[[docs:funcstructs:ggml.h]]
== ggml.h

[[docs:funcstructs:ggml.h:enum-ggml_object_type]]
=== enum ggml_object_type

Enumerates all possible types of [.codebit]#`struct ggml_object`#. These are [.codebit]#`GGML_OBJECT_TYPE_TENSOR`#, [.codebit]#`GGML_OBJECT_TYPE_GRAPH`# and [.codebit]#`GGML_OBJECT_TYPE_WORK_BUFFER`#.


[[docs:funcstructs:ggml.h:struct-ggml_init_params]]
=== struct ggml_init_params

Ties together the parameters needed by [.codebit]#`ggml_init(...)`#. These are:

[source,C++]
----
// memory pool
size_t mem_size;   // bytes
void * mem_buffer; // if NULL, memory will be allocated internally
bool   no_alloc;   // don't allocate memory for the tensor data
----


[[docs:funcstructs:ggml.h:struct-ggml_tensor]]
=== struct ggml_tensor

Represents a unit of computation. Has the following members:

* [.codebit]#`ggml_type type`#: enum that indicates the data type the tensor works with
* [.codebit]#`ggml_backend_buffer buffer`#
* [.codebit]#`int64_t ne[GGML_MAX_DIMS]`#: dimensions in terms of logical elements (i.e. for quantized data types that use batches, ne[0] holds total number of values the batches on a single "row" hold)
* [.codebit]#`size_t nb[GGML_MAX_DIMS]`#: from comments:

[source,C++]
----
// stride in bytes:
// nb[0] = ggml_type_size(type)
// nb[1] = nb[0]   * (ne[0] / ggml_blck_size(type)) + padding
// nb[i] = nb[i-1] * ne[i-1]
----

* [.codebit]#`ggml_op op`#: enum indicating the operation the tensor does
* [.codebit]#`int32_t op_params[GGML_MAX_OP_PARAMS / sizeof(int32_t)]`#
* [.codebit]#`int32_t flags`#
* [.codebit]#`ggml_tensor* src[GGML_MAX_SRC]`#: source tensors, a.k.a. tensors used as inputs for the operation
* [.codebit]#`ggml_tensor * view_src`#
* [.codebit]#`size_t view_offs`#
* [.codebit]#`void* data`#: the result of the operation, with structure defined by ne and nb
* [.codebit]#`char name[GGML_MAX_NAME]`#: name
* [.codebit]#`void* extra`#: "extra things e.g. for ggml-cuda.cu"
* [.codebit]#`char padding[8]`#: padding to 336 bytes, which is divisible by 16 ([.codebit]#`GGML_MEM_ALIGN`# is either 16 or 4), see struct ggml_context for more details


[[docs:funcstructs:ggml.h:struct-ggml_type_traits]]
=== struct ggml_type_traits

This structure describes a data type and thus dictates how [.codebit]#`ggml_tensor.data`# is interpreted. It has the following members:

* [.codebit]#`const char * type_name`#
* [.codebit]#`int64_t blck_size`#: the number of logical values held in a single block (this is 0 for deprecated and removed types, 1 for non-quantized types, and something else for quantized ones)
* [.codebit]#`int64_t blck_size_interleave`#: currently not set for any type
* [.codebit]#`size_t type_size`#: the size of the data type for unquantized types, and the size of the structure representing a block of said type for quantized ones
* [.codebit]#`bool is_quantized`#
* [.codebit]#`ggml_to_float_t to_float`#: pointer to a function for conversion to float (see exact definition below)
* [.codebit]#`ggml_from_float_t from_float_ref`#: pointer to a function for conversion from float (see exact definition below)

The conversion function pointer types mentioned are defined as such:

[source,C++]
----
typedef void (*ggml_to_float_t)  (const void  * GGML_RESTRICT x, float * GGML_RESTRICT y, int64_t k);
typedef void (*ggml_from_float_t)(const float * GGML_RESTRICT x, void  * GGML_RESTRICT y, int64_t k);
----