gmsm/internal/subtle/xor_s390x.s
2024-08-28 08:56:01 +08:00

72 lines
1.2 KiB
ArmAsm

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//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, $64, less_than64
loop64b:
VLM (R2)(R5*1), V0, V3
VLM (R3)(R5*1), V4, V7
VX V0, V4, V4
VX V1, V5, V5
VX V2, V6, V6
VX V3, V7, V7
VSTM V4, V7, (R1)(R5*1)
LAY 64(R5), R5
SUB $64, R4
CMPBGE R4, $64, loop64b
less_than64:
CMPBEQ R4, $0, done // quick end
CMPBLT R4, $32, less_than32
VLM (R2)(R5*1), V0, V1
VLM (R3)(R5*1), V2, V3
VX V0, V2, V2
VX V1, V3, V3
VSTM V2, V3, (R1)(R5*1)
LAY 32(R5), R5
SUB $32, R4
less_than32:
CMPBLT R4, $16, less_than16
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
less_than16:
CMPBLT R4, $8, tail
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
tail:
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)
LAY 1(R5), R5
SUB $1, R4
BR tail
done:
RET