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FFmpeg/libavutil/riscv/bswap_rvb.S
Rémi Denis-Courmont bd0c3edb13 lavu/riscv: count bytes rather than words for bswap32
This removes the dependency on Zba at essentially zero cost.
2024-07-30 18:41:51 +03:00

66 lines
2.0 KiB
ArmAsm

/*
* Copyright © 2022 Rémi Denis-Courmont.
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if (__riscv_xlen >= 64)
.macro bswap32_rvb out, in, count
andi t0, \count, 1
beqz t0, 1f
/* Align input to 64-bit */
lwu t0, (\in)
addi \out, \out, 4
rev8 t0, t0
addi \count, \count, -4
srli t0, t0, __riscv_xlen - 32
addi \in, \in, 4
sw t0, -4(\out)
1:
andi t3, \count, -8
add \count, \count, \out
beqz t3, 3f
add t3, t3, \out
2: /* 2 elements (64 bits) at a time on a 64-bit boundary */
ld t0, (\in)
addi \out, \out, 8
rev8 t0, t0
#if (__riscv_xlen == 64)
srli t2, t0, 32
sw t0, -4(\out)
#else
srli t1, t0, __riscv_xlen - 64
srli t2, t0, __riscv_xlen - 32
sw t1, -4(\out)
#endif
addi \in, \in, 8
sw t2, -8(\out)
bne \out, t3, 2b
3:
beq \out, \count, 5f
4: /* Process last element */
lwu t0, (\in)
addi \out, \out, 4
rev8 t0, t0
addi \in, \in, 4
srli t0, t0, __riscv_xlen - 32
sw t0, -4(\out)
5:
ret
.endm
#endif