ppsspp/Common/BitScan.h

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#pragma once
#include "ppsspp_config.h"
#if PPSSPP_PLATFORM(WINDOWS)
#include "Common/CommonWindows.h"
// Use this if you know the value is non-zero.
inline uint32_t clz32_nonzero(uint32_t value) {
DWORD index;
BitScanReverse(&index, value);
return 31 ^ (uint32_t)index;
}
inline uint32_t clz32(uint32_t value) {
if (!value)
return 32;
DWORD index;
BitScanReverse(&index, value);
return 31 ^ (uint32_t)index;
}
#else
// Use this if you know the value is non-zero.
inline uint32_t clz32_nonzero(uint32_t value) {
return __builtin_clz(value);
}
inline uint32_t clz32(uint32_t value) {
if (!value)
return 32;
return __builtin_clz(value);
}
#endif