gemv_fused_quant_bias.c File Reference

Fused GEMV kernels with online quantization and bias. More...

#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <math.h>
#include "ckernel_quant.h"

Go to the source code of this file.

Functions
static int	ck_round_nearest (float v)
	Round to nearest int, half away from zero (matches quantize_row_q8_0)
static float	dot_fp32_q5_0_block (const float *x, const block_q5_0 *block)
	Compute dot product of FP32 input with Q5_0 weight block, with online Q8 quantization.
static float	dot_fp32_q8_0_block (const float *x, const block_q8_0 *block)
	Compute dot product of FP32 input with Q8_0 weight block, with online Q8 quantization.
void	gemv_fused_q5_0_bias (float *y, const void *W, const float *x, const float *bias, int M, int K)
void	gemv_fused_q5_0_bias_dispatch (float *y, const void *W, const float *x, const float *bias, int M, int K)
void	gemv_fused_q8_0_bias (float *y, const void *W, const float *x, const float *bias, int M, int K)
void	gemv_fused_q8_0_bias_dispatch (float *y, const void *W, const float *x, const float *bias, int M, int K)

Detailed Description

Fused GEMV kernels with online quantization and bias.

These kernels fuse:

1. Quantize FP32 input to Q8_0/Q8_K (no memory write)
2. GEMV with quantized weights
3. Bias add

Benefits:

• Eliminates memory traffic for quantized activations
• Better cache utilization
• Reduces total ops in IR from 3 to 1

Kernel signature: gemv_fused_q5_0_bias(y, W, x, bias, M, K)

• x: FP32 input [K]
• W: Q5_0 weights [M, K]
• bias: FP32 bias [M] (can be NULL)
• y: FP32 output [M]

Definition in file gemv_fused_quant_bias.c.

Function Documentation

ck_round_nearest()

static int ck_round_nearest ( float  v )

inlinestatic

Round to nearest int, half away from zero (matches quantize_row_q8_0)

Definition at line 40 of file gemv_fused_quant_bias.c.

                                            {
    return (int)(v + (v >= 0.0f ? 0.5f : -0.5f));
}

Referenced by dot_fp32_q5_0_block(), and dot_fp32_q8_0_block().

dot_fp32_q5_0_block()

static float dot_fp32_q5_0_block ( const float *  x, const block_q5_0 *  block  )

inlinestatic

Compute dot product of FP32 input with Q5_0 weight block, with online Q8 quantization.

Definition at line 375 of file gemv_fused_quant_bias.c.

                                                                                 {
    const float d_w = CK_FP16_TO_FP32(block->d);
 
    float amax = 0.0f;
    for (int j = 0; j < 32; j++) {
        float ax = x[j] >= 0 ? x[j] : -x[j];
        if (ax > amax) amax = ax;
    }
 
    float d_x = amax / 127.0f;
    d_x = CK_FP16_TO_FP32(CK_FP32_TO_FP16(d_x));
    const float id_x = (amax != 0.0f) ? 127.0f / amax : 0.0f;
    const float d = d_w * d_x;
 
    uint32_t qh;
    memcpy(&qh, block->qh, sizeof(qh));
 
    int32_t sumi = 0;
    for (int j = 0; j < 16; j++) {
        const uint8_t packed = block->qs[j];
        const int lo = (packed & 0x0F);
        const int hi = (packed >> 4);
        const int xh_0 = ((qh >> (j + 0)) << 4) & 0x10;
        const int xh_1 = ((qh >> (j + 12))) & 0x10;
        const int w0 = (lo | xh_0) - 16;
        const int w1 = (hi | xh_1) - 16;
 
        float v0 = x[j] * id_x;
        float v1 = x[j + 16] * id_x;
        int q0 = ck_round_nearest(v0);
        int q1 = ck_round_nearest(v1);
        if (q0 > 127) q0 = 127;
        if (q0 < -127) q0 = -127;
        if (q1 > 127) q1 = 127;
        if (q1 < -127) q1 = -127;
 
        sumi += q0 * w0 + q1 * w1;
    }
 
    return d * (float)sumi;
}

References CK_FP16_TO_FP32, CK_FP32_TO_FP16, ck_round_nearest(), block_q5_0::d, block_q5_0::qh, and block_q5_0::qs.

Referenced by gemv_fused_q5_0_bias().

dot_fp32_q8_0_block()

static float dot_fp32_q8_0_block ( const float *  x, const block_q8_0 *  block  )

inlinestatic

Compute dot product of FP32 input with Q8_0 weight block, with online Q8 quantization.

Definition at line 420 of file gemv_fused_quant_bias.c.

                                                                                 {
    const float d_w = CK_FP16_TO_FP32(block->d);
 
    float amax = 0.0f;
    for (int j = 0; j < 32; j++) {
        float ax = x[j] >= 0 ? x[j] : -x[j];
        if (ax > amax) amax = ax;
    }
 
    float d_x = amax / 127.0f;
    d_x = CK_FP16_TO_FP32(CK_FP32_TO_FP16(d_x));
    const float id_x = (amax != 0.0f) ? 127.0f / amax : 0.0f;
    const float d = d_w * d_x;
 
    int32_t sumi = 0;
    for (int j = 0; j < 32; j++) {
        float v = x[j] * id_x;
        int q = ck_round_nearest(v);
        if (q > 127) q = 127;
        if (q < -127) q = -127;
        sumi += q * (int32_t)block->qs[j];
    }
 
    return d * (float)sumi;
}

References CK_FP16_TO_FP32, CK_FP32_TO_FP16, ck_round_nearest(), block_q8_0::d, and block_q8_0::qs.

Referenced by gemv_fused_q8_0_bias().

gemv_fused_q5_0_bias()

void gemv_fused_q5_0_bias	(	float *	y,
		const void *	W,
		const float *	x,
		const float *	bias,
		int	M,
		int	K
	)

Definition at line 450 of file gemv_fused_quant_bias.c.

{
    const block_q5_0 *blocks = (const block_q5_0 *)W;
    const int blocks_per_row = K / QK5_0;
 
    for (int row = 0; row < M; row++) {
        float sum = 0.0f;
 
        for (int b = 0; b < blocks_per_row; b++) {
            const block_q5_0 *block = &blocks[row * blocks_per_row + b];
            const float *xp = &x[b * QK5_0];
            sum += dot_fp32_q5_0_block(xp, block);
        }
 
        if (bias) {
            sum += bias[row];
        }
 
        y[row] = sum;
    }
}

References dot_fp32_q5_0_block(), and QK5_0.

Referenced by gemv_fused_q5_0_bias_dispatch().

gemv_fused_q5_0_bias_dispatch()

void gemv_fused_q5_0_bias_dispatch	(	float *	y,
		const void *	W,
		const float *	x,
		const float *	bias,
		int	M,
		int	K
	)

Definition at line 510 of file gemv_fused_quant_bias.c.

{
#if defined(__AVX__)
    gemv_fused_q5_0_bias_avx(y, W, x, bias, M, K);
#else
    gemv_fused_q5_0_bias(y, W, x, bias, M, K);
#endif
}

References gemv_fused_q5_0_bias().

gemv_fused_q8_0_bias()

void gemv_fused_q8_0_bias	(	float *	y,
		const void *	W,
		const float *	x,
		const float *	bias,
		int	M,
		int	K
	)

Definition at line 478 of file gemv_fused_quant_bias.c.

{
    const block_q8_0 *blocks = (const block_q8_0 *)W;
    const int blocks_per_row = K / QK8_0;
 
    for (int row = 0; row < M; row++) {
        float sum = 0.0f;
 
        for (int b = 0; b < blocks_per_row; b++) {
            const block_q8_0 *block = &blocks[row * blocks_per_row + b];
            const float *xp = &x[b * QK8_0];
            sum += dot_fp32_q8_0_block(xp, block);
        }
 
        if (bias) {
            sum += bias[row];
        }
 
        y[row] = sum;
    }
}

References dot_fp32_q8_0_block(), and QK8_0.

Referenced by gemv_fused_q8_0_bias_dispatch().

gemv_fused_q8_0_bias_dispatch()

void gemv_fused_q8_0_bias_dispatch	(	float *	y,
		const void *	W,
		const float *	x,
		const float *	bias,
		int	M,
		int	K
	)

Definition at line 525 of file gemv_fused_quant_bias.c.

{
#if defined(__AVX__)
    gemv_fused_q8_0_bias_avx(y, W, x, bias, M, K);
#else
    gemv_fused_q8_0_bias(y, W, x, bias, M, K);
#endif
}

References gemv_fused_q8_0_bias().