void imageFilterSubFrom_SSE2(unsigned char *dst, unsigned char *src, int length)
{
int n = length;
// Compute first few values so we're on a 16-byte boundary in dst
while( (((long)dst & 0xF) > 0) && (n > 0) ) {
SUBFROM_PIXEL();
--n; ++dst; ++src;
}
// Do bulk of processing using SSE2 (sub 16 8-bit unsigned integers, with saturation)
while(n >= 16) {
__m128i s = _mm_loadu_si128((__m128i*)src);
__m128i d = _mm_load_si128((__m128i*)dst);
__m128i r = _mm_subs_epu8(d, s);
_mm_store_si128((__m128i*)dst, r);
n -= 16; src += 16; dst += 16;
}
// If any bytes are left over, deal with them individually
++n;
BASIC_SUBFROM();
}
void imageFilterSubFrom_Altivec(unsigned char *dst, unsigned char *src, int length)
{
int n = length;
// Compute first few values so we're on a 16-byte boundary in dst
while( (((long)dst & 0xF) > 0) && (n > 0) ) {
SUBFROM_PIXEL();
--n; ++dst; ++src;
}
// Do bulk of processing using Altivec (sub 16 8-bit unsigned integers, with saturation)
while(n >= 16) {
vector unsigned char s = vec_ld(0,src);
vector unsigned char d = vec_ld(0,dst);
vector unsigned char r = vec_subs(d, s);
vec_st(r,0,dst);
n -= 16; src += 16; dst += 16;
}
// If any bytes are left over, deal with them individually
++n;
BASIC_SUBFROM();
}
