diff options
author | Allan Sandfeld Jensen <allan.jensen@theqtcompany.com> | 2015-04-13 16:06:57 +0200 |
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committer | Allan Sandfeld Jensen <allan.jensen@theqtcompany.com> | 2015-04-16 19:24:06 +0000 |
commit | 964ccc58534aac436529007000d1c38d76c88834 (patch) | |
tree | d452d03dabe7c109527987b9f9385de5374c1b12 /src/gui/painting/qrgb.h | |
parent | 365c63e7b177701c0bf80a7cb138b7559b92f350 (diff) |
Remove separate SSE4 unpremultiply function
Merges the SSE4 specific unpremultiply with the normal version, and
adds a SSE2 fallback. There was no reason to split the two since
compile time options will ensure the right version is inlined.
Also adds short-cut for 0 and 255 values.
Change-Id: Ie5aa262f6964219fd3062d4a498f697cf79a4595
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/gui/painting/qrgb.h')
-rw-r--r-- | src/gui/painting/qrgb.h | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/src/gui/painting/qrgb.h b/src/gui/painting/qrgb.h index f7f2185bef..05b3a76bce 100644 --- a/src/gui/painting/qrgb.h +++ b/src/gui/painting/qrgb.h @@ -36,6 +36,11 @@ #include <QtCore/qglobal.h> #include <QtCore/qprocessordetection.h> +#if defined(__SSE4_1__) +#include <smmintrin.h> +#elif defined(__SSE2__) +#include <emmintrin.h> +#endif QT_BEGIN_NAMESPACE @@ -87,19 +92,45 @@ inline Q_DECL_RELAXED_CONSTEXPR QRgb qPremultiply(QRgb x) Q_GUI_EXPORT extern const uint qt_inv_premul_factor[]; +#if defined(__SSE2__) +inline QRgb qUnpremultiply(QRgb p) +{ + const uint alpha = qAlpha(p); + if (alpha == 255 || alpha == 0) + return p; + const uint invAlpha = qt_inv_premul_factor[alpha]; + const __m128i via = _mm_set1_epi32(invAlpha); + const __m128i vr = _mm_set1_epi32(0x8000); +#ifdef __SSE4_1__ + __m128i vl = _mm_cvtepu8_epi32(_mm_cvtsi32_si128(p)); + vl = _mm_mullo_epi32(vl, via); +#else + __m128i vl = _mm_unpacklo_epi8(_mm_cvtsi32_si128(p), _mm_setzero_si128()); + vl = _mm_unpacklo_epi16(vl, vl); + __m128i vll = _mm_mullo_epi16(vl, via); + __m128i vlh = _mm_mulhi_epu16(vl, via); + vl = _mm_add_epi32(vll, _mm_slli_epi32(vlh, 16)); +#endif + vl = _mm_add_epi32(vl, vr); + vl = _mm_srli_epi32(vl, 16); + vl = _mm_packs_epi32(vl, _mm_setzero_si128()); + vl = _mm_insert_epi16(vl, alpha, 3); + vl = _mm_packus_epi16(vl, _mm_setzero_si128()); + return _mm_cvtsi128_si32(vl); +} +#else inline QRgb qUnpremultiply(QRgb p) { const uint alpha = qAlpha(p); // Alpha 255 and 0 are the two most common values, which makes them beneficial to short-cut. - if (alpha == 255) + if (alpha == 255 || alpha == 0) return p; - if (alpha == 0) - return 0; // (p*(0x00ff00ff/alpha)) >> 16 == (p*255)/alpha for all p and alpha <= 256. const uint invAlpha = qt_inv_premul_factor[alpha]; // We add 0x8000 to get even rounding. The rounding also ensures that qPremultiply(qUnpremultiply(p)) == p for all p. return qRgba((qRed(p)*invAlpha + 0x8000)>>16, (qGreen(p)*invAlpha + 0x8000)>>16, (qBlue(p)*invAlpha + 0x8000)>>16, alpha); } +#endif QT_END_NAMESPACE |