| /* |
| * 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 |
| li t0, 1 |
| vsetvli zero, a2, e64, m8, ta, ma |
| 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 |