Sigmoid activation kernels with SIMD (AVX512) More...

#include <math.h>
#include <stddef.h>
#include <stdlib.h>

Functions
void	sigmoid_backward (const float input, const float d_output, float *d_input, size_t n)

void	sigmoid_forward (const float input, float output, size_t n)

float	sigmoid_scalar (float x)

Detailed Description

Sigmoid activation kernels with SIMD (AVX512)

CK-ENGINE KERNEL RULES:

NO malloc/free - memory via bump allocator, pointers passed in
NO OpenMP - parallelization at orchestrator/codegen layer
API must define: inputs, outputs, workspace, and memory layouts
Pure computation - deterministic, no side effects

After changes: make test && make llamacpp-parity-full

Sigmoid: y = 1 / (1 + exp(-x))

Definition in file sigmoid_kernels.c.

Function Documentation

◆ sigmoid_backward()

void sigmoid_backward	(	const float *	input,
		const float *	d_output,
		float *	d_input,
		size_t	n
	)

Definition at line 138 of file sigmoid_kernels.c.

{
#if defined(__AVX512F__)
    sigmoid_backward_avx512(input, d_output, d_input, n);
#else
    for (size_t i = 0; i < n; ++i) {
        float x = input[i];
        float s = sigmoid_scalar(x);
        float s_prime = s * (1.0f - s);
        d_input[i] = d_output[i] * s_prime;
    }
#endif
}

References sigmoid_scalar().

Referenced by sigmoid_backward_bf16().

◆ sigmoid_forward()

void sigmoid_forward	(	const float *	input,
		float *	output,
		size_t	n
	)

Definition at line 122 of file sigmoid_kernels.c.

{
#if defined(__AVX512F__)
    sigmoid_forward_avx512(input, output, n);
#else
    for (size_t i = 0; i < n; ++i) {
        output[i] = sigmoid_scalar(input[i]);
    }
#endif
}

References sigmoid_scalar().

Referenced by sigmoid_forward_bf16().

◆ sigmoid_scalar()

float sigmoid_scalar ( float x )

Definition at line 26 of file sigmoid_kernels.c.

{
    return 1.0f / (1.0f + expf(-x));
}