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Cleanup: add zero bit counting functions

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This commit is contained in:
Brecht Van Lommel 2019-08-26 15:08:46 +02:00
parent d133934ea4
commit 030a023eb2
2 changed files with 53 additions and 32 deletions
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34
intern/cycles/kernel/kernel_jitter.h
View File

@ -38,43 +38,13 @@ ccl_device_inline int cmj_fast_mod_pow2(int a, int b)
ccl_device_inline int cmj_fast_div_pow2(int a, int b)
{
kernel_assert(b > 1);
#if defined(__KERNEL_SSE2__)
# ifdef _MSC_VER
unsigned long ctz;
_BitScanForward(&ctz, b);
return a >> ctz;
# else
return a >> __builtin_ctz(b);
# endif
#elif defined(__KERNEL_CUDA__)
return a >> (__ffs(b) - 1);
#else
return a / b;
#endif
return a >> count_trailing_zeros(b);
}
ccl_device_inline uint cmj_w_mask(uint w)
{
kernel_assert(w > 1);
#if defined(__KERNEL_SSE2__)
# ifdef _MSC_VER
unsigned long leading_zero;
_BitScanReverse(&leading_zero, w);
return ((1 << (1 + leading_zero)) - 1);
# else
return ((1 << (32 - __builtin_clz(w))) - 1);
# endif
#elif defined(__KERNEL_CUDA__)
return ((1 << (32 - __clz(w))) - 1);
#else
w |= w >> 1;
w |= w >> 2;
w |= w >> 4;
w |= w >> 8;
w |= w >> 16;
return w;
#endif
return ((1 << (32 - count_leading_zeros(w))) - 1);
}
ccl_device_inline uint cmj_permute(uint i, uint l, uint p)

51
intern/cycles/util/util_math.h
View File

@ -617,6 +617,57 @@ ccl_device float bits_to_01(uint bits)
return bits * (1.0f / (float)0xFFFFFFFF);
}
ccl_device_inline uint count_leading_zeros(uint x)
{
assert(x != 0);
#if defined(__KERNEL_CUDA__) || defined(__KERNEL_OPTIX__)
return __clz(x);
#elif defined(__KERNEL_OPENCL__)
return clz(x);
#else
# ifdef _MSC_VER
unsigned long leading_zero = 0;
_BitScanReverse(&leading_zero, x);
return (31 - leading_zero);
# else
return __builtin_clz(x);
# endif
#endif
}
ccl_device_inline uint count_trailing_zeros(uint x)
{
assert(x != 0);
#if defined(__KERNEL_CUDA__) || defined(__KERNEL_OPTIX__)
return (__ffs(x) - 1);
#elif defined(__KERNEL_OPENCL__)
return (31 - count_leading_zeros(x & -x));
#else
# ifdef _MSC_VER
unsigned long ctz = 0;
_BitScanForward(&ctz, x);
return ctz;
# else
return __builtin_ctz(x);
# endif
#endif
}
ccl_device_inline uint find_first_set(uint x)
{
#if defined(__KERNEL_CUDA__) || defined(__KERNEL_OPTIX__)
return __ffs(x);
#elif defined(__KERNEL_OPENCL__)
return (x != 0) ? (32 - count_leading_zeros(x & (-x))) : 0;
#else
# ifdef _MSC_VER
return (x != 0) ? (32 - count_leading_zeros(x & (-x))) : 0;
# else
return __builtin_ffs(x);
# endif
#endif
}
/* projections */
ccl_device_inline float2 map_to_tube(const float3 co)
{