Contribution of PowerPC port (continuation of 422063005) - AIX Common1

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 1423 matching lines @@
     m *= m;
     if ((n & 2) != 0) p *= m;
     m *= m;
     n >>= 2;
   }
   return p;
 }
 
 
 double power_double_double(double x, double y) {
-#if defined(__MINGW64_VERSION_MAJOR) && \
-    (!defined(__MINGW64_VERSION_RC) || __MINGW64_VERSION_RC < 1)
-  // MinGW64 has a custom implementation for pow.  This handles certain
+#if (defined(__MINGW64_VERSION_MAJOR) &&                              \
+     (!defined(__MINGW64_VERSION_RC) || __MINGW64_VERSION_RC < 1)) || \
+    defined(V8_OS_AIX)
+  // MinGW64 and AIX have a custom implementation for pow.  This handles certain
   // special cases that are different.
-  if ((x == 0.0 || std::isinf(x)) && std::isfinite(y)) {
+  if ((x == 0.0 || std::isinf(x)) && y != 0.0 && std::isfinite(y)) {
     double f;
-    if (std::modf(y, &f) != 0.0) {
-      return ((x == 0.0) ^ (y > 0)) ? V8_INFINITY : 0;
-    }
+    double result = ((x == 0.0) ^ (y > 0)) ? V8_INFINITY : 0;
+    /* retain sign if odd integer exponent */
+    return ((std::modf(y, &f) == 0.0) && (static_cast<int64_t>(y) & 1))
+               ? copysign(result, x)
+               : result;
   }
 
   if (x == 2.0) {
     int y_int = static_cast<int>(y);
     if (y == y_int) {
       return std::ldexp(1.0, y_int);
     }
   }
 #endif
 
@@ skipping 125 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