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linux/arch/loongarch/lib/xor_simd.c
WANG Xuerui 75ded18a5e LoongArch: Add SIMD-optimized XOR routines
Add LSX and LASX implementations of xor operations, operating on 64
bytes (one L1 cache line) at a time, for a balance between memory
utilization and instruction mix. Huacai confirmed that all future
LoongArch implementations by Loongson (that we care) will likely also
feature 64-byte cache lines, and experiments show no throughput
improvement with further unrolling.

Performance numbers measured during system boot on a 3A5000 @ 2.5GHz:

> 8regs           : 12702 MB/sec
> 8regs_prefetch  : 10920 MB/sec
> 32regs          : 12686 MB/sec
> 32regs_prefetch : 10918 MB/sec
> lsx             : 17589 MB/sec
> lasx            : 26116 MB/sec

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 22:53:55 +08:00

94 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* LoongArch SIMD XOR operations
*
* Copyright (C) 2023 WANG Xuerui <git@xen0n.name>
*/
#include "xor_simd.h"
/*
* Process one cache line (64 bytes) per loop. This is assuming all future
* popular LoongArch cores are similar performance-characteristics-wise to the
* current models.
*/
#define LINE_WIDTH 64
#ifdef CONFIG_CPU_HAS_LSX
#define LD(reg, base, offset) \
"vld $vr" #reg ", %[" #base "], " #offset "\n\t"
#define ST(reg, base, offset) \
"vst $vr" #reg ", %[" #base "], " #offset "\n\t"
#define XOR(dj, k) "vxor.v $vr" #dj ", $vr" #dj ", $vr" #k "\n\t"
#define LD_INOUT_LINE(base) \
LD(0, base, 0) \
LD(1, base, 16) \
LD(2, base, 32) \
LD(3, base, 48)
#define LD_AND_XOR_LINE(base) \
LD(4, base, 0) \
LD(5, base, 16) \
LD(6, base, 32) \
LD(7, base, 48) \
XOR(0, 4) \
XOR(1, 5) \
XOR(2, 6) \
XOR(3, 7)
#define ST_LINE(base) \
ST(0, base, 0) \
ST(1, base, 16) \
ST(2, base, 32) \
ST(3, base, 48)
#define XOR_FUNC_NAME(nr) __xor_lsx_##nr
#include "xor_template.c"
#undef LD
#undef ST
#undef XOR
#undef LD_INOUT_LINE
#undef LD_AND_XOR_LINE
#undef ST_LINE
#undef XOR_FUNC_NAME
#endif /* CONFIG_CPU_HAS_LSX */
#ifdef CONFIG_CPU_HAS_LASX
#define LD(reg, base, offset) \
"xvld $xr" #reg ", %[" #base "], " #offset "\n\t"
#define ST(reg, base, offset) \
"xvst $xr" #reg ", %[" #base "], " #offset "\n\t"
#define XOR(dj, k) "xvxor.v $xr" #dj ", $xr" #dj ", $xr" #k "\n\t"
#define LD_INOUT_LINE(base) \
LD(0, base, 0) \
LD(1, base, 32)
#define LD_AND_XOR_LINE(base) \
LD(2, base, 0) \
LD(3, base, 32) \
XOR(0, 2) \
XOR(1, 3)
#define ST_LINE(base) \
ST(0, base, 0) \
ST(1, base, 32)
#define XOR_FUNC_NAME(nr) __xor_lasx_##nr
#include "xor_template.c"
#undef LD
#undef ST
#undef XOR
#undef LD_INOUT_LINE
#undef LD_AND_XOR_LINE
#undef ST_LINE
#undef XOR_FUNC_NAME
#endif /* CONFIG_CPU_HAS_LASX */