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#define BDNZ BC 16,0,
TEXT memmove(SB), $0
BR move
TEXT memcpy(SB), $0
move:
/*
* performance:
* (tba)
*/
MOVW R3, s1+0(FP)
MOVW n+8(FP), R9 /* R9 is count */
MOVW R3, R10 /* R10 is to-pointer */
CMP R9, $0
BEQ ret
BLT trap
MOVW s2+4(FP), R11 /* R11 is from-pointer */
/*
* if no more than 16 bytes, just use one lsw/stsw
*/
CMP R9, $16
BLE fout
ADD R9,R11, R13 /* R13 is end from-pointer */
ADD R9,R10, R12 /* R12 is end to-pointer */
/*
* easiest test is copy backwards if
* destination string has higher mem address
*/
CMPU R10, R11
BGT back
/*
* test if both pointers
* are similarly word aligned
*/
XOR R10,R11, R7
ANDCC $3,R7
BNE fbad
/*
* move a few bytes to align pointers
*/
ANDCC $3,R10,R7
BEQ f2
SUBC R7, $4, R7
SUB R7, R9
MOVW R7, XER
LSW (R11), R16
ADD R7, R11
STSW R16, (R10)
ADD R7, R10
/*
* turn R14 into doubleword count
* copy 16 bytes at a time while there's room.
*/
f2:
SRAWCC $4, R9, R14
BLE fout
MOVW R14, CTR
SUB $4, R11
SUB $4, R10
f3:
MOVWU 4(R11), R16
MOVWU 4(R11), R17
MOVWU 4(R11), R18
MOVWU 4(R11), R19
MOVWU R16, 4(R10)
MOVWU R17, 4(R10)
MOVWU R18, 4(R10)
MOVWU R19, 4(R10)
BDNZ f3
RLWNMCC $0, R9, $15, R9 /* residue */
BEQ ret
ADD $4, R11
ADD $4, R10
/*
* move up to 16 bytes through R16 .. R19; aligned and unaligned
*/
fout:
MOVW R9, XER
LSW (R11), R16
STSW R16, (R10)
BR ret
/*
* loop for unaligned copy, then copy up to 15 remaining bytes
*/
fbad:
SRAWCC $4, R9, R14
BLE f6
MOVW R14, CTR
f5:
LSW (R11), $16, R16
ADD $16, R11
STSW R16, $16, (R10)
ADD $16, R10
BDNZ f5
RLWNMCC $0, R9, $15, R9 /* residue */
BEQ ret
f6:
MOVW R9, XER
LSW (R11), R16
STSW R16, (R10)
BR ret
/*
* whole thing repeated for backwards
*/
back:
CMP R9, $4
BLT bout
XOR R12,R13, R7
ANDCC $3,R7
BNE bout
b1:
ANDCC $3,R13, R7
BEQ b2
MOVBZU -1(R13), R16
MOVBZU R16, -1(R12)
SUB $1, R9
BR b1
b2:
SRAWCC $4, R9, R14
BLE b4
MOVW R14, CTR
b3:
MOVWU -4(R13), R16
MOVWU -4(R13), R17
MOVWU -4(R13), R18
MOVWU -4(R13), R19
MOVWU R16, -4(R12)
MOVWU R17, -4(R12)
MOVWU R18, -4(R12)
MOVWU R19, -4(R12)
BDNZ b3
RLWNMCC $0, R9, $15, R9 /* residue */
BEQ ret
b4:
SRAWCC $2, R9, R14
BLE bout
MOVW R14, CTR
b5:
MOVWU -4(R13), R16
MOVWU R16, -4(R12)
BDNZ b5
RLWNMCC $0, R9, $3, R9 /* residue */
BEQ ret
bout:
CMPU R13, R11
BLE ret
MOVBZU -1(R13), R16
MOVBZU R16, -1(R12)
BR bout
trap:
MOVW $0, R0
MOVW 0(R0), R0
ret:
MOVW s1+0(FP), R3
RETURN
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