sycl: implement GGML_UNARY_OP_SOFTPLUS (llama/19114)

* sycl: add softplus unary op implementation

* sycl: add softplus unary op implementation

* docs(ops): mark SYCL SOFTPLUS as supported

* docs: update SYCL status for SOFTPLUS

Author: s8322

src/ggml-sycl/element_wise.cpp

@@ -123,6 +123,15 @@ static __dpct_inline__ T op_log(T x) {
     return sycl::log(x);
 }
 
+template<typename T>
+static __dpct_inline__ T op_softplus(T x) {
+    const float xf = (float) x;
+    const float ax = sycl::fabs(xf);
+    const float m  = sycl::fmax(xf, 0.0f);
+    const float y  = m + sycl::log1p(sycl::exp(-ax));
+    return (T) y;
+}
+
 template<typename T>
 static __dpct_inline__ T op_neg(T x) {
     return -x;
@@ -695,6 +704,12 @@ static inline void ggml_sycl_op_log(ggml_backend_sycl_context & ctx, ggml_tensor
         });
 }
 
+static inline void ggml_sycl_op_softplus(ggml_backend_sycl_context & ctx, ggml_tensor * dst) {
+    ggml_sycl_detail::ggml_sycl_op_unary(ctx, dst, [](auto x) {
+        return op_softplus(x);
+    });
+}
+
 static inline void ggml_sycl_op_neg(ggml_backend_sycl_context & ctx, ggml_tensor * dst) {
     ggml_sycl_detail::ggml_sycl_op_unary(ctx, dst, [](auto x) {
         return op_neg(x);
@@ -1101,6 +1116,11 @@ void ggml_sycl_log(ggml_backend_sycl_context & ctx, ggml_tensor * dst) {
     ggml_sycl_op_log(ctx, dst);
 }
 
+void ggml_sycl_softplus(ggml_backend_sycl_context & ctx, ggml_tensor * dst) {
+    scope_op_debug_print scope_dbg_print(__func__, dst, /*num_src=*/1);
+    ggml_sycl_op_softplus(ctx, dst);
+}
+
 void ggml_sycl_neg(ggml_backend_sycl_context & ctx, ggml_tensor * dst) {
     scope_op_debug_print scope_dbg_print(__func__, dst, /*num_src=*/1);
     ggml_sycl_op_neg(ctx, dst);

src/ggml-sycl/element_wise.hpp

@@ -61,6 +61,8 @@ void ggml_sycl_exp(ggml_backend_sycl_context & ctx, ggml_tensor * dst);
 
 void ggml_sycl_log(ggml_backend_sycl_context & ctx, ggml_tensor * dst);
 
+void ggml_sycl_softplus(ggml_backend_sycl_context & ctx, ggml_tensor * dst);
+
 void ggml_sycl_neg(ggml_backend_sycl_context & ctx, ggml_tensor * dst);
 
 void ggml_sycl_step(ggml_backend_sycl_context & ctx, ggml_tensor * dst);

src/ggml-sycl/ggml-sycl.cpp

@@ -3845,6 +3845,9 @@ static bool ggml_sycl_compute_forward(ggml_backend_sycl_context & ctx, struct gg
                 case GGML_UNARY_OP_EXP:
                     ggml_sycl_exp(ctx, dst);
                     break;
+                case GGML_UNARY_OP_SOFTPLUS:
+                    ggml_sycl_softplus(ctx, dst);
+                    break;
                 case GGML_UNARY_OP_SGN:
                     ggml_sycl_sgn(ctx, dst);
                     break;
@@ -4466,6 +4469,7 @@ static bool ggml_backend_sycl_device_supports_op(ggml_backend_dev_t dev, const g
                 case GGML_UNARY_OP_GELU_QUICK:
                 case GGML_UNARY_OP_GELU_ERF:
                 case GGML_UNARY_OP_EXP:
+                case GGML_UNARY_OP_SOFTPLUS:
                 case GGML_UNARY_OP_ELU:
                     return true;
                 case GGML_UNARY_OP_FLOOR: