summaryrefslogtreecommitdiff
path: root/mdct.c
diff options
context:
space:
mode:
Diffstat (limited to 'mdct.c')
-rw-r--r--mdct.c598
1 files changed, 320 insertions, 278 deletions
diff --git a/mdct.c b/mdct.c
index 460b736..e3e7c75 100644
--- a/mdct.c
+++ b/mdct.c
@@ -13,7 +13,7 @@
function: normalized modified discrete cosine transform
power of two length transform only [64 <= n ]
- last mod: $Id: mdct.c,v 1.4 2002/09/13 16:37:56 xiphmont Exp $
+ last mod: $Id: mdct.c,v 1.5 2002/09/20 00:10:31 xiphmont Exp $
Original algorithm adapted long ago from _The use of multirate filter
banks for coding of high quality digital audio_, by T. Sporer,
@@ -42,60 +42,56 @@
#include "mdct_lookup.h"
#include "misc.h"
-/* 8 point butterfly (in place, 4 register) */
+
+/* 8 point butterfly (in place) */
STIN void mdct_butterfly_8(DATA_TYPE *x){
- REG_TYPE r0 = x[6] + x[2];
- REG_TYPE r1 = x[6] - x[2];
- REG_TYPE r2 = x[4] + x[0];
- REG_TYPE r3 = x[4] - x[0];
-
- x[6] = r0 + r2;
- x[4] = r0 - r2;
-
- r0 = x[5] - x[1];
- r2 = x[7] - x[3];
- x[0] = r1 + r0;
- x[2] = r1 - r0;
-
- r0 = x[5] + x[1];
- r1 = x[7] + x[3];
- x[3] = r2 + r3;
- x[1] = r2 - r3;
- x[7] = r1 + r0;
- x[5] = r1 - r0;
-
+
+ REG_TYPE r0 = x[4] + x[0];
+ REG_TYPE r1 = x[4] - x[0];
+ REG_TYPE r2 = x[5] + x[1];
+ REG_TYPE r3 = x[5] - x[1];
+ REG_TYPE r4 = x[6] + x[2];
+ REG_TYPE r5 = x[6] - x[2];
+ REG_TYPE r6 = x[7] + x[3];
+ REG_TYPE r7 = x[7] - x[3];
+
+ x[0] = r5 + r3;
+ x[1] = r7 - r1;
+ x[2] = r5 - r3;
+ x[3] = r7 + r1;
+ x[4] = r4 - r0;
+ x[5] = r6 - r2;
+ x[6] = r4 + r0;
+ x[7] = r6 + r2;
+ MB();
}
/* 16 point butterfly (in place, 4 register) */
STIN void mdct_butterfly_16(DATA_TYPE *x){
- REG_TYPE r0 = x[1] - x[9];
- REG_TYPE r1 = x[0] - x[8];
-
- x[8] += x[0];
- x[9] += x[1];
- x[0] = MULT31((r0 + r1) , cPI2_8);
- x[1] = MULT31((r0 - r1) , cPI2_8);
-
- r0 = x[3] - x[11];
- r1 = x[10] - x[2];
- x[10] += x[2];
- x[11] += x[3];
- x[2] = r0;
- x[3] = r1;
-
- r0 = x[12] - x[4];
- r1 = x[13] - x[5];
- x[12] += x[4];
- x[13] += x[5];
- x[4] = MULT31((r0 - r1) , cPI2_8);
- x[5] = MULT31((r0 + r1) , cPI2_8);
-
- r0 = x[14] - x[6];
- r1 = x[15] - x[7];
- x[14] += x[6];
- x[15] += x[7];
- x[6] = r0;
- x[7] = r1;
+
+ REG_TYPE r0, r1;
+
+ r0 = x[ 0] - x[ 8]; x[ 8] += x[ 0];
+ r1 = x[ 1] - x[ 9]; x[ 9] += x[ 1];
+ x[ 0] = MULT31((r0 + r1) , cPI2_8);
+ x[ 1] = MULT31((r1 - r0) , cPI2_8);
+ MB();
+
+ r0 = x[10] - x[ 2]; x[10] += x[ 2];
+ r1 = x[ 3] - x[11]; x[11] += x[ 3];
+ x[ 2] = r1; x[ 3] = r0;
+ MB();
+
+ r0 = x[12] - x[ 4]; x[12] += x[ 4];
+ r1 = x[13] - x[ 5]; x[13] += x[ 5];
+ x[ 4] = MULT31((r0 - r1) , cPI2_8);
+ x[ 5] = MULT31((r0 + r1) , cPI2_8);
+ MB();
+
+ r0 = x[14] - x[ 6]; x[14] += x[ 6];
+ r1 = x[15] - x[ 7]; x[15] += x[ 7];
+ x[ 6] = r0; x[ 7] = r1;
+ MB();
mdct_butterfly_8(x);
mdct_butterfly_8(x+8);
@@ -103,161 +99,140 @@ STIN void mdct_butterfly_16(DATA_TYPE *x){
/* 32 point butterfly (in place, 4 register) */
STIN void mdct_butterfly_32(DATA_TYPE *x){
- REG_TYPE r0 = x[30] - x[14];
- REG_TYPE r1 = x[31] - x[15];
-
- x[30] += x[14];
- x[31] += x[15];
- x[14] = r0;
- x[15] = r1;
-
- r0 = x[28] - x[12];
- r1 = x[29] - x[13];
- x[28] += x[12];
- x[29] += x[13];
- x[12] = MULT31( r0 , cPI1_8 ) - MULT31( r1 , cPI3_8 );
- x[13] = MULT31( r0 , cPI3_8 ) + MULT31( r1 , cPI1_8 );
-
- r0 = x[26] - x[10];
- r1 = x[27] - x[11];
- x[26] += x[10];
- x[27] += x[11];
- x[10] = MULT31(( r0 - r1 ) , cPI2_8);
- x[11] = MULT31(( r0 + r1 ) , cPI2_8);
-
- r0 = x[24] - x[8];
- r1 = x[25] - x[9];
- x[24] += x[8];
- x[25] += x[9];
- x[8] = MULT31( r0 , cPI3_8 ) - MULT31( r1 , cPI1_8 );
- x[9] = MULT31( r1 , cPI3_8 ) + MULT31( r0 , cPI1_8 );
-
- r0 = x[22] - x[6];
- r1 = x[7] - x[23];
- x[22] += x[6];
- x[23] += x[7];
- x[6] = r1;
- x[7] = r0;
-
- r0 = x[4] - x[20];
- r1 = x[5] - x[21];
- x[20] += x[4];
- x[21] += x[5];
- x[4] = MULT31( r1 , cPI1_8 ) + MULT31( r0 , cPI3_8 );
- x[5] = MULT31( r1 , cPI3_8 ) - MULT31( r0 , cPI1_8 );
-
- r0 = x[2] - x[18];
- r1 = x[3] - x[19];
- x[18] += x[2];
- x[19] += x[3];
- x[2] = MULT31(( r1 + r0 ) , cPI2_8);
- x[3] = MULT31(( r1 - r0 ) , cPI2_8);
-
- r0 = x[0] - x[16];
- r1 = x[1] - x[17];
- x[16] += x[0];
- x[17] += x[1];
- x[0] = MULT31( r1 , cPI3_8 ) + MULT31( r0 , cPI1_8 );
- x[1] = MULT31( r1 , cPI1_8 ) - MULT31( r0 , cPI3_8 );
+
+ REG_TYPE r0, r1;
+
+ r0 = x[30] - x[14]; x[30] += x[14];
+ r1 = x[31] - x[15]; x[31] += x[15];
+ x[14] = r0; x[15] = r1;
+ MB();
+
+ r0 = x[28] - x[12]; x[28] += x[12];
+ r1 = x[29] - x[13]; x[29] += x[13];
+ XNPROD31( r0, r1, cPI1_8, cPI3_8, &x[12], &x[13] );
+ MB();
+
+ r0 = x[26] - x[10]; x[26] += x[10];
+ r1 = x[27] - x[11]; x[27] += x[11];
+ x[10] = MULT31((r0 - r1) , cPI2_8);
+ x[11] = MULT31((r0 + r1) , cPI2_8);
+ MB();
+
+ r0 = x[24] - x[ 8]; x[24] += x[ 8];
+ r1 = x[25] - x[ 9]; x[25] += x[ 9];
+ XNPROD31( r0, r1, cPI3_8, cPI1_8, &x[ 8], &x[ 9] );
+ MB();
+
+ r0 = x[22] - x[ 6]; x[22] += x[ 6];
+ r1 = x[ 7] - x[23]; x[23] += x[ 7];
+ x[ 6] = r1; x[ 7] = r0;
+ MB();
+
+ r0 = x[ 4] - x[20]; x[20] += x[ 4];
+ r1 = x[ 5] - x[21]; x[21] += x[ 5];
+ XPROD31 ( r0, r1, cPI3_8, cPI1_8, &x[ 4], &x[ 5] );
+ MB();
+
+ r0 = x[ 2] - x[18]; x[18] += x[ 2];
+ r1 = x[ 3] - x[19]; x[19] += x[ 3];
+ x[ 2] = MULT31((r1 + r0) , cPI2_8);
+ x[ 3] = MULT31((r1 - r0) , cPI2_8);
+ MB();
+
+ r0 = x[ 0] - x[16]; x[16] += x[ 0];
+ r1 = x[ 1] - x[17]; x[17] += x[ 1];
+ XPROD31 ( r0, r1, cPI1_8, cPI3_8, &x[ 0], &x[ 1] );
+ MB();
mdct_butterfly_16(x);
mdct_butterfly_16(x+16);
-
}
/* N/stage point generic N stage butterfly (in place, 2 register) */
STIN void mdct_butterfly_generic(DATA_TYPE *x,int points,int step){
- DATA_TYPE *T=sin_lookup+2048;
- DATA_TYPE *V=sin_lookup;
- DATA_TYPE *x1 = x + points - 8;
- DATA_TYPE *x2 = x + (points>>1) - 8;
+ DATA_TYPE *T = sincos_lookup0;
+ DATA_TYPE *x1 = x + points - 8;
+ DATA_TYPE *x2 = x + (points>>1) - 8;
REG_TYPE r0;
REG_TYPE r1;
do{
+ r0 = x1[6] - x2[6]; x1[6] += x2[6];
+ r1 = x2[7] - x1[7]; x1[7] += x2[7];
+ XPROD31( r1, r0, T[0], T[1], &x2[6], &x2[7] ); T+=step;
+
+ r0 = x1[4] - x2[4]; x1[4] += x2[4];
+ r1 = x2[5] - x1[5]; x1[5] += x2[5];
+ XPROD31( r1, r0, T[0], T[1], &x2[4], &x2[5] ); T+=step;
+
+ r0 = x1[2] - x2[2]; x1[2] += x2[2];
+ r1 = x2[3] - x1[3]; x1[3] += x2[3];
+ XPROD31( r1, r0, T[0], T[1], &x2[2], &x2[3] ); T+=step;
+
+ r0 = x1[0] - x2[0]; x1[0] += x2[0];
+ r1 = x2[1] - x1[1]; x1[1] += x2[1];
+ XPROD31( r1, r0, T[0], T[1], &x2[0], &x2[1] ); T+=step;
+
+ x1-=8; x2-=8;
+ }while(T<sincos_lookup0+1024);
+ do{
+ r0 = x1[6] - x2[6]; x1[6] += x2[6];
+ r1 = x1[7] - x2[7]; x1[7] += x2[7];
+ XNPROD31( r0, r1, T[0], T[1], &x2[6], &x2[7] ); T-=step;
+
+ r0 = x1[4] - x2[4]; x1[4] += x2[4];
+ r1 = x1[5] - x2[5]; x1[5] += x2[5];
+ XNPROD31( r0, r1, T[0], T[1], &x2[4], &x2[5] ); T-=step;
+
+ r0 = x1[2] - x2[2]; x1[2] += x2[2];
+ r1 = x1[3] - x2[3]; x1[3] += x2[3];
+ XNPROD31( r0, r1, T[0], T[1], &x2[2], &x2[3] ); T-=step;
+
+ r0 = x1[0] - x2[0]; x1[0] += x2[0];
+ r1 = x1[1] - x2[1]; x1[1] += x2[1];
+ XNPROD31( r0, r1, T[0], T[1], &x2[0], &x2[1] ); T-=step;
+
+ x1-=8; x2-=8;
+ }while(T>sincos_lookup0);
+ do{
+ r0 = x2[6] - x1[6]; x1[6] += x2[6];
+ r1 = x2[7] - x1[7]; x1[7] += x2[7];
+ XPROD31( r0, r1, T[0], T[1], &x2[6], &x2[7] ); T+=step;
+
+ r0 = x2[4] - x1[4]; x1[4] += x2[4];
+ r1 = x2[5] - x1[5]; x1[5] += x2[5];
+ XPROD31( r0, r1, T[0], T[1], &x2[4], &x2[5] ); T+=step;
- r0 = x1[6] - x2[6];
- r1 = x1[7] - x2[7];
- x1[6] += x2[6];
- x1[7] += x2[7];
- x2[6] = MULT31(r0 , *T) - MULT31(r1 , *V);
- x2[7] = MULT31(r1 , *T) + MULT31(r0 , *V);
- T -= step;
- V += step;
-
- r0 = x1[4] - x2[4];
- r1 = x1[5] - x2[5];
- x1[4] += x2[4];
- x1[5] += x2[5];
- x2[4] = MULT31(r0 , *T) - MULT31(r1 , *V);
- x2[5] = MULT31(r1 , *T) + MULT31(r0 , *V);
- T -= step;
- V += step;
-
- r0 = x1[2] - x2[2];
- r1 = x1[3] - x2[3];
- x1[2] += x2[2];
- x1[3] += x2[3];
- x2[2] = MULT31(r0 , *T) - MULT31(r1 , *V);
- x2[3] = MULT31(r1 , *T) + MULT31(r0 , *V);
- T -= step;
- V += step;
-
- r0 = x1[0] - x2[0];
- r1 = x1[1] - x2[1];
- x1[0] += x2[0];
- x1[1] += x2[1];
- x2[0] = MULT31(r0 , *T) - MULT31(r1 , *V);
- x2[1] = MULT31(r1 , *T) + MULT31(r0 , *V);
- T -= step;
- V += step;
-
- x1-=8;
- x2-=8;
- }while(T>sin_lookup);
+ r0 = x2[2] - x1[2]; x1[2] += x2[2];
+ r1 = x2[3] - x1[3]; x1[3] += x2[3];
+ XPROD31( r0, r1, T[0], T[1], &x2[2], &x2[3] ); T+=step;
+ r0 = x2[0] - x1[0]; x1[0] += x2[0];
+ r1 = x2[1] - x1[1]; x1[1] += x2[1];
+ XPROD31( r0, r1, T[0], T[1], &x2[0], &x2[1] ); T+=step;
+
+ x1-=8; x2-=8;
+ }while(T<sincos_lookup0+1024);
do{
-
- r0 = x2[6] - x1[6];
- r1 = x2[7] - x1[7];
- x1[6] += x2[6];
- x1[7] += x2[7];
- x2[6] = MULT31(r0 , *T) + MULT31(r1 , *V);
- x2[7] = MULT31(r1 , *T) - MULT31(r0 , *V);
- T += step;
- V -= step;
-
- r0 = x2[4] - x1[4];
- r1 = x2[5] - x1[5];
- x1[4] += x2[4];
- x1[5] += x2[5];
- x2[4] = MULT31(r0 , *T) + MULT31(r1 , *V);
- x2[5] = MULT31(r1 , *T) - MULT31(r0 , *V);
- T += step;
- V -= step;
-
- r0 = x2[2] - x1[2];
- r1 = x2[3] - x1[3];
- x1[2] += x2[2];
- x1[3] += x2[3];
- x2[2] = MULT31(r0 , *T) + MULT31(r1 , *V);
- x2[3] = MULT31(r1 , *T) - MULT31(r0 , *V);
- T += step;
- V -= step;
-
- r0 = x2[0] - x1[0];
- r1 = x2[1] - x1[1];
- x1[0] += x2[0];
- x1[1] += x2[1];
- x2[0] = MULT31(r0 , *T) + MULT31(r1 , *V);
- x2[1] = MULT31(r1 , *T) - MULT31(r0 , *V);
- T += step;
- V -= step;
-
- x1-=8;
- x2-=8;
- }while(x2>=x);
+ r0 = x1[6] - x2[6]; x1[6] += x2[6];
+ r1 = x2[7] - x1[7]; x1[7] += x2[7];
+ XNPROD31( r1, r0, T[0], T[1], &x2[6], &x2[7] ); T-=step;
+
+ r0 = x1[4] - x2[4]; x1[4] += x2[4];
+ r1 = x2[5] - x1[5]; x1[5] += x2[5];
+ XNPROD31( r1, r0, T[0], T[1], &x2[4], &x2[5] ); T-=step;
+
+ r0 = x1[2] - x2[2]; x1[2] += x2[2];
+ r1 = x2[3] - x1[3]; x1[3] += x2[3];
+ XNPROD31( r1, r0, T[0], T[1], &x2[2], &x2[3] ); T-=step;
+
+ r0 = x1[0] - x2[0]; x1[0] += x2[0];
+ r1 = x2[1] - x1[1]; x1[1] += x2[1];
+ XNPROD31( r1, r0, T[0], T[1], &x2[0], &x2[1] ); T-=step;
+
+ x1-=8; x2-=8;
+ }while(T>sincos_lookup0);
}
STIN void mdct_butterflies(DATA_TYPE *x,int points,int shift){
@@ -286,53 +261,83 @@ STIN void mdct_bitreverse(DATA_TYPE *x,int n,int step,int shift){
int bit = 0;
DATA_TYPE *w0 = x;
DATA_TYPE *w1 = x = w0+(n>>1);
- DATA_TYPE *T = sin_lookup-(step>>1);
- DATA_TYPE *V = sin_lookup+2048+(step>>1);
- REG_TYPE r2;
+ DATA_TYPE *T = (step>=4)?(sincos_lookup0+(step>>1)):sincos_lookup1;
+ DATA_TYPE *Ttop = T+1024;
+ DATA_TYPE r2;
do{
- REG_TYPE r3 = bitrev12(bit++);
+ DATA_TYPE r3 = bitrev12(bit++);
DATA_TYPE *x0 = x + ((r3 ^ 0xfff)>>shift) -1;
DATA_TYPE *x1 = x + (r3>>shift);
- REG_TYPE r0 = x0[1] - x1[1];
+ REG_TYPE r0 = x1[1] - x0[1];
REG_TYPE r1 = x0[0] + x1[0];
- T += step;
- V -= step;
- r2 = MULT32(r0 , *T) - MULT32(r1 , *V);
- r3 = MULT32(r1 , *T) + MULT32(r0 , *V);
+
+ XPROD32( T[0], T[1], r0, r1, &r2, &r3 ); T+=step;
w1 -= 4;
- r0 = (x0[1] + x1[1])>>1;
+ r0 = (x0[1] + x1[1])>>1;
r1 = (x0[0] - x1[0])>>1;
-
- w0[0] = r0 - r2;
- w1[2] = r0 + r2;
- w0[1] = r1 - r3;
- w1[3] =-r1 - r3;
+ w0[0] = r0 + r2;
+ w0[1] = r1 + r3;
+ w1[2] = r0 - r2;
+ w1[3] = r3 - r1;
r3 = bitrev12(bit++);
x0 = x + ((r3 ^ 0xfff)>>shift) -1;
x1 = x + (r3>>shift);
- r0 = x0[1] - x1[1];
+ r0 = x1[1] - x0[1];
r1 = x0[0] + x1[0];
- T += step;
- V -= step;
- r2 = MULT32(r0 , *T) - MULT32(r1 , *V);
- r3 = MULT32(r1 , *T) + MULT32(r0 , *V);
+
+ XPROD32( T[0], T[1], r0, r1, &r2, &r3 ); T+=step;
r0 = (x0[1] + x1[1])>>1;
r1 = (x0[0] - x1[0])>>1;
-
- w0[2] = r0 - r2;
- w1[0] = r0 + r2;
- w0[3] = r1 - r3;
- w1[1] =-r1 - r3;
+ w0[2] = r0 + r2;
+ w0[3] = r1 + r3;
+ w1[0] = r0 - r2;
+ w1[1] = r3 - r1;
w0 += 4;
+ }while(T<Ttop);
+ do{
+ DATA_TYPE r3 = bitrev12(bit++);
+ DATA_TYPE *x0 = x + ((r3 ^ 0xfff)>>shift) -1;
+ DATA_TYPE *x1 = x + (r3>>shift);
+
+ REG_TYPE r0 = x0[0] + x1[0];
+ REG_TYPE r1 = x1[1] - x0[1];
+ T-=step; XPROD32( r0, r1, T[0], T[1], &r2, &r3 );
+
+ w1 -= 4;
+
+ r0 = (x0[1] + x1[1])>>1;
+ r1 = (x0[0] - x1[0])>>1;
+ w0[0] = r0 + r2;
+ w0[1] = r1 + r3;
+ w1[2] = r0 - r2;
+ w1[3] = r3 - r1;
+
+ r3 = bitrev12(bit++);
+ x0 = x + ((r3 ^ 0xfff)>>shift) -1;
+ x1 = x + (r3>>shift);
+
+ r0 = x0[0] + x1[0];
+ r1 = x1[1] - x0[1];
+
+ T-=step; XPROD32( r0, r1, T[0], T[1], &r2, &r3 );
+
+ r0 = (x0[1] + x1[1])>>1;
+ r1 = (x0[0] - x1[0])>>1;
+ w0[2] = r0 + r2;
+ w0[3] = r1 + r3;
+ w1[0] = r0 - r2;
+ w1[1] = r3 - r1;
+
+ w0 += 4;
}while(w0<w1);
}
@@ -354,45 +359,36 @@ void mdct_backward(int n, DATA_TYPE *in, DATA_TYPE *out){
iX = in+n2-7;
oX = out+n2+n4;
- T = sin_lookup-step;
- V = sin_lookup+2048+step;
+ T = sincos_lookup0;
do{
-
- oX -= 4;
-
- T += step;
- V -= step;
- oX[2] = MULT31(iX[4] , *T) + MULT31(iX[6] , *V);
- oX[3] = MULT31(iX[6] , *T) - MULT31(iX[4] , *V);
- T += step;
- V -= step;
- oX[0] = MULT31(iX[0] , *T) + MULT31(iX[2] , *V);
- oX[1] = MULT31(iX[2] , *T) - MULT31(iX[0] , *V);
-
- iX -= 8;
-
+ oX-=4;
+ XPROD31( iX[4], iX[6], T[0], T[1], &oX[2], &oX[3] ); T+=step;
+ XPROD31( iX[0], iX[2], T[0], T[1], &oX[0], &oX[1] ); T+=step;
+ iX-=8;
+ }while(iX>=in+n4);
+ do{
+ oX-=4;
+ XPROD31( iX[4], iX[6], T[1], T[0], &oX[2], &oX[3] ); T-=step;
+ XPROD31( iX[0], iX[2], T[1], T[0], &oX[0], &oX[1] ); T-=step;
+ iX-=8;
}while(iX>=in);
iX = in+n2-8;
oX = out+n2+n4;
- T = sin_lookup;
- V = sin_lookup+2048;
+ T = sincos_lookup0;
do{
-
- T += step;
- V -= step;
- oX[0] = MULT31(iX[6] , *T) - MULT31(iX[4] , *V);
- oX[1] = MULT31(iX[4] , *T) + MULT31(iX[6] , *V);
- T += step;
- V -= step;
- oX[2] = MULT31(iX[2] , *T) - MULT31(iX[0] , *V);
- oX[3] = MULT31(iX[0] , *T) + MULT31(iX[2] , *V);
-
- iX -= 8;
- oX += 4;
-
+ T+=step; XNPROD31( iX[6], iX[4], T[0], T[1], &oX[0], &oX[1] );
+ T+=step; XNPROD31( iX[2], iX[0], T[0], T[1], &oX[2], &oX[3] );
+ iX-=8;
+ oX+=4;
+ }while(iX>=in+n4);
+ do{
+ T-=step; XNPROD31( iX[6], iX[4], T[1], T[0], &oX[0], &oX[1] );
+ T-=step; XNPROD31( iX[2], iX[0], T[1], T[0], &oX[2], &oX[3] );
+ iX-=8;
+ oX+=4;
}while(iX>=in);
mdct_butterflies(out+n2,n2,shift);
@@ -405,39 +401,85 @@ void mdct_backward(int n, DATA_TYPE *in, DATA_TYPE *out){
DATA_TYPE *oX1=out+n2+n4;
DATA_TYPE *oX2=out+n2+n4;
DATA_TYPE *iX =out;
- T =sin_lookup-(step>>1);
- V =sin_lookup+2048+(step>>1);
-
- do{
- oX1-=4;
-
- T += step;
- V -= step;
- oX1[3] = MULT31 (iX[0] , *T) - MULT31(iX[1] , *V);
- oX2[0] =-(MULT31 (iX[0] , *V) + MULT31(iX[1] , *T));
-
- T += step;
- V -= step;
- oX1[2] = MULT31 (iX[2] , *T) - MULT31(iX[3] , *V);
- oX2[1] =-(MULT31 (iX[2] , *V) + MULT31(iX[3] , *T));
-
- if(!step) T++,V--;
- T += step;
- V -= step;
- oX1[1] = MULT31 (iX[4] , *T) - MULT31(iX[5] , *V);
- oX2[2] =-(MULT31 (iX[4] , *V) + MULT31(iX[5] , *T));
-
- T += step;
- V -= step;
- oX1[0] = MULT31 (iX[6] , *T) - MULT31(iX[7] , *V);
- oX2[3] =-(MULT31 (iX[6] , *V) + MULT31(iX[7] , *T));
-
- if(!step) T++,V--;
-
- oX2+=4;
- iX += 8;
- }while(iX<oX1);
+ switch(step) {
+ default: {
+ T=(step>=4)?(sincos_lookup0+(step>>1)):sincos_lookup1;
+ do{
+ oX1-=4;
+ XPROD31( iX[0], -iX[1], T[0], T[1], &oX1[3], &oX2[0] ); T+=step;
+ XPROD31( iX[2], -iX[3], T[0], T[1], &oX1[2], &oX2[1] ); T+=step;
+ XPROD31( iX[4], -iX[5], T[0], T[1], &oX1[1], &oX2[2] ); T+=step;
+ XPROD31( iX[6], -iX[7], T[0], T[1], &oX1[0], &oX2[3] ); T+=step;
+ oX2+=4;
+ iX+=8;
+ }while(iX<oX1);
+ break;
+ }
+
+ case 1: {
+ /* linear interpolation between table values: offset=0.5, step=1 */
+ REG_TYPE t0,t1,v0,v1;
+ T = sincos_lookup0;
+ V = sincos_lookup1;
+ t0 = (*T++)>>1;
+ t1 = (*T++)>>1;
+ do{
+ oX1-=4;
+
+ t0 += (v0 = (*V++)>>1);
+ t1 += (v1 = (*V++)>>1);
+ XPROD31( iX[0], -iX[1], t0, t1, &oX1[3], &oX2[0] ); T+=step;
+ v0 += (t0 = (*T++)>>1);
+ v1 += (t1 = (*T++)>>1);
+ XPROD31( iX[2], -iX[3], v0, v1, &oX1[2], &oX2[1] ); T+=step;
+ t0 += (v0 = (*V++)>>1);
+ t1 += (v1 = (*V++)>>1);
+ XPROD31( iX[4], -iX[5], t0, t1, &oX1[1], &oX2[2] ); T+=step;
+ v0 += (t0 = (*T++)>>1);
+ v1 += (t1 = (*T++)>>1);
+ XPROD31( iX[6], -iX[7], v0, v1, &oX1[0], &oX2[3] ); T+=step;
+
+ oX2+=4;
+ iX+=8;
+ }while(iX<oX1);
+ break;
+ }
+
+ case 0: {
+ /* linear interpolation between table values: offset=0.25, step=0.5 */
+ REG_TYPE t0,t1,v0,v1,q0,q1;
+ T = sincos_lookup0;
+ V = sincos_lookup1;
+ t0 = *T++;
+ t1 = *T++;
+ do{
+ oX1-=4;
+
+ v0 = *V++;
+ v1 = *V++;
+ t0 += (q0 = (v0-t0)>>2);
+ t1 += (q1 = (v1-t1)>>2);
+ XPROD31( iX[0], -iX[1], t0, t1, &oX1[3], &oX2[0] ); T+=step;
+ t0 = v0-q0;
+ t1 = v1-q1;
+ XPROD31( iX[2], -iX[3], t0, t1, &oX1[2], &oX2[1] ); T+=step;
+
+ t0 = *T++;
+ t1 = *T++;
+ v0 += (q0 = (t0-v0)>>2);
+ v1 += (q1 = (t1-v1)>>2);
+ XPROD31( iX[4], -iX[5], v0, v1, &oX1[1], &oX2[2] ); T+=step;
+ v0 = t0-q0;
+ v1 = t1-q1;
+ XPROD31( iX[6], -iX[7], v0, v1, &oX1[0], &oX2[3] ); T+=step;
+
+ oX2+=4;
+ iX+=8;
+ }while(iX<oX1);
+ break;
+ }
+ }
iX=out+n2+n4;
oX1=out+n4;
View Lorry Controller Status