libavcodec/x86/fft_sse.c

   1 /*
   2  * FFT/MDCT transform with SSE optimizations
   3  * Copyright (c) 2008 Loren Merritt
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/x86_cpu.h"
  23 #include "libavcodec/dsputil.h"
  24
  25 DECLARE_ALIGNED(16, static const int, m1m1m1m1[4]) =
  26     { 1 << 31, 1 << 31, 1 << 31, 1 << 31 };
  27
  28 void ff_fft_dispatch_sse(FFTComplex *z, int nbits);
  29 void ff_fft_dispatch_interleave_sse(FFTComplex *z, int nbits);
  30
  31 void ff_fft_calc_sse(FFTContext *s, FFTComplex *z)
  32 {
  33     int n = 1 << s->nbits;
  34
  35     ff_fft_dispatch_interleave_sse(z, s->nbits);
  36
  37     if(n <= 16) {
  38         x86_reg i = -8*n;
  39         __asm__ volatile(
  40             "1: \n"
  41             "movaps     (%0,%1), %%xmm0 \n"
  42             "movaps      %%xmm0, %%xmm1 \n"
  43             "unpcklps 16(%0,%1), %%xmm0 \n"
  44             "unpckhps 16(%0,%1), %%xmm1 \n"
  45             "movaps      %%xmm0,   (%0,%1) \n"
  46             "movaps      %%xmm1, 16(%0,%1) \n"
  47             "add $32, %0 \n"
  48             "jl 1b \n"
  49             :"+r"(i)
  50             :"r"(z+n)
  51             :"memory"
  52         );
  53     }
  54 }
  55
  56 void ff_fft_permute_sse(FFTContext *s, FFTComplex *z)
  57 {
  58     int n = 1 << s->nbits;
  59     int i;
  60     for(i=0; i<n; i+=2) {
  61         __asm__ volatile(
  62             "movaps %2, %%xmm0 \n"
  63             "movlps %%xmm0, %0 \n"
  64             "movhps %%xmm0, %1 \n"
  65             :"=m"(s->tmp_buf[s->revtab[i]]),
  66              "=m"(s->tmp_buf[s->revtab[i+1]])
  67             :"m"(z[i])
  68         );
  69     }
  70     memcpy(z, s->tmp_buf, n*sizeof(FFTComplex));
  71 }
  72
  73 void ff_imdct_half_sse(MDCTContext *s, FFTSample *output, const FFTSample *input)
  74 {
  75     av_unused x86_reg i, j, k, l;
  76     long n = 1 << s->nbits;
  77     long n2 = n >> 1;
  78     long n4 = n >> 2;
  79     long n8 = n >> 3;
  80     const uint16_t *revtab = s->fft.revtab + n8;
  81     const FFTSample *tcos = s->tcos;
  82     const FFTSample *tsin = s->tsin;
  83     FFTComplex *z = (FFTComplex *)output;
  84
  85     /* pre rotation */
  86     for(k=n8-2; k>=0; k-=2) {
  87         __asm__ volatile(
  88             "movaps     (%2,%1,2), %%xmm0 \n" // { z[k].re,    z[k].im,    z[k+1].re,  z[k+1].im  }
  89             "movaps  -16(%2,%0,2), %%xmm1 \n" // { z[-k-2].re, z[-k-2].im, z[-k-1].re, z[-k-1].im }
  90             "movaps        %%xmm0, %%xmm2 \n"
  91             "shufps $0x88, %%xmm1, %%xmm0 \n" // { z[k].re,    z[k+1].re,  z[-k-2].re, z[-k-1].re }
  92             "shufps $0x77, %%xmm2, %%xmm1 \n" // { z[-k-1].im, z[-k-2].im, z[k+1].im,  z[k].im    }
  93             "movlps       (%3,%1), %%xmm4 \n"
  94             "movlps       (%4,%1), %%xmm5 \n"
  95             "movhps     -8(%3,%0), %%xmm4 \n" // { cos[k],     cos[k+1],   cos[-k-2],  cos[-k-1]  }
  96             "movhps     -8(%4,%0), %%xmm5 \n" // { sin[k],     sin[k+1],   sin[-k-2],  sin[-k-1]  }
  97             "movaps        %%xmm0, %%xmm2 \n"
  98             "movaps        %%xmm1, %%xmm3 \n"
  99             "mulps         %%xmm5, %%xmm0 \n" // re*sin
 100             "mulps         %%xmm4, %%xmm1 \n" // im*cos
 101             "mulps         %%xmm4, %%xmm2 \n" // re*cos
 102             "mulps         %%xmm5, %%xmm3 \n" // im*sin
 103             "subps         %%xmm0, %%xmm1 \n" // -> re
 104             "addps         %%xmm3, %%xmm2 \n" // -> im
 105             "movaps        %%xmm1, %%xmm0 \n"
 106             "unpcklps      %%xmm2, %%xmm1 \n" // { z[k],    z[k+1]  }
 107             "unpckhps      %%xmm2, %%xmm0 \n" // { z[-k-2], z[-k-1] }
 108             ::"r"(-4*k), "r"(4*k),
 109               "r"(input+n4), "r"(tcos+n8), "r"(tsin+n8)
 110         );
 111 #if ARCH_X86_64
 112         // if we have enough regs, don't let gcc make the luts latency-bound
 113         // but if not, latency is faster than spilling
 114         __asm__("movlps %%xmm0, %0 \n"
 115             "movhps %%xmm0, %1 \n"
 116             "movlps %%xmm1, %2 \n"
 117             "movhps %%xmm1, %3 \n"
 118             :"=m"(z[revtab[-k-2]]),
 119              "=m"(z[revtab[-k-1]]),
 120              "=m"(z[revtab[ k  ]]),
 121              "=m"(z[revtab[ k+1]])
 122         );
 123 #else
 124         __asm__("movlps %%xmm0, %0" :"=m"(z[revtab[-k-2]]));
 125         __asm__("movhps %%xmm0, %0" :"=m"(z[revtab[-k-1]]));
 126         __asm__("movlps %%xmm1, %0" :"=m"(z[revtab[ k  ]]));
 127         __asm__("movhps %%xmm1, %0" :"=m"(z[revtab[ k+1]]));
 128 #endif
 129     }
 130
 131     ff_fft_dispatch_sse(z, s->fft.nbits);
 132
 133     /* post rotation + reinterleave + reorder */
 134
 135 #define CMUL(j,xmm0,xmm1)\
 136         "movaps   (%2,"#j",2), %%xmm6 \n"\
 137         "movaps 16(%2,"#j",2), "#xmm0"\n"\
 138         "movaps        %%xmm6, "#xmm1"\n"\
 139         "movaps        "#xmm0",%%xmm7 \n"\
 140         "mulps      (%3,"#j"), %%xmm6 \n"\
 141         "mulps      (%4,"#j"), "#xmm0"\n"\
 142         "mulps      (%4,"#j"), "#xmm1"\n"\
 143         "mulps      (%3,"#j"), %%xmm7 \n"\
 144         "subps         %%xmm6, "#xmm0"\n"\
 145         "addps         %%xmm7, "#xmm1"\n"
 146
 147     j = -n2;
 148     k = n2-16;
 149     __asm__ volatile(
 150         "1: \n"
 151         CMUL(%0, %%xmm0, %%xmm1)
 152         CMUL(%1, %%xmm4, %%xmm5)
 153         "shufps    $0x1b, %%xmm1, %%xmm1 \n"
 154         "shufps    $0x1b, %%xmm5, %%xmm5 \n"
 155         "movaps   %%xmm4, %%xmm6 \n"
 156         "unpckhps %%xmm1, %%xmm4 \n"
 157         "unpcklps %%xmm1, %%xmm6 \n"
 158         "movaps   %%xmm0, %%xmm2 \n"
 159         "unpcklps %%xmm5, %%xmm0 \n"
 160         "unpckhps %%xmm5, %%xmm2 \n"
 161         "movaps   %%xmm6,   (%2,%1,2) \n"
 162         "movaps   %%xmm4, 16(%2,%1,2) \n"
 163         "movaps   %%xmm0,   (%2,%0,2) \n"
 164         "movaps   %%xmm2, 16(%2,%0,2) \n"
 165         "sub $16, %1 \n"
 166         "add $16, %0 \n"
 167         "jl 1b \n"
 168         :"+&r"(j), "+&r"(k)
 169         :"r"(z+n8), "r"(tcos+n8), "r"(tsin+n8)
 170         :"memory"
 171     );
 172 }
 173
 174 void ff_imdct_calc_sse(MDCTContext *s, FFTSample *output, const FFTSample *input)
 175 {
 176     x86_reg j, k;
 177     long n = 1 << s->nbits;
 178     long n4 = n >> 2;
 179
 180     ff_imdct_half_sse(s, output+n4, input);
 181
 182     j = -n;
 183     k = n-16;
 184     __asm__ volatile(
 185         "movaps %4, %%xmm7 \n"
 186         "1: \n"
 187         "movaps       (%2,%1), %%xmm0 \n"
 188         "movaps       (%3,%0), %%xmm1 \n"
 189         "shufps $0x1b, %%xmm0, %%xmm0 \n"
 190         "shufps $0x1b, %%xmm1, %%xmm1 \n"
 191         "xorps         %%xmm7, %%xmm0 \n"
 192         "movaps        %%xmm1, (%3,%1) \n"
 193         "movaps        %%xmm0, (%2,%0) \n"
 194         "sub $16, %1 \n"
 195         "add $16, %0 \n"
 196         "jl 1b \n"
 197         :"+r"(j), "+r"(k)
 198         :"r"(output+n4), "r"(output+n4*3),
 199          "m"(*m1m1m1m1)
 200     );
 201 }
 202