/* Optimized mempcpy implementation for POWER7.
Copyright (C) 2010-2018 Free Software Foundation, Inc.
Contributed by Luis Machado <luisgpm@br.ibm.com>.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
/* void * [r3] __mempcpy (void *dst [r3], void *src [r4], size_t len [r5]);
Returns 'dst' + 'len'. */
.machine power7
EALIGN (__mempcpy, 5, 0)
CALL_MCOUNT
stwu 1,-32(1)
cfi_adjust_cfa_offset(32)
stw 30,20(1)
cfi_offset(30,(20-32))
stw 31,24(1)
mr 30,3
cmplwi cr1,5,31
neg 0,3
cfi_offset(31,-8)
ble cr1,L(copy_LT_32) /* If move < 32 bytes use short move
code. */
andi. 11,3,7 /* Check alignment of DST. */
clrlwi 10,4,29 /* Check alignment of SRC. */
cmplw cr6,10,11 /* SRC and DST alignments match? */
mr 12,4
mr 31,5
bne cr6,L(copy_GE_32_unaligned)
srwi 9,5,3 /* Number of full quadwords remaining. */
beq L(copy_GE_32_aligned_cont)
clrlwi 0,0,29
mtcrf 0x01,0
subf 31,0,5
/* Get the SRC aligned to 8 bytes. */
1: bf 31,2f
lbz 6,0(12)
addi 12,12,1
stb 6,0(3)
addi 3,3,1
2: bf 30,4f
lhz 6,0(12)
addi 12,12,2
sth 6,0(3)
addi 3,3,2
4: bf 29,0f
lwz 6,0(12)
addi 12,12,4
stw 6,0(3)
addi 3,3,4
0:
clrlwi 10,12,29 /* Check alignment of SRC again. */
srwi 9,31,3 /* Number of full doublewords remaining. */
L(copy_GE_32_aligned_cont):
clrlwi 11,31,29
mtcrf 0x01,9
srwi 8,31,5
cmplwi cr1,9,4
cmplwi cr6,11,0
mr 11,12
/* Copy 1~3 doublewords so the main loop starts
at a multiple of 32 bytes. */
bf 30,1f
lfd 6,0(12)
lfd 7,8(12)
addi 11,12,16
mtctr 8
stfd 6,0(3)
stfd 7,8(3)
addi 10,3,16
bf 31,4f
lfd 0,16(12)
stfd 0,16(3)
blt cr1,3f
addi 11,12,24
addi 10,3,24
b 4f
.align 4
1: /* Copy 1 doubleword and set the counter. */
mr 10,3
mtctr 8
bf 31,4f
lfd 6,0(12)
addi 11,12,8
stfd 6,0(3)
addi 10,3,8
.align 4
4: /* Main aligned copy loop. Copies 32-bytes at a time. */
lfd 6,0(11)
lfd 7,8(11)
lfd 8,16(11)
lfd 0,24(11)
addi 11,11,32
stfd 6,0(10)
stfd 7,8(10)
stfd 8,16(10)
stfd 0,24(10)
addi 10,10,32
bdnz 4b
3:
/* Check for tail bytes. */
clrrwi 0,31,3
mtcrf 0x01,31
beq cr6,0f
.L9:
add 3,3,0
add 12,12,0
/* At this point we have a tail of 0-7 bytes and we know that the
destination is doubleword-aligned. */
4: /* Copy 4 bytes. */
bf 29,2f
lwz 6,0(12)
addi 12,12,4
stw 6,0(3)
addi 3,3,4
2: /* Copy 2 bytes. */
bf 30,1f
lhz 6,0(12)
addi 12,12,2
sth 6,0(3)
addi 3,3,2
1: /* Copy 1 byte. */
bf 31,0f
lbz 6,0(12)
stb 6,0(3)
0: /* Return DST + LEN pointer. */
add 3,30,5
lwz 30,20(1)
lwz 31,24(1)
addi 1,1,32
blr
/* Handle copies of 0~31 bytes. */
.align 4
L(copy_LT_32):
cmplwi cr6,5,8
mr 12,4
mtcrf 0x01,5
ble cr6,L(copy_LE_8)
/* At least 9 bytes to go. */
neg 8,4
clrrwi 11,4,2
andi. 0,8,3
cmplwi cr1,5,16
mr 10,5
beq L(copy_LT_32_aligned)
/* Force 4-bytes alignment for SRC. */
mtocrf 0x01,0
subf 10,0,5
2: bf 30,1f
lhz 6,0(12)
addi 12,12,2
sth 6,0(3)
addi 3,3,2
1: bf 31,L(end_4bytes_alignment)
lbz 6,0(12)
addi 12,12,1
stb 6,0(3)
addi 3,3,1
.align 4
L(end_4bytes_alignment):
cmplwi cr1,10,16
mtcrf 0x01,10
L(copy_LT_32_aligned):
/* At least 6 bytes to go, and SRC is word-aligned. */
blt cr1,8f
/* Copy 16 bytes. */
lwz 6,0(12)
lwz 7,4(12)
stw 6,0(3)
lwz 8,8(12)
stw 7,4(3)
lwz 6,12(12)
addi 12,12,16
stw 8,8(3)
stw 6,12(3)
addi 3,3,16
8: /* Copy 8 bytes. */
bf 28,4f
lwz 6,0(12)
lwz 7,4(12)
addi 12,12,8
stw 6,0(3)
stw 7,4(3)
addi 3,3,8
4: /* Copy 4 bytes. */
bf 29,2f
lwz 6,0(12)
addi 12,12,4
stw 6,0(3)
addi 3,3,4
2: /* Copy 2-3 bytes. */
bf 30,1f
lhz 6,0(12)
sth 6,0(3)
bf 31,0f
lbz 7,2(12)
stb 7,2(3)
/* Return DST + LEN pointer. */
add 3,30,5
lwz 30,20(1)
addi 1,1,32
blr
.align 4
1: /* Copy 1 byte. */
bf 31,0f
lbz 6,0(12)
stb 6,0(3)
0: /* Return DST + LEN pointer. */
add 3,30,5
lwz 30,20(1)
addi 1,1,32
blr
/* Handles copies of 0~8 bytes. */
.align 4
L(copy_LE_8):
bne cr6,4f
/* Though we could've used lfd/stfd here, they are still
slow for unaligned cases. */
lwz 6,0(4)
lwz 7,4(4)
stw 6,0(3)
stw 7,4(3)
/* Return DST + LEN pointer. */
add 3,30,5
lwz 30,20(1)
addi 1,1,32
blr
.align 4
4: /* Copies 4~7 bytes. */
bf 29,2b
lwz 6,0(4)
stw 6,0(3)
bf 30,5f
lhz 7,4(4)
sth 7,4(3)
bf 31,0f
lbz 8,6(4)
stb 8,6(3)
/* Return DST + LEN pointer. */
add 3,30,5
lwz 30,20(1)
addi 1,1,32
blr
.align 4
5: /* Copy 1 byte. */
bf 31,0f
lbz 6,4(4)
stb 6,4(3)
0: /* Return DST + LEN pointer. */
add 3,30,5
lwz 30,20(1)
addi 1,1,32
blr
/* Handle copies of 32+ bytes where DST is aligned (to quadword) but
SRC is not. Use aligned quadword loads from SRC, shifted to realign
the data, allowing for aligned DST stores. */
.align 4
L(copy_GE_32_unaligned):
andi. 11,3,15 /* Check alignment of DST. */
clrlwi 0,0,28 /* Number of bytes until the 1st
quadword of DST. */
srwi 9,5,4 /* Number of full quadwords remaining. */
beq L(copy_GE_32_unaligned_cont)
/* DST is not quadword aligned, get it aligned. */
mtcrf 0x01,0
subf 31,0,5
/* Vector instructions work best when proper alignment (16-bytes)
is present. Move 0~15 bytes as needed to get DST quadword-aligned. */
1: /* Copy 1 byte. */
bf 31,2f
lbz 6,0(12)
addi 12,12,1
stb 6,0(3)
addi 3,3,1
2: /* Copy 2 bytes. */
bf 30,4f
lhz 6,0(12)
addi 12,12,2
sth 6,0(3)
addi 3,3,2
4: /* Copy 4 bytes. */
bf 29,8f
lwz 6,0(12)
addi 12,12,4
stw 6,0(3)
addi 3,3,4
8: /* Copy 8 bytes. */
bf 28,0f
lfd 6,0(12)
addi 12,12,8
stfd 6,0(3)
addi 3,3,8
0:
clrlwi 10,12,28 /* Check alignment of SRC. */
srwi 9,31,4 /* Number of full quadwords remaining. */
/* The proper alignment is present, it is OK to copy the bytes now. */
L(copy_GE_32_unaligned_cont):
/* Setup two indexes to speed up the indexed vector operations. */
clrlwi 11,31,28
li 6,16 /* Index for 16-bytes offsets. */
li 7,32 /* Index for 32-bytes offsets. */
cmplwi cr1,11,0
srwi 8,31,5 /* Setup the loop counter. */
mr 10,3
mr 11,12
mtcrf 0x01,9
cmplwi cr6,9,1
#ifdef __LITTLE_ENDIAN__
lvsr 5,0,12
#else
lvsl 5,0,12
#endif
lvx 3,0,12
bf 31,L(setup_unaligned_loop)
/* Copy another 16 bytes to align to 32-bytes due to the loop . */
lvx 4,12,6
#ifdef __LITTLE_ENDIAN__
vperm 6,4,3,5
#else
vperm 6,3,4,5
#endif
addi 11,12,16
addi 10,3,16
stvx 6,0,3
vor 3,4,4
L(setup_unaligned_loop):
mtctr 8
ble cr6,L(end_unaligned_loop)
/* Copy 32 bytes at a time using vector instructions. */
.align 4
L(unaligned_loop):
/* Note: vr6/vr10 may contain data that was already copied,
but in order to get proper alignment, we may have to copy
some portions again. This is faster than having unaligned
vector instructions though. */
lvx 4,11,6 /* vr4 = r11+16. */
#ifdef __LITTLE_ENDIAN__
vperm 6,4,3,5
#else
vperm 6,3,4,5
#endif
lvx 3,11,7 /* vr3 = r11+32. */
#ifdef __LITTLE_ENDIAN__
vperm 10,3,4,5
#else
vperm 10,4,3,5
#endif
addi 11,11,32
stvx 6,0,10
stvx 10,10,6
addi 10,10,32
bdnz L(unaligned_loop)
.align 4
L(end_unaligned_loop):
/* Check for tail bytes. */
clrrwi 0,31,4
mtcrf 0x01,31
beq cr1,0f
add 3,3,0
add 12,12,0
/* We have 1~15 tail bytes to copy, and DST is quadword aligned. */
8: /* Copy 8 bytes. */
bf 28,4f
lwz 6,0(12)
lwz 7,4(12)
addi 12,12,8
stw 6,0(3)
stw 7,4(3)
addi 3,3,8
4: /* Copy 4 bytes. */
bf 29,2f
lwz 6,0(12)
addi 12,12,4
stw 6,0(3)
addi 3,3,4
2: /* Copy 2~3 bytes. */
bf 30,1f
lhz 6,0(12)
addi 12,12,2
sth 6,0(3)
addi 3,3,2
1: /* Copy 1 byte. */
bf 31,0f
lbz 6,0(12)
stb 6,0(3)
0: /* Return DST + LEN pointer. */
add 3,30,5
lwz 30,20(1)
lwz 31,24(1)
addi 1,1,32
blr
END (__mempcpy)
libc_hidden_def (__mempcpy)
weak_alias (__mempcpy, mempcpy)
libc_hidden_builtin_def (mempcpy)