optimize imdct_half:

remove tmp buffer.
skip fft reinterleave pass, leaving data in a format more convenient for simd.
merge post-rotate with post-reorder.

Originally committed as revision 14700 to svn://svn.ffmpeg.org/ffmpeg/trunk

6 files changed, 241 insertions, 352 deletions

diff --git a/libavcodec/dsputil.h b/libavcodec/dsputil.h
index 47ba4d72bc..18ee43cf7e 100644
--- a/libavcodec/dsputil.h
+++ b/libavcodec/dsputil.h
@@ -645,7 +645,7 @@ typedef struct FFTContext {
     void (*imdct_calc)(struct MDCTContext *s, FFTSample *output,
                        const FFTSample *input, FFTSample *tmp);
     void (*imdct_half)(struct MDCTContext *s, FFTSample *output,
-                       const FFTSample *input, FFTSample *tmp);
+                       const FFTSample *input);
 } FFTContext;
 
 int ff_fft_init(FFTContext *s, int nbits, int inverse);
@@ -696,16 +696,16 @@ void ff_sine_window_init(float *window, int n);
 int ff_mdct_init(MDCTContext *s, int nbits, int inverse);
 void ff_imdct_calc(MDCTContext *s, FFTSample *output,
                 const FFTSample *input, FFTSample *tmp);
-void ff_imdct_half(MDCTContext *s, FFTSample *output,
-                   const FFTSample *input, FFTSample *tmp);
+void ff_imdct_half(MDCTContext *s, FFTSample *output, const FFTSample *input);
+void ff_imdct_calc_3dn(MDCTContext *s, FFTSample *output,
+                       const FFTSample *input, FFTSample *tmp);
+void ff_imdct_half_3dn(MDCTContext *s, FFTSample *output, const FFTSample *input);
 void ff_imdct_calc_3dn2(MDCTContext *s, FFTSample *output,
                         const FFTSample *input, FFTSample *tmp);
-void ff_imdct_half_3dn2(MDCTContext *s, FFTSample *output,
-                        const FFTSample *input, FFTSample *tmp);
+void ff_imdct_half_3dn2(MDCTContext *s, FFTSample *output, const FFTSample *input);
 void ff_imdct_calc_sse(MDCTContext *s, FFTSample *output,
                        const FFTSample *input, FFTSample *tmp);
-void ff_imdct_half_sse(MDCTContext *s, FFTSample *output,
-                       const FFTSample *input, FFTSample *tmp);
+void ff_imdct_half_sse(MDCTContext *s, FFTSample *output, const FFTSample *input);
 void ff_mdct_calc(MDCTContext *s, FFTSample *out,
                const FFTSample *input, FFTSample *tmp);
 void ff_mdct_end(MDCTContext *s);
diff --git a/libavcodec/fft.c b/libavcodec/fft.c
index c8acfc6017..b659de16a1 100644
--- a/libavcodec/fft.c
+++ b/libavcodec/fft.c
@@ -106,6 +106,8 @@ int ff_fft_init(FFTContext *s, int nbits, int inverse)
         s->fft_calc = ff_fft_calc_3dn2;
     } else if (has_vectors & MM_3DNOW) {
         /* 3DNow! for K6-2/3 */
+        s->imdct_calc = ff_imdct_calc_3dn;
+        s->imdct_half = ff_imdct_half_3dn;
         s->fft_calc = ff_fft_calc_3dn;
     }
 #elif defined HAVE_ALTIVEC && !defined ALTIVEC_USE_REFERENCE_C_CODE
diff --git a/libavcodec/i386/fft_3dn2.c b/libavcodec/i386/fft_3dn2.c
index 635bc76658..b0ded8bc48 100644
--- a/libavcodec/i386/fft_3dn2.c
+++ b/libavcodec/i386/fft_3dn2.c
@@ -1,7 +1,6 @@
 /*
  * FFT/MDCT transform with Extended 3DNow! optimizations
- * Copyright (c) 2006 Zuxy MENG Jie, Loren Merritt
- * Based on fft_sse.c copyright (c) 2002 Fabrice Bellard.
+ * Copyright (c) 2006-2008 Zuxy MENG Jie, Loren Merritt
  *
  * This file is part of FFmpeg.
  *
@@ -23,16 +22,23 @@
 #include "libavutil/x86_cpu.h"
 #include "libavcodec/dsputil.h"
 
+DECLARE_ALIGNED_8(static const int, m1m1[2]) = { 1<<31, 1<<31 };
+
 #ifdef EMULATE_3DNOWEXT
+#define PSWAPD(s,d)\
+    "movq "#s","#d"\n"\
+    "psrlq $32,"#d"\n"\
+    "punpckldq "#s","#d"\n"
 #define ff_fft_calc_3dn2 ff_fft_calc_3dn
 #define ff_fft_dispatch_3dn2 ff_fft_dispatch_3dn
 #define ff_fft_dispatch_interleave_3dn2 ff_fft_dispatch_interleave_3dn
 #define ff_imdct_calc_3dn2 ff_imdct_calc_3dn
 #define ff_imdct_half_3dn2 ff_imdct_half_3dn
+#else
+#define PSWAPD(s,d) "pswapd "#s","#d"\n"
 #endif
 
 void ff_fft_dispatch_3dn2(FFTComplex *z, int nbits);
-void ff_fft_dispatch_interleave_3dn2(FFTComplex *z, int nbits);
 
 void ff_fft_calc_3dn2(FFTContext *s, FFTComplex *z)
 {
@@ -45,35 +51,45 @@ void ff_fft_calc_3dn2(FFTContext *s, FFTComplex *z)
             FFSWAP(FFTSample, z[i].im, z[i+1].re);
 }
 
-static void imdct_3dn2(MDCTContext *s, const FFTSample *input, FFTSample *tmp)
+void ff_imdct_half_3dn2(MDCTContext *s, FFTSample *output, const FFTSample *input)
 {
-    long n4, n2, n;
-    x86_reg k;
+    x86_reg j, k;
+    long n = 1 << s->nbits;
+    long n2 = n >> 1;
+    long n4 = n >> 2;
+    long n8 = n >> 3;
     const uint16_t *revtab = s->fft.revtab;
     const FFTSample *tcos = s->tcos;
     const FFTSample *tsin = s->tsin;
     const FFTSample *in1, *in2;
-    FFTComplex *z = (FFTComplex *)tmp;
-
-    n = 1 << s->nbits;
-    n2 = n >> 1;
-    n4 = n >> 2;
+    FFTComplex *z = (FFTComplex *)output;
 
     /* pre rotation */
     in1 = input;
     in2 = input + n2 - 1;
+#ifdef EMULATE_3DNOWEXT
+    asm volatile("movd %0, %%mm7" ::"r"(1<<31));
+#endif
     for(k = 0; k < n4; k++) {
         // FIXME a single block is faster, but gcc 2.95 and 3.4.x on 32bit can't compile it
         asm volatile(
-            "movd       %0, %%mm0 \n\t"
-            "movd       %2, %%mm1 \n\t"
-            "punpckldq  %1, %%mm0 \n\t"
-            "punpckldq  %3, %%mm1 \n\t"
-            "movq    %%mm0, %%mm2 \n\t"
-            "pfmul   %%mm1, %%mm0 \n\t"
-            "pswapd  %%mm1, %%mm1 \n\t"
-            "pfmul   %%mm1, %%mm2 \n\t"
-            "pfpnacc %%mm2, %%mm0 \n\t"
+            "movd         %0, %%mm0 \n"
+            "movd         %2, %%mm1 \n"
+            "punpckldq    %1, %%mm0 \n"
+            "punpckldq    %3, %%mm1 \n"
+            "movq      %%mm0, %%mm2 \n"
+            PSWAPD(    %%mm1, %%mm3 )
+            "pfmul     %%mm1, %%mm0 \n"
+            "pfmul     %%mm3, %%mm2 \n"
+#ifdef EMULATE_3DNOWEXT
+            "movq      %%mm0, %%mm1 \n"
+            "punpckhdq %%mm2, %%mm0 \n"
+            "punpckldq %%mm2, %%mm1 \n"
+            "pxor      %%mm7, %%mm0 \n"
+            "pfadd     %%mm1, %%mm0 \n"
+#else
+            "pfpnacc   %%mm2, %%mm0 \n"
+#endif
             ::"m"(in2[-2*k]), "m"(in1[2*k]),
               "m"(tcos[k]), "m"(tsin[k])
         );
@@ -83,101 +99,74 @@ static void imdct_3dn2(MDCTContext *s, const FFTSample *input, FFTSample *tmp)
         );
     }
 
-    ff_fft_calc_3dn2(&s->fft, z);
-
-    /* post rotation + reordering */
-    for(k = 0; k < n4; k++) {
-        asm volatile(
-            "movq       %0, %%mm0 \n\t"
-            "movd       %1, %%mm1 \n\t"
-            "punpckldq  %2, %%mm1 \n\t"
-            "movq    %%mm0, %%mm2 \n\t"
-            "pfmul   %%mm1, %%mm0 \n\t"
-            "pswapd  %%mm1, %%mm1 \n\t"
-            "pfmul   %%mm1, %%mm2 \n\t"
-            "pfpnacc %%mm2, %%mm0 \n\t"
-            "movq    %%mm0, %0    \n\t"
-            :"+m"(z[k])
-            :"m"(tcos[k]), "m"(tsin[k])
-        );
-    }
-}
-
-void ff_imdct_calc_3dn2(MDCTContext *s, FFTSample *output,
-                        const FFTSample *input, FFTSample *tmp)
-{
-    x86_reg k;
-    long n8, n2, n;
-    FFTComplex *z = (FFTComplex *)tmp;
-
-    n = 1 << s->nbits;
-    n2 = n >> 1;
-    n8 = n >> 3;
-
-    imdct_3dn2(s, input, tmp);
-
-    k = n-8;
-    asm volatile("movd %0, %%mm7" ::"r"(1<<31));
+    ff_fft_dispatch_3dn2(z, s->fft.nbits);
+
+#define CMUL(j,mm0,mm1)\
+        "movq  (%2,"#j",2), %%mm6 \n"\
+        "movq 8(%2,"#j",2), "#mm0"\n"\
+        "movq        %%mm6, "#mm1"\n"\
+        "movq        "#mm0",%%mm7 \n"\
+        "pfmul   (%3,"#j"), %%mm6 \n"\
+        "pfmul   (%4,"#j"), "#mm0"\n"\
+        "pfmul   (%4,"#j"), "#mm1"\n"\
+        "pfmul   (%3,"#j"), %%mm7 \n"\
+        "pfsub       %%mm6, "#mm0"\n"\
+        "pfadd       %%mm7, "#mm1"\n"
+
+    /* post rotation */
+    j = -n2;
+    k = n2-8;
     asm volatile(
-        "1: \n\t"
-        "movq    (%4,%0), %%mm0 \n\t" // z[n8+k]
-        "neg %0 \n\t"
-        "pswapd -8(%4,%0), %%mm1 \n\t" // z[n8-1-k]
-        "movq      %%mm0, %%mm2 \n\t"
-        "pxor      %%mm7, %%mm2 \n\t"
-        "punpckldq %%mm1, %%mm2 \n\t"
-        "pswapd    %%mm2, %%mm3 \n\t"
-        "punpckhdq %%mm1, %%mm0 \n\t"
-        "pswapd    %%mm0, %%mm4 \n\t"
-        "pxor      %%mm7, %%mm0 \n\t"
-        "pxor      %%mm7, %%mm4 \n\t"
-        "movq      %%mm3, -8(%3,%0) \n\t" // output[n-2-2*k] = { z[n8-1-k].im, -z[n8+k].re }
-        "movq      %%mm4, -8(%2,%0) \n\t" // output[n2-2-2*k]= { -z[n8-1-k].re, z[n8+k].im }
-        "neg %0 \n\t"
-        "movq      %%mm0, (%1,%0) \n\t"   // output[2*k]     = { -z[n8+k].im, z[n8-1-k].re }
-        "movq      %%mm2, (%2,%0) \n\t"   // output[n2+2*k]  = { -z[n8+k].re, z[n8-1-k].im }
-        "sub $8, %0 \n\t"
-        "jge 1b \n\t"
-        :"+r"(k)
-        :"r"(output), "r"(output+n2), "r"(output+n), "r"(z+n8)
+        "1: \n"
+        CMUL(%0, %%mm0, %%mm1)
+        CMUL(%1, %%mm2, %%mm3)
+        "movd   %%mm0,  (%2,%0,2) \n"
+        "movd   %%mm1,12(%2,%1,2) \n"
+        "movd   %%mm2,  (%2,%1,2) \n"
+        "movd   %%mm3,12(%2,%0,2) \n"
+        "psrlq  $32,   %%mm0 \n"
+        "psrlq  $32,   %%mm1 \n"
+        "psrlq  $32,   %%mm2 \n"
+        "psrlq  $32,   %%mm3 \n"
+        "movd   %%mm0, 8(%2,%0,2) \n"
+        "movd   %%mm1, 4(%2,%1,2) \n"
+        "movd   %%mm2, 8(%2,%1,2) \n"
+        "movd   %%mm3, 4(%2,%0,2) \n"
+        "sub $8, %1 \n"
+        "add $8, %0 \n"
+        "jl 1b \n"
+        :"+r"(j), "+r"(k)
+        :"r"(z+n8), "r"(tcos+n8), "r"(tsin+n8)
         :"memory"
     );
     asm volatile("femms");
 }
 
-void ff_imdct_half_3dn2(MDCTContext *s, FFTSample *output,
+void ff_imdct_calc_3dn2(MDCTContext *s, FFTSample *output,
                         const FFTSample *input, FFTSample *tmp)
 {
     x86_reg j, k;
-    long n8, n4, n;
-    FFTComplex *z = (FFTComplex *)tmp;
+    long n = 1 << s->nbits;
+    long n4 = n >> 2;
 
-    n = 1 << s->nbits;
-    n4 = n >> 2;
-    n8 = n >> 3;
-
-    imdct_3dn2(s, input, tmp);
+    ff_imdct_half_3dn2(s, output+n4, input);
 
     j = -n;
     k = n-8;
-    asm volatile("movd %0, %%mm7" ::"r"(1<<31));
     asm volatile(
-        "1: \n\t"
-        "movq    (%3,%1), %%mm0 \n\t" // z[n8+k]
-        "pswapd  (%3,%0), %%mm1 \n\t" // z[n8-1-k]
-        "movq      %%mm0, %%mm2 \n\t"
-        "punpckldq %%mm1, %%mm0 \n\t"
-        "punpckhdq %%mm2, %%mm1 \n\t"
-        "pxor      %%mm7, %%mm0 \n\t"
-        "pxor      %%mm7, %%mm1 \n\t"
-        "movq      %%mm0, (%2,%1) \n\t" // output[n4+2*k]   = { -z[n8+k].re, z[n8-1-k].im }
-        "movq      %%mm1, (%2,%0) \n\t" // output[n4-2-2*k] = { -z[n8-1-k].re, z[n8+k].im }
-        "sub $8, %1 \n\t"
-        "add $8, %0 \n\t"
-        "jl 1b \n\t"
+        "movq %4, %%mm7 \n"
+        "1: \n"
+        PSWAPD((%2,%1), %%mm0)
+        PSWAPD((%3,%0), %%mm1)
+        "pxor    %%mm7, %%mm0 \n"
+        "movq    %%mm1, (%3,%1) \n"
+        "movq    %%mm0, (%2,%0) \n"
+        "sub $8, %1 \n"
+        "add $8, %0 \n"
+        "jl 1b \n"
         :"+r"(j), "+r"(k)
-        :"r"(output+n4), "r"(z+n8)
-        :"memory"
+        :"r"(output+n4), "r"(output+n4*3),
+         "m"(*m1m1)
     );
     asm volatile("femms");
 }
diff --git a/libavcodec/i386/fft_sse.c b/libavcodec/i386/fft_sse.c
index 77a579011a..74150f9166 100644
--- a/libavcodec/i386/fft_sse.c
+++ b/libavcodec/i386/fft_sse.c
@@ -1,6 +1,6 @@
 /*
  * FFT/MDCT transform with SSE optimizations
- * Copyright (c) 2002 Fabrice Bellard.
+ * Copyright (c) 2008 Loren Merritt
  *
  * This file is part of FFmpeg.
  *
@@ -22,9 +22,6 @@
 #include "libavutil/x86_cpu.h"
 #include "libavcodec/dsputil.h"
 
-static const int p1m1p1m1[4] __attribute__((aligned(16))) =
-    { 0, 1 << 31, 0, 1 << 31 };
-
 static const int m1m1m1m1[4] __attribute__((aligned(16))) =
     { 1 << 31, 1 << 31, 1 << 31, 1 << 31 };
 
@@ -73,212 +70,134 @@ void ff_fft_permute_sse(FFTContext *s, FFTComplex *z)
     memcpy(z, s->tmp_buf, n*sizeof(FFTComplex));
 }
 
-static void imdct_sse(MDCTContext *s, const FFTSample *input, FFTSample *tmp)
+void ff_imdct_half_sse(MDCTContext *s, FFTSample *output, const FFTSample *input)
 {
-    x86_reg k;
-    long n4, n2, n;
-    const uint16_t *revtab = s->fft.revtab;
+    av_unused x86_reg i, j, k, l;
+    long n = 1 << s->nbits;
+    long n2 = n >> 1;
+    long n4 = n >> 2;
+    long n8 = n >> 3;
+    const uint16_t *revtab = s->fft.revtab + n8;
     const FFTSample *tcos = s->tcos;
     const FFTSample *tsin = s->tsin;
-    const FFTSample *in1, *in2;
-    FFTComplex *z = (FFTComplex *)tmp;
-
-    n = 1 << s->nbits;
-    n2 = n >> 1;
-    n4 = n >> 2;
-
-#ifdef ARCH_X86_64
-    asm volatile ("movaps %0, %%xmm8\n\t"::"m"(*p1m1p1m1));
-#define P1M1P1M1 "%%xmm8"
-#else
-#define P1M1P1M1 "%4"
-#endif
+    FFTComplex *z = (FFTComplex *)output;
 
     /* pre rotation */
-    in1 = input;
-    in2 = input + n2 - 4;
-
-    /* Complex multiplication */
-    for (k = 0; k < n4; k += 4) {
-        asm volatile (
-            "movaps          %0, %%xmm0 \n\t"   // xmm0 = r0 X  r1 X : in2
-            "movaps          %1, %%xmm3 \n\t"   // xmm3 = X  i1 X  i0: in1
-            "movaps    -16+1*%0, %%xmm4 \n\t"   // xmm4 = r0 X  r1 X : in2
-            "movaps     16+1*%1, %%xmm7 \n\t"   // xmm7 = X  i1 X  i0: in1
-            "movlps          %2, %%xmm1 \n\t"   // xmm1 = X  X  R1 R0: tcos
-            "movlps          %3, %%xmm2 \n\t"   // xmm2 = X  X  I1 I0: tsin
-            "movlps      8+1*%2, %%xmm5 \n\t"   // xmm5 = X  X  R1 R0: tcos
-            "movlps      8+1*%3, %%xmm6 \n\t"   // xmm6 = X  X  I1 I0: tsin
-            "shufps $95, %%xmm0, %%xmm0 \n\t"   // xmm0 = r1 r1 r0 r0
-            "shufps $160,%%xmm3, %%xmm3 \n\t"   // xmm3 = i1 i1 i0 i0
-            "shufps $95, %%xmm4, %%xmm4 \n\t"   // xmm4 = r1 r1 r0 r0
-            "shufps $160,%%xmm7, %%xmm7 \n\t"   // xmm7 = i1 i1 i0 i0
-            "unpcklps    %%xmm2, %%xmm1 \n\t"   // xmm1 = I1 R1 I0 R0
-            "unpcklps    %%xmm6, %%xmm5 \n\t"   // xmm5 = I1 R1 I0 R0
-            "movaps      %%xmm1, %%xmm2 \n\t"   // xmm2 = I1 R1 I0 R0
-            "movaps      %%xmm5, %%xmm6 \n\t"   // xmm6 = I1 R1 I0 R0
-            "xorps   "P1M1P1M1", %%xmm2 \n\t"   // xmm2 = -I1 R1 -I0 R0
-            "xorps   "P1M1P1M1", %%xmm6 \n\t"   // xmm6 = -I1 R1 -I0 R0
-            "mulps       %%xmm1, %%xmm0 \n\t"   // xmm0 = rI rR rI rR
-            "mulps       %%xmm5, %%xmm4 \n\t"   // xmm4 = rI rR rI rR
-            "shufps $177,%%xmm2, %%xmm2 \n\t"   // xmm2 = R1 -I1 R0 -I0
-            "shufps $177,%%xmm6, %%xmm6 \n\t"   // xmm6 = R1 -I1 R0 -I0
-            "mulps       %%xmm2, %%xmm3 \n\t"   // xmm3 = Ri -Ii Ri -Ii
-            "mulps       %%xmm6, %%xmm7 \n\t"   // xmm7 = Ri -Ii Ri -Ii
-            "addps       %%xmm3, %%xmm0 \n\t"   // xmm0 = result
-            "addps       %%xmm7, %%xmm4 \n\t"   // xmm4 = result
-            ::"m"(in2[-2*k]), "m"(in1[2*k]),
-              "m"(tcos[k]), "m"(tsin[k])
-#ifndef ARCH_X86_64
-              ,"m"(*p1m1p1m1)
-#endif
+    for(k=n8-2; k>=0; k-=2) {
+        asm volatile(
+            "movaps     (%2,%1,2), %%xmm0 \n" // { z[k].re,    z[k].im,    z[k+1].re,  z[k+1].im  }
+            "movaps  -16(%2,%0,2), %%xmm1 \n" // { z[-k-2].re, z[-k-2].im, z[-k-1].re, z[-k-1].im }
+            "movaps        %%xmm0, %%xmm2 \n"
+            "shufps $0x88, %%xmm1, %%xmm0 \n" // { z[k].re,    z[k+1].re,  z[-k-2].re, z[-k-1].re }
+            "shufps $0x77, %%xmm2, %%xmm1 \n" // { z[-k-1].im, z[-k-2].im, z[k+1].im,  z[k].im    }
+            "movlps       (%3,%1), %%xmm4 \n"
+            "movlps       (%4,%1), %%xmm5 \n"
+            "movhps     -8(%3,%0), %%xmm4 \n" // { cos[k],     cos[k+1],   cos[-k-2],  cos[-k-1]  }
+            "movhps     -8(%4,%0), %%xmm5 \n" // { sin[k],     sin[k+1],   sin[-k-2],  sin[-k-1]  }
+            "movaps        %%xmm0, %%xmm2 \n"
+            "movaps        %%xmm1, %%xmm3 \n"
+            "mulps         %%xmm5, %%xmm0 \n" // re*sin
+            "mulps         %%xmm4, %%xmm1 \n" // im*cos
+            "mulps         %%xmm4, %%xmm2 \n" // re*cos
+            "mulps         %%xmm5, %%xmm3 \n" // im*sin
+            "subps         %%xmm0, %%xmm1 \n" // -> re
+            "addps         %%xmm3, %%xmm2 \n" // -> im
+            "movaps        %%xmm1, %%xmm0 \n"
+            "unpcklps      %%xmm2, %%xmm1 \n" // { z[k],    z[k+1]  }
+            "unpckhps      %%xmm2, %%xmm0 \n" // { z[-k-2], z[-k-1] }
+            ::"r"(-4*k), "r"(4*k),
+              "r"(input+n4), "r"(tcos+n8), "r"(tsin+n8)
         );
-        /* Should be in the same block, hack for gcc2.95 & gcc3 */
-        asm (
-            "movlps      %%xmm0, %0     \n\t"
-            "movhps      %%xmm0, %1     \n\t"
-            "movlps      %%xmm4, %2     \n\t"
-            "movhps      %%xmm4, %3     \n\t"
-            :"=m"(z[revtab[k]]), "=m"(z[revtab[k + 1]]),
-             "=m"(z[revtab[k + 2]]), "=m"(z[revtab[k + 3]])
+#ifdef ARCH_X86_64
+        // if we have enough regs, don't let gcc make the luts latency-bound
+        // but if not, latency is faster than spilling
+        asm("movlps %%xmm0, %0 \n"
+            "movhps %%xmm0, %1 \n"
+            "movlps %%xmm1, %2 \n"
+            "movhps %%xmm1, %3 \n"
+            :"=m"(z[revtab[-k-2]]),
+             "=m"(z[revtab[-k-1]]),
+             "=m"(z[revtab[ k  ]]),
+             "=m"(z[revtab[ k+1]])
         );
-    }
-
-    ff_fft_calc_sse(&s->fft, z);
-
-#ifndef ARCH_X86_64
-#undef P1M1P1M1
-#define P1M1P1M1 "%3"
-#endif
-
-    /* post rotation + reordering */
-    for (k = 0; k < n4; k += 4) {
-        asm (
-            "movaps          %0, %%xmm0 \n\t"   // xmm0 = i1 r1 i0 r0: z
-            "movaps     16+1*%0, %%xmm4 \n\t"   // xmm4 = i1 r1 i0 r0: z
-            "movlps          %1, %%xmm1 \n\t"   // xmm1 = X  X  R1 R0: tcos
-            "movlps      8+1*%1, %%xmm5 \n\t"   // xmm5 = X  X  R1 R0: tcos
-            "movaps      %%xmm0, %%xmm3 \n\t"   // xmm3 = i1 r1 i0 r0
-            "movaps      %%xmm4, %%xmm7 \n\t"   // xmm7 = i1 r1 i0 r0
-            "movlps          %2, %%xmm2 \n\t"   // xmm2 = X  X  I1 I0: tsin
-            "movlps      8+1*%2, %%xmm6 \n\t"   // xmm6 = X  X  I1 I0: tsin
-            "shufps $160,%%xmm0, %%xmm0 \n\t"   // xmm0 = r1 r1 r0 r0
-            "shufps $245,%%xmm3, %%xmm3 \n\t"   // xmm3 = i1 i1 i0 i0
-            "shufps $160,%%xmm4, %%xmm4 \n\t"   // xmm4 = r1 r1 r0 r0
-            "shufps $245,%%xmm7, %%xmm7 \n\t"   // xmm7 = i1 i1 i0 i0
-            "unpcklps    %%xmm2, %%xmm1 \n\t"   // xmm1 = I1 R1 I0 R0
-            "unpcklps    %%xmm6, %%xmm5 \n\t"   // xmm5 = I1 R1 I0 R0
-            "movaps      %%xmm1, %%xmm2 \n\t"   // xmm2 = I1 R1 I0 R0
-            "movaps      %%xmm5, %%xmm6 \n\t"   // xmm6 = I1 R1 I0 R0
-            "xorps   "P1M1P1M1", %%xmm2 \n\t"   // xmm2 = -I1 R1 -I0 R0
-            "mulps       %%xmm1, %%xmm0 \n\t"   // xmm0 = rI rR rI rR
-            "xorps   "P1M1P1M1", %%xmm6 \n\t"   // xmm6 = -I1 R1 -I0 R0
-            "mulps       %%xmm5, %%xmm4 \n\t"   // xmm4 = rI rR rI rR
-            "shufps $177,%%xmm2, %%xmm2 \n\t"   // xmm2 = R1 -I1 R0 -I0
-            "shufps $177,%%xmm6, %%xmm6 \n\t"   // xmm6 = R1 -I1 R0 -I0
-            "mulps       %%xmm2, %%xmm3 \n\t"   // xmm3 = Ri -Ii Ri -Ii
-            "mulps       %%xmm6, %%xmm7 \n\t"   // xmm7 = Ri -Ii Ri -Ii
-            "addps       %%xmm3, %%xmm0 \n\t"   // xmm0 = result
-            "addps       %%xmm7, %%xmm4 \n\t"   // xmm4 = result
-            "movaps      %%xmm0, %0     \n\t"
-            "movaps      %%xmm4, 16+1*%0\n\t"
-            :"+m"(z[k])
-            :"m"(tcos[k]), "m"(tsin[k])
-#ifndef ARCH_X86_64
-             ,"m"(*p1m1p1m1)
+#else
+        asm("movlps %%xmm0, %0" :"=m"(z[revtab[-k-2]]));
+        asm("movhps %%xmm0, %0" :"=m"(z[revtab[-k-1]]));
+        asm("movlps %%xmm1, %0" :"=m"(z[revtab[ k  ]]));
+        asm("movhps %%xmm1, %0" :"=m"(z[revtab[ k+1]]));
 #endif
-        );
     }
-}
 
-void ff_imdct_calc_sse(MDCTContext *s, FFTSample *output,
-                       const FFTSample *input, FFTSample *tmp)
-{
-    x86_reg k;
-    long n8, n2, n;
-    FFTComplex *z = (FFTComplex *)tmp;
+    ff_fft_dispatch_sse(z, s->fft.nbits);
 
-    n = 1 << s->nbits;
-    n2 = n >> 1;
-    n8 = n >> 3;
+    /* post rotation + reinterleave + reorder */
 
-    imdct_sse(s, input, tmp);
+#define CMUL(j,xmm0,xmm1)\
+        "movaps   (%2,"#j",2), %%xmm6 \n"\
+        "movaps 16(%2,"#j",2), "#xmm0"\n"\
+        "movaps        %%xmm6, "#xmm1"\n"\
+        "movaps        "#xmm0",%%xmm7 \n"\
+        "mulps      (%3,"#j"), %%xmm6 \n"\
+        "mulps      (%4,"#j"), "#xmm0"\n"\
+        "mulps      (%4,"#j"), "#xmm1"\n"\
+        "mulps      (%3,"#j"), %%xmm7 \n"\
+        "subps         %%xmm6, "#xmm0"\n"\
+        "addps         %%xmm7, "#xmm1"\n"
 
-    /*
-       Mnemonics:
-       0 = z[k].re
-       1 = z[k].im
-       2 = z[k + 1].re
-       3 = z[k + 1].im
-       4 = z[-k - 2].re
-       5 = z[-k - 2].im
-       6 = z[-k - 1].re
-       7 = z[-k - 1].im
-    */
-    k = 16-n;
-    asm volatile("movaps %0, %%xmm7 \n\t"::"m"(*m1m1m1m1));
+    j = -n2;
+    k = n2-16;
     asm volatile(
-        "1: \n\t"
-        "movaps  -16(%4,%0), %%xmm1 \n\t"   // xmm1 = 4 5 6 7 = z[-2-k]
-        "neg %0 \n\t"
-        "movaps     (%4,%0), %%xmm0 \n\t"   // xmm0 = 0 1 2 3 = z[k]
-        "xorps       %%xmm7, %%xmm0 \n\t"   // xmm0 = -0 -1 -2 -3
-        "movaps      %%xmm0, %%xmm2 \n\t"   // xmm2 = -0 -1 -2 -3
-        "shufps $141,%%xmm1, %%xmm0 \n\t"   // xmm0 = -1 -3 4 6
-        "shufps $216,%%xmm1, %%xmm2 \n\t"   // xmm2 = -0 -2 5 7
-        "shufps $156,%%xmm0, %%xmm0 \n\t"   // xmm0 = -1 6 -3 4 !
-        "shufps $156,%%xmm2, %%xmm2 \n\t"   // xmm2 = -0 7 -2 5 !
-        "movaps      %%xmm0, (%1,%0) \n\t"  // output[2*k]
-        "movaps      %%xmm2, (%2,%0) \n\t"  // output[n2+2*k]
-        "neg %0 \n\t"
-        "shufps $27, %%xmm0, %%xmm0 \n\t"   // xmm0 = 4 -3 6 -1
-        "xorps       %%xmm7, %%xmm0 \n\t"   // xmm0 = -4 3 -6 1 !
-        "shufps $27, %%xmm2, %%xmm2 \n\t"   // xmm2 = 5 -2 7 -0 !
-        "movaps      %%xmm0, -16(%2,%0) \n\t" // output[n2-4-2*k]
-        "movaps      %%xmm2, -16(%3,%0) \n\t" // output[n-4-2*k]
-        "add $16, %0 \n\t"
-        "jle 1b \n\t"
-        :"+r"(k)
-        :"r"(output), "r"(output+n2), "r"(output+n), "r"(z+n8)
+        "1: \n"
+        CMUL(%0, %%xmm0, %%xmm1)
+        CMUL(%1, %%xmm4, %%xmm5)
+        "shufps    $0x1b, %%xmm1, %%xmm1 \n"
+        "shufps    $0x1b, %%xmm5, %%xmm5 \n"
+        "movaps   %%xmm4, %%xmm6 \n"
+        "unpckhps %%xmm1, %%xmm4 \n"
+        "unpcklps %%xmm1, %%xmm6 \n"
+        "movaps   %%xmm0, %%xmm2 \n"
+        "unpcklps %%xmm5, %%xmm0 \n"
+        "unpckhps %%xmm5, %%xmm2 \n"
+        "movaps   %%xmm6,   (%2,%1,2) \n"
+        "movaps   %%xmm4, 16(%2,%1,2) \n"
+        "movaps   %%xmm0,   (%2,%0,2) \n"
+        "movaps   %%xmm2, 16(%2,%0,2) \n"
+        "sub $16, %1 \n"
+        "add $16, %0 \n"
+        "jl 1b \n"
+        :"+&r"(j), "+&r"(k)
+        :"r"(z+n8), "r"(tcos+n8), "r"(tsin+n8)
         :"memory"
     );
 }
 
-void ff_imdct_half_sse(MDCTContext *s, FFTSample *output,
+void ff_imdct_calc_sse(MDCTContext *s, FFTSample *output,
                        const FFTSample *input, FFTSample *tmp)
 {
     x86_reg j, k;
-    long n8, n4, n;
-    FFTComplex *z = (FFTComplex *)tmp;
-
-    n = 1 << s->nbits;
-    n4 = n >> 2;
-    n8 = n >> 3;
+    long n = 1 << s->nbits;
+    long n4 = n >> 2;
 
-    imdct_sse(s, input, tmp);
+    ff_imdct_half_sse(s, output+n4, input);
 
     j = -n;
     k = n-16;
-    asm volatile("movaps %0, %%xmm7 \n\t"::"m"(*m1m1m1m1));
     asm volatile(
-        "1: \n\t"
-        "movaps     (%3,%1), %%xmm0 \n\t"
-        "movaps     (%3,%0), %%xmm1 \n\t"
-        "xorps       %%xmm7, %%xmm0 \n\t"
-        "movaps      %%xmm0, %%xmm2 \n\t"
-        "shufps $141,%%xmm1, %%xmm0 \n\t"
-        "shufps $216,%%xmm1, %%xmm2 \n\t"
-        "shufps $54, %%xmm0, %%xmm0 \n\t"
-        "shufps $156,%%xmm2, %%xmm2 \n\t"
-        "xorps       %%xmm7, %%xmm0 \n\t"
-        "movaps      %%xmm2, (%2,%1) \n\t"
-        "movaps      %%xmm0, (%2,%0) \n\t"
-        "sub $16, %1 \n\t"
-        "add $16, %0 \n\t"
-        "jl 1b \n\t"
+        "movaps %4, %%xmm7 \n"
+        "1: \n"
+        "movaps       (%2,%1), %%xmm0 \n"
+        "movaps       (%3,%0), %%xmm1 \n"
+        "shufps $0x1b, %%xmm0, %%xmm0 \n"
+        "shufps $0x1b, %%xmm1, %%xmm1 \n"
+        "xorps         %%xmm7, %%xmm0 \n"
+        "movaps        %%xmm1, (%3,%1) \n"
+        "movaps        %%xmm0, (%2,%0) \n"
+        "sub $16, %1 \n"
+        "add $16, %0 \n"
+        "jl 1b \n"
         :"+r"(j), "+r"(k)
-        :"r"(output+n4), "r"(z+n8)
-        :"memory"
+        :"r"(output+n4), "r"(output+n4*3),
+         "m"(*m1m1m1m1)
     );
 }
 
diff --git a/libavcodec/mdct.c b/libavcodec/mdct.c
index 6a3b69a014..86d447b910 100644
--- a/libavcodec/mdct.c
+++ b/libavcodec/mdct.c
@@ -100,18 +100,25 @@ int ff_mdct_init(MDCTContext *s, int nbits, int inverse)
     (pim) = _are * _bim + _aim * _bre;\
 }
 
-static void imdct_c(MDCTContext *s, const FFTSample *input, FFTSample *tmp)
+/**
+ * Compute the middle half of the inverse MDCT of size N = 2^nbits,
+ * thus excluding the parts that can be derived by symmetry
+ * @param output N/2 samples
+ * @param input N/2 samples
+ */
+void ff_imdct_half(MDCTContext *s, FFTSample *output, const FFTSample *input)
 {
-    int k, n4, n2, n, j;
+    int k, n8, n4, n2, n, j;
     const uint16_t *revtab = s->fft.revtab;
     const FFTSample *tcos = s->tcos;
     const FFTSample *tsin = s->tsin;
     const FFTSample *in1, *in2;
-    FFTComplex *z = (FFTComplex *)tmp;
+    FFTComplex *z = (FFTComplex *)output;
 
     n = 1 << s->nbits;
     n2 = n >> 1;
     n4 = n >> 2;
+    n8 = n >> 3;
 
     /* pre rotation */
     in1 = input;
@@ -125,9 +132,15 @@ static void imdct_c(MDCTContext *s, const FFTSample *input, FFTSample *tmp)
     ff_fft_calc(&s->fft, z);
 
     /* post rotation + reordering */
-    /* XXX: optimize */
-    for(k = 0; k < n4; k++) {
-        CMUL(z[k].re, z[k].im, z[k].re, z[k].im, tcos[k], tsin[k]);
+    output += n4;
+    for(k = 0; k < n8; k++) {
+        FFTSample r0, i0, r1, i1;
+        CMUL(r0, i1, z[n8-k-1].im, z[n8-k-1].re, tsin[n8-k-1], tcos[n8-k-1]);
+        CMUL(r1, i0, z[n8+k  ].im, z[n8+k  ].re, tsin[n8+k  ], tcos[n8+k  ]);
+        z[n8-k-1].re = r0;
+        z[n8-k-1].im = i0;
+        z[n8+k  ].re = r1;
+        z[n8+k  ].im = i1;
     }
 }
 
@@ -140,52 +153,16 @@ static void imdct_c(MDCTContext *s, const FFTSample *input, FFTSample *tmp)
 void ff_imdct_calc(MDCTContext *s, FFTSample *output,
                    const FFTSample *input, FFTSample *tmp)
 {
-    int k, n8, n2, n;
-    FFTComplex *z = (FFTComplex *)tmp;
-    n = 1 << s->nbits;
-    n2 = n >> 1;
-    n8 = n >> 3;
-
-    imdct_c(s, input, tmp);
-
-    for(k = 0; k < n8; k++) {
-        output[2*k] = -z[n8 + k].im;
-        output[n2-1-2*k] = z[n8 + k].im;
+    int k;
+    int n = 1 << s->nbits;
+    int n2 = n >> 1;
+    int n4 = n >> 2;
 
-        output[2*k+1] = z[n8-1-k].re;
-        output[n2-1-2*k-1] = -z[n8-1-k].re;
-
-        output[n2 + 2*k]=-z[k+n8].re;
-        output[n-1- 2*k]=-z[k+n8].re;
-
-        output[n2 + 2*k+1]=z[n8-k-1].im;
-        output[n-2 - 2 * k] = z[n8-k-1].im;
-    }
-}
+    ff_imdct_half(s, output+n4, input);
 
-/**
- * Compute the middle half of the inverse MDCT of size N = 2^nbits,
- * thus excluding the parts that can be derived by symmetry
- * @param output N/2 samples
- * @param input N/2 samples
- * @param tmp N/2 samples
- */
-void ff_imdct_half(MDCTContext *s, FFTSample *output,
-                   const FFTSample *input, FFTSample *tmp)
-{
-    int k, n8, n4, n;
-    FFTComplex *z = (FFTComplex *)tmp;
-    n = 1 << s->nbits;
-    n4 = n >> 2;
-    n8 = n >> 3;
-
-    imdct_c(s, input, tmp);
-
-    for(k = 0; k < n8; k++) {
-        output[n4-1-2*k]   =  z[n8+k].im;
-        output[n4-1-2*k-1] = -z[n8-k-1].re;
-        output[n4 + 2*k]   = -z[n8+k].re;
-        output[n4 + 2*k+1] =  z[n8-k-1].im;
+    for(k = 0; k < n4; k++) {
+        output[k] = -output[n2-k-1];
+        output[n-k-1] = output[n2+k];
     }
 }
 
@@ -203,7 +180,7 @@ void ff_mdct_calc(MDCTContext *s, FFTSample *out,
     const uint16_t *revtab = s->fft.revtab;
     const FFTSample *tcos = s->tcos;
     const FFTSample *tsin = s->tsin;
-    FFTComplex *x = (FFTComplex *)tmp;
+    FFTComplex *x = (FFTComplex *)out;
 
     n = 1 << s->nbits;
     n2 = n >> 1;
@@ -227,12 +204,14 @@ void ff_mdct_calc(MDCTContext *s, FFTSample *out,
     ff_fft_calc(&s->fft, x);
 
     /* post rotation */
-    for(i=0;i<n4;i++) {
-        re = x[i].re;
-        im = x[i].im;
-        CMUL(re1, im1, re, im, -tsin[i], -tcos[i]);
-        out[2*i] = im1;
-        out[n2-1-2*i] = re1;
+    for(i=0;i<n8;i++) {
+        FFTSample r0, i0, r1, i1;
+        CMUL(i1, r0, x[n8-i-1].re, x[n8-i-1].im, -tsin[n8-i-1], -tcos[n8-i-1]);
+        CMUL(i0, r1, x[n8+i  ].re, x[n8+i  ].im, -tsin[n8+i  ], -tcos[n8+i  ]);
+        x[n8-i-1].re = r0;
+        x[n8-i-1].im = i0;
+        x[n8+i  ].re = r1;
+        x[n8+i  ].im = i1;
     }
 }
 
diff --git a/libavcodec/vorbis_dec.c b/libavcodec/vorbis_dec.c
index 46ec7b690f..87e8afe96c 100644
--- a/libavcodec/vorbis_dec.c
+++ b/libavcodec/vorbis_dec.c
@@ -1517,18 +1517,18 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) {
 // MDCT, overlap/add, save data for next overlapping  FPMATH
 
     retlen = (blocksize + vc->blocksize[previous_window])/4;
-    dir = retlen <= blocksize/2; // pick an order so that ret[] can reuse residues[] without stepping on any data we need
+    dir = retlen <= blocksize/2; // pick an order so that ret[] can reuse floors[] without stepping on any data we need
     for(j=dir?0:vc->audio_channels-1; (unsigned)j<vc->audio_channels; j+=dir*2-1) {
         uint_fast16_t bs0=vc->blocksize[0];
         uint_fast16_t bs1=vc->blocksize[1];
         float *residue=vc->channel_residues+res_chan[j]*blocksize/2;
         float *floor=vc->channel_floors+j*blocksize/2;
         float *saved=vc->saved+j*bs1/4;
-        float *ret=vc->channel_residues+j*retlen;
-        float *buf=floor;
+        float *ret=vc->channel_floors+j*retlen;
+        float *buf=residue;
         const float *win=vc->win[blockflag&previous_window];
 
-        vc->mdct[0].fft.imdct_half(&vc->mdct[blockflag], buf, floor, residue);
+        vc->mdct[0].fft.imdct_half(&vc->mdct[blockflag], buf, floor);
 
         if(blockflag == previous_window) {
             vc->dsp.vector_fmul_window(ret, saved, buf, win, fadd_bias, blocksize/4);
@@ -1583,7 +1583,7 @@ static int vorbis_decode_frame(AVCodecContext *avccontext,
     AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
 
     for(i=0; i<vc->audio_channels; i++)
-        channel_ptrs[i] = vc->channel_residues+i*len;
+        channel_ptrs[i] = vc->channel_floors+i*len;
     vc->dsp.float_to_int16_interleave(data, channel_ptrs, len, vc->audio_channels);
     *data_size=len*2*vc->audio_channels;