[FFmpeg-devel] [PATCH] Altivec split-radix FFT

Loren Merritt lorenm
Mon Aug 24 06:09:14 CEST 2009


1.6x faster than altivec radix-2 as measured by fft-test on a G4.
2.0x as measured by gprof.
I failed to get oprofile or POWERPC_PERF to measure anything.

This is my first time writing ppc asm, so any optimization hints are 
appreciated.
I used raw asm rather than intrinsics because gcc adds a ginormous 
overhead to each function call. Is there anything I need to do to make it 
work on ppc64, if it doesn't already?

--Loren Merritt
-------------- next part --------------
>From 649c925625b58c477417be10a1a70c7cfdb517d6 Mon Sep 17 00:00:00 2001
From: Loren Merritt <pengvado at akuvian.org>
Date: Mon, 24 Aug 2009 01:59:29 +0100
Subject: [PATCH 1/2] altivec split-radix FFT
 1.6x faster than altivec radix-2 on G4
 8% faster overall vorbis decoding

---
 libavcodec/Makefile            |    1 +
 libavcodec/fft.c               |    1 -
 libavcodec/ppc/fft_altivec.c   |  150 +++++++-------------
 libavcodec/ppc/fft_altivec_s.S |  302 ++++++++++++++++++++++++++++++++++++++++
 libavcodec/ppc/types_altivec.h |    1 +
 5 files changed, 355 insertions(+), 100 deletions(-)
 create mode 100644 libavcodec/ppc/fft_altivec_s.S

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 24e6af4..5a9113b 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -523,6 +523,7 @@ OBJS-$(HAVE_ALTIVEC)                   += ppc/check_altivec.o           \
                                           ppc/dsputil_altivec.o         \
                                           ppc/fdct_altivec.o            \
                                           ppc/fft_altivec.o             \
+                                          ppc/fft_altivec_s.o           \
                                           ppc/float_altivec.o           \
                                           ppc/gmc_altivec.o             \
                                           ppc/idct_altivec.o            \
diff --git a/libavcodec/fft.c b/libavcodec/fft.c
index a3f1151..d864f82 100644
--- a/libavcodec/fft.c
+++ b/libavcodec/fft.c
@@ -110,7 +110,6 @@ av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
     has_vectors = mm_support();
     if (has_vectors & FF_MM_ALTIVEC) {
         s->fft_calc = ff_fft_calc_altivec;
-        split_radix = 0;
     }
 #endif
 
diff --git a/libavcodec/ppc/fft_altivec.c b/libavcodec/ppc/fft_altivec.c
index 7391131..ae15771 100644
--- a/libavcodec/ppc/fft_altivec.c
+++ b/libavcodec/ppc/fft_altivec.c
@@ -1,8 +1,7 @@
 /*
  * FFT/IFFT transforms
  * AltiVec-enabled
- * Copyright (c) 2003 Romain Dolbeau <romain at dolbeau.org>
- * Based on code Copyright (c) 2002 Fabrice Bellard
+ * Copyright (c) 2009 Loren Merritt
  *
  * This file is part of FFmpeg.
  *
@@ -23,6 +22,7 @@
 #include "libavcodec/dsputil.h"
 #include "dsputil_ppc.h"
 #include "util_altivec.h"
+#include "types_altivec.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
@@ -30,106 +30,58 @@
  * AltiVec-enabled
  * This code assumes that the 'z' pointer is 16 bytes-aligned
  * It also assumes all FFTComplex are 8 bytes-aligned pair of float
- * The code is exactly the same as the SSE version, except
- * that successive MUL + ADD/SUB have been merged into
- * fused multiply-add ('vec_madd' in altivec)
  */
-void ff_fft_calc_altivec(FFTContext *s, FFTComplex *z)
-{
-POWERPC_PERF_DECLARE(altivec_fft_num, s->nbits >= 6);
-    register const vector float vczero = (const vector float)vec_splat_u32(0.);
 
-    int ln = s->nbits;
-    int j, np, np2;
-    int nblocks, nloops;
-    register FFTComplex *p, *q;
-    FFTComplex *cptr, *cptr1;
-    int k;
-
-POWERPC_PERF_START_COUNT(altivec_fft_num, s->nbits >= 6);
-
-    np = 1 << ln;
-
-    {
-        vector float *r, a, b, a1, c1, c2;
-
-        r = (vector float *)&z[0];
-
-        c1 = vcii(p,p,n,n);
-
-        if (s->inverse) {
-            c2 = vcii(p,p,n,p);
-        } else {
-            c2 = vcii(p,p,p,n);
-        }
-
-        j = (np >> 2);
-        do {
-            a = vec_ld(0, r);
-            a1 = vec_ld(sizeof(vector float), r);
-
-            b = vec_perm(a,a,vcprmle(1,0,3,2));
-            a = vec_madd(a,c1,b);
-            /* do the pass 0 butterfly */
-
-            b = vec_perm(a1,a1,vcprmle(1,0,3,2));
-            b = vec_madd(a1,c1,b);
-            /* do the pass 0 butterfly */
-
-            /* multiply third by -i */
-            b = vec_perm(b,b,vcprmle(2,3,1,0));
-
-            /* do the pass 1 butterfly */
-            vec_st(vec_madd(b,c2,a), 0, r);
-            vec_st(vec_nmsub(b,c2,a), sizeof(vector float), r);
-
-            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 {
-                vector float a,b,c,t1;
-
-                a = vec_ld(0, (float*)p);
-                b = vec_ld(0, (float*)q);
-
-                /* complex mul */
-                c = vec_ld(0, (float*)cptr);
-                /*  cre*re cim*re */
-                t1 = vec_madd(c, vec_perm(b,b,vcprmle(2,2,0,0)),vczero);
-                c = vec_ld(sizeof(vector float), (float*)cptr);
-                /*  -cim*im cre*im */
-                b = vec_madd(c, vec_perm(b,b,vcprmle(3,3,1,1)),t1);
-
-                /* butterfly */
-                vec_st(vec_add(a,b), 0, (float*)p);
-                vec_st(vec_sub(a,b), 0, (float*)q);
-
-                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);
-
-POWERPC_PERF_STOP_COUNT(altivec_fft_num, s->nbits >= 6);
-}
+extern FFTSample ff_cos_16[];
+extern void (*ff_fft_dispatch_interleave_altivec[])(float*);
+
+// convert from simd order to C order
+static void swizzle(vec_f *z, int n)
+{
+    int i;
+    n >>= 1;
+    for(i=0; i<n; i+=2) {
+        vec_f re = z[i];
+        vec_f im = z[i+1];
+        z[i]   = vec_mergeh(re, im);
+        z[i+1] = vec_mergel(re, im);
+    }
+}
+
+void ff_fft_calc_altivec(FFTContext *s, FFTComplex *z)
+{
+    register vec_f  v14 __asm__("v14") = (const vec_f){0,0,0,0};
+    register vec_f  v15 __asm__("v15") = *(const vec_f*)ff_cos_16;
+    register vec_f  v16 __asm__("v16") = (const vec_f){0, 0.38268343, M_SQRT1_2, 0.92387953};
+    register vec_f  v17 __asm__("v17") = (const vec_f){-M_SQRT1_2, M_SQRT1_2, M_SQRT1_2,-M_SQRT1_2};
+    register vec_f  v18 __asm__("v18") = (const vec_f){ M_SQRT1_2, M_SQRT1_2, M_SQRT1_2, M_SQRT1_2};
+    register vec_u8 v19 __asm__("v19") = vcprm(s0,3,2,1);
+    register vec_u8 v20 __asm__("v20") = vcprm(0,1,s2,s1);
+    register vec_u8 v21 __asm__("v21") = vcprm(2,3,s0,s3);
+    register vec_u8 v22 __asm__("v22") = vcprm(2,s3,3,s2);
+    register vec_u8 v23 __asm__("v23") = vcprm(0,1,s0,s1);
+    register vec_u8 v24 __asm__("v24") = vcprm(2,3,s2,s3);
+    register vec_u8 v25 __asm__("v25") = vcprm(2,3,0,1);
+    register vec_u8 v26 __asm__("v26") = vcprm(1,2,s3,s0);
+    register vec_u8 v27 __asm__("v27") = vcprm(0,3,s2,s1);
+    register vec_u8 v28 __asm__("v28") = vcprm(0,2,s1,s3);
+    register vec_u8 v29 __asm__("v29") = vcprm(1,3,s0,s2);
+    register FFTSample **cos_tabs __asm__("r12") = ff_cos_tabs;
+    register FFTComplex *zarg __asm__("r3") = z;
+    __asm__(
+        "mtctr %0 \n"
+        "stw 2,-4(1) \n"
+        "li 2,16 \n"
+        "bctrl \n"
+        "lwz 2,-4(1) \n" // ABI docs say r2 is general purpose and caller-saved, but gcc doesn't save it and crashes
+        ::"r"(ff_fft_dispatch_interleave_altivec[s->nbits-2]),
+          "r"(zarg), "r"(cos_tabs),
+          "v"(v14),"v"(v15),"v"(v16),"v"(v17),"v"(v18),"v"(v19),"v"(v20),"v"(v21),
+          "v"(v22),"v"(v23),"v"(v24),"v"(v25),"v"(v26),"v"(v27),"v"(v28),"v"(v29)
+        : "lr","ctr","r0","r1","r2","r4","r5","r6","r7","r8","r9","r10",
+          "v0","v1","v2","v3","v4","v5","v6","v7","v8","v9","v10","v11","v12","v13"
+    );
+    if(s->nbits <= 4)
+        swizzle((vec_f*)z, 1<<s->nbits);
+}
+
diff --git a/libavcodec/ppc/fft_altivec_s.S b/libavcodec/ppc/fft_altivec_s.S
new file mode 100644
index 0000000..61ec9d1
--- /dev/null
+++ b/libavcodec/ppc/fft_altivec_s.S
@@ -0,0 +1,302 @@
+/*
+ * FFT transform with Altivec optimizations
+ * Copyright (c) 2009 Loren Merritt
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * 51, Inc., Foundation Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * These functions are not individually interchangeable with the C versions.
+ * While C takes arrays of FFTComplex, Altivec leaves intermediate results
+ * in blocks as convenient to the vector size.
+ * i.e. {4x real, 4x imaginary, 4x real, ...}
+ *
+ * I ignore standard calling convention.
+ * Instead, the following registers are treated as global constants:
+ * v14: zero
+ * v15..v18: cosines
+ * v19..v29: permutations
+ * r2: 16
+ * r12: ff_cos_tabs
+ * and the rest are free for local use.
+ */
+
+.text
+
+.macro slwi ra, rb, imm
+    rlwinm \ra, \rb, \imm, 0, 31-\imm
+.endm
+
+.macro addi2 ra, imm // add 32-bit immediate
+.if \imm & 0xffff
+    addi \ra, \ra, \imm at l
+.endif
+.if (\imm+0x8000)>>16
+    addis \ra, \ra, ((\imm+0x8000)>>16) + (\imm&0x800000000000)*0x1fffe
+.endif
+.endm
+
+.macro FFT4 a0, a1, a2, a3 // in:0-1 out:2-3
+    vperm   \a2,\a0,\a1,20 // vcprm(0,1,s2,s1) // {r0,i0,r3,i2}
+    vperm   \a3,\a0,\a1,21 // vcprm(2,3,s0,s3) // {r1,i1,r2,i3}
+    vaddfp  \a0,\a2,\a3                        // {t1,t2,t6,t5}
+    vsubfp  \a1,\a2,\a3                        // {t3,t4,t8,t7}
+    vmrghw  \a2,\a0,\a1    // vcprm(0,s0,1,s1) // {t1,t3,t2,t4}
+    vperm   \a3,\a0,\a1,22 // vcprm(2,s3,3,s2) // {t6,t7,t5,t8}
+    vaddfp  \a0,\a2,\a3                        // {r0,r1,i0,i1}
+    vsubfp  \a1,\a2,\a3                        // {r2,r3,i2,i3}
+    vperm   \a2,\a0,\a1,23 // vcprm(0,1,s0,s1) // {r0,r1,r2,r3}
+    vperm   \a3,\a0,\a1,24 // vcprm(2,3,s2,s3) // {i0,i1,i2,i3}
+.endm
+
+.macro FFT4x2 a0, a1, b0, b1, a2, a3, b2, b3
+    vperm   \a2,\a0,\a1,20 // vcprm(0,1,s2,s1) // {r0,i0,r3,i2}
+    vperm   \a3,\a0,\a1,21 // vcprm(2,3,s0,s3) // {r1,i1,r2,i3}
+    vperm   \b2,\b0,\b1,20
+    vperm   \b3,\b0,\b1,21
+    vaddfp  \a0,\a2,\a3                        // {t1,t2,t6,t5}
+    vsubfp  \a1,\a2,\a3                        // {t3,t4,t8,t7}
+    vaddfp  \b0,\b2,\b3
+    vsubfp  \b1,\b2,\b3
+    vmrghw  \a2,\a0,\a1    // vcprm(0,s0,1,s1) // {t1,t3,t2,t4}
+    vperm   \a3,\a0,\a1,22 // vcprm(2,s3,3,s2) // {t6,t7,t5,t8}
+    vmrghw  \b2,\b0,\b1
+    vperm   \b3,\b0,\b1,22
+    vaddfp  \a0,\a2,\a3                        // {r0,r1,i0,i1}
+    vsubfp  \a1,\a2,\a3                        // {r2,r3,i2,i3}
+    vaddfp  \b0,\b2,\b3
+    vsubfp  \b1,\b2,\b3
+    vperm   \a2,\a0,\a1,23 // vcprm(0,1,s0,s1) // {r0,r1,r2,r3}
+    vperm   \a3,\a0,\a1,24 // vcprm(2,3,s2,s3) // {i0,i1,i2,i3}
+    vperm   \b2,\b0,\b1,23
+    vperm   \b3,\b0,\b1,24
+.endm
+
+.macro FFT8 a0, a1, b0, b1, a2, a3, b2, b3, b4 // in,out:a0-b1
+    vmrghw  \b2,\b0,\b1    // vcprm(0,s0,1,s1) // {r4,r6,i4,i6}
+    vmrglw  \b3,\b0,\b1    // vcprm(2,s2,3,s3) // {r5,r7,i5,i7}
+    vperm   \a2,\a0,\a1,20         // FFT4 ...
+    vperm   \a3,\a0,\a1,21
+    vaddfp  \b0,\b2,\b3                        // {t1,t3,t2,t4}
+    vsubfp  \b1,\b2,\b3                        // {r5,r7,i5,i7}
+    vperm   \b4,\b1,\b1,25 // vcprm(2,3,0,1)   // {i5,i7,r5,r7}
+    vaddfp  \a0,\a2,\a3
+    vsubfp  \a1,\a2,\a3
+    vmaddfp \b1,\b1,17,14  // * {-1,1,1,-1}/sqrt(2)
+    vmaddfp \b1,\b4,18,\b1 // * { 1,1,1,1 }/sqrt(2) // {t8,ta,t7,t9}
+    vmrghw  \a2,\a0,\a1
+    vperm   \a3,\a0,\a1,22
+    vperm   \b2,\b0,\b1,26 // vcprm(1,2,s3,s0) // {t3,t2,t9,t8}
+    vperm   \b3,\b0,\b1,27 // vcprm(0,3,s2,s1) // {t1,t4,t7,ta}
+    vaddfp  \a0,\a2,\a3
+    vsubfp  \a1,\a2,\a3
+    vaddfp  \b0,\b2,\b3                        // {t1,t2,t9,ta}
+    vsubfp  \b1,\b2,\b3                        // {t6,t5,tc,tb}
+    vperm   \a2,\a0,\a1,23
+    vperm   \a3,\a0,\a1,24
+    vperm   \b2,\b0,\b1,28 // vcprm(0,2,s1,s3) // {t1,t9,t5,tb}
+    vperm   \b3,\b0,\b1,29 // vcprm(1,3,s0,s2) // {t2,ta,t6,tc}
+    vsubfp  \b0,\a2,\b2                        // {r4,r5,r6,r7}
+    vsubfp  \b1,\a3,\b3                        // {i4,i5,i6,i7}
+    vaddfp  \a0,\a2,\b2                        // {r0,r1,r2,r3}
+    vaddfp  \a1,\a3,\b3                        // {i0,i1,i2,i3}
+.endm
+
+.macro BF d0,d1,s0,s1
+    vsubfp  \d1,\s0,\s1
+    vaddfp  \d0,\s0,\s1
+.endm
+
+fft4_altivec:
+    lvx    0,0,3
+    lvx    1,2,3
+    FFT4   0,1,2,3
+    stvx   2,0,3
+    stvx   3,2,3
+    blr
+
+fft8_altivec:
+    addi   4,3,32
+    lvx    0,0,3
+    lvx    1,2,3
+    lvx    2,0,4
+    lvx    3,2,4
+    FFT8   0,1,2,3,4,5,6,7,8
+    stvx   0,0,3
+    stvx   1,2,3
+    stvx   2,0,4
+    stvx   3,2,4
+    blr
+
+fft16_altivec:
+    addi   5,3,64
+    addi   6,3,96
+    addi   4,3,32
+    lvx    0,0,5
+    lvx    1,2,5
+    lvx    2,0,6
+    lvx    3,2,6
+    FFT4x2 0,1,2,3,4,5,6,7
+    lvx    0,0,3
+    lvx    1,2,3
+    lvx    2,0,4
+    lvx    3,2,4
+    FFT8   0,1,2,3,8,9,10,11,12
+    vmaddfp   8,4,15,14 // r2*wre
+    vmaddfp   9,5,15,14 // i2*wre
+    vmaddfp  10,6,15,14 // r3*wre
+    vmaddfp  11,7,15,14 // i3*wre
+    vmaddfp   8,5,16,8  // i2*wim
+    vnmsubfp  9,4,16,9  // r2*wim
+    vnmsubfp 10,7,16,10 // i3*wim
+    vmaddfp  11,6,16,11 // r3*wim
+    BF     10,12,10,8
+    BF     11,13,9,11
+    BF     0,4,0,10
+    BF     3,7,3,12
+    stvx   0,0,3
+    stvx   4,0,5
+    stvx   3,2,4
+    stvx   7,2,6
+    BF     1,5,1,11
+    BF     2,6,2,13
+    stvx   1,2,3
+    stvx   5,2,5
+    stvx   2,0,4
+    stvx   6,0,6
+    blr
+
+// void pass(float *z, float *wre, int n)
+.macro PASS interleave
+fft_pass\interleave\()_altivec:
+    mtctr  5
+    slwi  10,5,4
+    slwi   7,5,6  // o2
+    slwi   5,5,5  // o1
+    add    9,5,7  // o3
+    add   10,4,10 // wim
+    addi   6,5,16 // o1+16
+    addi   8,7,16 // o2+16
+    addi   0,9,16 // o3+16
+1:
+    lvx    8,0,4  // wre
+    lvx   10,0,10
+    subi  10,10,16
+    lvx    9,0,10
+    vperm  9,9,10,19   // vcprm(s0,3,2,1) => wim[0 .. -3]
+    lvx    4,3,7       // r2 = z[o2]
+    lvx    5,3,8       // i2 = z[o2+16]
+    lvx    6,3,9       // r3 = z[o3]
+    lvx    7,3,0       // i3 = z[o3+16]
+    vmaddfp  10,4,8,14 // r2*wre
+    vmaddfp  11,5,8,14 // i2*wre
+    vmaddfp  12,6,8,14 // r3*wre
+    vmaddfp  13,7,8,14 // i3*wre
+    lvx    0,0,3       // r0 = z[0]
+    lvx    3,3,6       // i1 = z[o1+16]
+    vmaddfp  10,5,9,10 // i2*wim
+    vnmsubfp 11,4,9,11 // r2*wim
+    vnmsubfp 12,7,9,12 // i3*wim
+    vmaddfp  13,6,9,13 // r3*wim
+    lvx    1,3,2       // i0 = z[16]
+    lvx    2,3,5       // r1 = z[o1]
+    BF     12,8,12,10
+    BF     13,9,11,13
+    BF     0,4,0,12
+    BF     3,7,3,8
+.ifb \interleave
+    stvx   0,0,3
+    stvx   4,3,7
+    stvx   3,3,6
+    stvx   7,3,0
+.endif
+    BF     1,5,1,13
+    BF     2,6,2,9
+.ifb \interleave
+    stvx   1,3,2
+    stvx   2,3,5
+    stvx   5,3,8
+    stvx   6,3,9
+.else
+    vmrghw 8,0,1
+    vmrglw 9,0,1
+    stvx   8,0,3
+    stvx   9,3,2
+    vmrghw 8,2,3
+    vmrglw 9,2,3
+    stvx   8,3,5
+    stvx   9,3,6
+    vmrghw 8,4,5
+    vmrglw 9,4,5
+    stvx   8,3,7
+    stvx   9,3,8
+    vmrghw 8,6,7
+    vmrglw 9,6,7
+    stvx   8,3,9
+    stvx   9,3,0
+.endif
+    addi   3,3,32
+    addi   4,4,16
+    bdnz 1b
+    sub    3,3,5
+    blr
+.endm
+
+.macro DECL_FFT ver, bits, n, n2, n4
+fft\n\ver\()_altivec:
+    mflr  0
+    stw   0,12-\bits*4(1)
+    bl    fft\n2\()_altivec
+    addi2 3,\n*4
+    bl    fft\n4\()_altivec
+    addi2 3,\n*2
+    bl    fft\n4\()_altivec
+    addi2 3,\n*-6
+    lwz   0,12-\bits*4(1)
+    mtlr  0
+    lwz   4,\bits*4-16(12)
+    li    5,\n/16
+    b     fft_pass\ver\()_altivec
+.endm
+
+.macro DECL_FFTS ver
+PASS \ver
+DECL_FFT \ver,5,32,16,8
+DECL_FFT \ver,6,64,32,16
+DECL_FFT \ver,7,128,64,32
+DECL_FFT \ver,8,256,128,64
+DECL_FFT \ver,9,512,256,128
+DECL_FFT \ver,10,1024,512,256
+DECL_FFT \ver,11,2048,1024,512
+DECL_FFT \ver,12,4096,2048,1024
+DECL_FFT \ver,13,8192,4096,2048
+DECL_FFT \ver,14,16384,8192,4096
+DECL_FFT \ver,15,32768,16384,8192
+DECL_FFT \ver,16,65536,32768,16384
+.rodata
+.global ff_fft_dispatch\ver\()_altivec
+ff_fft_dispatch\ver\()_altivec:
+.int fft4_altivec, fft8_altivec, fft16_altivec, fft32\ver\()_altivec,\
+    fft64\ver\()_altivec, fft128\ver\()_altivec, fft256\ver\()_altivec,\
+    fft512\ver\()_altivec, fft1024\ver\()_altivec, fft2048\ver\()_altivec,\
+    fft4096\ver\()_altivec, fft8192\ver\()_altivec, fft16384\ver\()_altivec,\
+    fft32768\ver\()_altivec, fft65536\ver\()_altivec
+.text
+.endm
+
+DECL_FFTS
+DECL_FFTS _interleave
diff --git a/libavcodec/ppc/types_altivec.h b/libavcodec/ppc/types_altivec.h
index 2870e83..36b6e1f 100644
--- a/libavcodec/ppc/types_altivec.h
+++ b/libavcodec/ppc/types_altivec.h
@@ -30,6 +30,7 @@
 #define vec_s16 vector signed short
 #define vec_u32 vector unsigned int
 #define vec_s32 vector signed int
+#define vec_f   vector float
 
 /***********************************************************************
  * Null vector
-- 
1.6.4

-------------- next part --------------
>From 8456248f3c63ee27d903f33e41fa3058d4022430 Mon Sep 17 00:00:00 2001
From: Loren Merritt <pengvado at akuvian.org>
Date: Mon, 24 Aug 2009 01:59:29 +0100
Subject: [PATCH 2/2] remove vestiges of radix-2 FFT

---
 libavcodec/dsputil.h |    2 -
 libavcodec/fft.c     |  107 ++++++++-----------------------------------------
 2 files changed, 18 insertions(+), 91 deletions(-)

diff --git a/libavcodec/dsputil.h b/libavcodec/dsputil.h
index 2d15bd3..19c55a5 100644
--- a/libavcodec/dsputil.h
+++ b/libavcodec/dsputil.h
@@ -691,8 +691,6 @@ typedef struct FFTContext {
     int nbits;
     int inverse;
     uint16_t *revtab;
-    FFTComplex *exptab;
-    FFTComplex *exptab1; /* only used by SSE code */
     FFTComplex *tmp_buf;
     void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
     void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
diff --git a/libavcodec/fft.c b/libavcodec/fft.c
index d864f82..bf791c1 100644
--- a/libavcodec/fft.c
+++ b/libavcodec/fft.c
@@ -60,9 +60,7 @@ static int split_radix_permutation(int i, int n, int inverse)
 
 av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
 {
-    int i, j, m, n;
-    float alpha, c1, s1, s2;
-    int split_radix = 1;
+    int i, j, n;
     int av_unused has_vectors;
 
     if (nbits < 2 || nbits > 16)
@@ -70,22 +68,18 @@ av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
     s->nbits = nbits;
     n = 1 << nbits;
 
-    s->tmp_buf = NULL;
-    s->exptab  = av_malloc((n / 2) * sizeof(FFTComplex));
-    if (!s->exptab)
-        goto fail;
     s->revtab = av_malloc(n * sizeof(uint16_t));
     if (!s->revtab)
         goto fail;
+    s->tmp_buf = av_malloc(n * sizeof(FFTComplex));
+    if (!s->tmp_buf)
+        goto fail;
     s->inverse = inverse;
 
-    s2 = inverse ? 1.0 : -1.0;
-
     s->fft_permute = ff_fft_permute_c;
     s->fft_calc    = ff_fft_calc_c;
     s->imdct_calc  = ff_imdct_calc_c;
     s->imdct_half  = ff_imdct_half_c;
-    s->exptab1     = NULL;
 
 #if HAVE_MMX && HAVE_YASM
     has_vectors = mm_support();
@@ -113,103 +107,38 @@ av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
     }
 #endif
 
-    if (split_radix) {
-        for(j=4; j<=nbits; j++) {
-            int m = 1<<j;
-            double freq = 2*M_PI/m;
-            FFTSample *tab = ff_cos_tabs[j-4];
-            for(i=0; i<=m/4; i++)
-                tab[i] = cos(i*freq);
-            for(i=1; i<m/4; i++)
-                tab[m/2-i] = tab[i];
-        }
-        for(i=0; i<n; i++)
-            s->revtab[-split_radix_permutation(i, n, s->inverse) & (n-1)] = i;
-        s->tmp_buf = av_malloc(n * sizeof(FFTComplex));
-    } else {
-        int np, nblocks, np2, l;
-        FFTComplex *q;
-
-        for(i=0; i<(n/2); i++) {
-            alpha = 2 * M_PI * (float)i / (float)n;
-            c1 = cos(alpha);
-            s1 = sin(alpha) * s2;
-            s->exptab[i].re = c1;
-            s->exptab[i].im = s1;
-        }
-
-        np = 1 << nbits;
-        nblocks = np >> 3;
-        np2 = np >> 1;
-        s->exptab1 = av_malloc(np * 2 * sizeof(FFTComplex));
-        if (!s->exptab1)
-            goto fail;
-        q = s->exptab1;
-        do {
-            for(l = 0; l < np2; l += 2 * nblocks) {
-                *q++ = s->exptab[l];
-                *q++ = s->exptab[l + nblocks];
-
-                q->re = -s->exptab[l].im;
-                q->im = s->exptab[l].re;
-                q++;
-                q->re = -s->exptab[l + nblocks].im;
-                q->im = s->exptab[l + nblocks].re;
-                q++;
-            }
-            nblocks = nblocks >> 1;
-        } while (nblocks != 0);
-        av_freep(&s->exptab);
-
-        /* compute bit reverse table */
-        for(i=0;i<n;i++) {
-            m=0;
-            for(j=0;j<nbits;j++) {
-                m |= ((i >> j) & 1) << (nbits-j-1);
-            }
-            s->revtab[i]=m;
-        }
+    for(j=4; j<=nbits; j++) {
+        int m = 1<<j;
+        double freq = 2*M_PI/m;
+        FFTSample *tab = ff_cos_tabs[j-4];
+        for(i=0; i<=m/4; i++)
+            tab[i] = cos(i*freq);
+        for(i=1; i<m/4; i++)
+            tab[m/2-i] = tab[i];
     }
+    for(i=0; i<n; i++)
+        s->revtab[-split_radix_permutation(i, n, s->inverse) & (n-1)] = i;
 
     return 0;
  fail:
     av_freep(&s->revtab);
-    av_freep(&s->exptab);
-    av_freep(&s->exptab1);
     av_freep(&s->tmp_buf);
     return -1;
 }
 
 void ff_fft_permute_c(FFTContext *s, FFTComplex *z)
 {
-    int j, k, np;
-    FFTComplex tmp;
+    int j, np;
     const uint16_t *revtab = s->revtab;
     np = 1 << s->nbits;
-
-    if (s->tmp_buf) {
-        /* TODO: handle split-radix permute in a more optimal way, probably in-place */
-        for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j];
-        memcpy(z, s->tmp_buf, np * sizeof(FFTComplex));
-        return;
-    }
-
-    /* reverse */
-    for(j=0;j<np;j++) {
-        k = revtab[j];
-        if (k < j) {
-            tmp = z[k];
-            z[k] = z[j];
-            z[j] = tmp;
-        }
-    }
+    /* TODO: handle split-radix permute in a more optimal way, probably in-place */
+    for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j];
+    memcpy(z, s->tmp_buf, np * sizeof(FFTComplex));
 }
 
 av_cold void ff_fft_end(FFTContext *s)
 {
     av_freep(&s->revtab);
-    av_freep(&s->exptab);
-    av_freep(&s->exptab1);
     av_freep(&s->tmp_buf);
 }
 
-- 
1.6.4




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