Making exp_rotation1() use MAC16_16(), which saves a few cycles on ARM

This commit is contained in:
Jean-Marc Valin 2014-01-04 21:06:24 -05:00
parent ccec752a38
commit ed01a596dc

View file

@ -42,15 +42,17 @@
static void exp_rotation1(celt_norm *X, int len, int stride, opus_val16 c, opus_val16 s)
{
int i;
opus_val16 ms;
celt_norm *Xptr;
Xptr = X;
ms = NEG16(s);
for (i=0;i<len-stride;i++)
{
celt_norm x1, x2;
x1 = Xptr[0];
x2 = Xptr[stride];
Xptr[stride] = EXTRACT16(PSHR32(MULT16_16(c,x2) + MULT16_16(s,x1), 15));
*Xptr++ = EXTRACT16(PSHR32(MULT16_16(c,x1) - MULT16_16(s,x2), 15));
Xptr[stride] = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x2), s, x1), 15));
*Xptr++ = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x1), ms, x2), 15));
}
Xptr = &X[len-2*stride-1];
for (i=len-2*stride-1;i>=0;i--)
@ -58,8 +60,8 @@ static void exp_rotation1(celt_norm *X, int len, int stride, opus_val16 c, opus_
celt_norm x1, x2;
x1 = Xptr[0];
x2 = Xptr[stride];
Xptr[stride] = EXTRACT16(PSHR32(MULT16_16(c,x2) + MULT16_16(s,x1), 15));
*Xptr-- = EXTRACT16(PSHR32(MULT16_16(c,x1) - MULT16_16(s,x2), 15));
Xptr[stride] = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x2), s, x1), 15));
*Xptr-- = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x1), ms, x2), 15));
}
}