forked from bartvdbraak/blender
80d1d624d3
This is mainly to address old issue when one need to have SDL library installed in order to use our official builds. Some hip distros already installs SDL, but it's not quite the same across all the variety of the distros. We also now switching to SDL-2.0, most of the distros have it in repositories already, so it shouldn't be huge deal to install it if needed. Reviewers: campbellbarton Reviewed By: campbellbarton Differential Revision: https://developer.blender.org/D878
54 lines
730 B
C
54 lines
730 B
C
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#ifndef _SDL_bits_h
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#define _SDL_bits_h
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#include "SDL_stdinc.h"
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#include "begin_code.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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SDL_FORCE_INLINE int
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SDL_MostSignificantBitIndex32(Uint32 x)
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{
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#if defined(__GNUC__) && __GNUC__ >= 4
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if (x == 0) {
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return -1;
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}
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return 31 - __builtin_clz(x);
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#else
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const Uint32 b[] = {0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000};
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const int S[] = {1, 2, 4, 8, 16};
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int msbIndex = 0;
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int i;
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if (x == 0) {
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return -1;
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}
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for (i = 4; i >= 0; i--)
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{
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if (x & b[i])
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{
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x >>= S[i];
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msbIndex |= S[i];
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}
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}
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return msbIndex;
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#endif
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}
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#ifdef __cplusplus
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}
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#endif
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#include "close_code.h"
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#endif
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