gmsm/internal/subtle/xor_s390x.s

61 lines
948 B
ArmAsm

//go:build !purego
#include "textflag.h"
// func xorBytes(dst, a, b *byte, n int)
TEXT ·xorBytes(SB),NOSPLIT,$0-32
MOVD dst+0(FP), R1
MOVD a+8(FP), R2
MOVD b+16(FP), R3
MOVD n+24(FP), R4
MOVD $0, R5
CMPBLT R4, $16, tail
loop16b:
VL 0(R2)(R5*1), V0
VL 0(R3)(R5*1), V1
VX V0, V1, V2
VST V2, 0(R1)(R5*1)
LAY 16(R5), R5
SUB $16, R4
CMPBGE R4, $16, loop16b
tail:
CMPBEQ R4, $0, done
CMPBLT R4, $8, less_than8
MOVD 0(R2)(R5*1), R7
MOVD 0(R3)(R5*1), R8
XOR R7, R8
MOVD R8, 0(R1)(R5*1)
LAY 8(R5), R5
SUB $8, R4
less_than8:
CMPBLT R4, $4, less_than4
MOVWZ 0(R2)(R5*1), R7
MOVWZ 0(R3)(R5*1), R8
XOR R7, R8
MOVW R8, 0(R1)(R5*1)
LAY 4(R5), R5
SUB $4, R4
less_than4:
CMPBLT R4, $2, less_than2
MOVHZ 0(R2)(R5*1), R7
MOVHZ 0(R3)(R5*1), R8
XOR R7, R8
MOVH R8, 0(R1)(R5*1)
LAY 2(R5), R5
SUB $2, R4
less_than2:
CMPBEQ R4, $0, done
MOVB 0(R2)(R5*1), R7
MOVB 0(R3)(R5*1), R8
XOR R7, R8
MOVB R8, 0(R1)(R5*1)
done:
RET