new generic FFT/MDCT code for audio codecs

Originally committed as revision 1088 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 128 insertions, 0 deletions

diff --git a/libavcodec/i386/fft_sse.c b/libavcodec/i386/fft_sse.c
new file mode 100644
index 0000000000..8e8e36b0f7
--- /dev/null
+++ b/libavcodec/i386/fft_sse.c
@@ -0,0 +1,128 @@
+/*
+ * FFT/MDCT transform with SSE optimizations
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include "../dsputil.h"
+#include <math.h>
+
+#include <xmmintrin.h>
+
+static const float p1p1p1m1[4] __attribute__((aligned(16))) = 
+    { 1.0, 1.0, 1.0, -1.0 };
+
+static const float p1p1m1m1[4] __attribute__((aligned(16))) = 
+    { 1.0, 1.0, -1.0, -1.0 };
+
+#if 0
+static void print_v4sf(const char *str, __m128 a)
+{
+    float *p = (float *)&a;
+    printf("%s: %f %f %f %f\n",
+           str, p[0], p[1], p[2], p[3]);
+}
+#endif
+
+/* XXX: handle reverse case */
+void fft_calc_sse(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;
+
+    {
+        __m128 *r, a, b, a1, c1, c2;
+
+        r = (__m128 *)&z[0];
+        c1 = *(__m128 *)p1p1m1m1;
+        c2 = *(__m128 *)p1p1p1m1;
+        j = (np >> 2);
+        do {
+            a = r[0];
+            b = _mm_shuffle_ps(a, a, _MM_SHUFFLE(1, 0, 3, 2));
+            a = _mm_mul_ps(a, c1);
+            /* do the pass 0 butterfly */
+            a = _mm_add_ps(a, b);
+
+            a1 = r[1];
+            b = _mm_shuffle_ps(a1, a1, _MM_SHUFFLE(1, 0, 3, 2));
+            a1 = _mm_mul_ps(a1, c1);
+            /* do the pass 0 butterfly */
+            b = _mm_add_ps(a1, b);
+
+            /* multiply third by -i */
+            b = _mm_shuffle_ps(b, b, _MM_SHUFFLE(2, 3, 1, 0));
+            b = _mm_mul_ps(b, c2);
+
+            /* do the pass 1 butterfly */
+            r[0] = _mm_add_ps(a, b);
+            r[1] = _mm_sub_ps(a, b);
+            r += 2;
+        } 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 {
+                __m128 a, b, c, t1, t2;
+
+                a = *(__m128 *)p;
+                b = *(__m128 *)q;
+                
+                /* complex mul */
+                c = *(__m128 *)cptr;
+                /*  cre*re cim*re */
+                t1 = _mm_mul_ps(c, 
+                                _mm_shuffle_ps(b, b, _MM_SHUFFLE(2, 2, 0, 0))); 
+                c = *(__m128 *)(cptr + 2);
+                /*  -cim*im cre*im */
+                t2 = _mm_mul_ps(c,
+                                _mm_shuffle_ps(b, b, _MM_SHUFFLE(3, 3, 1, 1))); 
+                b = _mm_add_ps(t1, t2);
+                
+                /* butterfly */
+                *(__m128 *)p = _mm_add_ps(a, b);
+                *(__m128 *)q = _mm_sub_ps(a, b);
+                
+                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);
+}