Faster NaN-free tanh

stduhpf · stduhpf · commit d94ff95565bd · 2024-12-08T18:30:18.000+01:00
diff --git a/ggml/src/ggml-vulkan/vulkan-shaders/tanh.comp b/ggml/src/ggml-vulkan/vulkan-shaders/tanh.comp
@@ -16,6 +16,5 @@ void main() {
     if (i >= p.KX) {
         return;
     }
-    float th = tanh(data_a[i]);
-    data_d[i] = D_TYPE(th==th ? th : sign(data_a[i]));
+    data_d[i] = D_TYPE(1. - 2. / (exp(2.*data_a[i]) + 1.));
 }

Original file line number	Diff line number	Diff line change
`@@ -16,6 +16,5 @@ void main() {`
`16`	`16`	`if (i >= p.KX) {`
`17`	`17`	`return;`
`18`	`18`	`}`
`19`		`- float th = tanh(data_a[i]);`
`20`		`- data_d[i] = D_TYPE(th==th ? th : sign(data_a[i]));`
	`19`	`+ data_d[i] = D_TYPE(1. - 2. / (exp(2.*data_a[i]) + 1.));`
`21`	`20`	`}`