Make sure double to int conversion is correct.

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 3737 matching lines @@
   // We have a fast integer-only case here to avoid a conversion to double in
   // the common case where from and to are Smis.
   if (args[1]->IsSmi() && args[2]->IsSmi()) {
     CONVERT_SMI_ARG_CHECKED(from_number, 1);
     CONVERT_SMI_ARG_CHECKED(to_number, 2);
     start = from_number;
     end = to_number;
   } else {
     CONVERT_DOUBLE_ARG_CHECKED(from_number, 1);
     CONVERT_DOUBLE_ARG_CHECKED(to_number, 2);
-    start = FastD2I(from_number);
-    end = FastD2I(to_number);
+    start = FastD2IChecked(from_number);
+    end = FastD2IChecked(to_number);
   }
   RUNTIME_ASSERT(end >= start);
   RUNTIME_ASSERT(start >= 0);
   RUNTIME_ASSERT(end <= value->length());
   isolate->counters()->sub_string_runtime()->Increment();
   return value->SubString(start, end);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringMatch) {
@@ skipping 447 matching lines @@
   if (isnan(value)) {
     return *isolate->factory()->nan_symbol();
   }
   if (isinf(value)) {
     if (value < 0) {
       return *isolate->factory()->minus_infinity_symbol();
     }
     return *isolate->factory()->infinity_symbol();
   }
   CONVERT_DOUBLE_ARG_CHECKED(f_number, 1);
-  int f = FastD2I(f_number);
+  int f = FastD2IChecked(f_number);
   RUNTIME_ASSERT(f >= 0);
   char* str = DoubleToFixedCString(value, f);
   MaybeObject* res =
       isolate->heap()->AllocateStringFromAscii(CStrVector(str));
   DeleteArray(str);
   return res;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_NumberToExponential) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_DOUBLE_ARG_CHECKED(value, 0);
   if (isnan(value)) {
     return *isolate->factory()->nan_symbol();
   }
   if (isinf(value)) {
     if (value < 0) {
       return *isolate->factory()->minus_infinity_symbol();
     }
     return *isolate->factory()->infinity_symbol();
   }
   CONVERT_DOUBLE_ARG_CHECKED(f_number, 1);
-  int f = FastD2I(f_number);
+  int f = FastD2IChecked(f_number);
   RUNTIME_ASSERT(f >= -1 && f <= 20);
   char* str = DoubleToExponentialCString(value, f);
   MaybeObject* res =
       isolate->heap()->AllocateStringFromAscii(CStrVector(str));
   DeleteArray(str);
   return res;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_NumberToPrecision) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_DOUBLE_ARG_CHECKED(value, 0);
   if (isnan(value)) {
     return *isolate->factory()->nan_symbol();
   }
   if (isinf(value)) {
     if (value < 0) {
       return *isolate->factory()->minus_infinity_symbol();
     }
     return *isolate->factory()->infinity_symbol();
   }
   CONVERT_DOUBLE_ARG_CHECKED(f_number, 1);
-  int f = FastD2I(f_number);
+  int f = FastD2IChecked(f_number);
   RUNTIME_ASSERT(f >= 1 && f <= 21);
   char* str = DoubleToPrecisionCString(value, f);
   MaybeObject* res =
       isolate->heap()->AllocateStringFromAscii(CStrVector(str));
   DeleteArray(str);
   return res;
 }
 
 
 // Returns a single character string where first character equals
@@ skipping 9427 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