Faster implementation of Math.exp()

src/platform.h

Index: src/platform.h
diff --git a/src/platform.h b/src/platform.h
index d4c91b4a1db1e05f3409c945b70f1af879ac30ef..67f6792e1af52ee76d6dd58c16a46afb1a58403e 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -119,12 +119,16 @@ class Mutex;
 double ceiling(double x);
 double modulo(double x, double y);
 
-// Custom implementation of sin, cos, tan and log.
+// Custom implementation of math functions.
 double fast_sin(double input);
 double fast_cos(double input);
 double fast_tan(double input);
 double fast_log(double input);
+double fast_exp(double input);
 double fast_sqrt(double input);
+// The custom exp implementation needs 16KB of lookup data; initialize it
+// on demand.
+void lazily_initialize_fast_exp();
 
 // Forward declarations.
 class Socket;