shm_simd Namespace Reference

Classes
class	SimdArray
	Helper class for SIMD operations on shm_array. More...

Functions
bool	is_aligned (const void *ptr, size_t alignment) noexcept
	Check if pointer is aligned to boundary.
float	sum_floats (const float *data, size_t count) noexcept
	Vectorized sum of float array using AVX2.
float	dot_product (const float *a, const float *b, size_t count) noexcept
	Vectorized dot product of two float arrays.
void	scale_floats (float *data, size_t count, float scale) noexcept
	Vectorized array scaling (multiply by scalar)
void	fma_floats (const float *a, const float *b, const float *c, float *result, size_t count) noexcept
	Vectorized FMA operation: result = a * b + c.
float	min_float (const float *data, size_t count) noexcept
	Find minimum value in float array.
float	max_float (const float *data, size_t count) noexcept
	Find maximum value in float array.
template<int distance = 1>
void	prefetch_read (const void *ptr) noexcept
	Prefetch data for read.
void	prefetch_write (void *ptr) noexcept
	Prefetch data for write.
void	stream_store_floats (float *dest, const float *src, size_t count) noexcept
	Stream store (bypass cache) for large arrays.

Function Documentation

dot_product()

float shm_simd::dot_product ( const float *  a, const float *  b, size_t  count  )

inlinenoexcept

Vectorized dot product of two float arrays.

Parameters

a	First array
b	Second array
count	Number of elements

Returns

Dot product a·b

Performance:

~8x faster than scalar for aligned arrays

Definition at line 94 of file shm_simd_utils.h.

Referenced by calculate_kinetic_energy_simd(), and shm_simd::SimdArray< TableType >::dot().

fma_floats()

void shm_simd::fma_floats ( const float *  a, const float *  b, const float *  c, float *  result, size_t  count  )

inlinenoexcept

Vectorized FMA operation: result = a * b + c.

Parameters

a	First multiplicand array
b	Second multiplicand array
c	Addend array
result	Output array
count	Number of elements

Note

Uses FMA instructions if available (single rounding)

Definition at line 162 of file shm_simd_utils.h.

is_aligned()

bool shm_simd::is_aligned ( const void *  ptr, size_t  alignment  )

inlinenoexcept

Check if pointer is aligned to boundary.

Parameters

ptr	Pointer to check
alignment	Required alignment (must be power of 2)

Returns

true if aligned

Definition at line 28 of file shm_simd_utils.h.

Referenced by main(), and stream_store_floats().

max_float()

float shm_simd::max_float ( const float *  data, size_t  count  )

inlinenoexcept

Find maximum value in float array.

Parameters

data	Input array
count	Number of elements

Returns

Maximum value

Definition at line 218 of file shm_simd_utils.h.

Referenced by shm_simd::SimdArray< TableType >::max().

min_float()

float shm_simd::min_float ( const float *  data, size_t  count  )

inlinenoexcept

Find minimum value in float array.

Parameters

data	Input array
count	Number of elements

Returns

Minimum value

Definition at line 187 of file shm_simd_utils.h.

Referenced by shm_simd::SimdArray< TableType >::min().

prefetch_read()

template<int distance = 1>

void shm_simd::prefetch_read ( const void *  ptr )

inlinenoexcept

Prefetch data for read.

Parameters

ptr	Address to prefetch
distance	How many cache lines ahead (0-3)

Note

Hints to CPU to load data into cache

Definition at line 251 of file shm_simd_utils.h.

prefetch_write()

void shm_simd::prefetch_write ( void *  ptr )

inlinenoexcept

Prefetch data for write.

Parameters

ptr	Address to prefetch

Note

Prepares cache line for modification

Definition at line 262 of file shm_simd_utils.h.

scale_floats()

void shm_simd::scale_floats ( float *  data, size_t  count, float  scale  )

inlinenoexcept

Vectorized array scaling (multiply by scalar)

Parameters

data	Array to scale (modified in-place)
count	Number of elements
scale	Scale factor

Example:

shm_array<float> values(shm, "values", 1000);
shm_simd::scale_floats(values.data(), values.size(), 2.0f);

Definition at line 135 of file shm_simd_utils.h.

Referenced by calculate_kinetic_energy_simd(), and shm_simd::SimdArray< TableType >::scale().

stream_store_floats()

void shm_simd::stream_store_floats ( float *  dest, const float *  src, size_t  count  )

inlinenoexcept

Stream store (bypass cache) for large arrays.

Parameters

dest	Destination (should be 32-byte aligned)
src	Source data
count	Number of floats to copy

Note

Use for data that won't be read soon (avoids cache pollution)

Definition at line 275 of file shm_simd_utils.h.

References is_aligned().

sum_floats()

float shm_simd::sum_floats ( const float *  data, size_t  count  )

inlinenoexcept

Vectorized sum of float array using AVX2.

Parameters

data	Input array (should be 32-byte aligned for best performance)
count	Number of elements

Returns

Sum of all elements

Note

Falls back to scalar for unaligned or small arrays

Example:

shm_array<float> temps(shm, "temperatures", 1000);
float total = shm_simd::sum_floats(temps.data(), temps.size());

Definition at line 47 of file shm_simd_utils.h.

Referenced by shm_simd::SimdArray< TableType >::sum().