/* Cloned and hacked for uClibc by Paul Mundt, December 2003 */
/* Modified by SuperH, Inc. September 2003 */
!
! Fast SH memcpy
!
! by Toshiyasu Morita (tm@netcom.com)
! hacked by J"orn Rernnecke (joern.rennecke@superh.com) ("o for o-umlaut)
! SH5 code Copyright 2002 SuperH Ltd.
!
! Entry: ARG0: destination pointer
! ARG1: source pointer
! ARG2: byte count
!
! Exit: RESULT: destination pointer
! any other registers in the range r0-r7: trashed
!
! Notes: Usually one wants to do small reads and write a longword, but
! unfortunately it is difficult in some cases to concatanate bytes
! into a longword on the SH, so this does a longword read and small
! writes.
!
! This implementation makes two assumptions about how it is called:
!
! 1.: If the byte count is nonzero, the address of the last byte to be
! copied is unsigned greater than the address of the first byte to
! be copied. This could be easily swapped for a signed comparison,
! but the algorithm used needs some comparison.
!
! 2.: When there are two or three bytes in the last word of an 11-or-more
! bytes memory chunk to b copied, the rest of the word can be read
! without side effects.
! This could be easily changed by increasing the minimum size of
! a fast memcpy and the amount subtracted from r7 before L_2l_loop be 2,
! however, this would cost a few extra cyles on average.
! For SHmedia, the assumption is that any quadword can be read in its
! enirety if at least one byte is included in the copy.
!
.section .text..SHmedia32,"ax"
.globl memcpy
.type memcpy, @function
.align 5
memcpy:
#define LDUAQ(P,O,D0,D1) ldlo.q P,O,D0; ldhi.q P,O+7,D1
#define STUAQ(P,O,D0,D1) stlo.q P,O,D0; sthi.q P,O+7,D1
#define LDUAL(P,O,D0,D1) ldlo.l P,O,D0; ldhi.l P,O+3,D1
#define STUAL(P,O,D0,D1) stlo.l P,O,D0; sthi.l P,O+3,D1
ld.b r3,0,r63
pta/l Large,tr0
movi 25,r0
bgeu/u r4,r0,tr0
nsb r4,r0
shlli r0,5,r0
movi (L1-L0+63*32 + 1) & 0xffff,r1
sub r1, r0, r0
L0: ptrel r0,tr0
add r2,r4,r5
ptabs r18,tr1
add r3,r4,r6
blink tr0,r63
/* Rearranged to make cut2 safe */
.balign 8
L4_7: /* 4..7 byte memcpy cntd. */
stlo.l r2, 0, r0
or r6, r7, r6
sthi.l r5, -1, r6
stlo.l r5, -4, r6
blink tr1,r63
.balign 8
L1: /* 0 byte memcpy */
nop
blink tr1,r63
nop
nop
nop
nop
L2_3: /* 2 or 3 byte memcpy cntd. */
st.b r5,-1,r6
blink tr1,r63
/* 1 byte memcpy */
ld.b r3,0,r0
st.b r2,0,r0
blink tr1,r63
L8_15: /* 8..15 byte memcpy cntd. */
stlo.q r2, 0, r0
or r6, r7, r6
sthi.q r5, -1, r6
stlo.q r5, -8, r6
blink tr1,r63
/* 2 or 3 byte memcpy */
ld.b r3,0,r0
ld.b r2,0,r63
ld.b r3,1,r1
st.b r2,0,r0
pta/l L2_3,tr0
ld.b r6,-1,r6
st.b r2,1,r1
blink tr0, r63
/* 4 .. 7 byte memcpy */
LDUAL (r3, 0, r0, r1)
pta L4_7, tr0
ldlo.l r6, -4, r7
or r0, r1, r0
sthi.l r2, 3, r0
ldhi.l r6, -1, r6
blink tr0, r63
/* 8 .. 15 byte memcpy */
LDUAQ (r3, 0, r0, r1)
pta L8_15, tr0
ldlo.q r6, -8, r7
or r0, r1, r0
sthi.q r2, 7, r0
ldhi.q r6, -1, r6
blink tr0, r63
/* 16 .. 24 byte memcpy */
LDUAQ (r3, 0, r0, r1)
LDUAQ (r3, 8, r8, r9)
or r0, r1, r0
sthi.q r2, 7, r0
or r8, r9, r8
sthi.q r2, 15, r8
ldlo.q r6, -8, r7
ldhi.q r6, -1, r6
stlo.q r2, 8, r8
stlo.q r2, 0, r0
or r6, r7, r6
sthi.q r5, -1, r6
stlo.q r5, -8, r6
blink tr1,r63
Large:
ld.b r2, 0, r63
pta/l Loop_ua, tr1
ori r3, -8, r7
sub r2, r7, r22
sub r3, r2, r6
add r2, r4, r5
ldlo.q r3, 0, r0
addi r5, -16, r5
movi 64+8, r27 // could subtract r7 from that.
stlo.q r2, 0, r0
sthi.q r2, 7, r0
ldx.q r22, r6, r0
bgtu/l r27, r4, tr1
addi r5, -48, r27
pta/l Loop_line, tr0
addi r6, 64, r36
addi r6, -24, r19
addi r6, -16, r20
addi r6, -8, r21
Loop_line:
ldx.q r22, r36, r63
alloco r22, 32
addi r22, 32, r22
ldx.q r22, r19, r23
sthi.q r22, -25, r0
ldx.q r22, r20, r24
ldx.q r22, r21, r25
stlo.q r22, -32, r0
ldx.q r22, r6, r0
sthi.q r22, -17, r23
sthi.q r22, -9, r24
sthi.q r22, -1, r25
stlo.q r22, -24, r23
stlo.q r22, -16, r24
stlo.q r22, -8, r25
bgeu r27, r22, tr0
Loop_ua:
addi r22, 8, r22
sthi.q r22, -1, r0
stlo.q r22, -8, r0
ldx.q r22, r6, r0
bgtu/l r5, r22, tr1
add r3, r4, r7
ldlo.q r7, -8, r1
sthi.q r22, 7, r0
ldhi.q r7, -1, r7
ptabs r18,tr1
stlo.q r22, 0, r0
or r1, r7, r1
sthi.q r5, 15, r1
stlo.q r5, 8, r1
blink tr1, r63
.size memcpy,.-memcpy
