int count = SkTMin(ndst, nsrc);
ndst -= count;
const uint32_t* src = srcStart;
- const uint32_t* end = src + (count & ~3);
+ const uint32_t* end = dst + (count & ~3);
+ ptrdiff_t delta = src - dst;
- while (src < end) {
+ while (dst < end) {
__m128i pixels = load(src);
if (_mm_testc_si128(pixels, alphaMask)) {
+ uint32_t* start = dst;
do {
store(dst, pixels);
dst += 4;
- src += 4;
- } while (src < end && _mm_testc_si128(pixels = load(src), alphaMask));
+ } while (dst < end
+ && _mm_testc_si128(pixels = load(dst + delta), alphaMask));
+ src += dst - start;
} else if (_mm_testz_si128(pixels, alphaMask)) {
do {
dst += 4;
src += 4;
- } while (src < end && _mm_testz_si128(pixels = load(src), alphaMask));
+ } while (dst < end
+ && _mm_testz_si128(pixels = load(src), alphaMask));
} else {
+ uint32_t* start = dst;
do {
- srcover_srgb_srgb_4(dst, src);
+ srcover_srgb_srgb_4(dst, dst + delta);
dst += 4;
- src += 4;
- } while (src < end && _mm_testnzc_si128(pixels = load(src), alphaMask));
+ } while (dst < end
+ && _mm_testnzc_si128(pixels = load(dst + delta), alphaMask));
+ src += dst - start;
}
}
}
#else
// SSE2 versions
+
+ // Note: In the next three comparisons a group of 4 pixels is converted to a group of
+ // "signed" pixels because the sse2 does not have an unsigned comparison.
+ // Make it so that we can use the signed comparison operators by biasing
+ // 0x00xxxxxx to 0x80xxxxxxx which is the smallest values and biasing 0xffxxxxxx to
+ // 0x7fxxxxxx which is the largest set of values.
static inline bool check_opaque_alphas(__m128i pixels) {
+ __m128i signedPixels = _mm_xor_si128(pixels, _mm_set1_epi32(0x80000000));
int mask =
_mm_movemask_epi8(
- _mm_cmpeq_epi32(
- _mm_andnot_si128(pixels, _mm_set1_epi32(0xFF000000)),
- _mm_setzero_si128()));
- return mask == 0xFFFF;
+ _mm_cmplt_epi32(signedPixels, _mm_set1_epi32(0x7F000000)));
+ return mask == 0;
}
static inline bool check_transparent_alphas(__m128i pixels) {
+ __m128i signedPixels = _mm_xor_si128(pixels, _mm_set1_epi32(0x80000000));
int mask =
_mm_movemask_epi8(
- _mm_cmpeq_epi32(
- _mm_and_si128(pixels, _mm_set1_epi32(0xFF000000)),
- _mm_setzero_si128()));
- return mask == 0xFFFF;
+ _mm_cmpgt_epi32(signedPixels, _mm_set1_epi32(0x80FFFFFF)));
+ return mask == 0;
}
static inline bool check_partial_alphas(__m128i pixels) {
- __m128i alphas = _mm_and_si128(pixels, _mm_set1_epi32(0xFF000000));
- int mask =
- _mm_movemask_epi8(
- _mm_cmpeq_epi8(
- _mm_srai_epi32(alphas, 8),
- alphas));
- return mask == 0xFFFF;
+ __m128i signedPixels = _mm_xor_si128(pixels, _mm_set1_epi32(0x80000000));
+ __m128i opaque = _mm_cmplt_epi32(signedPixels, _mm_set1_epi32(0x7F000000));
+ __m128i transparent = _mm_cmpgt_epi32(signedPixels, _mm_set1_epi32(0x80FFFFFF));
+ int mask = _mm_movemask_epi8(_mm_xor_si128(opaque, transparent));
+ return mask == 0;
}
void srcover_srgb_srgb(
int count = SkTMin(ndst, nsrc);
ndst -= count;
const uint32_t* src = srcStart;
- const uint32_t* end = src + (count & ~3);
+ const uint32_t* end = dst + (count & ~3);
+ const ptrdiff_t delta = src - dst;
__m128i pixels = load(src);
do {
if (check_opaque_alphas(pixels)) {
+ uint32_t* start = dst;
do {
store(dst, pixels);
dst += 4;
- src += 4;
- } while (src < end && check_opaque_alphas(pixels = load(src)));
+ } while (dst < end && check_opaque_alphas((pixels = load(dst + delta))));
+ src += dst - start;
} else if (check_transparent_alphas(pixels)) {
- const uint32_t* start = src;
+ const uint32_t* start = dst;
do {
- src += 4;
- } while (src < end && check_transparent_alphas(pixels = load(src)));
- dst += src - start;
+ dst += 4;
+ } while (dst < end && check_transparent_alphas(pixels = load(dst + delta)));
+ src += dst - start;
} else {
+ const uint32_t* start = dst;
do {
- srcover_srgb_srgb_4(dst, src);
+ srcover_srgb_srgb_4(dst, dst + delta);
dst += 4;
- src += 4;
- } while (src < end && check_partial_alphas(pixels = load(src)));
+ } while (dst < end && check_partial_alphas(pixels = load(dst + delta)));
+ src += dst - start;
}
- } while (src < end);
+ } while (dst < end);
count = count & 3;
while (count-- > 0) {