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x86/tx_float: generalize iMDCT

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To support non-aligned buffers during the post-transform step, just iterate
backwards over the array.

This allows using the 15xN-point FFT, with which the speed is 2.1 times
faster than our old libavcodec implementation.
This commit is contained in:
Lynne 2022-09-23 10:38:29 +02:00
parent ace42cf581
commit 74e8541bab
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GPG Key ID: A2FEA5F03F034464
2 changed files with 40 additions and 29 deletions
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52
libavutil/x86/tx_float.asm
View File

@ -1389,17 +1389,16 @@ FFT_SPLIT_RADIX_FN avx2, 1
%macro IMDCT_FN 1
INIT_YMM %1
cglobal mdct_sr_inv_float, 4, 13, 16, 272, ctx, out, in, stride, len, lut, exp, t1, t2, t3, t4, t5, bctx
cglobal mdct_inv_float, 4, 14, 16, 320, ctx, out, in, stride, len, lut, exp, t1, t2, t3, \
t4, t5, btmp
movsxd lenq, dword [ctxq + AVTXContext.len]
mov expq, [ctxq + AVTXContext.exp]
lea t1d, [lend - 1]
imul t1d, strided
mov bctxq, ctxq ; backup original context
mov t5q, [ctxq + AVTXContext.fn] ; subtransform's jump point
mov ctxq, [ctxq + AVTXContext.sub] ; load subtransform's context
mov lutq, [ctxq + AVTXContext.map] ; load subtransform's map
mov btmpq, ctxq ; backup original context
mov lutq, [ctxq + AVTXContext.map] ; load map
cmp strideq, 4
je .stride4
@ -1444,8 +1443,8 @@ cglobal mdct_sr_inv_float, 4, 13, 16, 272, ctx, out, in, stride, len, lut, exp,
fmaddsubps m10, m12, m2, m10
fmaddsubps m11, m13, m3, m11
mova [t2q + 0*mmsize], m10
mova [t2q + 1*mmsize], m11
movups [t2q + 0*mmsize], m10
movups [t2q + 1*mmsize], m11
add expq, mmsize*2
add lutq, mmsize
@ -1462,16 +1461,16 @@ cglobal mdct_sr_inv_float, 4, 13, 16, 272, ctx, out, in, stride, len, lut, exp,
lea t2q, [lenq*2 - mmsize/2]
.stride4_pre:
movaps m4, [inq]
movaps m3, [t1q]
movups m4, [inq]
movups m3, [t1q]
movsldup m1, m4 ; im im, im im
movshdup m0, m3 ; re re, re re
movshdup m4, m4 ; re re, re re (2)
movsldup m3, m3 ; im im, im im (2)
movaps m2, [expq] ; tab
movaps m5, [expq + 2*t2q] ; tab (2)
movups m2, [expq] ; tab
movups m5, [expq + 2*t2q] ; tab (2)
vpermpd m0, m0, q0123 ; flip
shufps m7, m2, m2, q2301
@ -1513,29 +1512,31 @@ cglobal mdct_sr_inv_float, 4, 13, 16, 272, ctx, out, in, stride, len, lut, exp,
add inq, mmsize
sub t1q, mmsize
sub t2q, mmsize
jg .stride4_pre
jge .stride4_pre
.transform:
mov t4q, ctxq ; backup original context
mov t5q, [ctxq + AVTXContext.fn] ; subtransform's jump point
mov ctxq, [ctxq + AVTXContext.sub]
mov lutq, [ctxq + AVTXContext.map]
movsxd lenq, dword [ctxq + AVTXContext.len]
mov inq, outq ; in-place transform
call t5q ; call the FFT
mov ctxq, bctxq ; restore original context
mov ctxq, t4q ; restore original context
movsxd lenq, dword [ctxq + AVTXContext.len]
mov expq, [ctxq + AVTXContext.exp]
lea expq, [expq + lenq*4]
lea t1q, [lenq*2] ; high
lea t2q, [lenq*2 - mmsize] ; low
neg lenq
lea outq, [outq + lenq*4]
xor t1q, t1q ; low
lea t2q, [lenq*4 - mmsize] ; high
.post:
movaps m2, [expq + t1q] ; tab h
movaps m3, [expq + t2q] ; tab l
movaps m0, [outq + t1q] ; in h
movaps m1, [outq + t2q] ; in l
movaps m2, [expq + t2q] ; tab h
movaps m3, [expq + t1q] ; tab l
movups m0, [outq + t2q] ; in h
movups m1, [outq + t1q] ; in l
movshdup m4, m2 ; tab h imim
movshdup m5, m3 ; tab l imim
@ -1557,12 +1558,13 @@ cglobal mdct_sr_inv_float, 4, 13, 16, 272, ctx, out, in, stride, len, lut, exp,
blendps m1, m2, m5, 01010101b
blendps m0, m3, m4, 01010101b
movaps [outq + t2q], m1
movaps [outq + t1q], m0
movups [outq + t2q], m0
movups [outq + t1q], m1
add t1q, mmsize
sub t2q, mmsize
jge .post
sub lenq, mmsize/2
jg .post
RET
%endmacro

17
libavutil/x86/tx_float_init.c
View File

@ -46,7 +46,7 @@ TX_DECL_FN(fft_sr_ns, avx2)
TX_DECL_FN(fft_pfa_15xM, avx2)
TX_DECL_FN(fft_pfa_15xM_ns, avx2)
TX_DECL_FN(mdct_sr_inv, avx2)
TX_DECL_FN(mdct_inv, avx2)
TX_DECL_FN(fft2_asm, sse3)
TX_DECL_FN(fft4_fwd_asm, sse2)
@ -87,7 +87,7 @@ static av_cold int m_inv_init(AVTXContext *s, const FFTXCodelet *cd,
int len, int inv, const void *scale)
{
int ret;
FFTXCodeletOptions sub_opts = { .invert_lookup = -1 };
FFTXCodeletOptions sub_opts = { .invert_lookup = 1 };
s->scale_d = *((SCALE_TYPE *)scale);
s->scale_f = s->scale_d;
@ -101,7 +101,16 @@ static av_cold int m_inv_init(AVTXContext *s, const FFTXCodelet *cd,
inv, scale)))
return ret;
if ((ret = ff_tx_mdct_gen_exp_float(s, s->sub->map)))
s->map = av_malloc(len*sizeof(*s->map));
if (!s->map)
return AVERROR(ENOMEM);
memcpy(s->map, s->sub->map, (len >> 1)*sizeof(*s->map));
/* Invert lookup table for unstrided path */
for (int i = 0; i < (len >> 1); i++)
s->map[(len >> 1) + s->map[i]] = i;
if ((ret = ff_tx_mdct_gen_exp_float(s, s->map)))
return ret;
return 0;
@ -226,7 +235,7 @@ const FFTXCodelet * const ff_tx_codelet_list_float_x86[] = {
TX_DEF(fft_pfa_15xM_ns, FFT, 60, TX_LEN_UNLIMITED, 15, TX_FACTOR_ANY, 384, fft_pfa_init, avx2, AVX2,
AV_TX_INPLACE | FF_TX_PRESHUFFLE, AV_CPU_FLAG_AVXSLOW | AV_CPU_FLAG_SLOW_GATHER),
TX_DEF(mdct_sr_inv, MDCT, 16, TX_LEN_UNLIMITED, 2, TX_FACTOR_ANY, 384, m_inv_init, avx2, AVX2,
TX_DEF(mdct_inv, MDCT, 16, TX_LEN_UNLIMITED, 2, TX_FACTOR_ANY, 384, m_inv_init, avx2, AVX2,
FF_TX_INVERSE_ONLY, AV_CPU_FLAG_AVXSLOW | AV_CPU_FLAG_SLOW_GATHER),
#endif
#endif