Package 'RsimdDispatch'

Full one-dimensional convolution with the selected SIMD backend

Description

Demonstration numeric kernel for the runtime dispatch template. convolve1d() computes the same full convolution as a simple nested-loop R definition. For each pair of positions it adds a[i] * b[j] to out[i + j - 1]. SIMD backends vectorize the inner multiply-add over b and the shifted output window.

Usage

convolve1d(a, b)

Arguments

a, b	Numeric vectors.

Value

A numeric vector of length length(a) + length(b) - 1, or numeric(0) when either input is empty.

Examples

convolve1d(c(1, 2, 3), c(10, 100))

---

Count non-zero bytes with the selected SIMD backend

Description

Demonstration kernel for the runtime dispatch template. count_nonzero() counts bytes that are not 00 in a raw vector using the currently selected backend. The default backend is "auto", which selects the best compiled backend supported by the current CPU/runtime.

Usage

count_nonzero(x)

Arguments

x	A raw vector.

Value

A double scalar giving the count of non-zero bytes. The return type is double rather than integer to accommodate vectors longer than .Machine$integer.max without overflow.

Examples

count_nonzero(as.raw(c(0, 1, 0, 2)))

---

Report the currently selected SIMD backend

Description

Report the currently selected SIMD backend

Usage

simd_backend()

Value

A character scalar naming the selected backend summary.

Examples

simd_backend()

---

Configure an R package for C runtime SIMD dispatch

Description

use_simd_dispatch() copies the dispatch scaffold into an R package and performs the package-name and C-prefix substitutions needed for a working package. It writes package files, updates DESCRIPTION, .Rbuildignore, and .gitignore, and returns the copied paths invisibly.

Usage

simd_dispatch_template_path()

use_simd_dispatch(
  path = ".",
  pkg = NULL,
  prefix = NULL,
  overwrite = FALSE,
  quiet = FALSE
)

Arguments

path	Package root where the template should be copied.
pkg	R package name. If NULL, the name is read from DESCRIPTION.
prefix	C symbol prefix used to replace sd_ in the copied sources. The default is a sanitized lowercase package name.
overwrite	Whether to overwrite existing files.
quiet	Whether to suppress progress messages.

Value

Invisibly returns copied file paths.

Developer utility

This function is intended for package authors. It is not needed at runtime by users of packages that already include generated dispatch code.

Examples

simd_dispatch_template_path()

---

Report runtime SIMD dispatch diagnostics

Description

Returns the requested backend, selected backend, compiled backends, CPU-supported backends, operation-level backend availability, operation-level selected backends, SIMDe-native backends, and target architecture information. Calling this initializes the lazy auto-dispatch selection if it has not already been initialized. For SIMDe provenance (version, commit, date) use simde_info().

Usage

simd_info()

Value

A named list with the following elements:

dispatch_mode

Character scalar. Internal dispatch implementation strategy string (stable across patch releases).

requested_backend

Character scalar. The last value passed to simd_set_backend(), or "auto" if not explicitly set.

selected_backend

Character scalar. Summary of the currently active backend: a backend name, "mixed", or "unavailable".

compiled_backends

Character vector. Backends compiled into the shared library (not necessarily supported by the current CPU).

cpu_supported_backends

Character vector. Backends whose required CPU features are present at runtime.

available_backends

Character vector. Backends that are both compiled and CPU-supported (i.e. usable).

simde_native_backends

Character vector. Backends for which the compiler emitted native intrinsics rather than SIMDe emulation.

operations

Character vector. Names of registered operations (e.g. "count_nonzero", "convolve1d").

operation_backends

Named list of character vectors. For each operation, the backends that provide a kernel for it.

operation_selected_backends

Named character vector. For each operation, the backend currently selected for dispatch (or NA if none is resolved).

cpu_sse2

Logical scalar. TRUE if SSE2 is detected at runtime.

cpu_sse41

Logical scalar. TRUE if SSE4.1 is detected.

cpu_avx2

Logical scalar. TRUE if AVX2 is detected.

cpu_avx512

Logical scalar. TRUE if AVX-512 (F/BW/VL) is detected.

cpu_neon

Logical scalar. TRUE if NEON/AdvSIMD is detected.

cpu_wasm_simd128

Logical scalar. TRUE if WASM SIMD128 is available.

target_arch

Character scalar. Compiler target CPU architecture (e.g. "x86_64", "aarch64").

target_os

Character scalar. Compiler target OS family (e.g. "linux", "macos", "windows", "emscripten").

Examples

names(simd_info())

---

Select the runtime SIMD backend

Description

Select the backend used by subsequent calls to dispatched demo kernels such as count_nonzero() and convolve1d(). RsimdDispatch keeps all compiled variants in one shared object and switches a guarded resolved operation table. This makes same-process benchmarking possible.

Usage

simd_set_backend(backend = "auto")

Arguments

backend

Character scalar. Use "auto" to select the best available backend, or one of simd_info()$available_backends for an explicit choice.

Value

The selected backend summary string, invisibly. Possible values:

"<name>"

All operations resolved to the same named backend.

"mixed"

Different operations resolved to different backends (only possible under "auto").

"unavailable"

No operation could be resolved for the requested backend.

Examples

old <- simd_backend()
simd_set_backend("scalar")
simd_set_backend("auto")

---

Report vendored SIMDe provenance

Description

simde_info() reports the version, upstream repository, pinned commit, and commit date for the bundled header-only SIMDe library.

Usage

simde_info()

Value

A named list of character scalars describing the vendored SIMDe copy.

Examples

simde_info()[c("version", "commit")]

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