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Removed use of LUT16to32 in HQx asm versions, replacing some MMX code with 'plain' x86 code. Advantage: got rid of a 256kb table (reduces cache load, so over here the code is about as fast as before; in particular, since the affected interpolators are not used that often, it seems). Moreover, the new code is more accurate than the old ASM code, which actually differed from what our C++ HQx did (sacrificing precision for speed, i.e., cheating ;-)

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svn-id: r36078
This commit is contained in:
Max Horn 2009-01-26 18:31:06 +00:00
parent 80ba7ec844
commit 4098ff66aa
3 changed files with 288 additions and 154 deletions
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57
graphics/scaler.cpp
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@ -53,17 +53,26 @@ extern "C" {
#if !defined(_WIN32) && !defined(MACOSX) && !defined(__OS2__)
#define RGBtoYUV _RGBtoYUV
#define LUT16to32 _LUT16to32
#define hqx_highbits _hqx_highbits
#define hqx_lowbits _hqx_lowbits
#define hqx_low2bits _hqx_low2bits
#define hqx_low3bits _hqx_low3bits
#define hqx_greenMask _hqx_greenMask
#define hqx_redBlueMask _hqx_redBlueMask
#define hqx_green_redBlue_Mask _hqx_green_redBlue_Mask
#endif
#endif
uint32 hqx_highbits = 0xF7DEF7DE;
uint32 hqx_lowbits = 0x0821;
uint32 hqx_low2bits = 0x0C63;
uint32 hqx_low3bits = 0x1CE7;
uint32 hqx_greenMask = 0;
uint32 hqx_redBlueMask = 0;
uint32 hqx_green_redBlue_Mask = 0;
// FIXME/TODO: The following two tables suck up 512 KB. This is bad.
// FIXME/TODO: The RGBtoYUV table sucks up 256 KB. This is bad.
// In addition we never free them...
//
// Note: a memory lookup table is *not* necessarily faster than computing
@ -72,14 +81,7 @@ uint32 hqx_lowbits = 0x0821;
// systems, so main memory has to be accessed, which is about the worst thing
// that can happen to code which tries to be fast...
//
// So we should think about ways to get these smaller / removed. The LUT16to32
// is only used by the HQX asm right now; maybe somebody can modify the code
// there to work w/o it (and do some benchmarking, too?). To do that, just
// do the conversion on the fly, or even do w/o it (as the C++ code manages to),
// by making different versions of the code based on gBitFormat (or by writing
// bit masks into registers which are computed based on gBitFormat).
//
// RGBtoYUV is also used by the C(++) version of the HQX code. Maybe we can
// So we should think about ways to get these smaller / removed. Maybe we can
// use the same technique which is employed by our MPEG code to reduce the
// size of the lookup tables at the cost of some additional computations? That
// might actually result in a speedup, too, if done right (and the code code
@ -89,7 +91,6 @@ uint32 hqx_lowbits = 0x0821;
// differences are likely to vary a lot between different architectures and
// CPUs.
uint32 *RGBtoYUV = 0;
uint32 *LUT16to32 = 0;
}
void InitLUT(Graphics::PixelFormat format) {
@ -101,18 +102,29 @@ void InitLUT(Graphics::PixelFormat format) {
// Allocate the YUV/LUT buffers on the fly if needed.
if (RGBtoYUV == 0)
RGBtoYUV = (uint32 *)malloc(65536 * sizeof(uint32));
if (LUT16to32 == 0)
LUT16to32 = (uint32 *)malloc(65536 * sizeof(uint32));
for (int color = 0; color < 65536; ++color) {
format.colorToRGB(color, r, g, b);
LUT16to32[color] = (r << 16) | (g << 8) | b;
Y = (r + g + b) >> 2;
u = 128 + ((r - b) >> 2);
v = 128 + ((-r + 2 * g - b) >> 3);
RGBtoYUV[color] = (Y << 16) | (u << 8) | v;
}
#ifdef USE_NASM
hqx_lowbits = (1 << format.rShift) | (1 << format.gShift) | (1 << format.bShift),
hqx_low2bits = (3 << format.rShift) | (3 << format.gShift) | (3 << format.bShift),
hqx_low3bits = (7 << format.rShift) | (7 << format.gShift) | (7 << format.bShift),
hqx_highbits = format.RGBToColor(255,255,255) ^ hqx_lowbits;
// FIXME: The following code only does the right thing
// if the color order is RGB or BGR, i.e., green is in the middle.
hqx_greenMask = format.RGBToColor(0,255,0);
hqx_redBlueMask = format.RGBToColor(255,0,255);
hqx_green_redBlue_Mask = (hqx_greenMask << 16) | hqx_redBlueMask;
#endif
}
#endif
@ -121,24 +133,11 @@ void InitScalers(uint32 BitFormat) {
gBitFormat = BitFormat;
#ifndef DISABLE_HQ_SCALERS
#undef kHighBitsMask
#undef kLowBitsMask
if (gBitFormat == 555) {
InitLUT(Graphics::createPixelFormat<555>());
#ifdef USE_NASM
hqx_highbits = Graphics::ColorMasks<555>::kHighBitsMask;
hqx_lowbits = Graphics::ColorMasks<555>::kLowBitsMask & 0xFFFF;
#endif
}
if (gBitFormat == 565) {
InitLUT(Graphics::createPixelFormat<565>());
#ifdef USE_NASM
// The uint32 cast here is needed to silence an MSVC warning
// (warning C4245: '=': conversion from '' to 'uint32', signed/unsigned mismatch
hqx_highbits = (uint32)Graphics::ColorMasks<565>::kHighBitsMask;
hqx_lowbits = Graphics::ColorMasks<565>::kLowBitsMask & 0xFFFF;
#endif
}
#endif
}
@ -146,9 +145,7 @@ void InitScalers(uint32 BitFormat) {
void DestroyScalers(){
#ifndef DISABLE_HQ_SCALERS
free(RGBtoYUV);
free(LUT16to32);
RGBtoYUV = 0;
LUT16to32 = 0;
#endif
}