[builtins] Introduce proper Float64Log1p operator.

src/assembler.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 1635 matching lines @@
   return ExternalReference(isolate->regexp_stack()->memory_size_address());
 }
 
 #endif  // V8_INTERPRETED_REGEXP
 
 ExternalReference ExternalReference::ieee754_log_function(Isolate* isolate) {
   return ExternalReference(
       Redirect(isolate, FUNCTION_ADDR(base::ieee754::log), BUILTIN_FP_CALL));
 }
 
+ExternalReference ExternalReference::ieee754_log1p_function(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(base::ieee754::log1p), BUILTIN_FP_CALL));
+}
 
 ExternalReference ExternalReference::math_exp_constants(int constant_index) {
   DCHECK(math_exp_data_initialized);
   return ExternalReference(
       reinterpret_cast<void*>(math_exp_constants_array + constant_index));
 }
 
 
 ExternalReference ExternalReference::math_exp_log_table() {
   DCHECK(math_exp_data_initialized);
@@ skipping 447 matching lines @@
 
 
 void Assembler::DataAlign(int m) {
   DCHECK(m >= 2 && base::bits::IsPowerOfTwo32(m));
   while ((pc_offset() & (m - 1)) != 0) {
     db(0);
   }
 }
 }  // namespace internal
 }  // namespace v8