cpu.h file

Compiled / runtime / selected ISA bits and vm_cpu_* probes.

Enums

enum (anonymous) { VM_CPU_SCALAR = 1u << 0, VM_CPU_AVX2 = 1u << 1, VM_CPU_SVE = 1u << 2, VM_CPU_AVX512F = 1u << 3, VM_CPU_SVE2 = 1u << 4, VM_CPU_AVX = 1u << 5, VM_CPU_NEON = 1u << 6, VM_CPU_BACKEND = 1u << 7 }

Typedefs

using vm_cpu_features_t = uint32_t: Bit mask of compiled or detected CPU ISA features.

Functions

auto vm_cpu_compiled_features(void) -> vm_cpu_features_t: ISA bits compiled into this library (VECMAT_ENABLE_*).
auto vm_cpu_runtime_features(void) -> vm_cpu_features_t: ISA bits detected on this CPU (runtime probe).
auto vm_cpu_selected_features(void) -> vm_cpu_features_t: ISA the picker bound: registered backend, else best compiled-and-runtime.
auto vm_cpu_name(vm_cpu_features_t features) -> const char*: Short name for a feature mask (avx2, neon, scalar, etc.).
void vm_cpu_init(void): Probe once and bind dispatched _ptr names.
auto vm_cpu_note(void) -> const char*: Optional one-line note set by a registered module.
void vm_cpu_set_note(const char* note): Attach a module note for banners.
auto vm_compiled_float_bits(void) -> unsigned: Float widths compiled into this library (32, 64, or 32|64).
static auto vm_abi_mismatch(void) -> int: Non-zero when this TU's VECMAT_FLOAT_BITS is missing from the linked lib.

Enum documentation

enum (anonymous)

Enumerators
VM_CPU_SCALAR
VM_CPU_AVX2
VM_CPU_SVE
VM_CPU_AVX512F
VM_CPU_SVE2
VM_CPU_AVX
VM_CPU_NEON
VM_CPU_BACKEND	Registered external backend with no ISA bit of its own.

Function documentation

vm_cpu_features_t vm_cpu_compiled_features(void)

ISA bits compiled into this library (VECMAT_ENABLE_*).

Returns	Feature mask of enabled backends.

ISA bits compiled into this library (VECMAT_ENABLE_*).

vm_cpu_features_t vm_cpu_runtime_features(void)

ISA bits detected on this CPU (runtime probe).

Returns	Feature mask of usable backends.

ISA bits detected on this CPU (runtime probe).

vm_cpu_features_t vm_cpu_selected_features(void)

ISA the picker bound: registered backend, else best compiled-and-runtime.

Returns	Single selected feature bit (or scalar).

VECMAT_FORCE_ISA=scalar|avx|avx2|avx512f|neon|sve|sve2 overrides the compiled/runtime pick when that ISA is compiled in. A registered backend still wins. The override is read once, on the first probe.

ISA the picker bound: registered backend, else best compiled-and-runtime.

const char* vm_cpu_name(vm_cpu_features_t features)

Short name for a feature mask (avx2, neon, scalar, etc.).

Parameters
features	Feature mask.
Returns	Stable string such as `avx2` or `scalar`.

Short name for a feature mask (avx2, neon, scalar, etc.).

void vm_cpu_init(void)

Probe once and bind dispatched _ptr names.

Thread-safe and idempotent (C11 atomics, double-checked locking). Call before reading vm_cpu_selected_features() if you care about the first-use race; kernels themselves call this on first use.

const char* vm_cpu_note(void)

Optional one-line note set by a registered module.

NULL until a module calls vm_cpu_set_note(). The pointer is not copied.

void vm_cpu_set_note(const char* note)

Attach a module note for banners.

Pass NULL to clear.