From 588596b60cc4f01e82e6efe68aa5c185c8e3f413 Mon Sep 17 00:00:00 2001
From: Jonas Knobloch <jonas.knobloch@t-online.de>
Date: Mon, 10 Nov 2025 15:54:26 +0100
Subject: Initial commit

---
 main.go | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 main.go

(limited to 'main.go')

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..6b5bd84
--- /dev/null
+++ b/main.go
@@ -0,0 +1,109 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"math"
+	"sort"
+
+	ort "github.com/yalue/onnxruntime_go"
+)
+
+func main() {
+	ort.SetSharedLibraryPath("lib/onnxruntime-osx-arm64-1.22.0/lib/libonnxruntime.1.22.0.dylib")
+
+	if err := ort.InitializeEnvironment(); err != nil {
+		log.Fatal(err)
+	}
+
+	defer ort.DestroyEnvironment()
+
+	inputNames := []string{"input_ids", "position_ids", "attention_mask"}
+	outputNames := []string{"logits"}
+
+	tokens, _ := ort.NewTensor[int64]([]int64{1, 1}, []int64{464})
+	positions, _ := ort.NewTensor[int64]([]int64{1, 1}, []int64{0})
+	attentionMask, _ := ort.NewTensor[int64]([]int64{1, 1}, []int64{1})
+	output, _ := ort.NewEmptyTensor[float32]([]int64{1, 1, 50257})
+
+	session, err := ort.NewAdvancedSession(
+		"scripts/onnx-gpt2/model.onnx",
+		inputNames,
+		outputNames,
+		[]ort.Value{ort.Value(tokens), ort.Value(positions), ort.Value(attentionMask)},
+		[]ort.Value{ort.Value(output)},
+		nil,
+	)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer session.Destroy()
+
+	if err := session.Run(); err != nil {
+		log.Fatal(err)
+	}
+
+	logits := output.GetData()
+	probs := softmax(logits)
+
+	idx, p := topK(probs, 10)
+
+	for i, t := range idx {
+		fmt.Printf("%.4f [%d]\n", p[i], t)
+	}
+}
+
+func softmax(logits []float32) []float32 {
+	m := float32(0)
+
+	for _, v := range logits {
+		if v > m {
+			m = v
+		}
+	}
+
+	s := float32(0.0)
+	r := make([]float32, len(logits))
+
+	for i, v := range logits {
+		e := float32(math.Exp(float64(v - m)))
+
+		r[i] = e
+		s += e
+	}
+
+	for i := range r {
+		r[i] /= s
+	}
+
+	return r
+}
+
+func topK(p []float32, k int) ([]int, []float32) {
+	n := len(p)
+
+	if k > n {
+		k = n
+	}
+
+	idx := make([]int, n)
+
+	for i := range idx {
+		idx[i] = i
+	}
+
+	sort.Slice(idx, func(i, j int) bool {
+		return p[idx[i]] > p[idx[j]]
+	})
+
+	topIdx := idx[:k]
+	topP := make([]float32, k)
+
+	for i := 0; i < k; i++ {
+		topP[i] = p[topIdx[i]]
+	}
+
+	return topIdx, topP
+}
-- 
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