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Implemented 64-bit reference cntlz/cnttz.

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bkaradzic
2013-03-03 00:12:23 -08:00
parent ab4c7dcd7e
commit 356836e186
1 changed files with 24 additions and 6 deletions
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30
include/bx/uint32_t.h
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@@ -35,9 +35,11 @@
// must be included before intrin.h.
# include <intrin.h>
# pragma intrinsic(_BitScanForward)
# pragma intrinsic(_BitScanForward64)
# pragma intrinsic(_BitScanReverse)
# pragma intrinsic(_BitScanReverse64)
# if BX_ARCH_64BIT
# pragma intrinsic(_BitScanForward64)
# pragma intrinsic(_BitScanReverse64)
# endif // BX_ARCH_64BIT
# endif // BX_PLATFORM_WINDOWS
#endif // BX_COMPILER_MSVC
@@ -580,30 +582,46 @@ namespace bx
return _a < _b ? _b : _a;
}
inline uint64_t uint64_cntlz_ref(uint64_t _val)
{
return _val & UINT64_C(0xffffffff00000000)
? uint32_cntlz(uint32_t(_val>>32) ) + 32
: uint32_cntlz(uint32_t(_val) )
;
}
/// Count number of leading zeros.
inline uint64_t uint64_cntlz(uint64_t _val)
{
#if BX_COMPILER_GCC
return __builtin_clz(_val);
#elif BX_COMPILER_MSVC && BX_PLATFORM_WINDOWS
#elif BX_COMPILER_MSVC && BX_PLATFORM_WINDOWS && BX_ARCH_64BIT
unsigned long index;
_BitScanReverse64(&index, _val);
return 63 - index;
#else
return uint32_cntlz_ref(_val);
return uint64_cntlz_ref(_val);
#endif // BX_COMPILER_
}
inline uint64_t uint64_cnttz_ref(uint64_t _val)
{
return _val & UINT64_C(0xffffffff)
? uint32_cnttz(uint32_t(_val) )
: uint32_cnttz(uint32_t(_val>>32) ) + 32
;
}
inline uint64_t uint64_cnttz(uint64_t _val)
{
#if BX_COMPILER_GCC
return __builtin_ctz(_val);
#elif BX_COMPILER_MSVC && BX_PLATFORM_WINDOWS
#elif BX_COMPILER_MSVC && BX_PLATFORM_WINDOWS && BX_ARCH_64BIT
unsigned long index;
_BitScanForward64(&index, _val);
return index;
#else
# error "not implemented" // return uint64_cnttz_ref(_val);
return uint64_cnttz_ref(_val);
#endif // BX_COMPILER_
}