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Add POPCNT32 and CTZ32 macros

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This commit is contained in:
Chris Robinson 2018-12-13 22:05:47 -08:00
parent 0d73b13f59
commit d18ae81e9c
1 changed files with 41 additions and 13 deletions
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54
OpenAL32/Include/alMain.h
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@ -129,11 +129,14 @@ typedef ALuint64SOFT ALuint64;
#endif
#endif
/* Define a CTZ64 macro (count trailing zeros, for 64-bit integers). The result
* is *UNDEFINED* if the value is 0.
/* Define CTZ macros (count trailing zeros), and POPCNT macros (population
* count/count 1 bits), for 32- and 64-bit integers. The CTZ macros' results
* are *UNDEFINED* if the value is 0.
*/
#ifdef __GNUC__
#define POPCNT32 __builtin_popcount
#define CTZ32 __builtin_ctz
#if SIZEOF_LONG == 8
#define POPCNT64 __builtin_popcountl
#define CTZ64 __builtin_ctzl
@ -144,12 +147,20 @@ typedef ALuint64SOFT ALuint64;
#elif defined(HAVE_BITSCANFORWARD64_INTRINSIC)
inline int msvc64_popcnt64(ALuint64 v)
inline int msvc64_popcnt32(ALuint v)
{ return (int)__popcnt(v); }
#define POPCNT32 msvc64_popcnt32
inline int msvc64_ctz32(ALuint v)
{
return (int)__popcnt64(v);
unsigned long idx = 32;
_BitScanForward(&idx, v);
return (int)idx;
}
#define POPCNT64 msvc64_popcnt64
#define CTZ32 msvc64_ctz32
inline int msvc64_popcnt64(ALuint64 v)
{ return (int)__popcnt64(v); }
#define POPCNT64 msvc64_popcnt64
inline int msvc64_ctz64(ALuint64 v)
{
unsigned long idx = 64;
@ -160,12 +171,20 @@ inline int msvc64_ctz64(ALuint64 v)
#elif defined(HAVE_BITSCANFORWARD_INTRINSIC)
inline int msvc_popcnt64(ALuint64 v)
inline int msvc_popcnt32(ALuint v)
{ return (int)__popcnt(v); }
#define POPCNT32 msvc_popcnt32
inline int msvc_ctz32(ALuint v)
{
return (int)(__popcnt((ALuint)v) + __popcnt((ALuint)(v>>32)));
unsigned long idx = 32;
_BitScanForward(&idx, v);
return (int)idx;
}
#define POPCNT64 msvc_popcnt64
#define CTZ32 msvc_ctz32
inline int msvc_popcnt64(ALuint64 v)
{ return (int)(__popcnt((ALuint)v) + __popcnt((ALuint)(v>>32))); }
#define POPCNT64 msvc_popcnt64
inline int msvc_ctz64(ALuint64 v)
{
unsigned long idx = 64;
@ -180,13 +199,25 @@ inline int msvc_ctz64(ALuint64 v)
#else
/* There be black magics here. The popcnt64 method is derived from
/* There be black magics here. The popcnt method is derived from
* https://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
* while the ctz-utilizing-popcnt algorithm is shown here
* http://www.hackersdelight.org/hdcodetxt/ntz.c.txt
* as the ntz2 variant. These likely aren't the most efficient methods, but
* they're good enough if the GCC or MSVC intrinsics aren't available.
*/
inline int fallback_popcnt32(ALuint v)
{
v = v - ((v >> 1) & 0x55555555u);
v = (v & 0x33333333u) + ((v >> 2) & 0x33333333u);
v = (v + (v >> 4)) & 0x0f0f0f0fu;
return (int)((v * 0x01010101u) >> 24);
}
#define POPCNT32 fallback_popcnt32
inline int fallback_ctz32(ALuint value)
{ return fallback_popcnt32(~value & (value - 1)); }
#define CTZ32 fallback_ctz32
inline int fallback_popcnt64(ALuint64 v)
{
v = v - ((v >> 1) & U64(0x5555555555555555));
@ -195,11 +226,8 @@ inline int fallback_popcnt64(ALuint64 v)
return (int)((v * U64(0x0101010101010101)) >> 56);
}
#define POPCNT64 fallback_popcnt64
inline int fallback_ctz64(ALuint64 value)
{
return fallback_popcnt64(~value & (value - 1));
}
{ return fallback_popcnt64(~value & (value - 1)); }
#define CTZ64 fallback_ctz64
#endif