Faster implementation of Math.exp()

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 7135 matching lines @@
   return isolate->transcendental_cache()->Get(TranscendentalCache::COS, x);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_Math_exp) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
   isolate->counters()->math_exp()->Increment();
 
   CONVERT_DOUBLE_ARG_CHECKED(x, 0);
-  return isolate->transcendental_cache()->Get(TranscendentalCache::EXP, x);
+  lazily_initialize_fast_exp();
+  return isolate->heap()->NumberFromDouble(fast_exp(x));
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_Math_floor) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
   isolate->counters()->math_floor()->Increment();
 
   CONVERT_DOUBLE_ARG_CHECKED(x, 0);
   return isolate->heap()->NumberFromDouble(floor(x));
@@ skipping 6215 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal