Reviewers: Kasper Lund, Description: Replaced the implementation of %StringEquals, which was a poorly optimized duplicate of String::Equals, with a simple call to String::Equals.
Please review this at http://codereview.chromium.org/8054 Affected files: M src/runtime.cc Index: src/runtime.cc diff --git a/src/runtime.cc b/src/runtime.cc index bfb68c254445d1718e057140bddc961377e115b2..936518a15c5e093bf7a3d233d944fb3380f672e1 100644 --- a/src/runtime.cc +++ b/src/runtime.cc @@ -2790,38 +2790,14 @@ static Object* Runtime_StringEquals(Arguments args) { CONVERT_CHECKED(String, x, args[0]); CONVERT_CHECKED(String, y, args[1]); - // This is very similar to String::Equals(String*) but that version - // requires flattened strings as input, whereas we flatten the - // strings only if the fast cases fail. Note that this may fail, - // requiring a GC. String::Equals(String*) returns a bool and has - // no way to signal a failure. - if (y == x) return Smi::FromInt(EQUAL); - if (x->IsSymbol() && y->IsSymbol()) return Smi::FromInt(NOT_EQUAL); - // Compare contents - int len = x->length(); - if (len != y->length()) return Smi::FromInt(NOT_EQUAL); - if (len == 0) return Smi::FromInt(EQUAL); - - // Handle one elment strings. - if (x->Get(0) != y->Get(0)) return Smi::FromInt(NOT_EQUAL); - if (len == 1) return Smi::FromInt(EQUAL); - - // Fast case: First, middle and last characters. - if (x->Get(len>>1) != y->Get(len>>1)) return Smi::FromInt(NOT_EQUAL); - if (x->Get(len - 1) != y->Get(len - 1)) return Smi::FromInt(NOT_EQUAL); - - x->TryFlatten(); - y->TryFlatten(); - - static StringInputBuffer buf1; - static StringInputBuffer buf2; - buf1.Reset(x); - buf2.Reset(y); - while (buf1.has_more()) { - if (buf1.GetNext() != buf2.GetNext()) - return Smi::FromInt(NOT_EQUAL); - } - return Smi::FromInt(EQUAL); + bool not_equal = !x->Equals(y); + // This is slightly convoluted because the value that signifies + // equality is 0 and inequality is 1 so we have to negate the result + // from String::Equals. + ASSERT(not_equal == 0 || not_equal == 1); + STATIC_CHECK(EQUAL == 0); + STATIC_CHECK(NOT_EQUAL == 1); + return Smi::FromInt(not_equal); } --~--~---------~--~----~------------~-------~--~----~ v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev -~----------~----~----~----~------~----~------~--~---
