void imageFilterSubFrom(unsigned char *dst, unsigned char *src, int length)
{
#if defined(USE_PPC_GFX)
if(cpufuncs & CPUF_PPC_ALTIVEC) {
imageFilterSubFrom_Altivec(dst, src, length);
} else {
int n = length + 1;
BASIC_SUBFROM();
}
#elif defined(USE_X86_GFX)
#ifndef MACOSX
if (cpufuncs & CPUF_X86_SSE2) {
#endif // !MACOSX
imageFilterSubFrom_SSE2(dst, src, length);
#ifndef MACOSX
} else if (cpufuncs & CPUF_X86_MMX) {
imageFilterSubFrom_MMX(dst, src, length);
} else {
int n = length + 1;
BASIC_SUBFROM();
}
#endif // !MACOSX
#else // no special gfx handling
int n = length + 1;
BASIC_SUBFROM();
#endif
}
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();
}
