Faster implementation of Math.exp()

src/platform-win32.cc

Index: src/platform-win32.cc
diff --git a/src/platform-win32.cc b/src/platform-win32.cc
index 27433b25afd7a47d214efec550a2ea53e33fb373..261a946a869802cee9646eb1db7ec0939acc587c 100644
--- a/src/platform-win32.cc
+++ b/src/platform-win32.cc
@@ -199,11 +199,19 @@ UNARY_MATH_FUNCTION(sin, CreateTranscendentalFunction(TranscendentalCache::SIN))
 UNARY_MATH_FUNCTION(cos, CreateTranscendentalFunction(TranscendentalCache::COS))
 UNARY_MATH_FUNCTION(tan, CreateTranscendentalFunction(TranscendentalCache::TAN))
 UNARY_MATH_FUNCTION(log, CreateTranscendentalFunction(TranscendentalCache::LOG))
+UNARY_MATH_FUNCTION(exp, CreateExpFunction())
 UNARY_MATH_FUNCTION(sqrt, CreateSqrtFunction())
 
 #undef MATH_FUNCTION
 
 
+void lazily_initialize_fast_exp() {
+  if (fast_exp_function == NULL) {
+    init_fast_exp_function();
+  }
+}
+
+
 void MathSetup() {
 #ifdef _WIN64
   init_modulo_function();
@@ -212,6 +220,7 @@ void MathSetup() {
   init_fast_cos_function();
   init_fast_tan_function();
   init_fast_log_function();
+  // fast_exp is initialized lazily.
   init_fast_sqrt_function();
 }