ggml : hide ggml_object, ggml_cgraph, ggml_hash_set (#9408)

* ggml : hide ggml_object, ggml_cgraph, ggml_hash_set

ggml-ci

* ggml : add ggml-impl.h to backends

* ggml : fix compiler warnings

ggml-ci

* ggml : add assert upon adding nodes

examples/benchmark/benchmark-matmult.cpp

@@ -183,7 +183,7 @@ int main(int argc, char ** argv)  {
 
     ggml_graph_compute_helper(work_buffer, gf, benchmark_params.n_threads);
 
-    TENSOR_DUMP(gf->nodes[0]);
+    TENSOR_DUMP(ggml_graph_node(gf, 0));
 
     printf("\n------ Test 2 - Matrix Mult via %s code\n", ggml_type_name(qtype));
 
@@ -224,7 +224,7 @@ int main(int argc, char ** argv)  {
 
 
     // Let's use the F32 result from above as a reference for the quantized multiplication
-    float sum_of_F32_reference = tensor_sum_elements(gf->nodes[0]);
+    float sum_of_F32_reference = tensor_sum_elements(ggml_graph_node(gf, 0));
 
     printf("Iteration;NThreads; SizeX; SizeY; SizeZ; Required_FLOPS; Elapsed_u_Seconds; gigaFLOPS\n");
     printf("=====================================================================================\n");
@@ -252,7 +252,7 @@ int main(int argc, char ** argv)  {
 
         // Check that the matrix multiplication result is in the right ballpark
         // We cannot use the exact value from the F32 multiplication because the quantizuation will be slightly different
-        float sum_of_Q4_result = tensor_sum_elements(gf31->nodes[0]);
+        float sum_of_Q4_result = tensor_sum_elements(ggml_graph_node(gf31, 0));
         float delta = std::abs(sum_of_Q4_result - sum_of_F32_reference);
         float allowed_delta = (sum_of_F32_reference) / 1000 / 1000; //  Let's accept an epsilon of 10^-6
 

examples/cvector-generator/pca.hpp

@@ -226,8 +226,8 @@ static ggml_status compute_piter(
         result.eigenvectors.resize(params.n_batch);
         result.distances.resize(params.n_batch);
         // get output nodes
-        for (int i = 0; i < gf->n_nodes; ++i) {
+        for (int i = 0; i < ggml_graph_n_nodes(gf); ++i) {
-            auto node = gf->nodes[i];
+            auto node = ggml_graph_node(gf, i);
             int iter = -1;
             // find b_tensor (without copying data from device)
             if ((iter = extract_i("b_tensor_norm_", node->name)) > -1) {

examples/export-lora/export-lora.cpp

@@ -370,7 +370,7 @@ struct lora_merge_ctx {
 
         // write data to output file
         {
-            auto result = gf->nodes[gf->n_nodes - 1];
+            auto * result = ggml_graph_node(gf, -1);
             size_t len = ggml_nbytes(result);
             if (read_buf.size() < len) {
                 read_buf.resize(len);

examples/llava/clip.cpp

@@ -2449,7 +2449,7 @@ bool clip_image_batch_encode(clip_ctx * ctx, const int n_threads, const clip_ima
     ggml_backend_graph_compute(ctx->backend, gf);
 
     // the last node is the embedding tensor
-    struct ggml_tensor * embeddings = gf->nodes[gf->n_nodes - 1];
+    struct ggml_tensor * embeddings = ggml_graph_node(gf, -1);
 
     // copy the embeddings to the location passed by the user
     ggml_backend_tensor_get(embeddings, vec, 0, ggml_nbytes(embeddings));

examples/llava/llava.cpp

@@ -184,7 +184,7 @@ static bool clip_llava_handle_patches(clip_ctx * ctx_clip, std::vector<float *>
     // ggml_tensor_printf(flatten,"flatten",__LINE__,false,false);
     ggml_build_forward_expand(gf, flatten);
     ggml_graph_compute_with_ctx(model.ctx, gf, 1);
-    struct ggml_tensor* result = gf->nodes[gf->n_nodes - 1];
+    struct ggml_tensor* result = ggml_graph_node(gf, -1);
 
     memcpy(image_embd_out, image_embd_v[0], clip_embd_nbytes(ctx_clip)); // main image as global context
     // append without newline tokens (default behavior in llava_arch when not using unpad ):

ggml/include/ggml.h

@@ -358,6 +358,7 @@ extern "C" {
 
     struct ggml_object;
     struct ggml_context;
+    struct ggml_cgraph;
 
     // NOTE: always add types at the end of the enum to keep backward compatibility
     enum ggml_type {
@@ -575,20 +576,6 @@ extern "C" {
         GGML_TENSOR_FLAG_PARAM  = 4,
     };
 
-    // ggml object
-    struct ggml_object {
-        size_t offs;
-        size_t size;
-
-        struct ggml_object * next;
-
-        enum ggml_object_type type;
-
-        char padding[4];
-    };
-
-    static const size_t GGML_OBJECT_SIZE = sizeof(struct ggml_object);
-
     // n-dimensional tensor
     struct ggml_tensor {
         enum ggml_type type;
@@ -671,35 +658,6 @@ extern "C" {
         void *              abort_callback_data;
     };
 
-    enum ggml_cgraph_eval_order {
-        GGML_CGRAPH_EVAL_ORDER_LEFT_TO_RIGHT = 0,
-        GGML_CGRAPH_EVAL_ORDER_RIGHT_TO_LEFT,
-        GGML_CGRAPH_EVAL_ORDER_COUNT
-    };
-
-    typedef uint32_t ggml_bitset_t;
-
-    struct ggml_hash_set {
-        size_t size;
-        ggml_bitset_t * used;       // whether or not the keys are in use i.e. set
-        struct ggml_tensor ** keys; // actual tensors in the set, keys[i] is only defined if ggml_bitset_get(used, i)
-    };
-
-    // computation graph
-    struct ggml_cgraph {
-        int size;
-        int n_nodes;
-        int n_leafs;
-
-        struct ggml_tensor ** nodes;
-        struct ggml_tensor ** grads;
-        struct ggml_tensor ** leafs;
-
-        struct ggml_hash_set visited_hash_set;
-
-        enum ggml_cgraph_eval_order order;
-    };
-
     // scratch buffer
     struct ggml_scratch {
         size_t offs;
@@ -2017,8 +1975,6 @@ extern "C" {
     typedef void (*ggml_custom2_op_t)(struct ggml_tensor * dst , const struct ggml_tensor * a, const struct ggml_tensor * b, int ith, int nth, void * userdata);
     typedef void (*ggml_custom3_op_t)(struct ggml_tensor * dst , const struct ggml_tensor * a, const struct ggml_tensor * b, const struct ggml_tensor * c, int ith, int nth, void * userdata);
 
-    #define GGML_N_TASKS_MAX -1
-
     GGML_API struct ggml_tensor * ggml_map_custom1(
             struct ggml_context   * ctx,
             struct ggml_tensor    * a,
@@ -2088,7 +2044,6 @@ extern "C" {
             struct ggml_context * ctx,
             struct ggml_tensor  * tensor);
 
-
     GGML_API void ggml_build_forward_expand (struct ggml_cgraph * cgraph, struct ggml_tensor * tensor);
     GGML_API void ggml_build_backward_expand(struct ggml_context * ctx, struct ggml_cgraph * gf, struct ggml_cgraph * gb, bool keep);
 
@@ -2096,11 +2051,17 @@ extern "C" {
     GGML_API struct ggml_cgraph * ggml_new_graph       (struct ggml_context * ctx); // size = GGML_DEFAULT_GRAPH_SIZE, grads = false
     GGML_API struct ggml_cgraph * ggml_new_graph_custom(struct ggml_context * ctx, size_t size, bool grads);
     GGML_API struct ggml_cgraph * ggml_graph_dup       (struct ggml_context * ctx, struct ggml_cgraph * cgraph);
-    GGML_API struct ggml_cgraph   ggml_graph_view        (struct ggml_cgraph * cgraph, int i0, int i1);
     GGML_API void                 ggml_graph_cpy       (struct ggml_cgraph * src, struct ggml_cgraph * dst);
     GGML_API void                 ggml_graph_reset     (struct ggml_cgraph * cgraph);  // zero grads
     GGML_API void                 ggml_graph_clear     (struct ggml_cgraph * cgraph);
 
+    GGML_API int                   ggml_graph_size   (struct ggml_cgraph * cgraph);
+    GGML_API struct ggml_tensor *  ggml_graph_node   (struct ggml_cgraph * cgraph, int i); // if i < 0, returns nodes[n_nodes + i]
+    GGML_API struct ggml_tensor ** ggml_graph_nodes  (struct ggml_cgraph * cgraph);
+    GGML_API int                   ggml_graph_n_nodes(struct ggml_cgraph * cgraph);
+
+    GGML_API void   ggml_graph_add_node(struct ggml_cgraph * cgraph, struct ggml_tensor * tensor);
+
     GGML_API size_t ggml_graph_overhead(void);
     GGML_API size_t ggml_graph_overhead_custom(size_t size, bool grads);
 

ggml/src/ggml-blas.cpp

@@ -1,3 +1,4 @@
+#include "ggml-impl.h"
 #include "ggml-blas.h"
 #include "ggml-backend-impl.h"
 

ggml/src/ggml-cann.cpp

@@ -30,6 +30,7 @@
 #include <cstring>
 #include <mutex>
 
+#include "ggml-impl.h"
 #include "ggml-backend-impl.h"
 #include "ggml-cann/aclnn_ops.h"
 #include "ggml-cann/common.h"

ggml/src/ggml-cuda.cu

@@ -1,5 +1,5 @@
 #include "ggml-cuda.h"
-#include "ggml.h"
+#include "ggml-impl.h"
 #include "ggml-backend-impl.h"
 
 #include "ggml-cuda/common.cuh"

ggml/src/ggml-impl.h

@@ -629,8 +629,16 @@ inline static float ggml_lookup_fp16_to_fp32(ggml_fp16_t f) {
 #define GGML_FP32_TO_FP16(x) GGML_COMPUTE_FP32_TO_FP16(x)
 #endif
 
+enum ggml_cgraph_eval_order {
+    GGML_CGRAPH_EVAL_ORDER_LEFT_TO_RIGHT = 0,
+    GGML_CGRAPH_EVAL_ORDER_RIGHT_TO_LEFT,
+    GGML_CGRAPH_EVAL_ORDER_COUNT
+};
+
 // bitset
 
+typedef uint32_t ggml_bitset_t;
+
 static_assert(sizeof(ggml_bitset_t) == 4, "bitset_t constants must be updated");
 #define BITSET_SHR 5 // log2(sizeof(ggml_bitset_t)*8)
 #define BITSET_MASK (sizeof(ggml_bitset_t)*8 - 1)
@@ -656,6 +664,12 @@ static inline void ggml_bitset_clear(ggml_bitset_t * bitset, size_t i) {
 #define GGML_HASHSET_FULL ((size_t)-1)
 #define GGML_HASHSET_ALREADY_EXISTS ((size_t)-2)
 
+struct ggml_hash_set {
+    size_t size;
+    ggml_bitset_t * used;       // whether or not the keys are in use i.e. set
+    struct ggml_tensor ** keys; // actual tensors in the set, keys[i] is only defined if ggml_bitset_get(used, i)
+};
+
 struct ggml_hash_set ggml_hash_set_new(size_t size);
 void                 ggml_hash_set_free(struct ggml_hash_set * hash_set);
 
@@ -745,6 +759,24 @@ static size_t ggml_hash_find_or_insert(struct ggml_hash_set * hash_set, struct g
     GGML_ABORT("fatal error");
 }
 
+// computation graph
+
+struct ggml_cgraph {
+    int size;
+    int n_nodes;
+    int n_leafs;
+
+    struct ggml_tensor ** nodes;
+    struct ggml_tensor ** grads;
+    struct ggml_tensor ** leafs;
+
+    struct ggml_hash_set visited_hash_set;
+
+    enum ggml_cgraph_eval_order order;
+};
+
+struct ggml_cgraph ggml_graph_view(struct ggml_cgraph * cgraph, int i0, int i1);
+
 #ifdef __cplusplus
 }
 #endif

ggml/src/ggml-kompute.cpp

@@ -1,4 +1,4 @@
-#include "ggml.h"
+#include "ggml-impl.h"
 #include "ggml-backend.h"
 #include "ggml-backend-impl.h"
 #include "ggml-kompute.h"

ggml/src/ggml-metal.m

@@ -1,7 +1,7 @@
 #import "ggml-metal.h"
 
+#import "ggml-impl.h"
 #import "ggml-backend-impl.h"
-#import "ggml.h"
 
 #import <Foundation/Foundation.h>
 

ggml/src/ggml-rpc.cpp

@@ -1,5 +1,5 @@
 #include "ggml-rpc.h"
-#include "ggml.h"
+#include "ggml-impl.h"
 #include "ggml-backend-impl.h"
 
 #include <cinttypes>

ggml/src/ggml-sycl.cpp

@@ -33,7 +33,7 @@
 #include <sycl/half_type.hpp>
 
 #include "ggml-sycl.h"
-#include "ggml.h"
+#include "ggml-impl.h"
 #include "ggml-backend-impl.h"
 
 #include "ggml-sycl/backend.hpp"

ggml/src/ggml-vulkan.cpp

@@ -21,7 +21,7 @@
 #include <memory>
 #include <mutex>
 
-#include "ggml.h"
+#include "ggml-impl.h"
 #include "ggml-backend-impl.h"
 
 #include "ggml-vulkan-shaders.hpp"

ggml/src/ggml.c

@@ -287,6 +287,7 @@ void ggml_abort(const char * file, int line, const char * fmt, ...) {
 #define GGML_DEBUG 0
 #define GGML_GELU_FP16
 #define GGML_GELU_QUICK_FP16
+#define GGML_N_TASKS_MAX (-1)
 
 #define GGML_SOFT_MAX_UNROLL 4
 #define GGML_VEC_DOT_UNROLL  2
@@ -1124,17 +1125,17 @@ ggml_type_traits_t ggml_internal_get_type_traits(enum ggml_type type) {
 {                                                  \
     int offset = GGML_F32_ARR >> 1;                \
     for (int i = 0; i < offset; ++i) {             \
-        x[i] = vaddq_f32(x[i], x[offset+i]);   \
+        (x)[i] = vaddq_f32((x)[i], (x)[offset+i]); \
     }                                              \
     offset >>= 1;                                  \
     for (int i = 0; i < offset; ++i) {             \
-        x[i] = vaddq_f32(x[i], x[offset+i]);   \
+        (x)[i] = vaddq_f32((x)[i], (x)[offset+i]); \
     }                                              \
     offset >>= 1;                                  \
     for (int i = 0; i < offset; ++i) {             \
-        x[i] = vaddq_f32(x[i], x[offset+i]);   \
+        (x)[i] = vaddq_f32((x)[i], (x)[offset+i]); \
     }                                              \
-    res = GGML_F32x4_REDUCE_ONE(x[0]);         \
+    (res) = GGML_F32x4_REDUCE_ONE((x)[0]);         \
 }
 
 #define GGML_F32_VEC        GGML_F32x4
@@ -1165,26 +1166,26 @@ ggml_type_traits_t ggml_internal_get_type_traits(enum ggml_type type) {
     do {                                                            \
         int offset = GGML_F16_ARR >> 1;                             \
         for (int i = 0; i < offset; ++i) {                          \
-            x[i] = vaddq_f16(x[i], x[offset+i]);                  \
+            (x)[i] = vaddq_f16((x)[i], (x)[offset+i]);              \
         }                                                           \
         offset >>= 1;                                               \
         for (int i = 0; i < offset; ++i) {                          \
-            x[i] = vaddq_f16(x[i], x[offset+i]);                  \
+            (x)[i] = vaddq_f16((x)[i], (x)[offset+i]);              \
         }                                                           \
         offset >>= 1;                                               \
         for (int i = 0; i < offset; ++i) {                          \
-            x[i] = vaddq_f16(x[i], x[offset+i]);                  \
+            (x)[i] = vaddq_f16((x)[i], (x)[offset+i]);              \
         }                                                           \
-        const float32x4_t t0 = vcvt_f32_f16(vget_low_f16 (x[0])); \
+        const float32x4_t t0 = vcvt_f32_f16(vget_low_f16 ((x)[0])); \
-        const float32x4_t t1 = vcvt_f32_f16(vget_high_f16(x[0])); \
+        const float32x4_t t1 = vcvt_f32_f16(vget_high_f16((x)[0])); \
-        res = (ggml_float) vaddvq_f32(vaddq_f32(t0, t1));         \
+        (res) = (ggml_float) vaddvq_f32(vaddq_f32(t0, t1));         \
     } while (0)
 
     #define GGML_F16_VEC                GGML_F16x8
     #define GGML_F16_VEC_ZERO           GGML_F16x8_ZERO
     #define GGML_F16_VEC_SET1           GGML_F16x8_SET1
     #define GGML_F16_VEC_LOAD(p, i)     GGML_F16x8_LOAD(p)
-    #define GGML_F16_VEC_STORE(p, r, i) GGML_F16x8_STORE((ggml_fp16_internal_t *)(p), r[i])
+    #define GGML_F16_VEC_STORE(p, r, i) GGML_F16x8_STORE((ggml_fp16_internal_t *)(p), (r)[i])
     #define GGML_F16_VEC_FMA            GGML_F16x8_FMA
     #define GGML_F16_VEC_ADD            GGML_F16x8_ADD
     #define GGML_F16_VEC_MUL            GGML_F16x8_MUL
@@ -1893,6 +1894,23 @@ static inline void __lsx_f16x4_store(ggml_fp16_t * x, __m128 y) {
 #define GGML_F16_ARR (GGML_F16_STEP/GGML_F16_EPR)
 #endif
 
+//
+// ggml object
+//
+
+struct ggml_object {
+    size_t offs;
+    size_t size;
+
+    struct ggml_object * next;
+
+    enum ggml_object_type type;
+
+    char padding[4];
+};
+
+static const size_t GGML_OBJECT_SIZE = sizeof(struct ggml_object);
+
 //
 // ggml context
 //
@@ -19161,6 +19179,34 @@ void ggml_graph_clear(struct ggml_cgraph * cgraph) {
     ggml_hash_set_reset(&cgraph->visited_hash_set);
 }
 
+int ggml_graph_size(struct ggml_cgraph * cgraph) {
+    return cgraph->size;
+}
+
+struct ggml_tensor * ggml_graph_node(struct ggml_cgraph * cgraph, int i) {
+    if (i < 0) {
+        GGML_ASSERT(cgraph->n_nodes + i >= 0);
+        return cgraph->nodes[cgraph->n_nodes + i];
+    }
+
+    GGML_ASSERT(i < cgraph->n_nodes);
+    return cgraph->nodes[i];
+}
+
+struct ggml_tensor ** ggml_graph_nodes(struct ggml_cgraph * cgraph) {
+    return cgraph->nodes;
+}
+
+int ggml_graph_n_nodes(struct ggml_cgraph * cgraph) {
+    return cgraph->n_nodes;
+}
+
+void ggml_graph_add_node(struct ggml_cgraph * cgraph, struct ggml_tensor * tensor) {
+    GGML_ASSERT(cgraph->size > cgraph->n_nodes);
+    cgraph->nodes[cgraph->n_nodes] = tensor;
+    cgraph->n_nodes++;
+}
+
 // Android's libc implementation "bionic" does not support setting affinity
 #if defined(__gnu_linux__)
 static void set_numa_thread_affinity(int thread_n) {

src/llama.cpp

@@ -9877,8 +9877,8 @@ struct llm_build_context {
     struct ggml_cgraph * append_pooling(struct ggml_cgraph * gf) {
         // find result_norm tensor for input
         struct ggml_tensor * inp = nullptr;
-        for (int i = gf->n_nodes - 1; i >= 0; --i) {
+        for (int i = ggml_graph_n_nodes(gf) - 1; i >= 0; --i) {
-            inp = gf->nodes[i];
+            inp = ggml_graph_node(gf, i);
             if (strcmp(inp->name, "result_norm") == 0 || strcmp(inp->name, "result_embd") == 0) {
                 break;
             } else {
@@ -16207,8 +16207,8 @@ static int llama_decode_internal(
         ggml_cgraph * gf = llama_build_graph(lctx, ubatch, false);
 
         // the output is always the last tensor in the graph
-        struct ggml_tensor * res  = gf->nodes[gf->n_nodes - 1];
+        struct ggml_tensor * res  = ggml_graph_node(gf, -1);
-        struct ggml_tensor * embd = gf->nodes[gf->n_nodes - 2];
+        struct ggml_tensor * embd = ggml_graph_node(gf, -2);
 
         if (lctx.n_outputs == 0) {
             // no output
@@ -16217,9 +16217,9 @@ static int llama_decode_internal(
         } else if (cparams.embeddings) {
             res  = nullptr; // do not extract logits for embedding case
             embd = nullptr;
-            for (int i = gf->n_nodes - 1; i >= 0; --i) {
+            for (int i = ggml_graph_n_nodes(gf) - 1; i >= 0; --i) {
-                if (strcmp(gf->nodes[i]->name, "result_embd_pooled") == 0) {
+                if (strcmp(ggml_graph_node(gf, i)->name, "result_embd_pooled") == 0) {
-                    embd = gf->nodes[i];
+                    embd = ggml_graph_node(gf, i);
                     break;
                 }
             }
@@ -16436,15 +16436,15 @@ static int llama_encode_internal(
     // there are two cases here
     if (llama_model_has_decoder(&lctx.model)) {
         // first case is an encoder-decoder T5 model where embeddings are passed to decoder
-        embd = gf->nodes[gf->n_nodes - 1];
+        embd = ggml_graph_node(gf, -1);
         GGML_ASSERT(strcmp(embd->name, "result_norm") == 0 && "missing result_output tensor");
     } else {
         // second case is an encoder-only T5 model
         if (cparams.embeddings) {
             // only output embeddings if required
-            embd = gf->nodes[gf->n_nodes - 1];
+            embd = ggml_graph_node(gf, -1);
             if (strcmp(embd->name, "result_embd_pooled") != 0) {
-                embd = gf->nodes[gf->n_nodes - 2];
+                embd = ggml_graph_node(gf, -2);
             }
             GGML_ASSERT(strcmp(embd->name, "result_embd_pooled") == 0 && "missing embeddings tensor");
         }
@@ -18492,7 +18492,7 @@ struct llama_context * llama_new_context_with_model(
 
             // note: the number of splits during measure is higher than during inference due to the kv shift
             int n_splits = ggml_backend_sched_get_n_splits(ctx->sched);
-            LLAMA_LOG_INFO("%s: graph nodes  = %d\n", __func__, gf->n_nodes);
+            LLAMA_LOG_INFO("%s: graph nodes  = %d\n", __func__, ggml_graph_n_nodes(gf));
             LLAMA_LOG_INFO("%s: graph splits = %d\n", __func__, n_splits);
         }
     }

tests/test-backend-ops.cpp

@@ -519,7 +519,7 @@ struct test_case {
 
         // add sentinels as graph nodes so that they are checked in the callback
         for (ggml_tensor * sentinel : sentinels) {
-            gf->nodes[gf->n_nodes++] = sentinel;
+            ggml_graph_add_node(gf, sentinel);
         }
 
         // randomize tensors
@@ -679,9 +679,9 @@ struct test_case {
 
         // duplicate the op
         size_t target_size = ggml_backend_is_cpu(backend) ? 1ULL << 33 : 1ULL << 35; // 8 GB CPU, 32 GB GPU
-        int n_runs = std::min((size_t)gf->size - gf->n_nodes, target_size / op_size(out)) + 1;
+        int n_runs = std::min((size_t) ggml_graph_size(gf) - ggml_graph_n_nodes(gf), target_size / op_size(out)) + 1;
         for (int i = 1; i < n_runs; i++) {
-            gf->nodes[gf->n_nodes++] = out;
+            ggml_graph_add_node(gf, out);
         }
 
         // calculate memory
@@ -696,11 +696,11 @@ struct test_case {
             }
             return size;
         };
-        for (int i = 0; i < gf->n_nodes; i++) {
+        for (int i = 0; i < ggml_graph_n_nodes(gf); ++i) {
-            if (ggml_is_view_op(gf->nodes[i]->op) || gf->nodes[i] == out) {
+            if (ggml_is_view_op(ggml_graph_node(gf, i)->op) || ggml_graph_node(gf, i) == out) {
                 continue;
             }
-            mem += tensor_op_size(gf->nodes[i]);
+            mem += tensor_op_size(ggml_graph_node(gf, i));
         }
 
         // run
@@ -804,7 +804,7 @@ struct test_case {
         ggml_graph_cpy(gf, gb);
         ggml_build_backward_expand(ctx, gf, gb, false);
         if (expect.size() != 1 || expect[0] != 0.0f) {
-            GGML_ASSERT(gb->n_nodes > gf->n_nodes);
+            GGML_ASSERT(ggml_graph_n_nodes(gb) > ggml_graph_n_nodes(gf));
             for (ggml_tensor * t = ggml_get_first_tensor(ctx); t != NULL; t = ggml_get_next_tensor(ctx, t)) {
                 GGML_ASSERT(!(t->flags & GGML_TENSOR_FLAG_PARAM) || t->grad->op != GGML_OP_NONE);
             }