3DNow! & Extended 3DNow! versions of FFT

Patch by Zuxy Meng, zuxy <<dot>> meng >>at<< gmail <<dot>> com
Minor non-functional diff-related fixes by me.

Originally committed as revision 5125 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 136 insertions, 0 deletions

diff --git a/libavcodec/i386/fft_3dn2.c b/libavcodec/i386/fft_3dn2.c
new file mode 100644
index 0000000000..aa8f0aee2e
--- /dev/null
+++ b/libavcodec/i386/fft_3dn2.c
@@ -0,0 +1,136 @@
+/*
+ * FFT/MDCT transform with Extended 3DNow! optimizations
+ * Copyright (c) 2006 Zuxy MENG Jie.
+ * Based on fft_sse.c copyright (c) 2002 Fabrice Bellard.
+ *
+ * This library 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 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "../dsputil.h"
+#include <math.h>
+
+#ifdef HAVE_MM3DNOW
+
+#include <mm3dnow.h>
+
+static const int p1m1[2] __attribute__((aligned(8))) =
+    { 0, 1 << 31 };
+
+static const int m1p1[2] __attribute__((aligned(8))) =
+    { 1 << 31, 0 };
+
+void ff_fft_calc_3dn2(FFTContext *s, FFTComplex *z)
+{
+    int ln = s->nbits;
+    int j, np, np2;
+    int nblocks, nloops;
+    register FFTComplex *p, *q;
+    FFTComplex *cptr, *cptr1;
+    int k;
+
+    np = 1 << ln;
+    /* FEMMS is not a must here but recommended by AMD */
+    _m_femms();
+
+    {
+        __m64 *r, a0, a1, b0, b1, c;
+
+        r = (__m64 *)&z[0];
+        if (s->inverse)
+            c = *(__m64 *)m1p1;
+        else
+            c = *(__m64 *)p1m1;
+
+        j = (np >> 2);
+        do {
+            /* do the pass 0 butterfly */
+            a0 = _m_pfadd(r[0], r[1]);
+            a1 = _m_pfsub(r[0], r[1]);
+
+            /* do the pass 0 butterfly */
+            b0 = _m_pfadd(r[2], r[3]);
+            b1 = _m_pfsub(r[2], r[3]);
+
+            /* multiply third by -i */
+            b1 = _m_pswapd(b1);
+            b1 = _m_pxor(b1, c);
+
+            r[0] = _m_pfadd(a0, b0);
+            r[1] = _m_pfadd(a1, b1);
+            r[2] = _m_pfsub(a0, b0);
+            r[3] = _m_pfsub(a1, b1);
+            r += 4;
+        } while (--j != 0);
+    }
+    /* pass 2 .. ln-1 */
+
+    nblocks = np >> 3;
+    nloops = 1 << 2;
+    np2 = np >> 1;
+
+    cptr1 = s->exptab1;
+    do {
+        p = z;
+        q = z + nloops;
+        j = nblocks;
+        do {
+            cptr = cptr1;
+            k = nloops >> 1;
+            do {
+                __m64 a0, a1, b0, b1, c0, c1, t10, t11, t20, t21;
+
+                a0 = *(__m64 *)&p[0];
+                a1 = *(__m64 *)&p[1];
+                b0 = *(__m64 *)&q[0];
+                b1 = *(__m64 *)&q[1];
+
+                /* complex mul */
+                c0 = *(__m64 *)&cptr[0];
+                c1 = *(__m64 *)&cptr[1];
+                /* cre*re cim*im */
+                t10 = _m_pfmul(c0, b0);
+                t11 = _m_pfmul(c1, b1);
+                /* no need to access cptr[2] & cptr[3] */
+                c0 = _m_pswapd(c0);
+                c1 = _m_pswapd(c1);
+                /* cim*re cre*im */
+                t20 = _m_pfmul(c0, b0);
+                t21 = _m_pfmul(c1, b1);
+
+                /* cre*re-cim*im cim*re+cre*im */
+                b0 = _m_pfpnacc(t10, t20);
+                b1 = _m_pfpnacc(t11, t21);
+
+                /* butterfly */
+                *(__m64 *)&p[0] = _m_pfadd(a0, b0);
+                *(__m64 *)&p[1] = _m_pfadd(a1, b1);
+                *(__m64 *)&q[0] = _m_pfsub(a0, b0);
+                *(__m64 *)&q[1] = _m_pfsub(a1, b1);
+
+                p += 2;
+                q += 2;
+                cptr += 4;
+            } while (--k);
+
+            p += nloops;
+            q += nloops;
+        } while (--j);
+        cptr1 += nloops * 2;
+        nblocks = nblocks >> 1;
+        nloops = nloops << 1;
+    } while (nblocks != 0);
+    _m_femms();
+}
+
+#endif