 /* reorder */
vst1.64 {d1}, [r3:64]! /* store a dword */
vmov d1, d2 /* prepare for next dword */
beq .Ldone
vld1.64 {d2}, [r1:64]! /* load a dword */
b .Lincongruent_finish /* write last partial dowrd */
#endif
.Lcongruent_main:
vld1.32 {d0}, [r1:64]! /* load next dword */
cmp r2, #8 /* compare current ptr against end */
blt .Lfinish /* greater so write final dword */
vst1.32 {d0}, [r3:64]! /* store dword */
subs r2, r2, #8 /* compare current ptr against end */
beq .Ldone /* equal? we're done! */
tst r3, #63 /* have we hit a 64-byte boundary? */
bne .Lcongruent_main /* no, write next word */
cmp r2, #64 /* can we write 4 dwords? */
blt .Lcongruent_loop /* no, this dword by dword */
vldm r1!, {d0-d7} /* load next 7 dwords */
cmp r2, #128 /* can we write 16 dwords */
blt 3f /* no, then deal with 8 dwords */
/*
* The following writes two 64-byte interleaving stores and loads.
*/
1: vldm r1!, {d8-d15} /* load next 8 dwords */
vstm r3!, {d0-d7} /* store 8 more dwords */
cmp r2, #192 /* can we write 16+8 dwords? */
blt 2f /* no, don't load the next 8 dwords */
vldm r1!, {d0-d7} /* yes, load next 8 dwords */
2: vstm r3!, {d8-d15} /* store 8 more dwords */
sub r2, r2, #128 /* we just stored 16 (8+8) dwords */
beq .Ldone /* if 0, we're done! */
cmp r2, #128 /* can we write 16 dwords */
bge 1b /* yes, do it again */
cmp r2, #64 /* have we loaded 8 dwords? */
blt .Lcongruent_loop /* no, proceed to do it dword */
/*
* We now have 8 dwords we can write in d0-d7.
*/
3: vstm r3!, {d0-d7} /* store 8 more dwords */
subs r2, r2, #64 /* we wrote 8 dwords */
beq .Ldone /* if 0, we're done! */
.Lcongruent_loop:
vld1.32 {d0}, [r1]! /* load dword from src */
cmp r2, #8 /* can we write a full dword? */
blt .Lfinish /* no, write last partial dword */
.Lcongruent_loop_start:
vst1.32 {d0}, [r3]! /* store dword into dst */
subs r2, r2, #8 /* subtract it from length */
beq .Ldone /* if 0, we're done! */
vld1.32 {d0}, [r1]! /* load dword from src */
cmp r2, #8 /* can we write a full dword? */
bge .Lcongruent_loop_start /* yes, so do it */
.Lfinish:
vmov r4, r5, d0 /* get last dword from NEON */
tst r2, #4 /* do we have at least 4 bytes left? */
strne r4, [r3], #4 /* store the 1st word */
movne r4, r5 /* move 2nd word into place */
tst r2, #2 /* do we have at least 2 bytes left? */
#ifdef __ARMEB__
movne r4, r4, ror #16 /* yes, swap halfwords */
#endif
strneh r4, [r3], #2 /* yes, store the halfword */
#ifdef __ARMEL__
movne r4, r4, lsr #16 /* yes, discard just written bytes */
#endif
tst r2, #1 /* do we have a final byte? */
#ifdef __ARMEB__
movne r4, r4, lsr #24 /* yes, move MSB to LSB */
#endif
strneb r4, [r3], #1 /* yes, store it */
.Ldone:
pop {r4-r5} /* restore registers */
RET
.p2align 3
.Ltbl_value:
#ifdef __ARMEL__
.quad 0x0706050403020100
#else
.quad 0x0001020304050607
#endif
END(memcpy)
|
