ggml: Use pointer receivers for Context

Context is currently mixed between pointer and value receivers. Change
this to be all pointer receivers so don't have to reason about whether
the things we are updating in the struct will be retained.

ml/backend/ggml/ggml.go

@@ -484,7 +484,7 @@ type Context struct {
 	maxGraphNodes int
 }
 
-func (c Context) Input() ml.Context {
+func (c *Context) Input() ml.Context {
 	if c.b.input != nil {
 		return &Context{
 			b:             c.b,
@@ -494,10 +494,10 @@ func (c Context) Input() ml.Context {
 		}
 	}
 
-	return &c
+	return c
 }
 
-func (c Context) Layer(i int) ml.Context {
+func (c *Context) Layer(i int) ml.Context {
 	if buft, ok := c.b.layers[i]; ok {
 		return &Context{
 			b:             c.b,
@@ -507,7 +507,7 @@ func (c Context) Layer(i int) ml.Context {
 		}
 	}
 
-	return &c
+	return c
 }
 
 func (c *Context) Forward(tensors ...ml.Tensor) ml.Context {
@@ -522,7 +522,7 @@ func (c *Context) Forward(tensors ...ml.Tensor) ml.Context {
 	return c
 }
 
-func (c Context) Compute(tensors ...ml.Tensor) {
+func (c *Context) Compute(tensors ...ml.Tensor) {
 	C.ggml_backend_sched_graph_compute_async(c.b.sched, c.graph)
 	C.ggml_backend_sched_reset(c.b.sched)
 
@@ -541,7 +541,7 @@ func (c Context) Compute(tensors ...ml.Tensor) {
 	}
 }
 
-func (c Context) Reserve() error {
+func (c *Context) Reserve() error {
 	if !C.ggml_backend_sched_reserve(c.b.sched, c.graph) {
 		C.ggml_backend_sched_reset(c.b.sched)
 		return errors.New("failed to reserve graph")
@@ -559,7 +559,7 @@ func (c Context) Reserve() error {
 	return nil
 }
 
-func (c Context) MaxGraphNodes() int {
+func (c *Context) MaxGraphNodes() int {
 	return c.maxGraphNodes
 }
 
@@ -576,7 +576,7 @@ func pad(length, pad C.size_t) C.size_t {
 	return ((length + pad - 1) / pad) * pad
 }
 
-func (c Context) newTensor(dtype ml.DType, shape []int) (ml.Tensor, error) {
+func (c *Context) newTensor(dtype ml.DType, shape []int) (ml.Tensor, error) {
 	if c.buft == nil {
 		panic("set Input or Layer before creating tensors")
 	}
@@ -621,7 +621,7 @@ func (c Context) newTensor(dtype ml.DType, shape []int) (ml.Tensor, error) {
 	return &Tensor{b: c.b, t: t}, nil
 }
 
-func (c Context) Empty(dtype ml.DType, shape ...int) ml.Tensor {
+func (c *Context) Empty(dtype ml.DType, shape ...int) ml.Tensor {
 	t, err := c.newTensor(dtype, shape)
 	if err != nil {
 		panic(err)
@@ -630,7 +630,7 @@ func (c Context) Empty(dtype ml.DType, shape ...int) ml.Tensor {
 	return t
 }
 
-func (c Context) Zeros(dtype ml.DType, shape ...int) ml.Tensor {
+func (c *Context) Zeros(dtype ml.DType, shape ...int) ml.Tensor {
 	t, err := c.newTensor(dtype, shape)
 	if err != nil {
 		panic(err)
@@ -658,7 +658,7 @@ func checkShape[S ~[]E, E any](s S, shape ...int) error {
 	return nil
 }
 
-func (c Context) FromFloatSlice(s []float32, shape ...int) (ml.Tensor, error) {
+func (c *Context) FromFloatSlice(s []float32, shape ...int) (ml.Tensor, error) {
 	if err := checkShape(s, shape...); err != nil {
 		return nil, err
 	}
@@ -675,7 +675,7 @@ func (c Context) FromFloatSlice(s []float32, shape ...int) (ml.Tensor, error) {
 	return t, nil
 }
 
-func (c Context) FromIntSlice(s []int32, shape ...int) (ml.Tensor, error) {
+func (c *Context) FromIntSlice(s []int32, shape ...int) (ml.Tensor, error) {
 	if err := checkShape(s, shape...); err != nil {
 		return nil, err
 	}