ref: 39aad911d96dc80509a9402c4eeefe333b56d212
parent: 558c50eb3d052182cabcbe4c6276a257fe49d8cc
author: Jean-Marc Valin <[email protected]>
date: Thu Apr 17 03:29:53 EDT 2008
Made twiddle pointer in mdct more explicit
--- a/libcelt/mdct.c
+++ b/libcelt/mdct.c
@@ -104,6 +104,7 @@
const kiss_fft_scalar * restrict xp1 = in+N4;
const kiss_fft_scalar * restrict xp2 = in+N2+N4-1;
kiss_fft_scalar * restrict yp = out;
+ kiss_fft_scalar *t = &l->trig[0];
for(i=0;i<N/8;i++)
{kiss_fft_scalar re, im;
@@ -114,8 +115,9 @@
xp2-=2;
/* We could remove the HALF32 above and just use MULT16_32_Q16 below
(MIXED_PRECISION only) */
- *yp++ = S_MUL(re,l->trig[i]) - S_MUL(im,l->trig[i+N4]);
- *yp++ = S_MUL(im,l->trig[i]) + S_MUL(re,l->trig[i+N4]);
+ *yp++ = S_MUL(re,t[0]) - S_MUL(im,t[N4]);
+ *yp++ = S_MUL(im,t[0]) + S_MUL(re,t[N4]);
+ t++;
}
for(;i<N4;i++)
{@@ -127,8 +129,9 @@
xp2-=2;
/* We could remove the HALF32 above and just use MULT16_32_Q16 below
(MIXED_PRECISION only) */
- *yp++ = S_MUL(re,l->trig[i]) - S_MUL(im,l->trig[i+N4]);
- *yp++ = S_MUL(im,l->trig[i]) + S_MUL(re,l->trig[i+N4]);
+ *yp++ = S_MUL(re,t[0]) - S_MUL(im,t[N4]);
+ *yp++ = S_MUL(im,t[0]) + S_MUL(re,t[N4]);
+ t++;
}
}
@@ -141,14 +144,16 @@
const kiss_fft_scalar * restrict fp = f;
kiss_fft_scalar * restrict yp1 = out;
kiss_fft_scalar * restrict yp2 = out+N2-1;
+ kiss_fft_scalar *t = &l->trig[0];
/* Temp pointers to make it really clear to the compiler what we're doing */
for(i=0;i<N4;i++)
{- *yp1 = -S_MUL(fp[1],l->trig[i+N4]) + S_MUL(fp[0],l->trig[i]);
- *yp2 = -S_MUL(fp[0],l->trig[i+N4]) - S_MUL(fp[1],l->trig[i]);
+ *yp1 = -S_MUL(fp[1],t[N4]) + S_MUL(fp[0],t[0]);
+ *yp2 = -S_MUL(fp[0],t[N4]) - S_MUL(fp[1],t[0]);
fp += 2;
yp1 += 2;
yp2 -= 2;
+ t++;
}
}
RESTORE_STACK;
@@ -172,12 +177,14 @@
const kiss_fft_scalar * restrict xp1 = in;
const kiss_fft_scalar * restrict xp2 = in+N2-1;
kiss_fft_scalar * restrict yp = out;
+ kiss_fft_scalar *t = &l->trig[0];
for(i=0;i<N4;i++)
{- *yp++ = -S_MUL(*xp2, l->trig[i]) - S_MUL(*xp1,l->trig[i+N4]);
- *yp++ = S_MUL(*xp2, l->trig[i+N4]) - S_MUL(*xp1,l->trig[i]);
+ *yp++ = -S_MUL(*xp2, t[0]) - S_MUL(*xp1,t[N4]);
+ *yp++ = S_MUL(*xp2, t[N4]) - S_MUL(*xp1,t[0]);
xp1+=2;
xp2-=2;
+ t++;
}
}