Constant fold math and string operations.

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 1380 matching lines @@
   return ExternalReference(reinterpret_cast<Address>(page) +
                            MemoryChunk::kFlagsOffset);
 }
 
 
 ExternalReference ExternalReference::ForDeoptEntry(Address entry) {
   return ExternalReference(entry);
 }
 
 
+double power_helper(double x, double y) {
+  int y_int = static_cast<int>(y);
+  if (y == y_int) {
+    return power_double_int(x, y_int);  // Returns 1 if exponent is 0.
+  }
+  if (y == 0.5) {
+    return (isinf(x)) ? V8_INFINITY : fast_sqrt(x + 0.0);  // Convert -0 to +0.
+  }
+  if (y == -0.5) {
+    return (isinf(x)) ? 0 : 1.0 / fast_sqrt(x + 0.0);  // Convert -0 to +0.
+  }
+  return power_double_double(x, y);
+}
+
+
 // Helper function to compute x^y, where y is known to be an
 // integer. Uses binary decomposition to limit the number of
 // multiplications; see the discussion in "Hacker's Delight" by Henry
 // S. Warren, Jr., figure 11-6, page 213.
 double power_double_int(double x, int y) {
   double m = (y < 0) ? 1 / x : x;
   unsigned n = (y < 0) ? -y : y;
   double p = 1;
   while (n != 0) {
     if ((n & 1) != 0) p *= m;
@@ skipping 171 matching lines @@
     assembler_->RecordRelocInfo(RelocInfo::POSITION, state_.current_position);
     state_.written_position = state_.current_position;
     written = true;
   }
 
   // Return whether something was written.
   return written;
 }
 
 } }  // namespace v8::internal