ppc: fft: Build AltiVec optimizations in the standard way

1 files changed, 156 insertions, 0 deletions

diff --git a/libavcodec/ppc/fft_init.c b/libavcodec/ppc/fft_init.c
new file mode 100644
index 0000000000..8fcc033b53
--- /dev/null
+++ b/libavcodec/ppc/fft_init.c
@@ -0,0 +1,156 @@
+/*
+ * FFT/IFFT transforms
+ * AltiVec-enabled
+ * Copyright (c) 2009 Loren Merritt
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "libavutil/cpu.h"
+#include "libavutil/ppc/cpu.h"
+#include "libavutil/ppc/types_altivec.h"
+#include "libavutil/ppc/util_altivec.h"
+#include "libavcodec/fft.h"
+
+/**
+ * Do a complex FFT with the parameters defined in ff_fft_init().
+ * The input data must be permuted before with s->revtab table.
+ * No 1.0 / sqrt(n) normalization is done.
+ * AltiVec-enabled:
+ * This code assumes that the 'z' pointer is 16 bytes-aligned.
+ * It also assumes all FFTComplex are 8 bytes-aligned pairs of floats.
+ */
+
+void ff_fft_calc_altivec(FFTContext *s, FFTComplex *z);
+void ff_fft_calc_interleave_altivec(FFTContext *s, FFTComplex *z);
+
+#if HAVE_GNU_AS && HAVE_ALTIVEC
+static void imdct_half_altivec(FFTContext *s, FFTSample *output, const FFTSample *input)
+{
+    int j, k;
+    int n = 1 << s->mdct_bits;
+    int n4 = n >> 2;
+    int n8 = n >> 3;
+    int n32 = n >> 5;
+    const uint16_t *revtabj = s->revtab;
+    const uint16_t *revtabk = s->revtab+n4;
+    const vec_f *tcos = (const vec_f*)(s->tcos+n8);
+    const vec_f *tsin = (const vec_f*)(s->tsin+n8);
+    const vec_f *pin = (const vec_f*)(input+n4);
+    vec_f *pout = (vec_f*)(output+n4);
+
+    /* pre rotation */
+    k = n32-1;
+    do {
+        vec_f cos,sin,cos0,sin0,cos1,sin1,re,im,r0,i0,r1,i1,a,b,c,d;
+#define CMULA(p,o0,o1,o2,o3)\
+        a = pin[ k*2+p];                       /* { z[k].re,    z[k].im,    z[k+1].re,  z[k+1].im  } */\
+        b = pin[-k*2-p-1];                     /* { z[-k-2].re, z[-k-2].im, z[-k-1].re, z[-k-1].im } */\
+        re = vec_perm(a, b, vcprm(0,2,s0,s2)); /* { z[k].re,    z[k+1].re,  z[-k-2].re, z[-k-1].re } */\
+        im = vec_perm(a, b, vcprm(s3,s1,3,1)); /* { z[-k-1].im, z[-k-2].im, z[k+1].im,  z[k].im    } */\
+        cos = vec_perm(cos0, cos1, vcprm(o0,o1,s##o2,s##o3)); /* { cos[k], cos[k+1], cos[-k-2], cos[-k-1] } */\
+        sin = vec_perm(sin0, sin1, vcprm(o0,o1,s##o2,s##o3));\
+        r##p = im*cos - re*sin;\
+        i##p = re*cos + im*sin;
+#define STORE2(v,dst)\
+        j = dst;\
+        vec_ste(v, 0, output+j*2);\
+        vec_ste(v, 4, output+j*2);
+#define STORE8(p)\
+        a = vec_perm(r##p, i##p, vcprm(0,s0,0,s0));\
+        b = vec_perm(r##p, i##p, vcprm(1,s1,1,s1));\
+        c = vec_perm(r##p, i##p, vcprm(2,s2,2,s2));\
+        d = vec_perm(r##p, i##p, vcprm(3,s3,3,s3));\
+        STORE2(a, revtabk[ p*2-4]);\
+        STORE2(b, revtabk[ p*2-3]);\
+        STORE2(c, revtabj[-p*2+2]);\
+        STORE2(d, revtabj[-p*2+3]);
+
+        cos0 = tcos[k];
+        sin0 = tsin[k];
+        cos1 = tcos[-k-1];
+        sin1 = tsin[-k-1];
+        CMULA(0, 0,1,2,3);
+        CMULA(1, 2,3,0,1);
+        STORE8(0);
+        STORE8(1);
+        revtabj += 4;
+        revtabk -= 4;
+        k--;
+    } while(k >= 0);
+
+    ff_fft_calc_altivec(s, (FFTComplex*)output);
+
+    /* post rotation + reordering */
+    j = -n32;
+    k = n32-1;
+    do {
+        vec_f cos,sin,re,im,a,b,c,d;
+#define CMULB(d0,d1,o)\
+        re = pout[o*2];\
+        im = pout[o*2+1];\
+        cos = tcos[o];\
+        sin = tsin[o];\
+        d0 = im*sin - re*cos;\
+        d1 = re*sin + im*cos;
+
+        CMULB(a,b,j);
+        CMULB(c,d,k);
+        pout[2*j]   = vec_perm(a, d, vcprm(0,s3,1,s2));
+        pout[2*j+1] = vec_perm(a, d, vcprm(2,s1,3,s0));
+        pout[2*k]   = vec_perm(c, b, vcprm(0,s3,1,s2));
+        pout[2*k+1] = vec_perm(c, b, vcprm(2,s1,3,s0));
+        j++;
+        k--;
+    } while(k >= 0);
+}
+
+static void imdct_calc_altivec(FFTContext *s, FFTSample *output, const FFTSample *input)
+{
+    int k;
+    int n = 1 << s->mdct_bits;
+    int n4 = n >> 2;
+    int n16 = n >> 4;
+    vec_u32 sign = {1U<<31,1U<<31,1U<<31,1U<<31};
+    vec_u32 *p0 = (vec_u32*)(output+n4);
+    vec_u32 *p1 = (vec_u32*)(output+n4*3);
+
+    imdct_half_altivec(s, output + n4, input);
+
+    for (k = 0; k < n16; k++) {
+        vec_u32 a = p0[k] ^ sign;
+        vec_u32 b = p1[-k-1];
+        p0[-k-1] = vec_perm(a, a, vcprm(3,2,1,0));
+        p1[k]    = vec_perm(b, b, vcprm(3,2,1,0));
+    }
+}
+#endif /* HAVE_GNU_AS && HAVE_ALTIVEC */
+
+av_cold void ff_fft_init_ppc(FFTContext *s)
+{
+#if HAVE_GNU_AS && HAVE_ALTIVEC
+    if (!PPC_ALTIVEC(av_get_cpu_flags()))
+        return;
+
+    s->fft_calc   = ff_fft_calc_interleave_altivec;
+    if (s->mdct_bits >= 5) {
+        s->imdct_calc = imdct_calc_altivec;
+        s->imdct_half = imdct_half_altivec;
+    }
+#endif /* HAVE_GNU_AS && HAVE_ALTIVEC */
+}