stable-diffusion.cpp/ggml/tests/test-xpos.c

#include "ggml/ggml.h"

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

bool is_close(float a, float b, float epsilon) {
    return fabs(a - b) < epsilon;
}

int main(int argc, char ** argv) {
    const int n_threads = 1;
    const int n_embd_head = 4; // aka head_dim
    const int n_head = 1;
    const int N = 8;

    struct ggml_init_params params = {
        .mem_size   = 16*1024*1024,
        .mem_buffer = NULL,
    };

    // memory allocation happens here
    struct ggml_context * ctx = ggml_init(params);

    struct ggml_tensor * Q = ggml_new_tensor_3d(ctx, GGML_TYPE_F32, n_embd_head, n_head, N);
    struct ggml_tensor * K = ggml_new_tensor_3d(ctx, GGML_TYPE_F32, n_embd_head, n_head, N);

    for (int i = 0; i < ggml_nelements(Q); i++) {
        ((float*) Q->data)[i] = 2.0f;
        ((float*) K->data)[i] = 2.0f;
    }

    struct ggml_tensor * KQ_pos = ggml_new_tensor_1d(ctx, GGML_TYPE_I32, N);
    int * data = (int *) KQ_pos->data;
    for (int i = 0; i < N; ++i) {
        data[i] = 1 + i;
    }

    struct ggml_tensor * Qx = ggml_rope_xpos_inplace(ctx, Q, KQ_pos, n_embd_head, 512.0f, false);
    struct ggml_tensor * Kx = ggml_rope_xpos_inplace(ctx, K, KQ_pos, n_embd_head, 512.0f, true);

    struct ggml_cgraph gf = ggml_build_forward(Qx);
    ggml_build_forward_expand(&gf, Kx);
    ggml_graph_compute_with_ctx(ctx, &gf, n_threads);

	// expected output for Qx:
    // -0.6009  2.7568  1.9782  2.0182
    // -2.6379  0.9815  1.9562  2.0361
    // -2.2457 -1.6853  1.9341  2.0538
    //  0.2043 -2.7934  1.9118  2.0712
    //  2.4550 -1.3341  1.8894  2.0884
    //  2.4430  1.3417  1.8668  2.1054
    //  0.1905  2.7739  1.8440  2.1221
    // -2.2257  1.6550  1.8212  2.1386

    for (int i = 0; i < ggml_nelements(Q); i++) {
        if (((float*) Qx->data)[i] > 0) printf(" ");
        printf("%.4f ", ((float*) Qx->data)[i]);
        if ((i+1) % n_embd_head == 0) printf("\n");
    }
    printf("\n");

    GGML_ASSERT(is_close(((float*) Qx->data)[7 * n_embd_head + 0], -2.2257f, 0.0001f));
    GGML_ASSERT(is_close(((float*) Qx->data)[7 * n_embd_head + 1],  1.6550f, 0.0001f));
    GGML_ASSERT(is_close(((float*) Qx->data)[7 * n_embd_head + 2],  1.8212f, 0.0001f));
    GGML_ASSERT(is_close(((float*) Qx->data)[7 * n_embd_head + 3],  2.1386f, 0.0001f));

    // expected output for Kx:
	// -0.6038  2.7703  1.9816  2.0216
    // -2.6639  0.9911  1.9630  2.0431
    // -2.2789 -1.7103  1.9441  2.0644
    //  0.2083 -2.8486  1.9251  2.0856
    //  2.5158 -1.3671  1.9057  2.1065
    //  2.5158  1.3816  1.8862  2.1273
    //  0.1972  2.8705  1.8665  2.1479
    // -2.3146  1.7211  1.8465  2.1684

    for (int i = 0; i < ggml_nelements(K); i++) {
        if (((float*) Kx->data)[i] > 0) printf(" ");
        printf("%.4f ", ((float*) Kx->data)[i]);
        if ((i+1) % n_embd_head == 0) printf("\n");
    }
    printf("\n");

    GGML_ASSERT(is_close(((float*) Kx->data)[7 * n_embd_head + 0], -2.3146f, 0.0001f));
    GGML_ASSERT(is_close(((float*) Kx->data)[7 * n_embd_head + 1],  1.7211f, 0.0001f));
    GGML_ASSERT(is_close(((float*) Kx->data)[7 * n_embd_head + 2],  1.8465f, 0.0001f));
    GGML_ASSERT(is_close(((float*) Kx->data)[7 * n_embd_head + 3],  2.1684f, 0.0001f));

    ggml_free(ctx);

    return 0;
}