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FFmpeg/libavcodec/riscv/lpc_rvv.S
Rémi Denis-Courmont 4fe8f2cc43 riscv: allow passing addend to vtype_vli macro
A constant (-1) is added to the length value, so we can have an added
for free, and optimise the addition away if the addend is exactly 1.
2024-05-30 18:30:52 +03:00

120 lines
3.7 KiB
ArmAsm

/*
* Copyright © 2023 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
*/
#include "libavutil/riscv/asm.S"
#if __riscv_xlen >= 64
func ff_lpc_apply_welch_window_rvv, zve64d
vsetvli t0, zero, e64, m8, ta, ma
vid.v v0
addi t2, a1, -1
vfcvt.f.xu.v v0, v0
li t3, 2
fcvt.d.l ft2, t2
srai t1, a1, 1
fcvt.d.l ft3, t3
li t4, 1
fdiv.d ft0, ft3, ft2 # ft0 = c = 2. / (len - 1)
fcvt.d.l fa1, t4 # fa1 = 1.
fsub.d ft1, ft0, fa1
vfrsub.vf v0, v0, ft1 # v0[i] = c - i - 1.
1:
vsetvli t0, t1, e64, m8, ta, ma
vfmul.vv v16, v0, v0 # no fused multipy-add as v0 is reused
sub t1, t1, t0
vle32.v v8, (a0)
fcvt.d.l ft2, t0
vfrsub.vf v16, v16, fa1 # v16 = 1. - w * w
sh2add a0, t0, a0
vsetvli zero, zero, e32, m4, ta, ma
vfwcvt.f.x.v v24, v8
vsetvli zero, zero, e64, m8, ta, ma
vfsub.vf v0, v0, ft2 # v0 -= vl
vfmul.vv v8, v24, v16
vse64.v v8, (a2)
sh3add a2, t0, a2
bnez t1, 1b
andi t1, a1, 1
beqz t1, 2f
sd zero, (a2)
addi a0, a0, 4
addi a2, a2, 8
2:
vsetvli t0, zero, e64, m8, ta, ma
vid.v v0
srai t1, a1, 1
vfcvt.f.xu.v v0, v0
fcvt.d.l ft1, t1
fsub.d ft1, ft0, ft1 # ft1 = c - (len / 2)
vfadd.vf v0, v0, ft1 # v0[i] = c - (len / 2) + i
3:
vsetvli t0, t1, e64, m8, ta, ma
vfmul.vv v16, v0, v0
sub t1, t1, t0
vle32.v v8, (a0)
fcvt.d.l ft2, t0
vfrsub.vf v16, v16, fa1 # v16 = 1. - w * w
sh2add a0, t0, a0
vsetvli zero, zero, e32, m4, ta, ma
vfwcvt.f.x.v v24, v8
vsetvli zero, zero, e64, m8, ta, ma
vfadd.vf v0, v0, ft2 # v0 += vl
vfmul.vv v8, v24, v16
vse64.v v8, (a2)
sh3add a2, t0, a2
bnez t1, 3b
ret
endfunc
func ff_lpc_compute_autocorr_rvv, zve64d, zbb
vtype_vli t1, a2, t2, e64, ta, ma, 1
addi a2, a2, 1
li t0, 1
vsetvl zero, a2, t1
fcvt.d.l ft0, t0
vle64.v v0, (a0)
sh3add a0, a2, a0 # data += lag
vfmv.v.f v16, ft0
bge a2, a1, 2f
1:
vfmv.f.s ft0, v0
fld ft1, (a0) # ft1 = data[lag + i]
vfmacc.vf v16, ft0, v0 # v16[j] += data[i] * data[i + j]
addi a1, a1, -1
vfslide1down.vf v0, v0, ft1
addi a0, a0, 8
bgt a1, a2, 1b # while (len > lag);
2:
vfmv.f.s ft0, v0
vsetvli zero, a1, e64, m8, tu, ma
vfmacc.vf v16, ft0, v0
addi a1, a1, -1
vslide1down.vx v0, v0, zero
bnez a1, 2b # while (len > 0);
vsetvli zero, a2, e64, m8, ta, ma
vse64.v v16, (a3)
ret
endfunc
#endif